This document discusses the key components and design considerations for extra high voltage (EHV) AC transmission lines. It covers:
1. The main components of transmission lines including conductors, earth wires, insulators, towers, and hardware.
2. The design methodology which involves calculating loads from climatic conditions, reliability requirements, and safety factors before designing each component.
3. Factors involved in selecting the transmission voltage level based on the power level, line length, voltage regulation needs, and costs.
4. The types of transmission towers used for different line angles and situations like river crossings.
5. Design of the tower structure including height, base width, cross arm length based
EHV (extra high voltage) AC transmission refers to equipment designed for voltages greater than 345 kV. Higher transmission voltages increase efficiency by reducing transmission losses and current, decrease infrastructure costs, and increase transmission capacity. However, they also present safety and interference risks. New technologies like FACTS (flexible AC transmission systems) help maximize the benefits of EHV transmission by enabling voltage control and power flow management. There is growing support for expanding national EHV transmission grids to facilitate large-scale renewable energy integration and inter-regional power sharing.
This document presents an overview of economic load dispatch in power systems. It discusses the objectives of economic dispatch as generating required power at minimum cost. It describes different constraints like generator limits, transmission limits and voltage limits that need to be considered. It explains the operating costs of thermal plants using heat rate and fuel cost curves. It provides formulations for economic dispatch neglecting and including transmission losses. The document uses examples to illustrate the iterative method used to solve economic dispatch problems.
This document discusses electrical grounding and earthing systems. It begins by introducing grounding and earthing, and distinguishing between ground and neutral conductors. It then describes different types of earthing systems according to the IEC standard, including TN, TT, and IT networks. The document also covers different types of grounding used in radio communications, AC power installations, and lightning protection. It discusses the concept of virtual ground and multipoint grounding. Overall, the document provides an overview of electrical grounding and earthing systems, their uses, and important concepts.
Representation of short & medium transmission linesvishalgohel12195
This document discusses the classification and modeling of overhead transmission lines. It notes that short transmission lines only consider resistance and inductance due to their lower voltages and distances. Medium and long transmission lines must account for capacitance effects. The document presents models for short lines using lumped resistance and inductance and models for medium lines using end condenser, nominal T, and nominal π methods which lump the distributed capacitance for simplified analysis. It also discusses voltage regulation and transmission efficiency calculations.
This document provides an overview of circuit breakers and their role in power systems. It discusses that circuit breakers are used to detect faults and quickly disconnect faulty equipment to prevent damage and service interruptions. They can be reset to resume normal power flow unlike fuses. The document then describes that circuit breakers must be able to safely interrupt high short circuit currents without being damaged. It explains that circuit breakers use various techniques like oil, gas, vacuum or air to quickly extinguish arcs during interruption of high fault currents.
This document provides information about substations, including:
1. Substations are facilities used to change characteristics of electric power supply like voltage, frequency, or converting AC to DC. They are located between generation/transmission and distribution.
2. Substations are classified by their function (transformer, switching, power factor correction etc.) and construction (indoor, outdoor, underground etc.).
3. Key equipment in substations includes transformers, busbars, circuit breakers, insulators, and protection devices. Instrument transformers like PTs and CTs are also used.
4. Distribution systems distribute power from substations to consumers using feeders, distributors, and service mains. Distribution systems are classified by supply type
A substation is a high-voltage electric facility used to switch generators, equipment, and circuits in and out of a system. It also changes AC voltages and converts between AC and DC. Substations can be classified by their service, mounting, function, type of apparatus, and control. They include transformers, switches, circuit breakers, and other equipment to distribute power at appropriate voltages for transmission and utilization.
Design of substation (with Transformer Design) SayanSarkar55
This ppt is made for the subject Machine Design. Here the basic types, equipment, designs of substation is described with the preocess and calculation of designing a transformer also.
EHV (extra high voltage) AC transmission refers to equipment designed for voltages greater than 345 kV. Higher transmission voltages increase efficiency by reducing transmission losses and current, decrease infrastructure costs, and increase transmission capacity. However, they also present safety and interference risks. New technologies like FACTS (flexible AC transmission systems) help maximize the benefits of EHV transmission by enabling voltage control and power flow management. There is growing support for expanding national EHV transmission grids to facilitate large-scale renewable energy integration and inter-regional power sharing.
This document presents an overview of economic load dispatch in power systems. It discusses the objectives of economic dispatch as generating required power at minimum cost. It describes different constraints like generator limits, transmission limits and voltage limits that need to be considered. It explains the operating costs of thermal plants using heat rate and fuel cost curves. It provides formulations for economic dispatch neglecting and including transmission losses. The document uses examples to illustrate the iterative method used to solve economic dispatch problems.
This document discusses electrical grounding and earthing systems. It begins by introducing grounding and earthing, and distinguishing between ground and neutral conductors. It then describes different types of earthing systems according to the IEC standard, including TN, TT, and IT networks. The document also covers different types of grounding used in radio communications, AC power installations, and lightning protection. It discusses the concept of virtual ground and multipoint grounding. Overall, the document provides an overview of electrical grounding and earthing systems, their uses, and important concepts.
Representation of short & medium transmission linesvishalgohel12195
This document discusses the classification and modeling of overhead transmission lines. It notes that short transmission lines only consider resistance and inductance due to their lower voltages and distances. Medium and long transmission lines must account for capacitance effects. The document presents models for short lines using lumped resistance and inductance and models for medium lines using end condenser, nominal T, and nominal π methods which lump the distributed capacitance for simplified analysis. It also discusses voltage regulation and transmission efficiency calculations.
This document provides an overview of circuit breakers and their role in power systems. It discusses that circuit breakers are used to detect faults and quickly disconnect faulty equipment to prevent damage and service interruptions. They can be reset to resume normal power flow unlike fuses. The document then describes that circuit breakers must be able to safely interrupt high short circuit currents without being damaged. It explains that circuit breakers use various techniques like oil, gas, vacuum or air to quickly extinguish arcs during interruption of high fault currents.
This document provides information about substations, including:
1. Substations are facilities used to change characteristics of electric power supply like voltage, frequency, or converting AC to DC. They are located between generation/transmission and distribution.
2. Substations are classified by their function (transformer, switching, power factor correction etc.) and construction (indoor, outdoor, underground etc.).
3. Key equipment in substations includes transformers, busbars, circuit breakers, insulators, and protection devices. Instrument transformers like PTs and CTs are also used.
4. Distribution systems distribute power from substations to consumers using feeders, distributors, and service mains. Distribution systems are classified by supply type
A substation is a high-voltage electric facility used to switch generators, equipment, and circuits in and out of a system. It also changes AC voltages and converts between AC and DC. Substations can be classified by their service, mounting, function, type of apparatus, and control. They include transformers, switches, circuit breakers, and other equipment to distribute power at appropriate voltages for transmission and utilization.
Design of substation (with Transformer Design) SayanSarkar55
This ppt is made for the subject Machine Design. Here the basic types, equipment, designs of substation is described with the preocess and calculation of designing a transformer also.
Relays are electromagnetic switches that are designed to detect faults on electrical circuits and trip circuit breakers. They use a low amperage control circuit to operate a high amperage tripping circuit. Relays can be classified based on their construction, applications, or time of operation. Common types include impedance, reactance, mho, and digital protective relays. Impedance relays have an overcurrent operative torque and a voltage-restraining torque. Reactance relays have a current operative torque and a directional restraining torque. Mho relays induce operative torque from both voltage and current and have a voltage-restraining torque. Digital protective relays use microprocessors to analyze voltages, currents, and
This document discusses earthing systems and the hazards of a broken neutral connection for a power transformer. It defines system earthing and equipment earthing, and explains that a broken neutral connection can cause overvoltage issues for the transformer and prevent protective relays from operating during a fault. The document also discusses the objectives and importance of proper earthing, including providing an alternative path for fault currents, ensuring safety from electric shocks, and maintaining system voltages. It provides examples of what can occur when a transformer's neutral connection to earth is broken.
This document discusses corona phenomenon in overhead transmission lines. It defines corona as the ionization of air surrounding power conductors, which causes a faint violet glow. Critical disruptive voltage and factors affecting corona such as atmospheric conditions, conductor size and spacing are explained. Methods to reduce corona loss include increasing conductor size, using bundled or hollow conductors, corona rings, and increasing spacing. While corona causes power loss and interference, it also reduces voltage surges and electrostatic stresses.
An electrical panel is an enclosure containing electrical components like switches, circuit breakers, and fuses to control and protect electrical systems. There are different types of panels for various applications like motor control, power control, low/medium/high voltage distribution. Key components within panels include switchgears for switching and protecting circuits, fuses that melt under excessive current, and circuit breakers that can safely interrupt faults. Panels also include bus bars to conduct electricity and current transformers to reduce current for measurement. Cables distribute power from panels and come in various core configurations depending on the application.
This presentation discusses transmission lines, including overhead power lines and underground cables. It classifies transmission lines as overhead or underground, and further divides them based on voltage and construction. Overhead lines are cheaper but can be affected by the environment, while underground cables are more expensive to install and maintain but are safer and not impacted by the environment. The presentation also covers nominal T and Pi circuit models that can be used to analyze medium transmission lines, and provides equations for calculating voltages and currents at the sending and receiving ends.
This presentation discusses the key protection devices used in electrical substations. It introduces current transformers and potential transformers, which reduce current and voltage levels for protection relays. Relays detect faults by measuring currents and voltages. When a fault is detected, relays signal circuit breakers to isolate the faulty component. Other protection devices discussed include lightning arresters, isolators, and surge diverters. The objective of the substation protection system is to isolate only faulty parts of the network while keeping the rest operational.
This document discusses voltage drop calculation in cable lines. It provides information on the data required to start calculations, including cable parameters, load characteristics, installation scheme, and maximum allowed voltage drop. It then covers calculations for simple radial lines under conditions of constant current and constant power. For constant current, the voltage drop is calculated based on cable resistance and reactance, line length, and load current. For constant power, an iterative method is used to calculate the voltage at the end of the line based on load power and reactive power. Sample calculations are shown for both cases.
Extra high voltage long ac transmission linesShivagee Raj
From economical point of view designing of transmission line system is very important in the electricity supply system. Extra High Voltage Transmission Lines are best suited for transmission of bulk power.
1. Surge arresters are selected with voltage ratings of 336kV, 360kV, 372kV or 390kV to account for temporary overvoltages during faults.
2. Condition monitoring techniques like third harmonic resistive current monitoring are effective for detecting failures in surge arresters due to moisture ingress or degradation.
3. Investigations found moisture entry through faulty seals or gaskets led to failures in many surge arresters, accelerated by manufacturing defects. Improved sealing methods using O-rings instead of flat gaskets and routine dip testing were implemented.
This document provides details on substation layout and busbar arrangements. Part A discusses substation layout, including a single line diagram and descriptions of common switchyard accessories like lightning arrestors, CVTs, isolators, circuit breakers, transformers, and other equipment. It also covers PLCC and SCADA systems. Part B covers various busbar arrangements like the single bus system, double bus system, one and a half breaker system, and ring main bus system. It discusses the advantages and disadvantages of each configuration. In summary, the document is a technical report that outlines and compares different substation and busbar designs.
This document discusses overvoltage phenomena and insulation coordination in high voltage engineering. It covers several topics:
1) Natural causes of overvoltages like lightning and the mechanisms behind lightning strokes.
2) Classification of transmission lines and the behavior of traveling waves at transition points like reflections and successive reflections shown through lattice diagrams.
3) Causes of overvoltages from switching surges during circuit operations, system faults, and abnormal conditions. Characteristics of switching surges and issues in extra high voltage systems are described.
4) Methods to control overvoltages including stepped energization of lines, phase controlled circuit breakers, and drainage of trapped charges. Protective devices like expulsion gaps, protector tubes
This is the simple ppt explaining about the main components of the power systems. especially we are determining the insulators and its types with real time pictures which are attractive,
The document discusses the key elements of a power system, including generation, transmission, distribution, and load. It describes the different types of power generation such as fossil, hydro, and nuclear. It then explains the transmission system, how power is transmitted through overhead lines or underground cables. Finally, it discusses power distribution to load through lower voltage networks.
Principles of Cable Sizing; current carrying capacity, voltage drop, short circuit.
Cables are often the last component considered during system design even if in many situations cables are the true system’s lifeline: if a cable fails, the entire system may stop. Cable reliability is therefore extremely important, then a cable system should be engineered to last the life of the system in the installation environment for the required application. Environments in which cable systems are being used are often challenging, as extreme temperatures, chemicals, abrasion, and extensive flexing. These variables have a direct impact on the materials used for cable insulation and jacketing as well as the construction of the cable. Using a systematic approach will help ensure that designer select the best cable for the required application in the installation environment. This lessons will provide students main guidelines for perform this approach.
The document discusses underground power cables. It describes the components of underground cables including conductors, insulation, metallic sheathing, bedding, armoring and serving. The main types of underground cables are discussed - solid cables like belted and screened cables used up to 66kV, and pressurized oil and gas cables used at higher voltages. Methods of laying cables underground include direct burying, draw-in systems using ducts, and solid systems within troughs. Underground cables have advantages over overhead lines like better appearance and reliability, but also challenges like higher installation costs and fault localization difficulties.
This document discusses different types of insulators used in overhead power lines. It describes pin insulators, suspension insulators, strain insulators, and shackle insulators. Suspension insulators consist of multiple porcelain discs connected in series by metal links. The voltage is not uniformly distributed across the discs of a suspension insulator string due to shunt capacitances. Methods to improve string efficiency include using longer cross arms, grading insulators with different capacitances, and adding a guard ring. The document also provides sample one mark and 12 mark questions related to insulators.
The document discusses electric power supply systems and transmission. It describes how electric power is generated at power stations, transmitted over long distances via transmission lines, and then distributed to consumers. There are three main components of an electric supply system: the power station, transmission lines, and the distribution network. Transmission is typically done using high voltages for efficiency and reduced line losses. While DC transmission has advantages, AC transmission is now universally used due to the ability to easily transform voltages using cost-effective transformers.
The document summarizes key aspects of transmission line design and components. It discusses the methodology for designing transmission lines, including gathering design data, selecting reliability levels, and calculating loads. It also covers the selection and design of various transmission line components such as conductors, insulators, towers, and grounding systems. Design considerations include voltage levels, safety clearances, mechanical requirements, and optimization of costs.
Relays are electromagnetic switches that are designed to detect faults on electrical circuits and trip circuit breakers. They use a low amperage control circuit to operate a high amperage tripping circuit. Relays can be classified based on their construction, applications, or time of operation. Common types include impedance, reactance, mho, and digital protective relays. Impedance relays have an overcurrent operative torque and a voltage-restraining torque. Reactance relays have a current operative torque and a directional restraining torque. Mho relays induce operative torque from both voltage and current and have a voltage-restraining torque. Digital protective relays use microprocessors to analyze voltages, currents, and
This document discusses earthing systems and the hazards of a broken neutral connection for a power transformer. It defines system earthing and equipment earthing, and explains that a broken neutral connection can cause overvoltage issues for the transformer and prevent protective relays from operating during a fault. The document also discusses the objectives and importance of proper earthing, including providing an alternative path for fault currents, ensuring safety from electric shocks, and maintaining system voltages. It provides examples of what can occur when a transformer's neutral connection to earth is broken.
This document discusses corona phenomenon in overhead transmission lines. It defines corona as the ionization of air surrounding power conductors, which causes a faint violet glow. Critical disruptive voltage and factors affecting corona such as atmospheric conditions, conductor size and spacing are explained. Methods to reduce corona loss include increasing conductor size, using bundled or hollow conductors, corona rings, and increasing spacing. While corona causes power loss and interference, it also reduces voltage surges and electrostatic stresses.
An electrical panel is an enclosure containing electrical components like switches, circuit breakers, and fuses to control and protect electrical systems. There are different types of panels for various applications like motor control, power control, low/medium/high voltage distribution. Key components within panels include switchgears for switching and protecting circuits, fuses that melt under excessive current, and circuit breakers that can safely interrupt faults. Panels also include bus bars to conduct electricity and current transformers to reduce current for measurement. Cables distribute power from panels and come in various core configurations depending on the application.
This presentation discusses transmission lines, including overhead power lines and underground cables. It classifies transmission lines as overhead or underground, and further divides them based on voltage and construction. Overhead lines are cheaper but can be affected by the environment, while underground cables are more expensive to install and maintain but are safer and not impacted by the environment. The presentation also covers nominal T and Pi circuit models that can be used to analyze medium transmission lines, and provides equations for calculating voltages and currents at the sending and receiving ends.
This presentation discusses the key protection devices used in electrical substations. It introduces current transformers and potential transformers, which reduce current and voltage levels for protection relays. Relays detect faults by measuring currents and voltages. When a fault is detected, relays signal circuit breakers to isolate the faulty component. Other protection devices discussed include lightning arresters, isolators, and surge diverters. The objective of the substation protection system is to isolate only faulty parts of the network while keeping the rest operational.
This document discusses voltage drop calculation in cable lines. It provides information on the data required to start calculations, including cable parameters, load characteristics, installation scheme, and maximum allowed voltage drop. It then covers calculations for simple radial lines under conditions of constant current and constant power. For constant current, the voltage drop is calculated based on cable resistance and reactance, line length, and load current. For constant power, an iterative method is used to calculate the voltage at the end of the line based on load power and reactive power. Sample calculations are shown for both cases.
Extra high voltage long ac transmission linesShivagee Raj
From economical point of view designing of transmission line system is very important in the electricity supply system. Extra High Voltage Transmission Lines are best suited for transmission of bulk power.
1. Surge arresters are selected with voltage ratings of 336kV, 360kV, 372kV or 390kV to account for temporary overvoltages during faults.
2. Condition monitoring techniques like third harmonic resistive current monitoring are effective for detecting failures in surge arresters due to moisture ingress or degradation.
3. Investigations found moisture entry through faulty seals or gaskets led to failures in many surge arresters, accelerated by manufacturing defects. Improved sealing methods using O-rings instead of flat gaskets and routine dip testing were implemented.
This document provides details on substation layout and busbar arrangements. Part A discusses substation layout, including a single line diagram and descriptions of common switchyard accessories like lightning arrestors, CVTs, isolators, circuit breakers, transformers, and other equipment. It also covers PLCC and SCADA systems. Part B covers various busbar arrangements like the single bus system, double bus system, one and a half breaker system, and ring main bus system. It discusses the advantages and disadvantages of each configuration. In summary, the document is a technical report that outlines and compares different substation and busbar designs.
This document discusses overvoltage phenomena and insulation coordination in high voltage engineering. It covers several topics:
1) Natural causes of overvoltages like lightning and the mechanisms behind lightning strokes.
2) Classification of transmission lines and the behavior of traveling waves at transition points like reflections and successive reflections shown through lattice diagrams.
3) Causes of overvoltages from switching surges during circuit operations, system faults, and abnormal conditions. Characteristics of switching surges and issues in extra high voltage systems are described.
4) Methods to control overvoltages including stepped energization of lines, phase controlled circuit breakers, and drainage of trapped charges. Protective devices like expulsion gaps, protector tubes
This is the simple ppt explaining about the main components of the power systems. especially we are determining the insulators and its types with real time pictures which are attractive,
The document discusses the key elements of a power system, including generation, transmission, distribution, and load. It describes the different types of power generation such as fossil, hydro, and nuclear. It then explains the transmission system, how power is transmitted through overhead lines or underground cables. Finally, it discusses power distribution to load through lower voltage networks.
Principles of Cable Sizing; current carrying capacity, voltage drop, short circuit.
Cables are often the last component considered during system design even if in many situations cables are the true system’s lifeline: if a cable fails, the entire system may stop. Cable reliability is therefore extremely important, then a cable system should be engineered to last the life of the system in the installation environment for the required application. Environments in which cable systems are being used are often challenging, as extreme temperatures, chemicals, abrasion, and extensive flexing. These variables have a direct impact on the materials used for cable insulation and jacketing as well as the construction of the cable. Using a systematic approach will help ensure that designer select the best cable for the required application in the installation environment. This lessons will provide students main guidelines for perform this approach.
The document discusses underground power cables. It describes the components of underground cables including conductors, insulation, metallic sheathing, bedding, armoring and serving. The main types of underground cables are discussed - solid cables like belted and screened cables used up to 66kV, and pressurized oil and gas cables used at higher voltages. Methods of laying cables underground include direct burying, draw-in systems using ducts, and solid systems within troughs. Underground cables have advantages over overhead lines like better appearance and reliability, but also challenges like higher installation costs and fault localization difficulties.
This document discusses different types of insulators used in overhead power lines. It describes pin insulators, suspension insulators, strain insulators, and shackle insulators. Suspension insulators consist of multiple porcelain discs connected in series by metal links. The voltage is not uniformly distributed across the discs of a suspension insulator string due to shunt capacitances. Methods to improve string efficiency include using longer cross arms, grading insulators with different capacitances, and adding a guard ring. The document also provides sample one mark and 12 mark questions related to insulators.
The document discusses electric power supply systems and transmission. It describes how electric power is generated at power stations, transmitted over long distances via transmission lines, and then distributed to consumers. There are three main components of an electric supply system: the power station, transmission lines, and the distribution network. Transmission is typically done using high voltages for efficiency and reduced line losses. While DC transmission has advantages, AC transmission is now universally used due to the ability to easily transform voltages using cost-effective transformers.
The document summarizes key aspects of transmission line design and components. It discusses the methodology for designing transmission lines, including gathering design data, selecting reliability levels, and calculating loads. It also covers the selection and design of various transmission line components such as conductors, insulators, towers, and grounding systems. Design considerations include voltage levels, safety clearances, mechanical requirements, and optimization of costs.
Concept of energy transmission & distribution ZunAib Ali
Downlaod is NOW Allowed (08/06/2016)
for more help: email me at zunaib_91@yahoo.com
Purpose of Electrical Transmission System
Main Parts of Power System
One-Line Diagram of Generating Station
Main Parts of Generating Station
Components of a Transmission Line
This document discusses the design methodology and components of extra high voltage transmission lines. It covers:
- The key components of transmission lines including conductors, earth wires, insulators, towers, and hardware.
- The design methodology which involves gathering preliminary data, selecting reliability levels, calculating climatic and other loads, choosing appropriate factors, and designing the components.
- Factors that influence the design such as reliability levels, transmission voltages, tower types, tower structures, heights, widths, clearances, and conductor selection criteria including mechanical and electrical requirements.
General condition-relating-to-electricity newDineshsenthil
This document outlines various regulations and standards relating to the supply and use of electrical energy in India. It provides classifications for voltage levels and permissible voltage variations. It also specifies minimum clearances for overhead power lines based on voltage level, clearances between power lines that cross each other, and clearances from buildings and the ground. Various insulation and current carrying capacities for underground cables are also included.
This document provides an overview of electrical substations, including their classification, components, and specifications. It discusses the different types of substations based on voltage levels, configuration, and application. It also describes the primary functions and components of outdoor switchyards, including incoming and outgoing lines, transformers, circuit breakers, and earthing systems. Clearance requirements and specifications for indoor electrical panels, busbars, grounding, and cabling are also outlined.
This document provides an overview of electrical substations, including their classification, components, and specifications. It discusses the different types of substations based on voltage levels, configuration, and application. It also describes the primary functions and components of outdoor switchyards, including incoming and outgoing lines, transformers, circuit breakers, and earthing systems. Clearance requirements and specifications for indoor electrical panels, busbars, grounding, and cabling are also outlined.
This document provides an overview of grid substations. It discusses that substations receive power from generating stations via transmission lines and transform the voltages to suitable levels for local distribution. Primary substations receive high voltages from EHV transmission lines and step down to lower voltages like 66kV or 33kV. Secondary substations further step down voltages to around 11kV. Distribution substations then step down to voltages suitable for low voltage distribution, around 415 volts. The document also briefly outlines the key components of transmission lines, including conductors, insulators, towers, and grounding systems. It concludes with a short description of transformers and their uses in grid substations.
This document discusses transforming an existing 220 kV double circuit transmission line into a 400 kV single circuit line using twin conductors. It analyzes the technical feasibility and provides the procedures, including system study, analysis of tower strength, possible configurations, clearance requirements, and cost benefits compared to building a new transmission line. Upgrading the existing line requires less land acquisition and has lower costs than new construction while meeting the increasing electricity demand.
This document provides details on the design of a 500kV extra high voltage transmission line that is 600 miles long. It discusses selecting an economic conductor size, calculating line parameters such as resistance, inductance and capacitance, and ensuring safety clearances are met. The selected conductor is a bundle of 3 ACSR conductors with a cross-sectional area of 468 mm2 each. Line losses are calculated to be 51.23 MW, which is 5.123% of the 1000MW transmission capacity. Surge impedance is determined to be 276.6 ohms. Safety clearances are in accordance with National Electrical Safety Code specifications.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Cigre test system description justifications and simulation results v3sebden
This document describes the CIGRE DC Grid Test System, which was developed to provide a standardized system configuration for simulations and discussions in CIGRE working groups related to DC grids. The test system includes: 2 onshore and 4 offshore AC systems connected through 3 VSC-based HVDC systems. It has overhead lines and submarine cables at voltage levels of ±200kV and ±400kV. Control schemes for the VSC converters are also described including outer power/voltage controls and inner current controls for both grid-connected and islanded operations. Simulation results on line loadings and costs are provided to validate the test system configuration and component choices.
This document discusses insulation coordination for electrical systems. It defines insulation coordination as selecting suitable insulation levels for system components and arranging them rationally. The goals of insulation coordination are to ensure insulation can withstand normal and abnormal stresses and efficiently discharge over voltages. It also discusses determining live insulation levels, equipment BIL levels, and selecting lightning arrestors. Various insulation levels for lines and equipment are recommended based on system voltage.
This document provides an overview of the High Voltage Engineering course code EE-4123. The summary includes:
1) The course covers topics such as high voltage DC circuits, high voltage AC circuits, impulse voltages, insulation testing, HVDC transmission, corona effects, high voltage measurement and testing, and overvoltage protection.
2) The objectives of the course are to teach students about different voltage levels, applications of high voltage, electrical insulation, dielectric materials, and breakdown mechanisms in solid, liquid, and gaseous dielectrics.
3) High voltage is defined as voltages above 11kV for power systems, with classifications of up to 100kV as high voltage, 100kV-400
This document provides an overview of the High Voltage Engineering course code EE-4123. The summary includes:
1) The course covers topics such as high voltage DC circuits, high voltage AC circuits, impulse voltages, insulation testing, HVDC transmission, corona effects, high voltage measurement and testing, and overvoltage protection.
2) The objectives of the course are to teach students about different voltage levels, applications of high voltage, electrical insulation, dielectric materials, and breakdown mechanisms in solid, liquid, and gaseous dielectrics.
3) High voltage is defined as voltages above 11kV for power systems, with classifications of very high voltage from 100kV-400kV and extra high
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.
The document discusses proper part number selection for Eaton's Cooper Power series 200A and 600A connector products used for terminating XLPE or EPR insulated underground electrical cables. It outlines using the cable conductor size to select the compression connector and using the cable insulation diameter to select an elbow housing that maintains a tight seal. An example is provided to demonstrate selecting the correct 200A loadbreak elbow part number for an AEIC standard 15kV cable with a 1/0 compact stranded conductor and 133% insulation with an outer jacket diameter of 1.07".
This document discusses transient recovery voltage (TRV) during circuit breaker switching and methods to reduce TRV. It presents:
1) An introduction covering TRV impacts, waveform shapes, and simulation software.
2) A literature review of problems caused by TRV and factors influencing TRV.
3) A methodology section describing derivation of TRV equations and simulations.
4) Results of simulations measuring TRV on an IEEE 39-bus network and reductions using switching resistance and capacitance techniques.
5) A conclusion that TRV can be reduced 35-40% using these techniques to prevent circuit breaker failure.
This document provides information about transmission towers. It begins with definitions of transmission towers and pylons. It then discusses different types of transmission towers, including those for HVAC, HVDC, and railway lines. It also covers towers for different current types. The document discusses factors that determine tower design, such as height, base width, and cross arm length. It provides formulas for calculating spacing between conductors and clearances. Finally, it briefly discusses tower erection methods.
This document provides an overview of electrical power transmission in India. It discusses the components of transmission lines including conductors, spacers, and supports. It also covers transmission line design considerations such as voltage levels, ground clearances, conductor spacing, and tower heights. The document outlines India's existing transmission system and some issues in further developing the system such as right of way, regulation of power flows, and integration of new technologies like HVDC transmission and gas insulated substations.
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
Assessment and Planning in Educational technology.pptxKavitha Krishnan
In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2. Component of Transmission Line
o Conductor
o Earth wire
o Insulator
o Transmission Tower
o Wave trap and other
hardware(Clamp, Spacer,
Vibration dampers,
connectors etc.
2
3. Design Methodology
Gather preliminary line design data and available climatic data
Select reliability level in terms of return period of design
Calculate climatic loading on components
Calculate loads corresponding to security requirements (failure containment)
Calculate loads related to safety during construction and maintenance
Select appropriate correction factors, if applicable, to the design components such
as use factor, strength factors related to numbers of components, strength
coordination, quality control, and the characteristic strength.
Design the components for the above loads and strength.
3
4. Reliability Levels
Reliability Level ≥1(One)
Higher the reliability level means higher safety factor and ultimately
more cost.
4
5. Selection of Transmission Voltage
Standard Voltage - 66,110,132, 220, 400 KV
Tolerances - ±10% up to 220 KV & ±5% for 400 KV
Selection Criterion of Economic Voltage –
Quantum of power to be evacuated
Length of line
Voltage regulation
Power loss in Transmission
Initial and operating cost
Present and future voltage in neighborhood
5
6. Economic Voltage of Transmission of Power
–
L KVA
E = 5.5 +
1.6 150
E = Transmission voltage (KV) (L-L).
L = Distance of transmission line in KM
KVA=Power to be transferred
6
7. Types of Towers
Type A Tower (Tangent Tower with suspension string)
o Used on straight runs and up to 2° line diversion
Type B Tower (Small Angle Tower with tension string)
o Used for line deviation from 2° to 15°
Type C Tower (Medium Angle Tower with tension string ).
o Used for line deviation from 15° to 30°.
Type D Tower (Large angle tower with tension string)
o Used for line deviation from 30° to 60°
Type E Tower (Dead End Tower with tension string)
o Used for line termination & starting
Special tower-
Suspension Tower (Span ≈ 1000 m)
o Used for River crossing, Mountain crossing etc.
Transposition Tower
o Used for transposition of tower
7
9. Selection of Tower Structure
Single circuit Tower/ double circuit Tower
Length of the insulator assembly
Minimum clearances to be maintained between ground conductors, and
between conductors and tower
Location of ground wire/wires with respect to the outermost conductor
Mid-span clearance required from considerations of the dynamic
behavior of conductors and lightning protection of the line
Minimum clearance of the lowest conductor above ground level
9
11. Height of Tower Structure
Height of tower is determine by-
H = h1 + h 2 + h3 + h 4
h1=Minimum permissible ground clearance
h2=Maximum sag
h3=Vertical spacing between conductors
h4=Vertical clearance between earthwire and
top conductor
11
12. Determination of Base Width
The base width(at the concrete level) is the distance between the
centre of gravity at one corner leg and the centre of gravity of
the adjacent corner leg.
A particular base width which gives the minimum total cost of the tower
and
Ryle
foundations.
Formula
The ratio of base width to total tower height for most towers is generally
about one-fifth to one-tenth.
12
12
13. Spacing and Clearances
Ground Clearances
CL = 5.182 + 0.305 * K
V − 33
Where- K =
33
Minimum permissible ground clearance as per IE Rules, 1956,Rule 77(4)
S.No. Voltage level Ground
clearance(m)
1. ≤33 KV 5.20
2. 66 KV 5.49
3. 132KV 6.10
4. 220 KV 7.01
5. 400 KV 8.84
13
14. Clearance for Power Line Crossings
Crossing over rivers:
• 3.05m above maximum flood level.
Crossing over telecommunication lines
Minimum clearances between the conductors of a power
line and telecommunication wires are-
Voltage Level Minimum
Clearance(mm)
≤33 KV 2440
66KV 2440
132 KV 2740
220 KV 3050
400 KV 4880
14
15. Power line Crossing over railway tracks
under maximum sag condition minimum clearance over rail level
stipulated in the regulations for Electrical Crossings of Railway Tracks,
1963
Table. For un-electrified tracks or tracks electrified on 1,500 volts D.C.
system
System Voltage Level Broad Gauge Meter & Narrow
Gauge
Inside station Out side Inside Out side
limits(m) station station station
limits(m) limits(m) limits(m)
≤66 KV 10.3 7.9 9.1 6.7
132 KV 10.9 8.5 9.8 7.3
220 KV 11.2 8.8 10.0 7.6
400 KV 13.6 11.2 12.4 10.0
15
16. Table. Tracks electrified on 25 kV A.C. system
System Voltage Level Broad Gauge
Inside station Out side station
limits(m) limits(m)
≤ 66 KV 10.3 7.9
132 KV 10.9 8.5
220 KV 11.2 8.8
400 KV 13.6 11.2
Power line Crossing another Power line
System Voltage Level Clearance(m)
≤ 66 KV 2.40
132 KV 2.75
220KV 4.55
400 KV 6.00
16
17. Spacing Between Conductor(Phases)
1) Mecomb's formula
D
Spacing (cm) = 0.3048 * V + 4.010 S
W
Where-
V= Voltage of system in KV
D= Diameter of Conductor in cm
S= Sag in cm
1) VDE formula W= weight of conductor in Kg/m
2
Spacing (cm) = 7.5 S + V
2000 Where-
V= Voltage of system in KV
17 S= Sag in cm
18. Still's formula
2
Spacing (cm) = 5.08 + 1.814 *V +
l
27.8
Where-
l = Average span length(m)
NESC formula
L
Spacing (cm) = 0.762 *V + 3.681 S +
2
Where-
V= Voltage of system in KV
S= Sag in cm
L= Length of insulator string in cm
18
19. Swedish formula
Spacing (cm) = 6.5 S + 0.7 * E
Where-
E= Line Voltage in KV
S= Sag in cm
French formula
E
Spacing (cm) = 8.0 S + L +
1.5
Where-
E= Line Voltage in KV
S= Sag in cm
L= length of insulating string(cm)
19
20. Offset of conductors (under ice-loading conditions)
Sleet Jump:
The jump of the conductor, resulting from ice dropping off
one span of an ice-covered line, has been the cause of many serious
outages on long-span lines where conductors are arranged in the same
vertical plane.
Offset in cm = 60 + Span in cm / 400
20
25. Selection of Conductor Size
Mechanical Requirement
Electrical Requirement
Mechanical Requirement
Tensile Strength(For Tension)
Strain Strength(For Vibration)
Use vibration damper for vibration control.
25
26. Electrical Requirement
o Continuous current rating.
o Short time current carrying rating.
o Voltage drop
o Power loss
o Minimum dia to avoid corona
o Length of line
o Charging current
26
27. Continuous Current Rating.
∆t 2 * R1
I 2 = I1*
∆t1 * R 2
I1=current rating for temp rise ∆t1
I2=current rating required to produced temp rise ∆t2
R1= conductor resistance at conductor total temp T1(say 75°C)
R2= conductor resistance at required conductor total temp T2
27
28. Short Time Rating
According to short time rating conductor size is given by-
A = 7.58 * IF * t
Where A=area of conductor(mm2)
IF= fault current(KA)
t= fault duration(1 sec.)
28
29. Corona
Visual corona voltage in fair weather condition is given by-
δ ∗ r (1 + 0.3) D
V 0 = 21.1 ∗ m log n r
r
V0= corona starting voltage, KV(rms)
r= radius of conductor in cm
D= GMD equivalent spacing b/n conductors in cm
m= roughness factor
= 1.0 for clean smooth conductor
=0.85 for stranded conductor
29
30. Voltage gradient at the surface of conductor at operating voltage-
V
3
g0 = D
(rms kv/cm)
Log n
r
Corona discharge form at the surface of conductor if g0≥ corona
starting gradient i.e.
(1 + 0.3)
g 0 ≥ 21.1∗ m ∗ δ ∗ r r
Conductor size will be so chosen that normal gradient of
conductor should not exceed 17.5 KV/cm.
For EHV transmission line 400KV and above use bundle
conductor from point view of corona.
30
31. Optimization of Conductor
When more than one conductor satisfied the requirement of current
capacity and corona performance than study required for conductor
optimization
C= cost in Rs. Per Km of 3-ø line
A= Annual fixed charge on capital in Rs./ Rupees of capital cost(interest
14%+depreciation 5%+ operation and maintenance cost 1-3%)
Pm= Maximum demand(KW)
Annual energy generated
LF=
V= Line voltage(KV) 8760*maximum demand
R= Resistance of conductor/Km/phase L= Energy charge in Rs/Kwh
M= Demand charge in Rs/Kwh
Cosø=Power factor
H= Loss load factor
= 0.3[LF+0.7(LF)2] (For normal load variation)
= 0.2[LF+0.8(LF)2] (For more uniform load variation)
31
32. J =
12 M ( LF ) +8760 ∗L ∗H
2
1000
Total annual fixed charge (C1)=C*A
Total annual running charges(C2)= (P2m*R*J)/(V2 Cos2 ø)
Total charges(T)= C*A + (P2m*R*J)/(V2 Cos2 ø)
Conductor giving minimum T will be optimum
Cost/KW/Km will be minimum i.e. T/Pm will be minimum when
Pm = V cos φ
[C ∗ A] 1/ 2
R
32
33. Some Others Consideration in
Conductor Selection
AL/St Area (For longer span & less sag with economic consider)
River crossing (Span≥1000 m use AAAC conductor because of more
tendency to vibration and twisting)
Weight/ Dia (Less Weight/Dia ratio conductor swing more hence require longer
cross arms witch increase torsional load. Consider optimum value W/d in design.)
33
34. INSULATOR
Insulator are required to support the line conductor and provide
clearance from ground and structure.
Insulator material-
High grade Electrical Porcelain
Toughened Glass
Fiber Glass
Choice of insulator material is govern by availability, price and ease of maintenance.
Porcelain insulator are largely used in India.
34
35. Type of Insulator-
Disc Type
Strut Type
Disc type Insulator
It consist of central suitable shaped porcelain/ glass body like a disc with an metal
clamp on one side and metal ball pin on other side
Cap is made of malleable cost iron and the ball pins is of forged steel.
35
36. Strut Type Insulator
It consist of several insulator disc cemented altogether without
any link.
It is rigid and can take both tension and compression load.
These are used for holding the conductor out of way of
structure.
Long Rod Insulator
36
37. INSULATOR STRING
Disc insulator are joint by their ball pins and
socket in their caps to form string.
No of insulator disc is decided by system
voltage, switching and lighting over voltage
amplitude and pollution level.
Insulator string can be used either suspension Fig. single string
or tension.
Two suspension string in parallel used at
railways, road and river crossing as statutory
requirement.
Swing of suspension string due to wind has to
be taken into consider.
Fig. Double string
37
38. Earth Wire
Earth wire provided above the phase conductor across the line and
grounded at every tower.
o It shield the line conductor from direct strokes
o Reduces voltage stress across the insulating strings during lightning strokes
Design criterion:
Shield angle
25°-30° up to 220 KV
20° for 400 KV and above
Earth wire should be adequate to carry very short duration lightning
surge current of 100 KA without excessive over heating
Duration should be consider as 200 µ-sec
Safe temp rise limited to 300°C
38
39. A = 5∗ I ∗ t
A= Area(in mm2) of cu conductor
I =current in KA
t = Time insecond
Area of Steel Wire = 3*A(cu mm2)
From mechanical consideration, size become higher than required
for current carrying rating.
For EHV line it is suggested as 70 mm2 (7/3.66 mm).
ACSR is used as earth wire (12/3.0 mm AL+7/3.0 mm steel) in
consideration of corrosion and resistance.
39
40. Mid span clearance:
Direct distance b/n earth wire and top power conductor.
As per IS 5613 following value of mid span clearance should be
considered
System voltage Mid span clearance(m)
≤ 66 KV 3.0
110 KV 4.5
132 KV 6.1
220 KV 8.5
400 KV 9.0
40
41. Tower Grounding
Used to reduce earth wire potential and stress on insulators at the
time of stroke and also for safety
Tower footing resistance will be 10Ω and should not be more than
20 Ω under any condition throughout the year.
Earth resistance depend upon soil resistivity(general 100 Ω-m)
41
42. Method of Tower Grounding
Buried Conductor
One or more conductor are connected to tower lags and buried in back
filled of tower foundation.
o Used where soil resistivity is low
Counterpoise Wire
A length of wire/ Strip of 50 m is buried horizontally at depth of 0.5 m bellow
ground. This wire is connected to tower lags.
o Used when earth resistance is very high and soil conductivity is mostly
confined to upper layer)
Rod Pipe
Pipe/Rod of 3 to 4 m is driven into ground near the tower and top of rod is
connected to tower by suitable wire/strip
o Used where ground conductivity increase with depth
Treated Earth Pits
Pipe/Rod of 3 to 4 m are buried in treated earth pits and top of rod is
connected to tower by suitable wire/strip.
o Used in very high resistivity near tower
42
43. Reference Standards
IS-398 Specification of Aluminium Conductor for Over Head
Transmission Line(ACSR)
Code of Practice for use of Structural Steel in over head
IS-802 Transmission Line Tower
IS 3853 Specification of Aluminium Steel Core Wire for Aluminium
Conductor
Code Practice for Design and Construction of Foundation of
IS 4091 Transmission Line Tower and Pole
Specification of Design, Installation and Maintenance of Line
IS 5613
above 11 KV and up to 220 KV
Manual on Transmission Line Tower, Technical Report N0. 9,
CBIP March 1977
43 IE Rules,
1956