The document summarizes a study on using Clarke's transform and fuzzy logic for power transformer differential protection. It proposes a new algorithm to improve on traditional percentage differential protection. The methodology section describes using Clarke's transform to calculate differential currents as inputs to a fuzzy system. The fuzzy system classifies conditions as internal fault, external fault, or normal. Simulation results on 690 cases showed the proposed algorithm had faster operation and fewer misoperations than a commercial relay. It was able to correctly discriminate all fault and operating conditions. The conclusions state the new algorithm improves protection coverage and performance while maintaining simplicity for commercial applications.
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.
Correlative Study on the Modeling and Control of Boost Converter using Advanc...IJSRD
DC-DC converters are switched power converters. The converters are most widely used in research and industrial applications. The DC-DC Boost Converters are used to step-up the supply voltage given to the plant model. The main advantage of using the Boost Converters is that it works in the low voltage according to the design specifications. In order to regulate the uncontrolled supply of voltage, a controller has to be designed and modeled to stabilize the output voltage. Since the convectional controllers cannot work under dynamic operating conditions, advanced controllers are to be designed to overcome the problems. In this article, the advanced controllers such as NARMA-L2, Fuzzy Logic (FLC) and Sliding Mode Controllers (SMC) are implemented and their responses are compared using MATLAB.
The traction inverter is a crucial power device in the electric vehicle’s powertrain, and its failure is intolerable as it would considerably compromise the system’s safety. For more reliable driving, installing a traction inverter that is sufficiently resistant to electrical failure is inherent. Due to its compact size and the small number of switches incorporated in three-phase four-switch inverter, this modular topology was used to compensate for the open switch’s failure. However, it is known to have manifold weaknesses mainly distinguished in the low-frequency region. This paper introduces a new fault-tolerant indirect control that handles the IGBT’s failure constituting the traction inverter. The fault compensator is designed first based on the Proportional Integral regulator combined with the notch filter to mitigate the current imbalance and restore the DC voltage equilibrium.Furthermore, to conceive a comprehensive fault-tolerant control, there must therefore contain an accurate fault detector. In this regard, an uncomplicated fault diagnosis method based on the current spectral analysis has been performed. The effectiveness of the submitted controller was validated by simulation using Matlab.
In power systems for smart grid, integration of renewable energy sources and super conducting devices brings more
positive effects. This paper suggests a Fuzzy controlled
Fault ride-through capability improvement of doubly fed induction generator (DFIG) for wind power generation. Since Fuzzy
controlled Active SFCL has higher controllability and flexibility,
derivation, cost evaluation and simulation are conducted and comparison is performed between with and without Active SFCL.
From the results active SFCL can limit the faulty currents flowing through t
compensate the terminal voltage
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.
Correlative Study on the Modeling and Control of Boost Converter using Advanc...IJSRD
DC-DC converters are switched power converters. The converters are most widely used in research and industrial applications. The DC-DC Boost Converters are used to step-up the supply voltage given to the plant model. The main advantage of using the Boost Converters is that it works in the low voltage according to the design specifications. In order to regulate the uncontrolled supply of voltage, a controller has to be designed and modeled to stabilize the output voltage. Since the convectional controllers cannot work under dynamic operating conditions, advanced controllers are to be designed to overcome the problems. In this article, the advanced controllers such as NARMA-L2, Fuzzy Logic (FLC) and Sliding Mode Controllers (SMC) are implemented and their responses are compared using MATLAB.
The traction inverter is a crucial power device in the electric vehicle’s powertrain, and its failure is intolerable as it would considerably compromise the system’s safety. For more reliable driving, installing a traction inverter that is sufficiently resistant to electrical failure is inherent. Due to its compact size and the small number of switches incorporated in three-phase four-switch inverter, this modular topology was used to compensate for the open switch’s failure. However, it is known to have manifold weaknesses mainly distinguished in the low-frequency region. This paper introduces a new fault-tolerant indirect control that handles the IGBT’s failure constituting the traction inverter. The fault compensator is designed first based on the Proportional Integral regulator combined with the notch filter to mitigate the current imbalance and restore the DC voltage equilibrium.Furthermore, to conceive a comprehensive fault-tolerant control, there must therefore contain an accurate fault detector. In this regard, an uncomplicated fault diagnosis method based on the current spectral analysis has been performed. The effectiveness of the submitted controller was validated by simulation using Matlab.
In power systems for smart grid, integration of renewable energy sources and super conducting devices brings more
positive effects. This paper suggests a Fuzzy controlled
Fault ride-through capability improvement of doubly fed induction generator (DFIG) for wind power generation. Since Fuzzy
controlled Active SFCL has higher controllability and flexibility,
derivation, cost evaluation and simulation are conducted and comparison is performed between with and without Active SFCL.
From the results active SFCL can limit the faulty currents flowing through t
compensate the terminal voltage
EEE 321( Power System Analysis and Principle of Power System and Power syste...UthsoNandy
Here is the knowledge of Power System Analysis and Principle of Power System that will help upgrade your knowledge upgrade yourself that will help to gather the knowledge and You can upgrade yourself by gathering the knowledge of Power system stability and control
Power System Analysis was a core subject for Electrical & Electronics Engineering, Based On Anna University Syllabus. The Whole Subject was there in this document.
Share with it ur friends & Follow me for more updates.!
International Refereed Journal of Engineering and Science (IRJES)irjes
The core of the vision IRJES is to disseminate new knowledge and technology for the benefit of all, ranging from academic research and professional communities to industry professionals in a range of topics in computer science and engineering. It also provides a place for high-caliber researchers, practitioners and PhD students to present ongoing research and development in these areas.
The extensive use of non-linear loads in industry becomes increasingly a serious problem that affects the quality of energy delivered to customers. Therefore, the shunt active power filter (SAPF) has emerged as an important industrial tool to eliminate induced harmonic currents and compensating of reactive power. This paper proposes an improved control configuration for SAPF based on a modern technique called predictive direct power control (Predictive-DPC). The principle of this control is based on the direct regulation of the instantaneous active and reactive powers to guarantee a good energy quality on the grid side. For this purpose the appropriate average voltage vector which cancels power tracking errors is calculated by a simple predictive model at the bigining of each control period. This type of control includes various features such as the lack of look up table (LUTs) and closed current loops and the constant switching frequency is achieved through the use of PWM modulation. The results of the simulation process show a high performance in the steady and transient state function for predictive-DPC control that might be a reasonable alternative to conventional DPC in the field of active power filtering.
Non-integer IMC Based PID Design for Load Frequency Control of Power System t...IJECEIAES
This paper deals with non-integer internal model control (FIMC) based proportional- integral-derivative(PID) design for load frequency control (LFC) of single area nonreheated thermal power system under parameter divergence and random load disturbance. Firstly, a fractional second order plus dead time(SOPDT) reduced system model is obtained using genetic algorithm through step error minimization. Secondly, a FIMC based PID controller is designed for single area power system based on reduced system model. Proposed controller is equipped with single area non-reheated thermal power system. The resulting controller is tested using MATLAB/SIMULINK under various conditions. The simulation results show that the controller can accommodate system parameter uncertainty and load disturbance. Further, simulation shows that it maintains robust performance as well as minimizes the effect of load fluctuations on frequency deviation. Finally, the proposed method applied to two area power system to show the effectiveness.
Control of inverters to support bidirectional power flow in grid connected sy...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.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Fault modeling and parametric fault detection in analog VLSI circuits using d...IJECEIAES
In this article we describe new model for determination of fault in circuit and also we provide detailed analysis of tolerance of circuit, which is considered one of the important parameter while designing the circuit. We have done mathematical analysis to provide strong base for our model and also done simulation for the same. This article describes detailed analysis of parametric fault in analog VLSI circuit. The model is tested for different frequencies for compactness and its flexibility. The tolerance analysis is also done for this purpose. All the simulation are done in MATLAB software.
NOVEL CONTROL STRATEGIES FOR DISTRIBUTED ACTIVE FILTER elelijjournal
ABSTRACT
This paper describes the implementation of Distributed Active Filters (DAFs). To share the workload of harmonic filtering, several Active Filter Units (AFUs) are placed on different locations which can perform the harmonic filtering without a direct communication. Different configurations of DAFs are described and are implemented using MATLAB /Simpower system Toolbox environment to observe their performances and comparison.
KEYWORDS
Distributed Active Filters (DAFs), Power Quality, Total Harmonic Distortion
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
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.
STATCOM is one of the shunt type FACTS controllers which can supply reactive power and improve bus voltage. STATCOM, a controlling device used on alternating current transmission networks, has advantages like transient free switching and smooth variation of reactive power. This paper proposes a cascaded multilevel inverter type DSTATCOM and DVR to compensate voltage sag in utilities in power distribution network. The proposed DSTATCOM is implemented using multilevel topology with isolated dc energy storage and reduced number of switches. A DVR injects a voltage in series with the system voltage and a D-STATCOM implant a current into the system to correct the voltage sag, swell and interruption. The phase shifter PWM technique is described to generate firing pulse to cascaded inverter. The proposed neuro-fuzzy controller follow itself to the sag and provides effective means of mitigation. The voltage sag with the minimum harmonic at the efficacy end. The proposed technique is simulated using MATLAB/Simulink.
Voltage profile Improvement Using Static Synchronous Compensator STATCOMINFOGAIN PUBLICATION
Static synchronous compensator (STATCOM) is a regulating device used in AC transmission systems as a source or a sink of reactive power. The most widely utilization of the STATCOM is in enhancing the voltage stability of the transmission line. A voltage regulator is a FACTs device used to adjust the voltage disturbance by injecting a controllable voltage into the system. This paper implement Nruro-Fuzzy controller to control the STATCOM to improve the voltage profile of the power network. The controller has been simulated for some kinds of disturbances and the results show improvements in voltage profile of the system. The performance of STATCOM with its controller was very close within 98% of the nominal value of the busbar voltage.
EEE 321( Power System Analysis and Principle of Power System and Power syste...UthsoNandy
Here is the knowledge of Power System Analysis and Principle of Power System that will help upgrade your knowledge upgrade yourself that will help to gather the knowledge and You can upgrade yourself by gathering the knowledge of Power system stability and control
Power System Analysis was a core subject for Electrical & Electronics Engineering, Based On Anna University Syllabus. The Whole Subject was there in this document.
Share with it ur friends & Follow me for more updates.!
International Refereed Journal of Engineering and Science (IRJES)irjes
The core of the vision IRJES is to disseminate new knowledge and technology for the benefit of all, ranging from academic research and professional communities to industry professionals in a range of topics in computer science and engineering. It also provides a place for high-caliber researchers, practitioners and PhD students to present ongoing research and development in these areas.
The extensive use of non-linear loads in industry becomes increasingly a serious problem that affects the quality of energy delivered to customers. Therefore, the shunt active power filter (SAPF) has emerged as an important industrial tool to eliminate induced harmonic currents and compensating of reactive power. This paper proposes an improved control configuration for SAPF based on a modern technique called predictive direct power control (Predictive-DPC). The principle of this control is based on the direct regulation of the instantaneous active and reactive powers to guarantee a good energy quality on the grid side. For this purpose the appropriate average voltage vector which cancels power tracking errors is calculated by a simple predictive model at the bigining of each control period. This type of control includes various features such as the lack of look up table (LUTs) and closed current loops and the constant switching frequency is achieved through the use of PWM modulation. The results of the simulation process show a high performance in the steady and transient state function for predictive-DPC control that might be a reasonable alternative to conventional DPC in the field of active power filtering.
Non-integer IMC Based PID Design for Load Frequency Control of Power System t...IJECEIAES
This paper deals with non-integer internal model control (FIMC) based proportional- integral-derivative(PID) design for load frequency control (LFC) of single area nonreheated thermal power system under parameter divergence and random load disturbance. Firstly, a fractional second order plus dead time(SOPDT) reduced system model is obtained using genetic algorithm through step error minimization. Secondly, a FIMC based PID controller is designed for single area power system based on reduced system model. Proposed controller is equipped with single area non-reheated thermal power system. The resulting controller is tested using MATLAB/SIMULINK under various conditions. The simulation results show that the controller can accommodate system parameter uncertainty and load disturbance. Further, simulation shows that it maintains robust performance as well as minimizes the effect of load fluctuations on frequency deviation. Finally, the proposed method applied to two area power system to show the effectiveness.
Control of inverters to support bidirectional power flow in grid connected sy...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.
Research Inventy : International Journal of Engineering and Scienceresearchinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Fault modeling and parametric fault detection in analog VLSI circuits using d...IJECEIAES
In this article we describe new model for determination of fault in circuit and also we provide detailed analysis of tolerance of circuit, which is considered one of the important parameter while designing the circuit. We have done mathematical analysis to provide strong base for our model and also done simulation for the same. This article describes detailed analysis of parametric fault in analog VLSI circuit. The model is tested for different frequencies for compactness and its flexibility. The tolerance analysis is also done for this purpose. All the simulation are done in MATLAB software.
NOVEL CONTROL STRATEGIES FOR DISTRIBUTED ACTIVE FILTER elelijjournal
ABSTRACT
This paper describes the implementation of Distributed Active Filters (DAFs). To share the workload of harmonic filtering, several Active Filter Units (AFUs) are placed on different locations which can perform the harmonic filtering without a direct communication. Different configurations of DAFs are described and are implemented using MATLAB /Simpower system Toolbox environment to observe their performances and comparison.
KEYWORDS
Distributed Active Filters (DAFs), Power Quality, Total Harmonic Distortion
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
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.
STATCOM is one of the shunt type FACTS controllers which can supply reactive power and improve bus voltage. STATCOM, a controlling device used on alternating current transmission networks, has advantages like transient free switching and smooth variation of reactive power. This paper proposes a cascaded multilevel inverter type DSTATCOM and DVR to compensate voltage sag in utilities in power distribution network. The proposed DSTATCOM is implemented using multilevel topology with isolated dc energy storage and reduced number of switches. A DVR injects a voltage in series with the system voltage and a D-STATCOM implant a current into the system to correct the voltage sag, swell and interruption. The phase shifter PWM technique is described to generate firing pulse to cascaded inverter. The proposed neuro-fuzzy controller follow itself to the sag and provides effective means of mitigation. The voltage sag with the minimum harmonic at the efficacy end. The proposed technique is simulated using MATLAB/Simulink.
Voltage profile Improvement Using Static Synchronous Compensator STATCOMINFOGAIN PUBLICATION
Static synchronous compensator (STATCOM) is a regulating device used in AC transmission systems as a source or a sink of reactive power. The most widely utilization of the STATCOM is in enhancing the voltage stability of the transmission line. A voltage regulator is a FACTs device used to adjust the voltage disturbance by injecting a controllable voltage into the system. This paper implement Nruro-Fuzzy controller to control the STATCOM to improve the voltage profile of the power network. The controller has been simulated for some kinds of disturbances and the results show improvements in voltage profile of the system. The performance of STATCOM with its controller was very close within 98% of the nominal value of the busbar voltage.
Design consideration of an mmc hvdc system based on 4500 v:4000a emitter turn...Ghazal Falahi
Excessive power loss is a major concern in high voltage and high power applications and is considered one of the main drawbacks of VSC-HVDC system when compared with traditional HVDC system based on thyristor technology. This is primarily caused by high switching loss associated with switching devices used in the VSC-HVDC. This issue can be largely addressed by using the emerging MMC-HVDC topology, which requires much lower switching frequency than traditional VSC-HVDC. Emitter turn-off thyristor (ETO) is one of the best high power switching devices packed with many advanced features. ETO thyristor based MMC-HVDC system is therefore an extremely attractive choice for ultra-high voltage and high power HVDCs. This paper discusses the operation principle of ETO based MMC-HVDC as well as its design and loss comparison with other solutions.
ENHANCING RELIABILITY BY RECONFIGURATION OF POWER DISTRIBUTION SYSTEMS CONSID...Suganthi Thangaraj
The paper describes an effective method to reconfigure a power distribution system using optimization techniques. Here genetic algorithm is used for the reconfiguration to enhance reliability and to reduce losses. The reliability at the load points is evaluated using probabilistic reliability approach. For finding minimal cut sets and losses different algorithms are used. To maximise the reliability and to reduce the losses, the status of the switch is controlled using genetic algorithm. The effectiveness of the system is tested in 33 bus distribution system.
Digital Relay for protection of high voltage transformers.
Link to the research paper:
https://www.researchgate.net/publication/262567749_Modeling_and_Testing_of_a_Digital_Differential_Relay_Using_MatLabSimuLink
The digital protective relay is a protective relay that uses a microprocessor to analyze power system voltages, currents or other process quantities for the purpose of detection of faults in an electric power system, industrial process system or High voltage applications.
The strategy is based on an autonomous distributed control
scheme in which the DC bus voltage level is used as an indicator of the power balance in the
microgrid. The autonomous control strategy does not rely on communication links or a
central controller, resulting in reduced costs and enhanced reliability. As part of the control
strategy, an adaptive droop control technique is proposed for PV sources in order to
maximize the utilization of power available from these sources while ensuring acceptable
levels of system voltage regulation
Wavelet Based Fault Detection, Classification in Transmission System with TCS...IJERA Editor
This paper presents simulation results of the application of distance relays for the protection of transmission systems employing flexible alternating current transmission controllers such as Thyristor Controlled Series Capacitor (TCSC). The complete digital simulation of TCSC within a transmission system is performed in the MATLAB/Simulink environment using the Power System Block set (PSB). This paper presents an efficient method based on wavelet transforms both fault detection and classification which is almost independent of fault impedance, fault location and fault inception angle of transmission line fault currents with FACTS controllers.
DESIGN, SIMULATION, IMPLEMENTATION AND CONTROL OF PLC BASED INTEGRAL CYCLE CO...IAEME Publication
The Class of ac power controllers consists of Solid State Power Controller (SSPC) which connects and disconnects the load to the supply according to the required power. Two important voltage control techniques are commonly used for heating power control in ac power controller are Phase Control Switching and Integral Cycle Control. In case that a PCS is used for the resistive load, it can produce higher order harmonics and heavy inrush current while switching on in a cold start. In the proposed method, a disadvantage of phase controlled is removed. In this paper authors have reported simulated results, design methodology, implementation and Control of PLC Based Integral Cycle Control (ICC) method for Resistance Spot Welding (RSW).
Modeling and simulation of three phases cascaded H-bridge grid-tied PV inverterjournalBEEI
In this paper a control scheme for three phase seven level cascaded H-bridge inverter for grid tied PV system is presented. As power generation from PV depends on varing environmental conditions, for extractraction of maximum power from PV array, fuzzy MPPT controller is incorporated with each PV array. It gives fast and accurate response. To maintain the grid current
sinusoidal under varying conditions, a digital PI controller scheme is adopted. A MATLAB/Simulink model is developed for this purpose and results are presented. At last THD analysis is carried out in order to validate the performance of the overall system. As discussed, with this control strategy the balanced grid current is obtained keeping THD values with in the specified range of IEEE-519 standard.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
1. Presenter: Muhammad Hamza
Roll No.: MS-F-19-008
Course: Power System Transients
Authors: Daniel Barbosa, Ulisses Chemin Netto, Denis V.
Coury & Mário Oleskovicz
Power Transformer Differential Protection
Based
on Clarke’s Transform and Fuzzy Systems
HEAVY INDUSTRY TAXILA EDUCATION CITY (HITEC)
Department of Electrical Engineering
3. Introduction (Abstract)
The power transformer is a piece of electrical equipment that
needs continuous monitoring and fast protection since it is very
expensive and an essential element for a power system to perform
effectively.
The most common protection technique used is the percentage
differential logic, which provides discrimination between an
internal fault and different operating conditions.
Unfortunately, there are some operating conditions of power
transformers that can affect the protection behavior and the power
system stability.
This paper proposes the development of a new algorithm to
improve the differential protection performance by using fuzzy
logic and Clarke’s transform.
4. Introduction (Continued)
The most common protection technique is the percentage
differential logic, which provides discrimination between an
internal fault and an external fault or a normal operating condition.
Differential relays compare the currents from all terminals of the
protected transformer to a predetermined threshold. in the case of
an internal fault, the equipment is disconnected from the power
supply.
Some condition can cause differential currents Like, presence of
magnetizing inrush currents due to energization, over-excitation,
and sympathetic inrush etc.
In order to prevent the relay disoperation in these cases, it is
necessary to differentiate inrush current from fault current.
5. Introduction (Continued)
In order to improve power transformer protection, various methods
were developed for accurate and efficient discrimination of the
situations.
This paper has discussed and implemented the fuzzy logic method
to separate or segregate of the obtained current readings.
The main concept of this particular fuzzy logic implementation is
to gain the current reading using Clark's transformation and
segregate those values in to either of the internal, external or
normal condition category.
6. METHODOLOGY
Figure: 1 is a typical differential relay connection diagram for the
protection of power transformers.
The connection of current transformers (CTs), coupled with the primary
and secondary branches, Np : Ns are shown. is the turn ratio between the
primary and secondary windings of the transformer.
1 : n1 and 1 : n1 are the turn ratios between the branches and CTs,
selected to make Np.n1 : Ns.n2 .
In normal conditions and external faults for a single-phase transformer,
currents ips and iss (secondary currents of CTs) are equal. However, in
the case of internal faults, the difference between these currents becomes
significant, causing the differential relay to trip.
The respective configuration of transformer primary and secondary coil
are Delta and Star. So, CT’s configuration will be Star and Delta.
8. METHODOLOGY
The proposed algorithm was implemented in the C++ programming
language and it is illustrated in Fig. 2. It uses the standard common format
for transient data exchange (COMTRADE) for power systems in order to
acquire the current signals from a transformer.
After acquiring the data, the signals are processed using Clarke’s
transform and the differential currents are calculated.
These currents are the input of the fuzzy system. If the output of the fuzzy
system is greater than the threshold value of 0.5, the control counter (ctr_
k) is increased by 1.
When this counter has exceeded the threshold 3, the relay sends a trip
signal to the CB. It is important to emphasize that the proposed fuzzy
system computes each differential α-β-γ component independently.
10. METHODOLOGY
Design of fuzzy system
Fuzzification: The fuzzy system applied to the proposed relay uses three
fuzzy inputs: 1) Δα ; 2) Δβ ;and 3) Δγ . These variables are obtained from
Clark’s transform equations. Figs. 3(a)–(c) show the membership
functions of the inputs and the output fuzzy set. For fuzzification of a
defined input variable Δα, a range is set between 0 and 100 and the
membership values range from 0 to 1. The other input variables Δβ and
Δγ are in the range from 0 to 50. The output variable is shown in Fig. 3(d)
ranging from 0 to 1 for two membership functions that determine block or
trip signals. After acquiring the data, the signals are processed using
Clarke’s transform and the differential currents are calculated.
Inference Method: The proposed relay uses 18 rules to discriminate two
operating conditions: steady state or internal faults. For this paper, in
order to perform a mathematical operation, the Mamdani inference
method was chosen. Fig. 4 shows the rules used in the proposed
algorithm.
12. METHODOLOGY
Design of fuzzy system
Defuzzification: The method needed a crisp value for control purposes.
The technique applied a centroid in accordance with:
After defuzzification, the output is compared with threshold value if it
is equal or greater then it then this will initiate the tripping protocol.
15. Result & Discussions
The main purpose of this section is to present some results
regarding the proposed algorithm and comparing them to a
commercial relay.
Various different tests were simulated for distinct operating
conditions of the power transformer in the system.
These simulations were converted into COMTRADE file format
and the files were stored in a database having 690 cases of interest,
including internal faults on both sides of the power transformer,
sympathetic inrush, energization, overexcitation, energization
under fault, and interturn faults.
This database was used to test and validate the proposed algorithm.
However, for brevity, only the 90 most relevant cases were used for
comparison with the commercial relay.
16. Result & Discussions
Fig. (5) shows the three-phase current waveforms in the windings
on both sides of the transformer, the digital channels of the
commercial relay, and the fuzzy output of the proposed algorithm for
energization under fault at 10% of the secondary (wye) winding
from phase A in the TR2E Transformer at 0.349s.
In the figure, a delay in the trip signal by the commercial relay can
be observed, when compared to the proposed algorithm.
The commercial relay took around 235ms to operated while this new
proposed system gave output at 10ms.Which make this system
faster then the current commercial relay protection mechanism.
The analysis of this condition is fundamental to test the algorithm’s
robustness facing practical field situations, taking into account that
the harmonic blocking increases the trip time of the commercial
relay.
17. Result & Discussions
Fig. 6 shows the signals in the case of an internal fault at 0.350 s.
The fault is located within 5% from the neutral of the wye winding
at the high-voltage side of phase A in the TR2E transformer.
Its current waveforms were shown in Fig. 6(a). The misoperation
of the commercial protective relay can be seen in Fig. 6(b) (i.e., the
device did not send the trip signal to the CB). This error could have
been caused by the low differential current observed.
STATISTICAL TESTS FOR THE PROPOSED ALGORITHM AND
THE COMMERCIAL RELAY
18. Result & Discussions
Fig. 5&6: Fault under energization and internal faults at 5% of secondary (P-A)
19. Conclusions
This paper presented a new method for digital protection of power
transformers using Clarke’s transform and fuzzy logic. This technique has
shown some advantages regarding the traditional ones.
The simulation results show that the average operating time for the
proposed technique is shorter than that of the commercial relay used, due
to the fact that this method doesn't use the harmonic components as the
basis of the relay decision.
Great stability of the proposed algorithm for all faults and operation
conditions can be observed, correctly discriminating each one.
The new algorithm improves the coverage of the wye-connected winding
to 95%. This value is greater than what is commonly found in commercial
protective relays. However, to protect the entire winding, it is still
necessary to use the restricted earth-fault protection scheme.
Another important advantage of the algorithm is its simplicity as well as its
computational efficiency, making it suitable for commercial applications.