Effective design of substation earth grid implies achieving low earth grid resistance and fulfillment of the safety criteria at the lowest possible cost. This paper presents an evaluation of IEEE Standard 80-2000 Equations 50 to 52 to determine the impact of buried conductor length on computation of earth grid resistance. Calculated results indicated that a saturation point is reached beyond which further addition of more conductor length does not significantly reduce the earth grid resistance but incurs more economic implications. These were validated by earth grids designed using CDEGS where good agreement between the calculated and simulated results was found.
Effect of HVTL Phase Transposition on Pipelines Induced Voltageijeei-iaes
In this work, a study of the effect of the phase conductor transposition for a multi-circuit high voltage power transmission lines on the induced voltage on a buried pipeline was conducted and considered through modelling. The modelling was done applying Carson’s concept of mutual impedances for a double circuit, three circuits and four circuit power transmission line on a buried pipeline. The simulated results obtained showed that the transmission line with un-transposed phase combination has the greater effect on the induced voltage while for the one or more of the other combinations, a cancellation or reduction can occur. This also is dependent on the tower geometry and the relative position of the pipeline and the transmission line. Also, the magnitude of the induced voltage increases with increasing number of circuits.
Load centers get generated electricity from power
stations that are usually far; uninterrupted consumption or usage
of power has increased in last few years. Transmission system is
the system by means of which electricity is transferred from place
of generation to the consumers. Overhead wires or conductors
are the medium used for transmission of power. These wires are
visible to wind, heat and ice. The efficiency of the power system
increases if the losses of these overhead wires are minimal. These
losses are based on the resistive, magnetic and capacitive nature
of the conductor. It is necessary to create or make proper design
of these conductors accompanied by proper installation. To
balance the working and strength of overhead transmission line
and to minimize its capacitive effect the conductors must be
installed in catenary shape. The sag is required in transmission
line for conductor suspension. The conductors are appended
between two overhead towers with ideal estimation of sag. It is
because of keeping conductor safety from inordinate tension. To
permit safe tension in the conductor, conductors are not
completely extended; rather they are allowed to have sag. For
same level supports this paper provides sag and tension
estimation with different wind speeds under low operating
temperature 2 °C. To calculate sag-tension estimation of ACSR
(Aluminum Conductor Steel Reinforced) overhead lines three
different cases are provided with normal and high wind speed
effects. Four different span lengths are taken for equal level
supports. ETAP (Electrical Transient and Analysis Program) is
used for simulation setup. The results shows that wind speed has
great impact upon line tension and with addition of wind speed
the sag of line remains unaltered while tension changes.
Moreover tension gets increase while increase in wind speed.
Review Paper Study on Steel Transmission Towerijtsrd
India has a large population residing all over the country and the electricity supply need of this population creates requirement of large transmission and dispersion framework. Likewise, the demeanor of the essential assets for electrical force age viz., coal, hydro potential is very lopsided, consequently again adding to the transmission prerequisites. Transmission line is a coordinated framework comprising of transmitter subsystem, ground wire subsystem and one subsystem for every class of help structure. Mechanical help of transmission line addresses a huge segment of the expense of the line and they assume a significant part in the solid force transmission. They are planned and developed in wide assortment of shapes, types, sizes, setup and materials. The supporting construction types utilized in transmission line by and large can be categorized as one of the three classes cross section, shaft and guyed. Aditya Shrivastava | Prof. Afzal Khan "Review Paper Study on Steel Transmission Tower" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46389.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/46389/review-paper-study-on-steel-transmission-tower/aditya-shrivastava
IRJET- A Review on Seismic Analysis of Buildings using Passive Energy Dis...IRJET Journal
The document summarizes research on using passive energy dissipating devices to improve the seismic performance of buildings. It reviews literature on three main types of passive dampers: fluid viscous dampers, viscoelastic dampers, and friction dampers. Studies show that incorporating these dampers can significantly reduce inter-story drifts, floor accelerations, and shear forces in buildings during earthquakes by dissipating seismic energy. Fluid viscous dampers and friction dampers in particular have been found to improve structural response and reduce damage when optimized for location and properties in the building design.
2 ijaems jul-2015-3-analysis and design of four leg steel transmission tower ...INFOGAIN PUBLICATION
In this project, the design of steel lattice tower prescribed for transmission of electricity by the categorized gravity and lateral loads has been studied and analysed for the employment of the project. The analysis has been done by taking different combination of loads and then the design has been come into picture using the code module IS 800:1984.
The present work describes the analysis and design of transmission line tower of 25 meter height viz. various parameters. In design of tower for weight optimization some parameters are considered such as; base width, height of tower , outline of tower. Using STAAD , analysis of transmission towers has been carried out as a 3-D structure. The tower members are designed as angle section.Prior to the design process the convincing site investigation and Envoirmental impact assessment data has to to collected through various modes via Electronic or Print media.
The desired safety factors has been actuated contemplating the selected location i.e Kasouli. The various factors including envoirmental and materials used for the structure is also be considered.The foundation detailing is chosen keeping in consideration the geotechnical investigation data. The software tool used in the process is STAAD.Pro 2008. The load calculations were performed manually but the analysis and design results were obtained through STAAD.Pro 2008. At all stages, the effort is to provide optimally safe design along with keeping the economic considerations.
GM Distributed Generation Inverters in a Micro grid by Controlling Energy Man...IOSRJEEE
This document describes a microgrid system with distributed generation units like a wind turbine and proton exchange membrane fuel cell connected to a distribution grid. An adaptive neural fuzzy inference system (ANFIS) controller is used for energy management and power distribution between the distributed generation units. Previously, a model predictive control algorithm was used but it had high computational complexity. The ANFIS controller reduces complexity by using logical operations instead of complex mathematical calculations. Simulation results in MATLAB/Simulink show the ANFIS controller provides better power quality and harmonic compensation compared to the previous model predictive control approach.
The document discusses the performance of a 4-story reinforced concrete building located in seismic zone III under dynamic forces from earthquakes. The researchers analyzed the building using equivalent static analysis and calculated demand capacity ratios (DCRs) for moments and shear in beams and columns. Members with DCRs over 1 were identified as failing. Fiber reinforced polymer jacketing was proposed as a strengthening method to improve the seismic resistance of failing members.
Seismic response of transmission tower a case studyeSAT Journals
Abstract Towers and tower like structures are the major infrastructure for the transmission of electrical power, telecommunication and broadcasting. The transmission towers are highly repetitive and therefore the analysis and designs should be highly competitive towards commercial solutions. In the present study, an attempt has been made to analyse the existing Electrical Transmission tower of voltage 220kV using FEM software NISA. The analysis of an existing structure without secondary bracings has been carried out for the North-South Component of EL-Centro Ground motion, 1940.In this analysis, the stiffness and damping properties have been considered for improving the seismic performance of the existing structure. By keeping the Group number as it is, using different sections, the geometric properties of the given angle section are optimized to optimized angle section and optimized tubular section. For cross braces, the damping value is varied ranging from 5%-25% for above sections. In this analysis, the displacement at top cross-arm of the tower is considered as the main parameter for conservative results. Finally the results obtained are regarding possible improvements in the analysis of the existing structure
Effect of HVTL Phase Transposition on Pipelines Induced Voltageijeei-iaes
In this work, a study of the effect of the phase conductor transposition for a multi-circuit high voltage power transmission lines on the induced voltage on a buried pipeline was conducted and considered through modelling. The modelling was done applying Carson’s concept of mutual impedances for a double circuit, three circuits and four circuit power transmission line on a buried pipeline. The simulated results obtained showed that the transmission line with un-transposed phase combination has the greater effect on the induced voltage while for the one or more of the other combinations, a cancellation or reduction can occur. This also is dependent on the tower geometry and the relative position of the pipeline and the transmission line. Also, the magnitude of the induced voltage increases with increasing number of circuits.
Load centers get generated electricity from power
stations that are usually far; uninterrupted consumption or usage
of power has increased in last few years. Transmission system is
the system by means of which electricity is transferred from place
of generation to the consumers. Overhead wires or conductors
are the medium used for transmission of power. These wires are
visible to wind, heat and ice. The efficiency of the power system
increases if the losses of these overhead wires are minimal. These
losses are based on the resistive, magnetic and capacitive nature
of the conductor. It is necessary to create or make proper design
of these conductors accompanied by proper installation. To
balance the working and strength of overhead transmission line
and to minimize its capacitive effect the conductors must be
installed in catenary shape. The sag is required in transmission
line for conductor suspension. The conductors are appended
between two overhead towers with ideal estimation of sag. It is
because of keeping conductor safety from inordinate tension. To
permit safe tension in the conductor, conductors are not
completely extended; rather they are allowed to have sag. For
same level supports this paper provides sag and tension
estimation with different wind speeds under low operating
temperature 2 °C. To calculate sag-tension estimation of ACSR
(Aluminum Conductor Steel Reinforced) overhead lines three
different cases are provided with normal and high wind speed
effects. Four different span lengths are taken for equal level
supports. ETAP (Electrical Transient and Analysis Program) is
used for simulation setup. The results shows that wind speed has
great impact upon line tension and with addition of wind speed
the sag of line remains unaltered while tension changes.
Moreover tension gets increase while increase in wind speed.
Review Paper Study on Steel Transmission Towerijtsrd
India has a large population residing all over the country and the electricity supply need of this population creates requirement of large transmission and dispersion framework. Likewise, the demeanor of the essential assets for electrical force age viz., coal, hydro potential is very lopsided, consequently again adding to the transmission prerequisites. Transmission line is a coordinated framework comprising of transmitter subsystem, ground wire subsystem and one subsystem for every class of help structure. Mechanical help of transmission line addresses a huge segment of the expense of the line and they assume a significant part in the solid force transmission. They are planned and developed in wide assortment of shapes, types, sizes, setup and materials. The supporting construction types utilized in transmission line by and large can be categorized as one of the three classes cross section, shaft and guyed. Aditya Shrivastava | Prof. Afzal Khan "Review Paper Study on Steel Transmission Tower" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd46389.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/46389/review-paper-study-on-steel-transmission-tower/aditya-shrivastava
IRJET- A Review on Seismic Analysis of Buildings using Passive Energy Dis...IRJET Journal
The document summarizes research on using passive energy dissipating devices to improve the seismic performance of buildings. It reviews literature on three main types of passive dampers: fluid viscous dampers, viscoelastic dampers, and friction dampers. Studies show that incorporating these dampers can significantly reduce inter-story drifts, floor accelerations, and shear forces in buildings during earthquakes by dissipating seismic energy. Fluid viscous dampers and friction dampers in particular have been found to improve structural response and reduce damage when optimized for location and properties in the building design.
2 ijaems jul-2015-3-analysis and design of four leg steel transmission tower ...INFOGAIN PUBLICATION
In this project, the design of steel lattice tower prescribed for transmission of electricity by the categorized gravity and lateral loads has been studied and analysed for the employment of the project. The analysis has been done by taking different combination of loads and then the design has been come into picture using the code module IS 800:1984.
The present work describes the analysis and design of transmission line tower of 25 meter height viz. various parameters. In design of tower for weight optimization some parameters are considered such as; base width, height of tower , outline of tower. Using STAAD , analysis of transmission towers has been carried out as a 3-D structure. The tower members are designed as angle section.Prior to the design process the convincing site investigation and Envoirmental impact assessment data has to to collected through various modes via Electronic or Print media.
The desired safety factors has been actuated contemplating the selected location i.e Kasouli. The various factors including envoirmental and materials used for the structure is also be considered.The foundation detailing is chosen keeping in consideration the geotechnical investigation data. The software tool used in the process is STAAD.Pro 2008. The load calculations were performed manually but the analysis and design results were obtained through STAAD.Pro 2008. At all stages, the effort is to provide optimally safe design along with keeping the economic considerations.
GM Distributed Generation Inverters in a Micro grid by Controlling Energy Man...IOSRJEEE
This document describes a microgrid system with distributed generation units like a wind turbine and proton exchange membrane fuel cell connected to a distribution grid. An adaptive neural fuzzy inference system (ANFIS) controller is used for energy management and power distribution between the distributed generation units. Previously, a model predictive control algorithm was used but it had high computational complexity. The ANFIS controller reduces complexity by using logical operations instead of complex mathematical calculations. Simulation results in MATLAB/Simulink show the ANFIS controller provides better power quality and harmonic compensation compared to the previous model predictive control approach.
The document discusses the performance of a 4-story reinforced concrete building located in seismic zone III under dynamic forces from earthquakes. The researchers analyzed the building using equivalent static analysis and calculated demand capacity ratios (DCRs) for moments and shear in beams and columns. Members with DCRs over 1 were identified as failing. Fiber reinforced polymer jacketing was proposed as a strengthening method to improve the seismic resistance of failing members.
Seismic response of transmission tower a case studyeSAT Journals
Abstract Towers and tower like structures are the major infrastructure for the transmission of electrical power, telecommunication and broadcasting. The transmission towers are highly repetitive and therefore the analysis and designs should be highly competitive towards commercial solutions. In the present study, an attempt has been made to analyse the existing Electrical Transmission tower of voltage 220kV using FEM software NISA. The analysis of an existing structure without secondary bracings has been carried out for the North-South Component of EL-Centro Ground motion, 1940.In this analysis, the stiffness and damping properties have been considered for improving the seismic performance of the existing structure. By keeping the Group number as it is, using different sections, the geometric properties of the given angle section are optimized to optimized angle section and optimized tubular section. For cross braces, the damping value is varied ranging from 5%-25% for above sections. In this analysis, the displacement at top cross-arm of the tower is considered as the main parameter for conservative results. Finally the results obtained are regarding possible improvements in the analysis of the existing structure
This document analyzes and compares the design of 220kV transmission line towers in different wind zones (I and V) and with different base widths (1/4, 1/5, and 1/6 of total tower height). Six towers are modeled and loads are calculated according to industry standards. After analysis, the towers are compared based on deflections, stresses, axial forces, and weight. The results show that towers in wind zone V experience higher deflections and stresses compared to zone I. Wider base widths result in lower deflections and stresses but higher tower weights. This study provides useful data for designing efficient and structurally sound 220kV transmission line towers.
Design and Simulation of a Fractal Micro-TransformerIJERA Editor
This document summarizes the design and simulation of a fractal micro-transformer. The researchers designed an air-core fractal micro-transformer using finite element modeling software. Simulation results showed improved performance parameters compared to macro transformers, including higher voltage gain. Electric displacement and magnetic energy density within the micro-transformer were determined to be 2 x 10-11 C/m2 and 100 J/m3 respectively. Losses within the air-core design were minimal at 3 W/m3. The micro-transformer was concluded to be suitable for integration in MEMS and VLSI applications due to its small size, high impedance, and isolation capabilities.
This document outlines the scope of work for detailed surveying of various 220/66kV transmission lines in Gujarat, India. The scope includes route alignment using satellite imagery and maps, detailed GPS surveying, profiling, tower spotting, soil investigations, and preparing survey reports. Route alignment will identify three alternative routes and select the optimal one considering economic and technical factors like minimizing forest/tree cutting, river/infrastructure crossings, and risks from flooding. Detailed surveying will generate digitized plans, profiles, contours and soil data to inform tower designs and foundations. The contractor will use modern surveying techniques and tools like GPS, total stations, scanners and software.
This document discusses the design of steel tower structures. It begins by outlining the process of analyzing member forces and sizing members based on their axial loads. It then describes various bracing systems used for towers, including single web, double web (Warren), Pratt, and portal systems. Factors affecting the design of compression members like effective length, slenderness ratio, and buckling are also summarized. Empirical formulas for determining safe compressive stresses based on material properties and member geometry are presented.
The key factors that determine tower configuration are:
1. The required insulator assembly length, conductor clearances, and ground wire placement.
2. The tower height is determined by the minimum ground clearance, maximum conductor sag, vertical conductor spacing, and clearance between the ground wire and top conductor.
3. Other factors influencing tower configuration include wind loads, temperature variations, conductor size and material, and span length. Proper configuration ensures safety clearances and allows the transmission line to reliably carry power loads with the required safety factors.
Study of RF-MEMS Capacitive Shunt Switch for Microwave Backhaul Applications IOSRJECE
In this research paper, we have proposed a new type of capacitive shunt RF-MEMS switch. MicroElectro-Mechanical System (MEMS) is a combination of mechanical and electromagnetics properties at micro level unit. This MEMS switch can be used for switching purpose at RF and microwave frequencies, called RFMEMS switch. The RF-MEMS switch has a potential characteristics and superior performances at radio frequency. The MEMS switch has excellent advantages such as zero power consumption, high power handling capacity, high performance, and low inter-modulation distortion. In this proposed design, a new type of capacitive shunt switch is designed and analyzed for RF applications. The switch is designed both in UP and DOWN-states. The proposed switch design consists of substrate, co-planar waveguide (CPW), dielectric material and suspended metallic bridge. The proposed MEMS switch has dimension of 508 µm × 620 µm with a height of 500 µm and implemented on GaAs as a substrate material with relative permittivity of 12.9. The geometry and results of the proposed switch is designed using Ansoft HFSS electromagnetic simulator based on finite element method (FEM). The electrostatic and electromagnetic result showed better performances such as return loss, insertion loss and isolation. The switch has also excellent isolation property of -48 dB at 26 GHz.
Study and Analysis of Insulator used in Substationijtsrd
This document discusses insulators used in electrical substations. It begins with an introduction to electrical distribution systems and the components of substations. It then focuses on the study and analysis of different types of insulators used in substations, including their design, material properties, and performance characteristics. Specifically, it provides data on the standards and specifications for lightning arresters, current transformers, and potential transformers used at various voltage levels. It analyzes the peak voltage ratings, creepage distances, and other parameters for these insulators. The conclusion discusses the importance of properly selecting insulators that meet the ratings of the transmission lines to protect the substation equipment.
This document discusses sizing underground power cables using MATLAB. It provides background on factors that affect cable sizing like voltage, current, power rating, cable properties, installation conditions, and permissible voltage drop. The general sizing methodology is described in 4 steps: 1) Gather data on the cable and load, 2) Determine minimum size based on continuous current capacity, 3) Determine minimum size based on voltage drop considerations, 4) Select highest size from steps 2 and 3. Tables provide example cable current and impedance ratings. Derating factors are discussed for installation conditions like temperature and cable grouping. A MATLAB code is developed to calculate cable cross-sectional area based on parameters and voltage drop limits.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Reducing Induced Voltages on Parallel Facilities in Shared Transmission Corri...Power System Operation
Routing, siting, and environmental constraints are pushing more transmission lines and other linear facilities such as pipelines and railroads into shared corridors. The future power system will see a greater number of these situations, often coupled with transmission lines with heavier loading than historic lines have experienced. When a transmission line is parallel or semi-parallel to an adjacent linear facility, the magnetic fields will induce voltages onto these facilities proportionally to the line loading and length of parallelism.
This paper briefly explores the general mechanisms of magnetic induction, a summary of some traditional mitigation approaches, and non-traditional designs to reduce the induction. These methods include shield wire and aerial counterpoise conductor configurations on a sampling of typical voltage levels and transmission line configurations.
Effect o f boundary layer and rotor speed on broadband noise from horizontal ...vasishta bhargava
In this paper, the effect of rotor speed and boundary layer on the broadband noise from wind turbines are discussed. The results from the computations have been validated using the far field acoustic measurements from a similar sized turbine
This study investigated the impact of a nickel interlayer on the electrical resistance of a tin-tin interface under fretting loading conditions. Two coating systems were tested: bronze-tin and bronze-nickel-tin. Using variable displacement amplitude testing, the transition amplitude from partial slip to gross slip was determined. Constant displacement amplitude tests then evaluated the influence of the nickel interlayer on electrical endurance. The results showed that the nickel interlayer did not influence endurance in gross slip but eliminated copper diffusion through the tin coating, preventing copper oxide formation and extending the domain of partial slip. This increased the reliability of the electrical contact.
James Fenwick - Engineering Design 4 IEEE Paper (RMIT)James Fenwick
The document discusses modeling different air terminal designs for lightning protection systems using finite element analysis software. It summarizes the objectives of conventional lightning protection systems and how they function. Three air terminal designs were modeled - a conventional smooth design and two non-conventional designs with textured surfaces. All three terminals were subjected to an electrostatic simulation replicating a thunderstorm environment to analyze their electric field distributions. Results showed discrepancies of up to 100kV between the conventional and non-conventional designs, suggesting opportunities to optimize conventional air terminal geometry.
This document outlines standards for transmission line grounding. It discusses the purposes of grounding systems, which are to safeguard people from electric shock during faults, dissipate fault currents and voltages within limits, provide a path for lightning and switching surges, and reduce static discharge. It covers fundamental considerations like soil properties, power system networks, grounding performance of structures, and types of disturbances. Specific sections address safety, grounding of different structure types, grounding conductors, electrodes, resistance requirements, and recommended conductor sizes.
1. Tower configuration is determined by factors like insulator length, required clearances, location of ground wires, and mid-span clearance.
2. Tower height is calculated based on minimum ground clearance, maximum conductor sag, vertical spacing between conductors, and clearance between ground wire and top conductor.
3. Other factors that influence tower design include wind pressure, temperature variations, and different types of loads on the tower from reliability, security, and safety requirements.
This document summarizes the analysis and design of a fixed-fixed beam RF MEMS capacitive switch to achieve low actuation voltage. It describes how RF MEMS switches using a fixed-fixed beam structure can exhibit lower actuation voltages than typical electrostatic RF MEMS switches. The paper analyzes various parameters that affect the actuation voltage of the proposed switch, such as the spring constant and beam gap. Simulation results show the designed fixed-fixed beam switch has a pull-in voltage range of 3.18V to 3.5V, indicating it can operate at lower voltages than many other RF MEMS switch designs. This switch structure has potential applications in reconfigurable antennas and circuits for satellite and mobile communications.
The document discusses different methods of earthing electrical systems. It defines earthing as providing a direct path for fault current and achieving a common reference potential. It describes designing earthing using rods, strips, infill material or foundations. It also discusses soil resistivity testing to determine the resistivity based on moisture, temperature and depth. It provides formulas to calculate the resistance to earth of rods, strips and infill material based on factors like soil resistivity, length, diameter and material used.
1. The document discusses the computer-aided design of grounding systems for transformer stations to ensure low grounding resistance and safe touch and step voltages. It presents the design of grounding systems for three transformer stations in Croatia using CDEGS software.
2. The design process involves measuring soil resistivity on site, modeling the soil as multiple layers, designing the grounding grid geometry, and simulating fault conditions to analyze touch and step voltages.
3. For a sample 110x80m grounding grid, the analysis shows that touch voltages are highest in the station corners. Additional measures like an outer ring conductor are recommended to improve safety.
Performance Analysis of Actual Step and Mesh Voltage of Substation Grounding ...Editor IJCATR
The performance of Earthing grid system is very important to ensure the human and protective devices in safe environment. Actual
Step and Mesh voltage of a substation must keep under the maximum allowable limits under fault condition. Ground potential rise, GPR is
greatly influence on actual step and mesh voltage of substation grounding system. Ground potential rise also mainly depends on the length and
numbers of ground rods and grid spacing. This paper presents performance analysis of actual step and mesh voltages of a substation grounding
system under the variance of length and number of ground rods. The performance result is also carried out by using current injection method and
with the help of MULTISIM simulation software.
This paper presents 230 66 kV, substation grounding system and calculation results of required parameters. The grounding system is essential to protect people working or walking in the vicinity of earthed facilities and equipments against the danger of electric shock. This paper provides the floor surface either assures an effective insulation from earth potential or effectively equipment to a close mesh grid. Calculations of grounding grid system in the substation area which the top soil layer resistivity is less than the bottom layer resistivity, can lessen the number of ground rod used in the grid because the value of Ground Potential Rise GPR is insignificantly different. Essential equations are used in the design of grounding system to get desired parameters such as touch and step voltage criteria for safety, earth resistance, grid resistance, maximum grid current, minimum conductor size and electrode size, maximum fault current level and resistivity of soil. Calculations of three separate earthing body earth, neutral earth and main earthing are described. Zin Wah Aung | Aung Thike "Design of Grounding System for Substation" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26641.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/26641/design-of-grounding-system-for-substation/zin-wah-aung
This document discusses the design of an earthing system for a 230 kV substation. It presents standard equations used to calculate parameters necessary for a safe earthing system design, such as touch and step voltage criteria, earth resistance, conductor size, and electrode size. It describes using MATLAB to simulate an earthing system design for a substation in Myanmar that meets safety requirements for touch and step voltages. The design includes calculating the grid conductor length, number of electrodes, and confirming the mesh and step voltages are below the defined safety limits.
This document analyzes and compares the design of 220kV transmission line towers in different wind zones (I and V) and with different base widths (1/4, 1/5, and 1/6 of total tower height). Six towers are modeled and loads are calculated according to industry standards. After analysis, the towers are compared based on deflections, stresses, axial forces, and weight. The results show that towers in wind zone V experience higher deflections and stresses compared to zone I. Wider base widths result in lower deflections and stresses but higher tower weights. This study provides useful data for designing efficient and structurally sound 220kV transmission line towers.
Design and Simulation of a Fractal Micro-TransformerIJERA Editor
This document summarizes the design and simulation of a fractal micro-transformer. The researchers designed an air-core fractal micro-transformer using finite element modeling software. Simulation results showed improved performance parameters compared to macro transformers, including higher voltage gain. Electric displacement and magnetic energy density within the micro-transformer were determined to be 2 x 10-11 C/m2 and 100 J/m3 respectively. Losses within the air-core design were minimal at 3 W/m3. The micro-transformer was concluded to be suitable for integration in MEMS and VLSI applications due to its small size, high impedance, and isolation capabilities.
This document outlines the scope of work for detailed surveying of various 220/66kV transmission lines in Gujarat, India. The scope includes route alignment using satellite imagery and maps, detailed GPS surveying, profiling, tower spotting, soil investigations, and preparing survey reports. Route alignment will identify three alternative routes and select the optimal one considering economic and technical factors like minimizing forest/tree cutting, river/infrastructure crossings, and risks from flooding. Detailed surveying will generate digitized plans, profiles, contours and soil data to inform tower designs and foundations. The contractor will use modern surveying techniques and tools like GPS, total stations, scanners and software.
This document discusses the design of steel tower structures. It begins by outlining the process of analyzing member forces and sizing members based on their axial loads. It then describes various bracing systems used for towers, including single web, double web (Warren), Pratt, and portal systems. Factors affecting the design of compression members like effective length, slenderness ratio, and buckling are also summarized. Empirical formulas for determining safe compressive stresses based on material properties and member geometry are presented.
The key factors that determine tower configuration are:
1. The required insulator assembly length, conductor clearances, and ground wire placement.
2. The tower height is determined by the minimum ground clearance, maximum conductor sag, vertical conductor spacing, and clearance between the ground wire and top conductor.
3. Other factors influencing tower configuration include wind loads, temperature variations, conductor size and material, and span length. Proper configuration ensures safety clearances and allows the transmission line to reliably carry power loads with the required safety factors.
Study of RF-MEMS Capacitive Shunt Switch for Microwave Backhaul Applications IOSRJECE
In this research paper, we have proposed a new type of capacitive shunt RF-MEMS switch. MicroElectro-Mechanical System (MEMS) is a combination of mechanical and electromagnetics properties at micro level unit. This MEMS switch can be used for switching purpose at RF and microwave frequencies, called RFMEMS switch. The RF-MEMS switch has a potential characteristics and superior performances at radio frequency. The MEMS switch has excellent advantages such as zero power consumption, high power handling capacity, high performance, and low inter-modulation distortion. In this proposed design, a new type of capacitive shunt switch is designed and analyzed for RF applications. The switch is designed both in UP and DOWN-states. The proposed switch design consists of substrate, co-planar waveguide (CPW), dielectric material and suspended metallic bridge. The proposed MEMS switch has dimension of 508 µm × 620 µm with a height of 500 µm and implemented on GaAs as a substrate material with relative permittivity of 12.9. The geometry and results of the proposed switch is designed using Ansoft HFSS electromagnetic simulator based on finite element method (FEM). The electrostatic and electromagnetic result showed better performances such as return loss, insertion loss and isolation. The switch has also excellent isolation property of -48 dB at 26 GHz.
Study and Analysis of Insulator used in Substationijtsrd
This document discusses insulators used in electrical substations. It begins with an introduction to electrical distribution systems and the components of substations. It then focuses on the study and analysis of different types of insulators used in substations, including their design, material properties, and performance characteristics. Specifically, it provides data on the standards and specifications for lightning arresters, current transformers, and potential transformers used at various voltage levels. It analyzes the peak voltage ratings, creepage distances, and other parameters for these insulators. The conclusion discusses the importance of properly selecting insulators that meet the ratings of the transmission lines to protect the substation equipment.
This document discusses sizing underground power cables using MATLAB. It provides background on factors that affect cable sizing like voltage, current, power rating, cable properties, installation conditions, and permissible voltage drop. The general sizing methodology is described in 4 steps: 1) Gather data on the cable and load, 2) Determine minimum size based on continuous current capacity, 3) Determine minimum size based on voltage drop considerations, 4) Select highest size from steps 2 and 3. Tables provide example cable current and impedance ratings. Derating factors are discussed for installation conditions like temperature and cable grouping. A MATLAB code is developed to calculate cable cross-sectional area based on parameters and voltage drop limits.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Reducing Induced Voltages on Parallel Facilities in Shared Transmission Corri...Power System Operation
Routing, siting, and environmental constraints are pushing more transmission lines and other linear facilities such as pipelines and railroads into shared corridors. The future power system will see a greater number of these situations, often coupled with transmission lines with heavier loading than historic lines have experienced. When a transmission line is parallel or semi-parallel to an adjacent linear facility, the magnetic fields will induce voltages onto these facilities proportionally to the line loading and length of parallelism.
This paper briefly explores the general mechanisms of magnetic induction, a summary of some traditional mitigation approaches, and non-traditional designs to reduce the induction. These methods include shield wire and aerial counterpoise conductor configurations on a sampling of typical voltage levels and transmission line configurations.
Effect o f boundary layer and rotor speed on broadband noise from horizontal ...vasishta bhargava
In this paper, the effect of rotor speed and boundary layer on the broadband noise from wind turbines are discussed. The results from the computations have been validated using the far field acoustic measurements from a similar sized turbine
This study investigated the impact of a nickel interlayer on the electrical resistance of a tin-tin interface under fretting loading conditions. Two coating systems were tested: bronze-tin and bronze-nickel-tin. Using variable displacement amplitude testing, the transition amplitude from partial slip to gross slip was determined. Constant displacement amplitude tests then evaluated the influence of the nickel interlayer on electrical endurance. The results showed that the nickel interlayer did not influence endurance in gross slip but eliminated copper diffusion through the tin coating, preventing copper oxide formation and extending the domain of partial slip. This increased the reliability of the electrical contact.
James Fenwick - Engineering Design 4 IEEE Paper (RMIT)James Fenwick
The document discusses modeling different air terminal designs for lightning protection systems using finite element analysis software. It summarizes the objectives of conventional lightning protection systems and how they function. Three air terminal designs were modeled - a conventional smooth design and two non-conventional designs with textured surfaces. All three terminals were subjected to an electrostatic simulation replicating a thunderstorm environment to analyze their electric field distributions. Results showed discrepancies of up to 100kV between the conventional and non-conventional designs, suggesting opportunities to optimize conventional air terminal geometry.
This document outlines standards for transmission line grounding. It discusses the purposes of grounding systems, which are to safeguard people from electric shock during faults, dissipate fault currents and voltages within limits, provide a path for lightning and switching surges, and reduce static discharge. It covers fundamental considerations like soil properties, power system networks, grounding performance of structures, and types of disturbances. Specific sections address safety, grounding of different structure types, grounding conductors, electrodes, resistance requirements, and recommended conductor sizes.
1. Tower configuration is determined by factors like insulator length, required clearances, location of ground wires, and mid-span clearance.
2. Tower height is calculated based on minimum ground clearance, maximum conductor sag, vertical spacing between conductors, and clearance between ground wire and top conductor.
3. Other factors that influence tower design include wind pressure, temperature variations, and different types of loads on the tower from reliability, security, and safety requirements.
This document summarizes the analysis and design of a fixed-fixed beam RF MEMS capacitive switch to achieve low actuation voltage. It describes how RF MEMS switches using a fixed-fixed beam structure can exhibit lower actuation voltages than typical electrostatic RF MEMS switches. The paper analyzes various parameters that affect the actuation voltage of the proposed switch, such as the spring constant and beam gap. Simulation results show the designed fixed-fixed beam switch has a pull-in voltage range of 3.18V to 3.5V, indicating it can operate at lower voltages than many other RF MEMS switch designs. This switch structure has potential applications in reconfigurable antennas and circuits for satellite and mobile communications.
The document discusses different methods of earthing electrical systems. It defines earthing as providing a direct path for fault current and achieving a common reference potential. It describes designing earthing using rods, strips, infill material or foundations. It also discusses soil resistivity testing to determine the resistivity based on moisture, temperature and depth. It provides formulas to calculate the resistance to earth of rods, strips and infill material based on factors like soil resistivity, length, diameter and material used.
1. The document discusses the computer-aided design of grounding systems for transformer stations to ensure low grounding resistance and safe touch and step voltages. It presents the design of grounding systems for three transformer stations in Croatia using CDEGS software.
2. The design process involves measuring soil resistivity on site, modeling the soil as multiple layers, designing the grounding grid geometry, and simulating fault conditions to analyze touch and step voltages.
3. For a sample 110x80m grounding grid, the analysis shows that touch voltages are highest in the station corners. Additional measures like an outer ring conductor are recommended to improve safety.
Performance Analysis of Actual Step and Mesh Voltage of Substation Grounding ...Editor IJCATR
The performance of Earthing grid system is very important to ensure the human and protective devices in safe environment. Actual
Step and Mesh voltage of a substation must keep under the maximum allowable limits under fault condition. Ground potential rise, GPR is
greatly influence on actual step and mesh voltage of substation grounding system. Ground potential rise also mainly depends on the length and
numbers of ground rods and grid spacing. This paper presents performance analysis of actual step and mesh voltages of a substation grounding
system under the variance of length and number of ground rods. The performance result is also carried out by using current injection method and
with the help of MULTISIM simulation software.
This paper presents 230 66 kV, substation grounding system and calculation results of required parameters. The grounding system is essential to protect people working or walking in the vicinity of earthed facilities and equipments against the danger of electric shock. This paper provides the floor surface either assures an effective insulation from earth potential or effectively equipment to a close mesh grid. Calculations of grounding grid system in the substation area which the top soil layer resistivity is less than the bottom layer resistivity, can lessen the number of ground rod used in the grid because the value of Ground Potential Rise GPR is insignificantly different. Essential equations are used in the design of grounding system to get desired parameters such as touch and step voltage criteria for safety, earth resistance, grid resistance, maximum grid current, minimum conductor size and electrode size, maximum fault current level and resistivity of soil. Calculations of three separate earthing body earth, neutral earth and main earthing are described. Zin Wah Aung | Aung Thike "Design of Grounding System for Substation" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26641.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/26641/design-of-grounding-system-for-substation/zin-wah-aung
This document discusses the design of an earthing system for a 230 kV substation. It presents standard equations used to calculate parameters necessary for a safe earthing system design, such as touch and step voltage criteria, earth resistance, conductor size, and electrode size. It describes using MATLAB to simulate an earthing system design for a substation in Myanmar that meets safety requirements for touch and step voltages. The design includes calculating the grid conductor length, number of electrodes, and confirming the mesh and step voltages are below the defined safety limits.
ANALISIS DESAIN SISTEM GRID PENTANAHAN PLTU BERAU KALIMANTAN TIMUR 2 X 7 MWSyamsirAbduh2
To be able to secure and safety the equipment and the workers who work in the power plant area Berau 2 x 7 MW, of course, required the earthing system design quality, reliable and efficient whereby the grounding grid resistance, voltage step and touch voltage according to the calculations contained in IEEE Std 80 -2000. This research will discuss the evaluation of system design with respect to the value of earthing resistance grounding grid, mesh voltage and step voltage. Evaluation parameters - parameters according to calculations published in IEEE Std 80-2000. Results from this study is the need for improvements to the design value of the voltage step and touch voltage is actually one - each 219.03 V and 383.29 V, which is greater than the voltage step and touch voltages are allowed each - amounting to 164.86 V for weight 50 kg; 223.13 V for weights 70 kg and 128.21 V to weight 50 kg; 173.53 V to 70 kg weight.
Successful operation of entire power system depends to a considerable extent on efficient and satisfactory performance of substations. Hence substations in general can be considered as heart of overall power system. In any substation, a well-designed grounding plays an important role. Since absence of safe and effective grounding system can result in mal-operation or non-operation of control and protective devices, grounding system design deserves considerable attention for all the substations. There are two primary functions of a safe earthing system. Firstly, ensure that a person who is in the vicinity of earthed facilities during a fault is not exposed to the possibility of a fatal electrical shock. Secondly, provide a low impedance path to earth for currents occurring under normal and fault conditions.The earthing conductors, composing the grid and connections to all equipment and structures, must possess sufficient thermal capacity to pass the highest fault current for the required time
The document provides instructions for determining the soil resistivity and installing an earthing system for a chlorine contact tank. It specifies that:
1) The surveyor should connect the earthing cable to rebar at the same level as the finished ground level around the tank, which is at elevation +578.15m or deeper according to the drawings.
2) A good connection should be made between the rebar and bare copper conductor using a clamp. Vertical rebar should be used for the connection.
3) Schwarz's method should be used to calculate the soil resistivity and design the earthing system, taking into account factors like soil type, moisture content, conductor size, rod length, and number
This document discusses designing safe and reliable grounding systems for AC substations located in areas with poor soil conditions and high resistivity. It provides an interpretation of IEEE Std. 80 and explores designing ground grids with high resistance while still maintaining safety. Key points discussed include:
1. Methods for designing ground grids in high resistivity soils without changing soil characteristics or adding deep ground wells, which can be costly.
2. Factors that influence ground potential rise and allowable touch/step voltages such as fault current, grid resistance, surface material properties, and fault clearing time.
3. Techniques for increasing ground grid safety like using a surface layer, limiting fault duration, and reducing current flow in the ground grid
Design of Earthing System for 230 kV High Voltage Substation by ETAP 12.6 Sof...ijtsrd
The design of earthing system for 230 kV substation is challenging task. A safety is one major concern in the operation and design of an electrical power system. This Paper is to provide information pertinent to safe earthing practice in substation design and to establish the safe limits of potential difference under normal and fault conditions. Substation earthing system design requires calculating of parameter such as touch and step voltage criteria for safety, grid resistance, maximum grid current, earth resistance, minimum conductor size and electrode size, maximum fault current level and soil resistivity. Soil resistivity is a major factor influencing substation grid design. In this paper, design of earthing grid for Square configuration to obtain the minimum cost and safety. Finally, simulation results were carried out using ETAP 12.6 software. This paper mentions the method proposed for substation earthing is in accordance with IEEE Std 80 2000. Khin Thuzar Soe | Thet Mon Aye | Aye Aye Mon "Design of Earthing System for 230 kV High Voltage Substation by ETAP 12.6 Software" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26747.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/26747/design-of-earthing-system-for-230-kv-high-voltage-substation-by-etap-126-software/khin-thuzar-soe
Investigation of overvoltage on square, rectangular and L-shaped ground grid...IJECEIAES
Ground grid system is important for preventing the hazardous effects of overvoltage in high voltage substations due to fault current perhaps from lightning strike or device malfunction. Therefore, this study aimed to investigate the effects of overvoltage on square, rectangular and L-shaped ground grids with ground rods being distributed in mesh-pattern by using alternate transients program/electromagnetic transients program (ATP/EMTP) program. The models were simulated in the cases that 25 kAfault current being injected into the center or one of the corners of ground grids. The results showed that the highest level of overvoltage (6.3349 kV) was detected at the corner of rectangular ground grid when the fault current was injected into its corner. However, the lowest level of overvoltage was found when the fault current was injected into the center of square ground grid. The results from this study indicated that ATP/EMTP program was useful for preliminary investigation of overvoltage on ground grids of different shapes. The obtained knowledge could be beneficial for further designing of ground grid systems of high voltage substations to receive the minimal damages due to fault current.
Ground potential rise at overhead AC transmission line structures during powe...Power System Operation
This document discusses ground potential rise (GPR) near overhead transmission line structures during phase-to-ground faults. It examines fault current magnitude and flow, analytical models for calculating GPR, soil characteristics, safety standards, and design considerations like structure footing resistance that impact line performance during faults. Case studies are presented on measured GPR effects. Guidelines are provided for assessing safety and mitigating hazards from touch and step voltages resulting from GPR.
This document discusses the analysis of grounding systems for substations. It analyzes the grounding system design for a 220/132/33 kV substation in India as a case study. The key factors considered in grounding system design are discussed, including fault current magnitude, transient overvoltage protection, and safety. Calculations are shown for sizing conductors, determining grid resistance and step/touch voltages based on soil resistivity and other input parameters. The results found that the designed grounding system met safety requirements, with attainable step and touch voltages below tolerable limits and a grid resistance under 1 ohm. Proper grounding system analysis and design is important for safety during faults.
The document discusses grounding systems and their objectives which are to provide safety, ensure correct operation of equipment, prevent damage, dissipate lightning, stabilize voltage, and divert stray RF energy. It describes the three main types of grounding as equipment, system, and lightning/surge grounding. Various grounding components and methods are defined including earth electrodes, earthing conductors, earthing grids, soil characteristics, recommended earth resistance values, and substation earthing systems. New methods to decrease ground resistance such as chemical rods, grounding augmentation fill, and cracks filled with low resistivity materials are also summarized.
The AC total interference of faulted power lines to gas pipelines sharing the same right of way, which may pose a threat to operating personnel and equipment, was studied. The main advantage of this work is to determine the effects of different soil structures on the induced voltage for various soil resistivities. Two main approaches were used to compute the induced voltages, namely the method of moment (MOM), which is based on electromagnetic field theory, and the circuit based method, which uses the circuit grounding analysis to compute the conductive interference and the circuit based models to compute the inductive interference. A 10-km-long parallel pipeline-transmission line model was developed. The soil resistivity was varied, and the induced voltages obtained from both approaches were compared. Soil resistivity and soil structure are important parameters that affect the AC interference level. The results of the study show that the earth potentials and the metal GPRS are independent. Higher soil resistivity causes the tower ground resistance to increase, thus making the shield wire’s attractiveness as a fault current return path to increase, which in turn forces the induced net EMF and the cumulative GPR in the pipeline to reduce.
Transient response of grounding systems under impulse lightning currentHimmelstern
This document summarizes research on modeling the transient response of grounding systems during lightning strikes. It develops a lumped parameter model using transmission line theory to represent the distributed parameters of grounding conductors. The model accounts for time-varying soil properties like resistivity and ionization around electrodes during high current injections. Simulation results show the model can accurately estimate voltages along the grounding system under different lightning impulse currents and validate analytical methods.
Analysis of transient enclosure voltages in gis (emtp simulation studies)eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Analysis of transient enclosure voltages in gis (emtp simulation studies)eSAT Journals
Abstract Transient Enclosure voltage is special case of very fast transient overvoltages which occurs due to disconnect switch operation or earth ground. Transient Enclosure Voltage appears on external of earthed enclosure of Gas Insulated Systems. Despite of proper grounding, this phenomenon indicates presence of high potentials on Gas Insulted System enclosures so the grounding system impedance is thoroughly examined and designed. In this study EMTP Software is used for analysis. Simulation was done by varying the different parameters. Variations of waveforms of the Transient Enclosure Voltage with various parameters have been studied. Index Terms: Transient Enclosure Voltage (TEV), Gas Insulated System (GIS), Very Fast Transient Overvoltages (VFTO) Transient Ground Potential Rise (TGPR), Disconnector Switch
New Waste Material to Enhance the Performance of Grounding SystemTELKOMNIKA JOURNAL
This paper presents the new waste material to enhance the grounding system application by using Rice Straw Ashes as backfill to reduce the grounding resistance of the grounding system. Due to the importance of the grounding system, this paper discussed the effectiveness of the grounding system after using the additive material. The additive material that used are rice straw ash and bagasse ash. The technique that used in this paper is a vertical type because more economical to install. From the result, it was found that depth of electrode and soil treatment has an impact in reducing the grounding resistance. In addition, Rice Straw ashes provide a better grounding performance comparable to Bagasse ashes.
Design of Earthing in Underground Substation using ETAP with ConstraintsYogeshIJTSRD
This paper describes the earthing design of a distribution substation 33kV 415V, 50Hz system. in this type of substation equipment’s are 33kV HV panel, transformer, battery, battery charger and Low voltage panels. The earth mat is below substation which is almost 15 18 Meter deep from ground level. The main considerable factors for earth mat design are soil resistivity which is higher due to basalt rock and system fault current. Fault current level of the system considered as 70kA derived from calculations. Earthing is essential for proper functioning of substation equipment’s and in the absence of proper designing affects in many ways like electric shock to personnel’s and malfunctions and damage to the equipment’s. The basic purpose of earthing is to ensure personnel safety, safe and reliable operation of equipment’s, prevent stray current, protection against interferences and keeps steps and touch potential within safe limit. This paper also discussed constraint in design due to below ground level. Result of manual calculation compared with design simulated through ETAP software version 19. The data used in design considered from a substation in Mumbai, Maharashtra. Daud Ahmad | Dr. Javed Ashraf "Design of Earthing in Underground Substation using ETAP with Constraints" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43787.pdf Paper URL: https://www.ijtsrd.com/engineering/electrical-engineering/43787/design-of-earthing-in-underground-substation-using-etap-with-constraints/daud-ahmad
PERANCANGAN SISTEM PENTANAHAN GAS INSULATED SWITCHGEAR 150KV PULOGADUNG DENGA...SyamsirAbduh2
The purpose of this research is to design Grid-Rod earthing system on Gas Insulated Switchgear (GIS) 150 kV Pulogadung based on IEEE Std. 80-2000. IEEE Guide for Safety in AC Substation Grounding uses Finite Element Method (FEM) to secure people and equipment around substation. By changing some configurations based on initial design, the section I grid size that will be applied are 7 x 4 meters with the number of parallel conductor in its length and width’s side are nx= 7 and ny= 10. The section II grid size are, 7 x 7 meters with the number of parallel conductor in its length and width’s side are nx= 3 dan ny= 5. Grid depth is 0.8 meters from the ground surface and the number of 3 meters earthing rod used are 14 pieces. This design results for grounding resistance is 0.112 Ohm, touch voltage is 642.5 Volts and step voltage is 433.8 Volts which have met the safety standard of IEEE Std. 80-2000.
Similar to Impact of Buried Conductor Length on Computation of Earth Grid Resistance (20)
Effects of the Droop Speed Governor and Automatic Generation Control AGC on G...IJAPEJOURNAL
In power system, as any inequality between production and consumption results in an instantaneous change in frequency from nominal, frequency should be always monitored and controlled. Traditionally, frequency regulation is provided by varying the power output of generators which have restricted ramp rates. The Automatic Generation Control AGC process performs the task of adjusting system generation to meet the load demand and of regulating the large system frequency changes. A result of the mismatches between system load and system generation, system frequency and the desired value of 50 Hz is the accumulation of time error. How equilibrium system frequency is calculated if load parameters are frequency dependent, and how can frequency be controlled. Also, how do parameters of a speed governor affect generated power. The transient processes before system frequency settles down to steady state. Finally, AGC in what way is it different from governor action. This paper presents new approaches for AGC of power system including two areas having one steam turbines and one hydro turbine tied together through power lines.
Underwater Target Tracking Using Unscented Kalman FilterIJAPEJOURNAL
Unlike conventional active sonar, that transmits the sound signals and revealing their presence and position to enemy forces. The probable advantage of passive sonar is that it detects the signals emitted by the target, leads to improve localization, target tracking, and categorization. The challenging aspect is to estimate the true bearing and frequency measurements from the noisy measurements of the target. Here in this paper, it is recommended for the Unscented Kalman Filter (UKF) to track the target by using these noisy measurements. The Target Motion Analysis (TMA), which is the way to find the target’s trajectory by using frequency and bearing measurements, is explored. This method provides a tactical advantage over the classical bearing only tracking target motion analysis. It makes the observer maneuver unnecessary.
Investigation of Dependent Rikitake System to Initiation PointIJAPEJOURNAL
In this paper we investigate depending of the Rikitake system to initiation point, and monitor changing behavior of this system. We will have 4 initiation points in Cartesian system. We at 4 positions, will monitor behavior of this system, while holding constant other values, and after per position, will draw operation of system on axes of x, y, z and 3-D plot. We want to know, what is the effect of initiation point on Rikitake system? Numerical simulations to illustrate the effect of initiation point are presented, and at the end conclusions and comparing the states together are obtained.
Optimization of Economic Load Dispatch with Unit Commitment on Multi MachineIJAPEJOURNAL
Economic load dispatch (ELD) and Unit Commitment (UC) are significant research applications in power systems that optimize the total production cost of the predicted load demand. The UC problem determines a turn-on and turn-off schedule for a given combination of generating units, thus satisfying a set of dynamic operational constraints. ELD optimizes the operation cost for all scheduled generating units with respect to the load demands of customers. The first phase in this project is to economically schedule the distribution of generating units using Gauss seidal and the second phase is to determine optimal load distribution for the scheduled units using dynamic programming method is applied to select and choose the combination of generating units that commit and de-commit during each hour. These precommitted schedules are optimized by dynamic programming method thus producing a global optimum solution with feasible and effective solution quality, minimal cost and time and higher precision. The effectiveness of the proposed techniques is investigated on two test systems consisting of five generating units and the experiments are carried out using MATLAB R2010b software. Experimental results prove that the proposed method is capable of yielding higher quality solution including mathematical simplicity, fast convergence, diversity maintenance, robustness and scalability for the complex ELD-UC problem.
Enhancing Photoelectric Conversion Efficiency of Solar Panel by Water CoolingIJAPEJOURNAL
Photovoltaic solar cell generates electricity by receiving solar irradiance. The electrical efficiency of photovoltaic (PV) cell is adversely affected by the significant increase of cell operating temperature during absorption of solar radiation. This undesirable effect can be partially avoided by cooling the back side of the photovoltaic panel using water absorption sponge which was fixed on of PV panel and maintain wet condition by circulation of drop by drop water. The objective of the present work is to reduce the temperature of the solar cell in order to increase its electrical efficiency. Experiments were performed with and without water cooling. A linear trend between the efficiency and temperature was found. Without cooling, the temperature of the panel was high and solar cells were achieved an efficiency of 8–9%. However, when the panel was operated under water cooling condition, the temperature dropped maximally by 40C leading to an increase in efficiency of solar cells by 12%.
PMU-Based Transmission Line Parameter Identification at China Southern Power ...IJAPEJOURNAL
China Southern Power Grid Company (CSG) recently developed and implemented an online PMU-based transmission line (TL) parameter identification system (TPIS). Traditionally, TL parameters are calculated based on transmission tower geometries, conductor dimension, estimates of line length, conductor sags, etc. These parameters only approximate the effect of conductor sag and ignore the dependence of impedance parameters on temperature variation. Recent development in PMU technology has made it possible to calculate TL parameters accurately. The challenges are that such application requires highly accurate PMU data while the accuracy of PMU measurements under different working/system conditions can be uncertain. With a large number of PMUs widely installed in its system, CSG plans to improve and update the EMS database using the newly developed TPIS. TPIS provides an innovative yet practical problem formulation and solution for TL parameter identification. In addition, it proposes a new metric that can be used to determine the credibility of the calculated parameters, which is missing in the literature. This paper discusses the methodologies, challenges, as well as implementation issues noticed during the development of TPIS.
Investigation of Electric Field Distribution Inside 500/220 kV Transformation...IJAPEJOURNAL
This study depicts the electric field distributions inside a typical 500/220 kV open distribution substation under actual loading conditions and during different working conditions, Hot-Stick position and Bar-Hand position. The electric field is investigated for different workers heights of 1m, 1.5m and 1.8m above ground during normal working condition (Hot-Stick position) inside this substation. This in addition to assessment of the electric field at a height levels of 8m, 11m, 14m and 17m above ground as positions for live line maintenance under 220 kV Busbars, 500 kV Busbars, 220 kV Incoming and Outgoing feeders and 500 kV Incoming and Outgoing feeders respectively. In this study the simulation results of the electric field obtained using three dimensional (3D) computer model for existing typical high voltage transformation substation are compared with field values measured inside this typical substation and presented and discussed not only in the form of contour maps but also in the form 3D surface and wireframe maps. The simulation results are good matched and agreed with measured values. This in addition to the electric field will be tabulated and compared to international guidelines for personnel exposure to electric field. This study will serve for planning service works or for inspection of equipment inside high voltage (HV) power transformation substations.
Economic Load Dispatch for Multi-Generator Systems with Units Having Nonlinea...IJAPEJOURNAL
This document presents an economic load dispatch problem that uses the Gravity Search Algorithm to minimize total generation costs for multi-generator power systems. It discusses how practical constraints like valve point loading, multi-fuel operation, and forbidden zones result in non-ideal, non-continuous generator cost curves. The Gravity Search Algorithm is applied to find the optimal dispatch schedule that accounts for these realistic cost functions and minimizes the total cost of generation while satisfying demand. The algorithm is tested on sample power systems and able to find solutions within acceptable timeframes that outperform traditional optimization methods for large, complex problems.
Improving Light-Load Efficiency by Eliminating Interaction Effect in the Grid...IJAPEJOURNAL
A wind turbine equipped with doubly-fed induction generator (DFIG) is used in wind power plant industry. This paper studies the maximum power extraction of DFIG via evaluation of state-space equations in closed loop control condition for improving light-load efficiency. The DFIG state-space equations have been considered in the form of a multi-input- multi output (MIMO) system. Also, the tracing table has been used to determine the speed which the generated power will be proportional to the maximum load. The tracing table input is the generator speed, and its output is the optimum active power that has been considered as the reference power of the active power control system of the convertor. A controller is presented for the tracing table and the extracted power is able to follow the reference power with minimum ripple. Then, the results are compared with the single-input and single-output (SISO) case, for the values up to 0.2 times of the rated load. Therefore, in MIMO modeling, in the case that the DFIG connected to the grid, by eliminating the interaction effect, the efficiency in light-load can be increased
An Application of Ulam-Hyers Stability in DC MotorsIJAPEJOURNAL
In this paper, a generalization to nonlinear systems is proposed and applied to the motor dynamic, rotor model and stator model in DC motor equation. We argue that Ulam-Hyers stability concept is quite significant in design problems and in design analysis for the class of DC motor’s parameters. We prove the stability of nonlinear partial differential equation by using Banach’s contraction principle. As an application, the Ulam-Hyers stability of DC motor dynamics equations is investigated. To the best of our knowledge this is the first time Ulam-Hyers stability is considered from the applications point of view.
Implementation of Hybrid Generation Power System in PakistanIJAPEJOURNAL
A solar-wind hybrid power generation system has been presented here. The application based system illustrated in this paper is designed on the basis of the solar and wind data for Pakistan. The power generated by the system is intended for domestic use. The most common source of unconventional power in homes is battery based UPS (Uninterrupted power supply) inverter. The UPS inverter charges the battery with conventional grid power. This system will charge the battery of UPS inverter by using only wind and solar power, which will make the system cost effective and more reliable. The reason for using both solar and wind is that recent studies have proven that combined system can be more productive and consistent and other thing is that neither of them can be used for continuous power generation. In the system illustrated in this paper the solar-wind system provides power periodically which is controlled by electronic methods and a microcontroller is used to monitor the power from both the inputs. The switching action is provided from the microcontroller to the battery charging based on the power received from solar photovoltaic panel and wind generators. In this paper, an efficient system has been presented comprising of solar panel, wind generator, charge controller and charge storage unit (battery). Solar panel is selected as the main input and the wind resource will be used only in the absence of the solar photovoltaic (PV) output.
Modeling and Simulation of SVPWM Based ApplicationIJAPEJOURNAL
Recent developments in power electronics and semiconductor technology have lead to widespread use of power electronic converters in the power electronic systems. A number of Pulse width modulation (PWM) schemes are used to obtain variable voltage and frequency supply from a three-phase voltage source inverter. Among the different PWM techniques proposed for voltage fed inverters, the sinusoidal PWM technique has been popularly accepted. But there is an increasing trend of using space vector PWM (SVPWM) because of their easier digital realization, reduced harmonics, reduced switching losses and better dc bus utilization. This project focuses on step by step development of SVPWM technique. Simulation results are obtained using MATLAB/Simulink software for effectiveness of the study.
Comparison of FACTS Devices for Two Area Power System Stability Enhancement u...IJAPEJOURNAL
This document compares the performance of SVC and STATCOM FACTS devices for enhancing transient stability in a two-area power system modelled in MATLAB. It first provides background on power system stability challenges and the role of FACTS devices in addressing these issues. It then reviews previous research comparing different FACTS devices. The paper models an SVC and STATCOM controller in MATLAB and simulates their performance under a three-phase fault. Simulation results indicate that the STATCOM controller provides better damping of rotor angle oscillations, suggesting it enhances transient stability more than the SVC in the two-area power system model.
Influence of Static VAR Compensator for Undervoltage Load Shedding to Avoid V...IJAPEJOURNAL
In the recent years, operation of power systems at lower stability margins has increased the importance of system protection methods that protect the system stability against various disturbances. Among these methods, the load shedding serves as an effective and last-resort tool to prevent system frequency/voltage instability. The analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, voltage also needs to be taken into account in load shedding schemes. This paper considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location .The amount of load to be shed from each bus is decided using the fixed step size method and it’s location has been identified by using voltage collapse proximity index method. SVC is shunt connected FACTS device used to improve the voltage profile of the system. In this paper impact of SVC on load shedding for IEEE 14 bus system has been presented and analyzed.
Assessment of Electric Field Distribution Inside 500/220 kV Open Distribution...IJAPEJOURNAL
The high level electric field intensity produced by high voltage (HV) equipments inside 500/220 kV substations is harmful for the human (staff) health. Therefore the minimum health and safety requirements regarding the exposure of workers to the risk arising from electric fields produced inside these substations is still considered as a competitive topic for utility designers, world health organization (WHO) and biomedical field researchers. It is very important to have knowledge about levels distribution of electric field intensity within these high voltage substations as early stage in the process of substation design. This paper presents results of investigation 50Hz electric field intensity distribution inside 500/220 kV power transmission substations in Cairo, Egypt. This paper presents a method for assessment the distribution of 50HZ electric field intensity distribution inside this substation, this method of analysis is based on the charge simulation technique (CSM). This study will serve for planning service works or for inspection of equipment on HV power transmission substations.
Towards An Accurate Modeling of Frequency-dependent Wind Farm Components Unde...IJAPEJOURNAL
This document describes modeling the components of a wind farm in order to accurately simulate its transient response under lightning conditions. It details models for the wind turbines, transformers, transmission lines, surge arresters, and other components. The models include frequency dependence to capture transient behavior. The wind farm model is implemented and validated in ATP/EMTP software. Comparison is made between models with and without frequency dependence. This accurate modeling of wind farm components allows simulation of the transient response and analysis of lightning hazards.
Hybrid Generation Power System for Domestic ApplicationsIJAPEJOURNAL
This work presents the plan and model of the control strategy for the interconnection of the hybrid energy system able to regulating this load’s voltage and controlling the energy generation with the energy options. The control strategy contains controlling the energy generated through each energy source, in a hierarchical mode using sliding/dropping mode control, while consuming consideration elements that have an impact on each electrical power source and transform the energy generated in order to suitable circumstances for lower power and domestic programs. The cross alternative energy system consists of photovoltaic cellular material, fuel cellular material and battery packs. A numerical equation in order to estimate the perfect voltage involving photovoltaic systems for virtually every solar irradiance and temperature circumstances is suggested. Simulations of a single or a lot more systems interconnected towards the load with the entire proposed control scheme, under different ecological and weight conditions, usually are introduced to indicate this efficiency with the procedure.
Ash Cooler Heat Recovery Under Energy Conservation SchemeIJAPEJOURNAL
A healthy fluidization state in circulating fluidized-bed combustion (CFBC) combustor is attributed to proper quantity of hot bed material (ash), which acts as a thermal fly-wheel. It receives & stores thermal energy from the burning of fuel (lignite) & distributes uniformly throughout the combustor & helps in maintaining a sustained combustion. The quantity of bed ash inside the combustor or size of the bed, depends upon boiler load & subsequently upon combustor temperature, lignite feed rate and ash % in lignite. As these parameters varies during process continuously, sometimes it becomes necessary to drain out the ash from the combustor. As & when differential pressure across the bed is increased from a justified level, draining of hot bed ash starts into Ash Coolers. Bed ash is drained at very high temperature of 850 oC & it also contains burning particles of lignite. This paper describes the heat recovery from bed ash, unloaded from the combustor into ash cooler, by pre-heating the condensate water of turbine cycle in a 125 MW CFB boiler of Surat Lignite Power Plant in India. The thermal performance of ash cooler was derived by doing a heat balance calculation based on the measured temperature of ash and cooling water with different load. From the heat balance calculation influence of ash temperature and ash amount on heat transfer coefficient is determined. Simulation is carried out around main turbine cycle indicates improved thermal economy of the unit, higher plant thermal efficiency, lower plant heat rate and reduce fuel consumption rate. Also simulation result shows that the heat transfer coefficient increase with ash amount and decreases with increase in ash temperature.
Harmonic Voltage Distortions in Power Systems Due to Non Linear LoadsIJAPEJOURNAL
This document summarizes research on harmonic voltage distortions in power systems due to non-linear loads. It describes how non-linear loads can generate harmonics and discusses their effects. It also examines harmonic reduction methods like passive filters. The research uses MiPower software to model a sample IEEE 5-bus power system and analyze harmonic distortions with and without filters. Installation of single and dual passive filters at different buses is shown to significantly reduce total harmonic distortion throughout the system. The document concludes that accurate harmonic analysis of power systems can be achieved using such simulation tools.
A Survey on Quality Changes in Positive, Negative and Combined Switching Stra...IJAPEJOURNAL
In this paper uses positive, negative and combined switching strategies for three phase ac/ac matrix converter .the author compares these strategies. The performance comparison of these three strategies is made under balanced operation. The simulation of three phase matrix converter feeding a three phase load was accomplished by means of the matlab/simulink software. After the simulation the comparison of the waveforms THD in three switching sequence is done. It must be mentioned that the duty cycle of the whole switches in the converter is according to Venturini switching algorithm
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
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KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
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IEEE Slovenia GRSS
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Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
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The main function of substation earthing grid is to provide a means to dissipate fault currents into
the ground without exceeding any operating and equipment limits under both normal as well as fault
conditions, and to assure that a person in the vicinity of earthed facilities is not exposed to the danger of
critical electric shock. Other functions performed by the earthing grid in a substation is to ensure the efficient
operation of the distribution system, and to guarantee the safety of personnel and equipment by limiting the
touch and step voltages and earth potential rise during earth fault conditions to tolerable limits. In order for a
substation earthing system to perform its functions effectively, the earth grid resistance Rg must be low
enough to assure that fault currents dissipate mainly through the earth grid into the ground. Usually, the
acceptable range of Rg for smaller distribution substations is from 1-5Ω depending on the local soil
conditions [3-6]. Consequently, one of the most important considerations during the design of substation
earthing is to achieve low resistance path to ground through which fault currents and lightning strikes are
discharged and to ensure the protection of equipment and personnel against transferred potentials [3, 7].
To design a substation earth grid, certain site-dependent parameters such as, maximum grid current
Ig, fault duration tt, shock duration ts, soil resistivity ρ, surface material resistivity ρs, and grid geometry are
considered to have substantial impact on the grid performance. The grid geometry, area occupied by the grid,
conductor spacing, depth of burial of grid and thickness of the surface layer material are the parameters that
influence the magnitude of mesh, step and touch voltages and earth potential rise (EPR), while the conductor
diameter has no impact at all on the safety criteria of the grid [3, 8]. Soil resistivity and area occupied by the
grid are the most important factors that determine the value of Rg. Generally, the lower the resistance of a
substation earth grid with respect to remote earth, the more effective it is [9]. There are two basic approaches
to the design of substation earth grid used worldwide. In some countries, an earth grid is considered adequate
when the value of Rg satisfies the recommended values by applicable standards. While in other countries,
such as the U.S.A, an earth grid is considered safe when step and touch potentials are made lower than the
permissible values. Among the two approaches, the second is assumed to be more valid as the magnitude of
tolerable current flowing through the human body is taken into consideration [10].
IEEE Standard 80:2000 which is considered as the earthing encyclopedia worldwide has
recommended the use of three different equations, i.e. equations (50) to (52) to determine the value Rg of an
earth grid expressed as equations (1) to (3) in this paper, respectively. This paper presents an evaluation of
these equations to calculate the values of Rg considering the contribution of buried conductor length to the
overall grid resistance. As stated earlier, soil resistivity, area occupied by the grid are the most influential
factors that determine the resistance to remote earth of an earth grid system. In addition, increasing the length
of buried conductors by addition of vertical earth rods to the horizontal grid conductors has been found to
affect the value of Rg hence the addition of conductor terms in IEEE equations (51) and (52). However, the
extent to which the addition of the buried conductor length affects the value of Rg has not been reported in
available literature. Therefore, this paper evaluates the IEEE equations (51) and (52) by increasing the
conductor length to different grid configurations to assess the extent to which the grid resistance could be
reduced. An earth grid with the same dimension was designed using SESCAD and executed in MALT
module of CDEGS for comparison purposes.
2. METHODOLOGY
The normal procedure in designing a distribution substation earth grid and any type of substation for
that matter is to conduct a preliminary survey at the proposed site to inspect the presence of utility
installations such as water or gas pipelines, followed by soil resistivity measurement to determine the soil
model which would provide information on the number of soil layers at the site, thickness of each layer and
the appropriate depth at which the earth grid should be buried. In this paper, soil resistivity measurement was
conducted at a proposed distribution substation site located in front of the prayer room, College 12, Universiti
Putra Malaysia, Serdang, Selangor, Malaysia using Wenner method with a 4-Pole Megger Earth Tester. The
RESAP module of CDEGS software was used to determine the soil model from the measured soil resistivity
field data. Tables 1 and 2 list the soil resistivity field data and the soil model, respectively. Note that, IEEE
Std. 80-2000 equation (50) was initially used to estimate the values of Rg considering the soil resistivity and
area occupied by the grid. Subsequently, equations (51) and (52) were used to calculate the value of Rg by
adding vertical earth rods initially at the grid periphery and then at all conductor intersections, respectively.
The calculation commenced with a small grid dimension of 5m x 5m and increased in steps of 10m until a
grid dimension of 70m x 70m which yielded a value of Rg lower than 5Ω. The spacing between the grid
conductor rows and columns was varied between 3m, 4m and 5m depending on which grid dimension was
exactly divisible by any of the spacing. Typical values of Rg for equations (50) to (52) and grid dimensions
are listed in Table 3. Note that, it was necessary to increase the grid dimension to ensure that Rg<5Ω was
obtained to fulfill the acceptable range recommended in [3] for small distribution substations.
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Finally, the earth grids were designed using SESCAD and executed by MALT module of CDEGS to
determine the value of Rg for comparison purposes. Only three grid dimensions of 50mx50m, 60mx60m and
70mx70m were considered due to the fact that computed results indicated these dimensions yielded values of
Rg<5Ω from all the three equations (50) to (52). The earth grids were designed in three different
arrangements, the first arrangement comprised of horizontal rows and columns of buried conductors only
referred to as Grid A, while the second arrangement comprised of horizontal rows and columns of buried
conductors and 3m long vertical earth rods installed at 3m intervals around the periphery of the grid which
was labeled as Grid B. The third arrangement consisted of horizontal rows and columns of conductors, 3m
long vertical earth rods installed at 3m intervals around the periphery of the grid and at all conductor
intersections of and referred to as Grid C. Note that, for each grid dimension mentioned, Grids A, B and C
have been constructed as shown in Figures 1, 2 and 3, respectively. The burial depth of all earth grids was
1.3m based on the soil model and the grid conductors and the earth rods were both made of hard dawn copper
with radius 0.00535m and 0.008m, respectively according to the conductor sizes used in Malaysia for earth
grid construction. The earth grid was energized by a current of magnitude of 3.125kA for duration of 0.3s.
A
Rg
4
(1)
T
g
LA
R
4
(2)
AhAL
R
T
g
201
1
1
20
11
(3)
Where, Rg is the grid resistance in (Ω), ρ is the soil resistivity in (Ω-m), A is the area occupied by
the earth grid in m2
, h is the grid burial depth in m, and LT is the total length of buried conductors in (m).
3. RESULTS AND DISCUSSION
Table 1 lists the measured apparent soil resistivity field data indicating apparent resistance and
resistivity values which are average values of five measurements conducted for each probe spacing. The
initial spacing between probes was 1m and was increased in steps of 1m up to 6m. To ensure accuracy of
measurement, the spacing between probes was equally maintained and all probes were arranged in a straight
line.
Table 1. Average values of measured soil resistivity field data
Probe Spacing (m) Average Apparent
Resistance (Ω)
Average Apparent Resistivity (Ω-m)
1.0
2.0
3.0
4.0
5.0
6.0
308.6
110.2
52.8
33.6
32.0
20.0
1,938
1,384
995
844
1,005
754
Table 2 depicts the soil model obtained after the RESAP run. It indicates that the soil at the
proposed site comprises of two layers, where the first soil layer has a resistivity of 2231.9Ω-m and thickness
of approximately 1.1m. And, the second soil layer is of resistivity 752.4Ω-m and infinite thickness. In other
words, the soil model is made of two layers with high resistivity layer above a low resistivity layer of infinite
thickness. For earth grid design, the grid would be buried in the second soil layer because it has a lower
resistivity compared to the upper layer and the burial depth was taken to as 1.3m. Note that, the burial depth
is normally varied between 0.5 to 1.5m as reported in [11].
Table 2. Soil structure parameters computed by RESAP
Layer Number Resistivity (Ω-m) Thickness (m)
1
2
2231.9
752.4
1.1
infinite
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Table 3 lists variables that are required for calculations of earth grid resistance and the results
obtained by substituting these variables into each of equations the IEEE equations (50) to (52) denoted by
equations (1) to (3) in this paper. Note that, equations (2) and (3) contains the LT term which defines the total
length of buried conductors while equation (1) does not, regardless, all the three equations could be used to
calculate value of Rg. Results indicated that, using equation (1), as the area occupied by the grid was
increased from 25m2
to 2,500m2
, the value of Rg decreased steadily from 66.65Ω to 6.66Ω. Observe that,
when the grid area was increased to 4,900m2
the value of Rg obtained was 4.76Ω, which is slightly lower than
5Ω recommended in [12] by IEEE Std. 142 as the maximum value of Rg for small distribution substations.
This implies that, an increase of 2,400m2
of grid area yielded a decrease of only 1.9Ω which is not
economical from the design point of view.
Table 3 Calculated values of Rg using IEEE Std. 80-2000 equations 50, 51 and 52.
Grid Dimension
(m)
Area (m2
) No. of rows and
columns (m)
LT (m) Rg eqtn. 50
(Ω)
Rg eqtn. 51
(Ω)
Rg eqtn. 52
(Ω)
5 x 5
10 x 10
20 x 20
30 x 30
40 x 40
50 x 50
60 x 60
70 x 70
25
100
400
900
1,600
2,500
3,600
4,900
2 x 2
3 x 3
6 x 6
11 x 11
11 x 11
11 x 11
21 x 21
15 x 15
20
80
280
660
880
1,100
2,520
2,100
66.65
33.32
16.66
11.11
8.33
6.66
5.55
4.76
104.36
45.89
19.80
12.25
9.19
7.35
5.85
5.12
71.88
30.00
12.36
7.60
5.95
4.95
4.02
3.69
Considering IEEE equation (51), it could be observed that, the value of Rg was initially computed as
104.36Ω when only 20m length of buried conductor was used. As the length, grid area and dimension were
increased, the value of Rg drastically decreased until 7.35Ω was obtained utilizing 1,100m length of buried
conductor. Further addition of conductor length from 1,100m to 2,520m, and increment of grid area from
2,500m2
to 4,900m2
and grid dimension from 50mx50m to 70mx70m resulted in the reduction of the value of
Rg from 7.35Ω to 5.12Ω, respectively. Again, it could be noted that, an addition of 1,000m of buried
conductor length yielded a decrease in the value of Rg by only 2.23Ω which is also considered uneconomical
in grid design. Similarly, using IEEE equation (52), it could be seen that, the initial value of Rg was 71.88Ω
with 20m length of buried conductor. As the length of buried conductor was increased as a result of the
increase in dimension and area occupied by the grid, the value of Rg decreased to 4.95Ω utilizing 1,100m of
buried conductor length. Note that, the value of Rg, i.e. 4.02Ω was obtained after the length of buried
conductor was increased from 1,100m to 2,520m indicating a difference of 1,420m which is considered
uneconomical for a reduction of less than 1Ω.
Comparing the three IEEE equations for calculating the value of Rg, it could be observed that
equation (50) utilized more grid area, i.e. 4,900m2
to yield a resistance of 4.76Ω as it does not contain any LT
term, while equation (51) which contains both the grid area and LT terms used the same grid area and 2,100m
length of buried conductor but could not yield a resistance value less than 5Ω which is slightly higher than
the result obtained from equation (50). Considering equation (52) which also contains both the grid area and
the LT terms, it was found that, a grid area of 4,900m2
and 2,100m of buried conductor length resulted to an
Rg of 3.69Ω. Therefore, from economic point of view, IEEE equations (50) and (52) are recommended for
estimating the initial values of Rg during substation earth grid design. Care must be exercised during design
process to avoid uneconomic practice as the value of Rg gets lower since the addition of large size of
conductor length does not contribute significantly to decrease the value of Rg.
Table 4 depicts the simulated values of Rg obtained using CDEGS for grids A, B and C containing
different values of buried conductor length as a result of the addition of 3m long earth rods in Grid B and C
arrangements. Considering the 50mx50m dimension with Grid A arrangement, the area occupied by the gird
was 2,500m2
, and the total length of buried conductor was 2100m which yielded an Rg of 6.54Ω. In Grid B
arrangement with the same dimension and area, the total length of buried conductors was increased to
2,340m as a result of the additional 3m long earth rods installed at the grid periphery, the value of Rg merely
decreased to 6.20Ω indicating a difference of only 0.34Ω. In the same vein, when additional earth rods were
installed at all the grid conductor crossings, the total length of buried conductors swelled to 3,423m but the
value of Rg reduced by only 0.49Ω which could be considered negligible for 1,083m increase in buried
conductor length.
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Table 4. Summary of earth grid results after simulation using CDEGS
Grid dimension (m) Grid Area (m2
) Arrangement Conductor length (m) Rg (Ω)
50 x 50 2500
Grid A
Grid B
Grid C
2100
2340
3423
6.54
6.20
6.05
60 x 60 3600
Grid A
Grid B
Grid C
2520
2760
3843
5.48
5.25
5.14
70 x 70 4900
Grid A
Grid B
Grid C
2940
3180
4263
4.72
4.56
4.48
Considering the 60mx60m dimension and Grid A arrangement, the area occupied by the grid is
3600m2
comprising of 2,520m length of buried conductors which produced an Rg of 5.48Ω. When the Grid B
arrangement was installed, the total length of buried conductor increased from 2,520m to 2,760m yielding an
Rg of 5.25Ω which seems to be slightly lower than the previous value with a difference of only 0.23Ω. Also,
for Grid C arrangement, the total length of buried conductor swelled to 3,843m when earth rods were added
at the grid intersections, however, the value of Rg obtained was barely 5.14Ω showing a difference of 0.34Ω
only when compared with the initial value of Rg for 60mx60m grid dimension. In the same vein, considering
the 70mx70m dimension Grid A arrangement, the grid covered an area of 4900m2
with 2,940m length of
buried copper conductor resulting in an Rg of 4.72Ω. The total lengths of buried conductor for Grid B and C
arrangements were 3,180m and 4,263m which produced 4.56Ω and 4.48Ω of Rg, for a grid area of 4900m2
respectively. Note that, the difference of buried conductor length between Grid B and C is 1,083m but
resulted in the reduction of the value of Rg by only 0.08Ω which could be considered as negligible and
uneconomical.
The results from the grid design and simulations have revealed that, for all the three grid
dimensions, addition of earth rods at grid conductor crossings (all cases of Grid C) have negligible or
precisely zero contribution to the reduction of the value of Rg and would certainly lead to huge increase in the
overall cost of grid installation. This further indicate the saturation boundary beyond which further addition
of buried conductor length does not lead to reduction of the value of Rg but incurs huge additional cost to the
grid design. It could also be deduced from the results that, the area occupied by the grid plays a more
significant role in reduction of the value of Rg as witnessed in the case of 70mx70m grid dimension.
Furthermore, the results from the calculations using the IEEE Equations (50) to (52) and CDEGS simulations
have good agreement for the three grid dimensions considered.
Figure 1c Top view of 50mx50m Figure 1b Top view of 50mx50m
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Figures 1a, 1b and 1c shows the arrangement of Grid A, B and C for 50mx50m grid dimension,
while Figures 2a, 2b and 2c illustrates the arrangement of Grid A, B and C for 60mx60m grid dimension.
Similarly, Figures 3a, 3b and 3c depicts the arrangement of Grid A, B and C for 70mx70m grid.
Figure 1a Top view of 50x50m Grid A Figure 2a Top view of 60mx60mGrid A
Figure 2b Top view of 60mx60m Grid B Figure 2c Top view of 60mx60m Grid C
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Impact of Buried Conduter Length on Computation of Earth Grid Resistance (S. D. Buba)
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Figure 3a Top view of 70mx70m Grid A Figure 3b Top view of 70mx70m Grid B
Figure 3c Top view of 70mx70m Grid C
Note that, the little dots at the grid periphery and conductor intersections in grid arrangements B and
C for all dimensions 50mx50m, 60mx60m and 70mx70m indicates the earth rod positions which is distinctly
absent in all cases of type A grid arrangements.
4. CONCLUSION
IEEE Standard 80:2000 equations 50, 51 and 52 have been evaluated to determine the contribution
of buried conductor length in computation of the value of earth grid resistance. Three different dimensions
and arrangements of earth grid have been designed by CDEGS to validate the impact of buried conductor
length on the value of grid resistance. It was found that there is a saturation boundary (grid periphery) beyond
which further addition of buried conductor length during earth grid design has negligible effect on the value
of Rg and thus leads to uneconomical design. It was also revealed that equation (52) utilized much less grid
area and buried conductor length to yield a lower value of Rg than equations (50) and (51). It could be
concluded that, vertical earth rods are specifically useful for creating multiple paths for dissipation of fault
currents into the soil, but their impact for reduction of grid resistance is limited beyond the grid periphery as
seen in this study.
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REFERENCES
[1] Y. Liu, “Transient Response of Grounding Systems Caused by Lightning: Modelling and Experiments,” PhD
Thesis, Uppsala University, 2004.
[2] J. D. McDonald, Electric Power Substation Engineering, 2nd
Edition, CRC Press, New York, 2007, Ch. 11-1.
[3] IEEE Standard 80-2000, Recommended Guide for Safety in AC Substation Grounding, ANSI, 2000.
[4] V. L. Coelho, A. Piantini, R. A. Altafim, H. A. Almaguer, R. A. Coelho, M. R. de Lima, W. do C. Boaventura, J.
O. S. Paulino, and P. L. Nosaki, International Symposium on Lightning Protection (XII SIPDA) 2013, Criciúma-
Brazil.
[5] S. Ghoneim, H. Hirsch, A. Elmorshedy, and R. Amer, “Improved Design of Square Grounding Grids,”
International Conference on Power System Technology, (PowerCon.) 2006, 22-26 Oct. 2006, Chongqing, China.
[6] A. A. El-Fergany, “Design and Optimize Substation Grounding Grid Based on IEEE Std. 80-2000 Using GUI
And MATLAB Codes,” International Journal of Engineering Science & Technology, vol. 3, No. 7, 2011.
[7] M. Mondal, D. K. Jarial, S. Ram, and G. Singh, “Design and Analysis of Substation Grounding Grid with and
without Considering Seasonal Factors using EDSA Software.” International Journal of Innovations in Engineering
and Technology, Special Issue, ICAECE, 2013.
[8] S. Raju and P. Upadhyay, “Design of Optimal Grounding Mats for High Voltage Substation,” International
Conference on Advances in Power Conversion and Energy Technologies (APCET) 2012, 2-4 Aug. 2012,
Mylavaram, Andhra Pradesh, India.
[9] A. Ackerman, P. K. Sen, and C. Oertli, “Designing Safe and Reliable Grounding in AC Substations With Poor
Soil Resistivity: An Interpretation of IEEE Std. 80,” IEEE Transactions on Industry Applications, vol. 49, no. 4,
pp. 1883–1889, Jul. 2013.
[10] K. D. Pham, “Design of a Safe Grounding System for Rural Electric Power Distribution Substations,” Presented
at the 34th Annual Conference on Rural Electric Power, (REPCON) 1990, 29 Apr-1 May 1990, Orlando, FL,
U.S.A.
[11] Design Guide for Rural Substations, United States Department of Agriculture, Rural Utilities Service Bulletin
1724E-300, June 2001.
[12] IEEE Standard 142-2007, Recommended Practice for Grounding Industrial and Commercial Power Systems,
ANSI, 2007.
BIOGRAPHIES OF AUTHORS
Sani D. Buba obtained National Diploma in Electrical and Electronic Engineering from the
Federal Polytechnic Mubi in 1991. He proceeded to University of Maiduguri, Borno State,
Nigeria, where he was awarded B. Eng. (Hons) Degree in Electrical and Electronic Engineering
in 2002. He worked as a Tutor in the Department of Electrical and Electronic Engineering,
Federal Polytechnic Mubi from November, 2002 until November, 2009. He enrolled for MSc
Programme in the Department of Electrical and Electronic Engineering, Universiti Putra
Malaysia (UPM) and obtained a Master of Science Degree in Electrical Power Engineering in
August 2012. Mr. Buba is currently a PhD student in the Department of Electrical & Electronic
Engineering at UPM. He is a Graduate Student Member of IEEE-PES, PELS and CIS. His
research interests include, earthing systems, Solar PV systems, Lightning Protection Systems and
Power System Analysis.
Wan F. Wan Ahmad (S’02, M’05) was born in Kelantan, Malaysia, on Sep. 6, 1978. She
graduated from Universiti Kebangsaan Malaysia, Malaysia in 2000 with Bachelor in Electrical,
Electronic and Systems Engineering with honours, and majoring in Electrical Power and Control
Engineering. She received her PhD in Electrical and Electronic
Engineering from University of Nottingham, Nottingham, U.K. in 2007, majoring in Lightning
Protection System and Electromagnetic Compatibility for Electrical Power Engineering. She is
currently with the Department of Electrical and Electronic Engineering, Faculty of Engineering,
Universiti Putra Malaysia which she joined since 2000. She has tremendous experiences in
teaching Bachelor of Engineering (Electrical and Electronics) with Honours students. At the
moment she is Deputy Director (Research and Collaboration) at Centre of Excellence on
Lightning Protection (CELP), Faculty of Engineering, Universiti Putra Malaysia, Malaysia.
Through her career, she has won 3 Research awards and 4 non-research awards. Her research
interests include electrical power engineering, grounding system, lightning protection system,
Electromagnetic Compatibility (EMC), Transmission Line Modelling (TLM), Radio Frequency
Electromagnetic Field (RF EM), Single Long Horizontal Ground Conductor and thin wire. Dr
Wan Ahmad is member of IEEE APS, IEEE EMCS, AND IEEE MTTS, IEEE MS, IEEE SA
AND MSSS.
9. IJAPE ISSN: 2252-8792
Impact of Buried Conduter Length on Computation of Earth Grid Resistance (S. D. Buba)
69
Professor Mohd Zainal Abidin Ab Kadir graduated with B.Eng. Degree in Electrical and
Electronic Engineering from Universiti Putra Malaysia in 2001, and obtained his PhD from the
University of Manchester, United Kingdom in 2006 in High Voltage Engineering. Currently, he
is the Head of Department of Electrical and Electronics Engineering, Faculty of Engineering,
Universiti Putra Malaysia (UPM). He is also the Director of Scientific Committee at the Centre
for Electromagnetic and Lightning Protection Research (CELP), UPM and a Member of
International Board of Advisors for the National Lightning Safety Institute (NLSI), USA.
Professor Zainal is a Professional Engineer (PEng) and a Chartered Engineer (CEng) from Board
of Engineers, Malaysia and Engineering Council, UK, respectively. He is currently the Chair of
IEEE-PES Malaysia Chapter, Working Group Member of IEEE-PES Lightning Performance on
Overhead Lines, Senior Member of IEEE (PES, EMC, Insulation and Dielectric Societies) and
IAENG. To date, he has authored and co-authored over 160 technical papers comprising of high
impact journals and conference proceedings. He is also an Editorial Board Member for several
international journals and Reviewer for many international journals and conference. His research
interests include high voltage engineering, insulation coordination, lightning protection,
EMC/EMI, keraunamedicine, renewable energy and power system transients.
Chandima Gomes was born in Colombo, Sri Lanka 0n 12th September 1966. He obtained his
B.Sc. from University of Colombo, Sri Lanka, and PhD from Universities of Colombo/Uppsala,
Sweden in 1999. He is a member of several professional bodies such as CEng (UK), CPhys
(UK), MInstP (UK), MIET (UK), and MIP (SL). Currently, he is a Professor of Electrical
Engineering in the department of Electrical & Electronic Engineering, Faculty of Engineering,
Universiti Putra Malaysia and also the Head, Centre for Electromagnetic and Lightning
Protection Research (CELP). In addition to his academic career, he is the Technical Director of
ProMan Ship Builders Ltd., China, Chief Technical Advisor and Senior Consultant of Steelman
Electro Mechanical Company LLC, Dubai, Chief Technical Advisor and Senior Consultant of
Indus Resources Ltd., Pakistan, Senior Consultant of Capital Consultants Pvt Ltd., Pakistan,
Director International Affairs of LP Consultants International Pvt Ltd., India, Director/ Technical
Operations of SATRIC-M, Malaysia and Senior Consultant of LLAMPEC International Pvt Ltd.,
Sri Lanka during the last few years. Prof. Gomes has conducted over 80 training programs on
lightning and transient protection technologies to the engineers in Saudi Arabia, Sweden, India,
Sri Lanka, Bangladesh, Bhutan, Pakistan, Nepal, Indonesia, Malaysia and Colombia. Prof.
Gomes has published over 80 research papers and several books on lightning protection. His
research interests include, Lightning & Transient Protection of LV, MV, HV & Signal Systems,
Grounding Systems & Backfill Materials EMI/EMC of Civil and Defense Systems and Electrical
Safety.
Jasronita Jasni (M’01) graduated with a B Eng Degree in Electrical Engineering from Universiti
Teknologi Malaysia, Malaysia in 1998 and received her Master Degree in Electrical Engineering
from the same University in 2001. She obtained her PhD Degree from Universiti Putra Malaysia,
Malaysia in May 2010. Currently she is a Senior lecturer in the Department of Electrical and
Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia. Dr. Jasni is a member
of IEEE. Her research interests include power system analysis for static and dynamics, load flow
analysis, embedded generation and renewable energy.
Miszaina Osman received a Bachelor of Electrical Engineering Degree in 1999 and a PhD in
Electrical Engineering in 2004 both from University of Southampton, United Kingdom. She is a
member of many international professional bodies such as C.Eng. (UK), IET and IEEE.
Currently, Dr. Miszaina is a Deputy Dean and Senior Lecturer in the Department of Electrical
Power Engineering, College of Engineering, Universiti Tenaga Nasional (UNITEN), Malaysia.
She is also a member under the Centre of Power System Simulation (CPSS) in UNITEN. Her
research interest includes power system grounding, power system transients and engineering
education.