For power system, transformer is a very key power supply equipment. Its failure is not only related to system operation, but also directly determines the reliability of power supply. Besides, for large-capacity transf...For power system, transformer is a very key power supply equipment. Its failure is not only related to system operation, but also directly determines the reliability of power supply. Besides, for large-capacity transformer, it also plays a key role in power system. Therefore, relay protection equipment should be further selected based on its capacity and importance to ensure its ideal performance and safe and stable operation. Aiming at the 10kV power supply system, some common transformer faults are analyzed below, and some suggestions related to relay protection are given, in order to provide reference for relevant personnel.展开更多
With the passage of time, the power system is constantly updated and optimized to highlight new features and functions and further enhance the requirements for relay protection. Relay protection personnel must constan...With the passage of time, the power system is constantly updated and optimized to highlight new features and functions and further enhance the requirements for relay protection. Relay protection personnel must constantly adapt to the development of society, constantly update relay protection technology to ensure reliable operation, keep their own relay protection growing up with the times, understand troubleshooting and further improve the safety and reliability of power grid. This paper analyzes the common faults and operations related to relay protection and provide protective measures for the reliability of current relay protection.展开更多
With the development of large-scale complicated modern power systems, the requirement for the associated protection scheme tends to be more stringent and its combination more complex. However, it is very difficult to ...With the development of large-scale complicated modern power systems, the requirement for the associated protection scheme tends to be more stringent and its combination more complex. However, it is very difficult to figure out the factors of failure of such systems. This paper proposes a Petri net model of a transmission line protection relaying system, including three types of relays as well as an automatic reclosing device, and shows how to diagnose serial failure of the system by analyzing invariant sets of the model. Furthermore, it gives four basic types of failure sequences and its execution is much more intuitive and effective than the traditional method.展开更多
The industrial power systems are moving to digital networks,and unmanned systems are increasing recently with the technological development of information and communication technology.In particular,reliability of syst...The industrial power systems are moving to digital networks,and unmanned systems are increasing recently with the technological development of information and communication technology.In particular,reliability of system operation is very important for stable power supply.Most industrial power distribution facilities use a 154 kV or 22.9 kV extra HV(high voltage)power system,and a special monitoring system is required because a large loss occurs when an error occurs in the power facility in the field.Although digital protection relay(IED;intelligent electronic device)and FR(fault recorder)are applied to the field to protect the power system,various improvement activities are still ongoing.In this paper,a 22.9 kV high-voltage panel and its test bed,which are widely used in railway stations,tunnels,substations and large plants,were tested as test subjects.The developed fault detection system automatically starts the AL(auto-lock)circuit or outputs an alarm signal to user by monitoring in real time problems such as CT(current transformer)-open and poor-contact that the existing digital protection relay cannot cover.In addition,it is intended to increase the safety and reliability of the power system by blocking various accidents in the system in advance and accurately analyzing the causes of faults with the developed fault detection system.展开更多
Under the background of rapid social and economic development, electric power has a close relationship with people's daily life. How to make the use of electric power resources more scientific and reasonable and c...Under the background of rapid social and economic development, electric power has a close relationship with people's daily life. How to make the use of electric power resources more scientific and reasonable and create greater benefits for people's daily life is currently the main in-depth research content. The work related to the State Grid takes people's development as the objective, continuously improves the efficiency in the operation process of enterprises, reasonably supplies power between regions, continuously upgrades and optimizes the power system, and ensures the demand for power resources with the development of society. Therefore, in daily work, the staff need to improve the relay protection level of electricians, improve the original electrical relay protection related scheme, and continuously innovate and improve it, so as to make the electrical resources equipment improve the safety and stability of the power system in use.展开更多
The main working principle of the relay protection device is to organically combine advanced electronic technology, network technology, control technology and other technologies, to realize automatic identification of...The main working principle of the relay protection device is to organically combine advanced electronic technology, network technology, control technology and other technologies, to realize automatic identification of electrical system faults through the relay protection device, and to timely make targeted treatment for faults according to different types of faults occurring in the system operation. During the operation of electrical engineering, relay protection devices can analyze the operation of the protected objects through the monitoring equipment in the system, and comprehensively protect and adjust the protection function and fixed value of the equipment in real time according to the operation status of the protected objects. Finally, the remote dynamic monitoring and correction of electrical engineering are realized.展开更多
A new principle for grounding fault feeder detection based on negative sequence current variation and energy dissipated in the fault point is presented. It has high precision in both isolated systems and resonance ear...A new principle for grounding fault feeder detection based on negative sequence current variation and energy dissipated in the fault point is presented. It has high precision in both isolated systems and resonance earthed systems, even in full compensated systems. And it can be installed at the local control unit of feeder in distribution automation systems, such as field terminal unit (FTU). This principle is verified by EMTP simulator and experimentation.展开更多
Determining the fault location using conventional impedance based distance relay in the presence of FACTS controllers is a challenging task in a transmission line. A new distance protection method is developed to loca...Determining the fault location using conventional impedance based distance relay in the presence of FACTS controllers is a challenging task in a transmission line. A new distance protection method is developed to locate the fault in a transmission line compensated with STATCOM with simple calculations. The proposed protection method considers the STATCOM injected/absorbed current to correct the fault loop apparent impedance and accordingly calculates the actual distance to the fault location. The comprehensive equations needed for apparent impedance calculation are also outlined and the performance is evaluated and tested with a typical 400 KV transmission system for different fault types and locations using MATLAB/SIMULINK software. The evaluation results indicate that the new protection method effectively estimates the exact fault location by mitigating the impact of STATCOM on distance relay performance with error less than 0.3%.展开更多
A vital attribute of electrical power network is the continuity of service with a high level of reliability. This motivated many researchers to investigate power systems in an effort to improve reliability by focusing...A vital attribute of electrical power network is the continuity of service with a high level of reliability. This motivated many researchers to investigate power systems in an effort to improve reliability by focusing on fault detection, classification and localization. In this paper, a new protective relaying framework to detect, classify and localize faults in an electrical power transmission system is presented. This work will extract phase current values during ( )th of a cycle to generate unique signatures. By utilizing principal component analysis (PCA) methods, this system will identify and classify any fault instantaneously. Also, by using the curve fitting polynomial technique with our index pattern obtained from the unique fault signature, the location of the fault can be determined with a significant accuracy.展开更多
Recently, power distribution system is getting larger and more complex. It is very difficult even for the experts to diagnosis and monitoring to made best action. This motivated many researchers to investigate power s...Recently, power distribution system is getting larger and more complex. It is very difficult even for the experts to diagnosis and monitoring to made best action. This motivated many researchers to investigate power systems in an effort to improve reliability by focusing on fault detection and classification. There have been many studies on problems but the results are not good enough for applying to real power system. In this paper, a new protective relaying framework to diagnosis and monitoring faults in an electrical power distribution system with. This work will extract fault signatures by using ellipse fit using least squares criterion during fault condition. By utilizing principal component analysis methods, this system will identify, classify and localize any fault instantaneously.展开更多
In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed i...In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.展开更多
文摘For power system, transformer is a very key power supply equipment. Its failure is not only related to system operation, but also directly determines the reliability of power supply. Besides, for large-capacity transformer, it also plays a key role in power system. Therefore, relay protection equipment should be further selected based on its capacity and importance to ensure its ideal performance and safe and stable operation. Aiming at the 10kV power supply system, some common transformer faults are analyzed below, and some suggestions related to relay protection are given, in order to provide reference for relevant personnel.
文摘With the passage of time, the power system is constantly updated and optimized to highlight new features and functions and further enhance the requirements for relay protection. Relay protection personnel must constantly adapt to the development of society, constantly update relay protection technology to ensure reliable operation, keep their own relay protection growing up with the times, understand troubleshooting and further improve the safety and reliability of power grid. This paper analyzes the common faults and operations related to relay protection and provide protective measures for the reliability of current relay protection.
文摘With the development of large-scale complicated modern power systems, the requirement for the associated protection scheme tends to be more stringent and its combination more complex. However, it is very difficult to figure out the factors of failure of such systems. This paper proposes a Petri net model of a transmission line protection relaying system, including three types of relays as well as an automatic reclosing device, and shows how to diagnose serial failure of the system by analyzing invariant sets of the model. Furthermore, it gives four basic types of failure sequences and its execution is much more intuitive and effective than the traditional method.
基金This study was conducted by the Ministry of Land,Infrastructure and Transport’s Research Project on Railway Technology-Projects(21RTRP-B146037-04).
文摘The industrial power systems are moving to digital networks,and unmanned systems are increasing recently with the technological development of information and communication technology.In particular,reliability of system operation is very important for stable power supply.Most industrial power distribution facilities use a 154 kV or 22.9 kV extra HV(high voltage)power system,and a special monitoring system is required because a large loss occurs when an error occurs in the power facility in the field.Although digital protection relay(IED;intelligent electronic device)and FR(fault recorder)are applied to the field to protect the power system,various improvement activities are still ongoing.In this paper,a 22.9 kV high-voltage panel and its test bed,which are widely used in railway stations,tunnels,substations and large plants,were tested as test subjects.The developed fault detection system automatically starts the AL(auto-lock)circuit or outputs an alarm signal to user by monitoring in real time problems such as CT(current transformer)-open and poor-contact that the existing digital protection relay cannot cover.In addition,it is intended to increase the safety and reliability of the power system by blocking various accidents in the system in advance and accurately analyzing the causes of faults with the developed fault detection system.
文摘Under the background of rapid social and economic development, electric power has a close relationship with people's daily life. How to make the use of electric power resources more scientific and reasonable and create greater benefits for people's daily life is currently the main in-depth research content. The work related to the State Grid takes people's development as the objective, continuously improves the efficiency in the operation process of enterprises, reasonably supplies power between regions, continuously upgrades and optimizes the power system, and ensures the demand for power resources with the development of society. Therefore, in daily work, the staff need to improve the relay protection level of electricians, improve the original electrical relay protection related scheme, and continuously innovate and improve it, so as to make the electrical resources equipment improve the safety and stability of the power system in use.
文摘The main working principle of the relay protection device is to organically combine advanced electronic technology, network technology, control technology and other technologies, to realize automatic identification of electrical system faults through the relay protection device, and to timely make targeted treatment for faults according to different types of faults occurring in the system operation. During the operation of electrical engineering, relay protection devices can analyze the operation of the protected objects through the monitoring equipment in the system, and comprehensively protect and adjust the protection function and fixed value of the equipment in real time according to the operation status of the protected objects. Finally, the remote dynamic monitoring and correction of electrical engineering are realized.
文摘A new principle for grounding fault feeder detection based on negative sequence current variation and energy dissipated in the fault point is presented. It has high precision in both isolated systems and resonance earthed systems, even in full compensated systems. And it can be installed at the local control unit of feeder in distribution automation systems, such as field terminal unit (FTU). This principle is verified by EMTP simulator and experimentation.
文摘Determining the fault location using conventional impedance based distance relay in the presence of FACTS controllers is a challenging task in a transmission line. A new distance protection method is developed to locate the fault in a transmission line compensated with STATCOM with simple calculations. The proposed protection method considers the STATCOM injected/absorbed current to correct the fault loop apparent impedance and accordingly calculates the actual distance to the fault location. The comprehensive equations needed for apparent impedance calculation are also outlined and the performance is evaluated and tested with a typical 400 KV transmission system for different fault types and locations using MATLAB/SIMULINK software. The evaluation results indicate that the new protection method effectively estimates the exact fault location by mitigating the impact of STATCOM on distance relay performance with error less than 0.3%.
文摘A vital attribute of electrical power network is the continuity of service with a high level of reliability. This motivated many researchers to investigate power systems in an effort to improve reliability by focusing on fault detection, classification and localization. In this paper, a new protective relaying framework to detect, classify and localize faults in an electrical power transmission system is presented. This work will extract phase current values during ( )th of a cycle to generate unique signatures. By utilizing principal component analysis (PCA) methods, this system will identify and classify any fault instantaneously. Also, by using the curve fitting polynomial technique with our index pattern obtained from the unique fault signature, the location of the fault can be determined with a significant accuracy.
文摘Recently, power distribution system is getting larger and more complex. It is very difficult even for the experts to diagnosis and monitoring to made best action. This motivated many researchers to investigate power systems in an effort to improve reliability by focusing on fault detection and classification. There have been many studies on problems but the results are not good enough for applying to real power system. In this paper, a new protective relaying framework to diagnosis and monitoring faults in an electrical power distribution system with. This work will extract fault signatures by using ellipse fit using least squares criterion during fault condition. By utilizing principal component analysis methods, this system will identify, classify and localize any fault instantaneously.
文摘In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.
