The probability-assessment analyses on the characteristic value of voltage dip by using Monte Carlo stochastic modeling method to stimulate the randomness of the short circuit fault are introduced. Using Matlab and Po...The probability-assessment analyses on the characteristic value of voltage dip by using Monte Carlo stochastic modeling method to stimulate the randomness of the short circuit fault are introduced. Using Matlab and Power Systems CAD(PSCAD), we design control interface which combines the electromagnetic transient simulation with the Monte Carlo method. Specifically, the designing of interface which is meant to employ the method of Matlab programming to control the electromagnetic transients including direct current(EMTDC)simulation is introduced. Furthermore, the influences of the protection devices on the voltage dip to ensure the authenticity and the referential reliability are simulated. A system with the inverse-time protection devices equipped on each line which can coordinate together is designed to cut off the short-circuit fault. The voltage dip of the designed system is assessed by the pre- and post-system average root mean square(RMS) variation frequency index, and the voltage dip index is compared with the Information Technology Industry Council(ITIC)curves. The simulation results demonstrate that the inverse-time relay protection equipments are well-coordinated,and the severity and the range of the voltage dip are influenced by the cooperation of the equipped inverse-time protection devices.展开更多
Distributed generators now is widely used in electrical power networks, in some cases it works seasonally, and some types works at special weather conditions like photo voltaic systems and wind energy, and due to this...Distributed generators now is widely used in electrical power networks, in some cases it works seasonally, and some types works at special weather conditions like photo voltaic systems and wind energy, and due to this continuous changes in generation condition, the fault current level in network will be affected, this changes in fault current level will affect in the coordination between protection relays and to keep the coordination at right way, an adaptive protection system is required that can adaptive its setting according to generation changes, the fault current level in each case is evaluated using ETAP software, and the required relay setting in each case is also evaluated using Grey Wolf Optimizer (GWO) algorithm, and to select suitable setting which required in each condition, to select the active setting group of protection relay according to generation capacity, central protection unite can be used, and to improve protection stability and minimizing relays tripping time, a proposed method for selecting suitable backup relay is used, which leads to decrease relays tripping time and increase system stability, output settings for relays in all cases achieved our constrains.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 article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. R...The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.展开更多
A novel operation control method for relay protection in flexible DC distribution networks with distributed power supply is proposed to address the issue of inaccurate fault location during relay protection,leading to...A novel operation control method for relay protection in flexible DC distribution networks with distributed power supply is proposed to address the issue of inaccurate fault location during relay protection,leading to poor performance.The method combines a fault-tolerant fault location method based on long-term and short-term memory networks to accurately locate the fault section.Then,an operation control method for relay protection based on adaptive weight and whale optimization algorithm(WOA)is used to construct an objective function considering the shortest relay protection action time and the smallest impulse current.The adaptive weight and WOA are employed to obtain the optimal strategy for relay protection operation control,reducing the action time and impulse current.Experimental results demonstrate the effectiveness of the proposed method in accurately locating faults and improving relay protection performance.The longest operation time is reduced by 4.7023 s,and the maximum impulse current is limited to 0.3 A,effectively controlling the impact of large impulse currents and enhancing control efficiency.展开更多
The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an a...The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.展开更多
In this paper, a method to calculate the slope of the ratio restraint characteristic of a transformer differential relay protection is proposed. The method allows using some concise but effective means to get the slop...In this paper, a method to calculate the slope of the ratio restraint characteristic of a transformer differential relay protection is proposed. The method allows using some concise but effective means to get the slope. Modulating the argument of current output from ONLLY testing equipment can make the relay protection device operate, thus, the data used for calculation would be obtained naturally after several trails. In order to make sure how effective that method could be, some experiment data is given as well.展开更多
With the rapid development of network technology and communication technology, all walks of life are moving towards the direction of intelligence, which has greatly promoted the social and economic progress in our cou...With the rapid development of network technology and communication technology, all walks of life are moving towards the direction of intelligence, which has greatly promoted the social and economic progress in our country. The power industry is no exception. The emergence of smart substations has greatly improved some problems existing in the operation and maintenance of Chinas power industry and played a key role in promoting the long-term development of smart grids. More importantly, the relay protection technology has also been greatly changed under the support of the smart grid. Based on this background, strengthening the research work on the operation and maintenance of relay protection has an extremely far-reaching guiding role, which is helpful to promote the sustainable development of Chinas power grid construction.展开更多
With the rapid development of electrical automation system, the factors that affect its internal operation safety are gradually increasing. Relevant professionals should make use of the rational use of relay protectio...With the rapid development of electrical automation system, the factors that affect its internal operation safety are gradually increasing. Relevant professionals should make use of the rational use of relay protection devices to strengthen the professional control of the system, and effectively solve the problems encountered. After clarifying the working principle of such devices, the application scope of relay protection devices can be effectively enhanced. Next, the article focuses on the analysis of influencing factors and solutions of relay protection safety of electrical automation system.展开更多
The power industry is an important basic industry of the national economy. Accelerating the rapid development of the power industry and promoting the integration of the power industry with other industries are the imp...The power industry is an important basic industry of the national economy. Accelerating the rapid development of the power industry and promoting the integration of the power industry with other industries are the important contents of the power industry in the new era. In the process of modernization of Chinas power grid, information technology has been continuously improved and developed, and the scale of Chinas power grid is also rapidly growing and expanding. At the same time, our countrys substation is also moving towards the direction of intelligence and development. The application of various intelligent equipment in the field of substation is becoming more and more extensive, which effectively improves and enhances the related work efficiency and safety of power transmission and transformation system. Technical personnel must strengthen the application of information technology and other advanced technologies, comprehensively analyze the shortcomings of relay protection technology in application, and continuously improve the efficiency and reliability of relay protection operation.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
The traditional relay protection debugging technology of generator-transformer group ignores the suppression of voltage distortion of generator-transformer group, which leads to the phase lag problem of generator-tran...The traditional relay protection debugging technology of generator-transformer group ignores the suppression of voltage distortion of generator-transformer group, which leads to the phase lag problem of generator-transformer group in the process of relay protection, and cannot realize the relay protection of generator-transformer group of power plant grid-connected unitsin stable and safe debugging. The protection effect of power relay is reduced with the application of automation and intelligent technology, so we should study new technology. This paper takes the remote operation and maintenance technology of power relay protection as the research object, and analyzes the specific application and development status of this technology in modern society. It is hoped that it can be helpful to the future development of power relay protection and is beneficial to my country's power relay protection with stable development.展开更多
In recent years, microelectronic components are more widely used in relay protection devices, but most of the electronic devices are electronic sensitive devices, which are easy to be affected by interference. When th...In recent years, microelectronic components are more widely used in relay protection devices, but most of the electronic devices are electronic sensitive devices, which are easy to be affected by interference. When the relay protection devices are interfered in the power system, if there is a fault, it will affect the overall security of the power grid, resulting in the power grid cannot operate stably. When the interference energy exceeds the maximum allowable energy of the logic circuit, it will directly damage the components and affect the normal operation of the relay protection device. Therefore, strengthening the anti-interference ability of relay protection and automation devices has become an important topic in power system.展开更多
In recent years, with the continuous development of society, people's demand for electricity continues to increase, so an important task at present is to ensure the stable operation of the power system. An effecti...In recent years, with the continuous development of society, people's demand for electricity continues to increase, so an important task at present is to ensure the stable operation of the power system. An effective measure is relay protection, through reasonable means to detect the fault in the power system, and to prevent the fault in advance and real-time control, to ensure that the various components in the power system will not be damaged. When the abnormal system is detected, the line connection in the system will be cut off automatically, and the alarm signal will be sent to the relevant personnel in time to ensure the stable operation of the power system. Facts have proved that the in-depth research and analysis of relay protection and fault detection methods can promote the continuous innovation of electric power technology and means, and lay a foundation for the follow-up research.展开更多
China's rapid economic growth promotes the vigorous development of the electric power industry, and as an important part of the power system, relay protection secondary equipment can operate normally, for the elec...China's rapid economic growth promotes the vigorous development of the electric power industry, and as an important part of the power system, relay protection secondary equipment can operate normally, for the electrical system to efficiently provide power resources is of great significance. In this paper, from the secondary loop anti-interference research, comprehensive analysis of its interference source, and put forward corresponding measures to improve anti-interference ability. It aims to provide solutions for the stable development of China's electric power industry and promote the continuous improvement of China's economic construction level.展开更多
With the continuous development of China's economic construction, the construction of the State Grid system has made great progress under the promotion of science and technology. At present, intelligent substation...With the continuous development of China's economic construction, the construction of the State Grid system has made great progress under the promotion of science and technology. At present, intelligent substation is widely used and popularized in China's power industry because of its low cost, safety and efficiency. During the operation of intelligent substation, the operation efficiency, stability and reliability of relay protection equipment are the guarantee of its operation. Therefore, the research on the operation and maintenance of relay system equipment in intelligent substation is of great significance, and it is also the guarantee for the sustainable development and progress of intelligent substation.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
The over-load protective relay is widely used directly affects the safe running of a motor. The reliability for motor protection. The reliability of the over-load protective relay testing and reliability analysis of t...The over-load protective relay is widely used directly affects the safe running of a motor. The reliability for motor protection. The reliability of the over-load protective relay testing and reliability analysis of the over-load protective relay is an important way to improve the reliability of products. In this paper, the reliability test method of the over-load protective relay is studied, and the reliability tests of the typical products are carried out on a reliability tester developed by authors. In terms of the testing results, the reliability analysis is finished. The failure reasons are found and the measures are put forward to improve the reliability of the products.展开更多
The reliability analysis of vertically integrated protection devices is crucial for designing International Electrotechnical Commission(IEC)61850-based substations.This paper presents the hardware architecture of a fo...The reliability analysis of vertically integrated protection devices is crucial for designing International Electrotechnical Commission(IEC)61850-based substations.This paper presents the hardware architecture of a four-inone vertically integrated device and the information transmission path of each function based on the functional information transmission chain of protection devices,measurement and control devices,merging units,and intelligent terminals.Additionally,a reliability analysis model of the protection device and its protection system is constructed using the fault tree analysis method while considering the characteristics of each module of the vertically integrated device.The stability probability of the protection system in each state is analyzed by combining the state-transfer equations of line and busbar protection with a Markov chain.Finally,the failure rate and availability of the protection device and its protection system are calculated under different ambient temperatures using a 110 kV intelligent substation as an example.The sensitivity of each device module is analyzed.展开更多
The selectivity of short circuit protection of high voltage lines in coal mines cannot be realized by existing protection systems. To solve this problem, a scheme based on double layer Ether CAT and optical fiber inte...The selectivity of short circuit protection of high voltage lines in coal mines cannot be realized by existing protection systems. To solve this problem, a scheme based on double layer Ether CAT and optical fiber interlock net was proposed. The system is mainly composed of double layer Ether CAT, optical fiber interlock net, ground monitoring station, underground control stations and integrated protection devices with Ether CAT communication interface and interlock interface. Double layer Ether CAT and optical fiber interlock net cooperate with each other, when one is interrupted, the other net carl realize selectivity of short circuit protection independently, Results of test show that the system can achieve selectivity of short circuit protection reliably, determine the fault location quickly, shorten troubleshooting time and improve safety and reliability of the power network in coal mines.展开更多
基金the Henan Tackle Key Problem of Science and Technology(No.102102210454)the Foundation of Education Committee of Henan Province(No.2011B520028)
文摘The probability-assessment analyses on the characteristic value of voltage dip by using Monte Carlo stochastic modeling method to stimulate the randomness of the short circuit fault are introduced. Using Matlab and Power Systems CAD(PSCAD), we design control interface which combines the electromagnetic transient simulation with the Monte Carlo method. Specifically, the designing of interface which is meant to employ the method of Matlab programming to control the electromagnetic transients including direct current(EMTDC)simulation is introduced. Furthermore, the influences of the protection devices on the voltage dip to ensure the authenticity and the referential reliability are simulated. A system with the inverse-time protection devices equipped on each line which can coordinate together is designed to cut off the short-circuit fault. The voltage dip of the designed system is assessed by the pre- and post-system average root mean square(RMS) variation frequency index, and the voltage dip index is compared with the Information Technology Industry Council(ITIC)curves. The simulation results demonstrate that the inverse-time relay protection equipments are well-coordinated,and the severity and the range of the voltage dip are influenced by the cooperation of the equipped inverse-time protection devices.
文摘Distributed generators now is widely used in electrical power networks, in some cases it works seasonally, and some types works at special weather conditions like photo voltaic systems and wind energy, and due to this continuous changes in generation condition, the fault current level in network will be affected, this changes in fault current level will affect in the coordination between protection relays and to keep the coordination at right way, an adaptive protection system is required that can adaptive its setting according to generation changes, the fault current level in each case is evaluated using ETAP software, and the required relay setting in each case is also evaluated using Grey Wolf Optimizer (GWO) algorithm, and to select suitable setting which required in each condition, to select the active setting group of protection relay according to generation capacity, central protection unite can be used, and to improve protection stability and minimizing relays tripping time, a proposed method for selecting suitable backup relay is used, which leads to decrease relays tripping time and increase system stability, output settings for relays in all cases achieved our constrains.
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.
文摘The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.
文摘A novel operation control method for relay protection in flexible DC distribution networks with distributed power supply is proposed to address the issue of inaccurate fault location during relay protection,leading to poor performance.The method combines a fault-tolerant fault location method based on long-term and short-term memory networks to accurately locate the fault section.Then,an operation control method for relay protection based on adaptive weight and whale optimization algorithm(WOA)is used to construct an objective function considering the shortest relay protection action time and the smallest impulse current.The adaptive weight and WOA are employed to obtain the optimal strategy for relay protection operation control,reducing the action time and impulse current.Experimental results demonstrate the effectiveness of the proposed method in accurately locating faults and improving relay protection performance.The longest operation time is reduced by 4.7023 s,and the maximum impulse current is limited to 0.3 A,effectively controlling the impact of large impulse currents and enhancing control efficiency.
文摘The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.
文摘In this paper, a method to calculate the slope of the ratio restraint characteristic of a transformer differential relay protection is proposed. The method allows using some concise but effective means to get the slope. Modulating the argument of current output from ONLLY testing equipment can make the relay protection device operate, thus, the data used for calculation would be obtained naturally after several trails. In order to make sure how effective that method could be, some experiment data is given as well.
文摘With the rapid development of network technology and communication technology, all walks of life are moving towards the direction of intelligence, which has greatly promoted the social and economic progress in our country. The power industry is no exception. The emergence of smart substations has greatly improved some problems existing in the operation and maintenance of Chinas power industry and played a key role in promoting the long-term development of smart grids. More importantly, the relay protection technology has also been greatly changed under the support of the smart grid. Based on this background, strengthening the research work on the operation and maintenance of relay protection has an extremely far-reaching guiding role, which is helpful to promote the sustainable development of Chinas power grid construction.
文摘With the rapid development of electrical automation system, the factors that affect its internal operation safety are gradually increasing. Relevant professionals should make use of the rational use of relay protection devices to strengthen the professional control of the system, and effectively solve the problems encountered. After clarifying the working principle of such devices, the application scope of relay protection devices can be effectively enhanced. Next, the article focuses on the analysis of influencing factors and solutions of relay protection safety of electrical automation system.
文摘The power industry is an important basic industry of the national economy. Accelerating the rapid development of the power industry and promoting the integration of the power industry with other industries are the important contents of the power industry in the new era. In the process of modernization of Chinas power grid, information technology has been continuously improved and developed, and the scale of Chinas power grid is also rapidly growing and expanding. At the same time, our countrys substation is also moving towards the direction of intelligence and development. The application of various intelligent equipment in the field of substation is becoming more and more extensive, which effectively improves and enhances the related work efficiency and safety of power transmission and transformation system. Technical personnel must strengthen the application of information technology and other advanced technologies, comprehensively analyze the shortcomings of relay protection technology in application, and continuously improve the efficiency and reliability of relay protection operation.
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The traditional relay protection debugging technology of generator-transformer group ignores the suppression of voltage distortion of generator-transformer group, which leads to the phase lag problem of generator-transformer group in the process of relay protection, and cannot realize the relay protection of generator-transformer group of power plant grid-connected unitsin stable and safe debugging. The protection effect of power relay is reduced with the application of automation and intelligent technology, so we should study new technology. This paper takes the remote operation and maintenance technology of power relay protection as the research object, and analyzes the specific application and development status of this technology in modern society. It is hoped that it can be helpful to the future development of power relay protection and is beneficial to my country's power relay protection with stable development.
文摘In recent years, microelectronic components are more widely used in relay protection devices, but most of the electronic devices are electronic sensitive devices, which are easy to be affected by interference. When the relay protection devices are interfered in the power system, if there is a fault, it will affect the overall security of the power grid, resulting in the power grid cannot operate stably. When the interference energy exceeds the maximum allowable energy of the logic circuit, it will directly damage the components and affect the normal operation of the relay protection device. Therefore, strengthening the anti-interference ability of relay protection and automation devices has become an important topic in power system.
文摘In recent years, with the continuous development of society, people's demand for electricity continues to increase, so an important task at present is to ensure the stable operation of the power system. An effective measure is relay protection, through reasonable means to detect the fault in the power system, and to prevent the fault in advance and real-time control, to ensure that the various components in the power system will not be damaged. When the abnormal system is detected, the line connection in the system will be cut off automatically, and the alarm signal will be sent to the relevant personnel in time to ensure the stable operation of the power system. Facts have proved that the in-depth research and analysis of relay protection and fault detection methods can promote the continuous innovation of electric power technology and means, and lay a foundation for the follow-up research.
文摘China's rapid economic growth promotes the vigorous development of the electric power industry, and as an important part of the power system, relay protection secondary equipment can operate normally, for the electrical system to efficiently provide power resources is of great significance. In this paper, from the secondary loop anti-interference research, comprehensive analysis of its interference source, and put forward corresponding measures to improve anti-interference ability. It aims to provide solutions for the stable development of China's electric power industry and promote the continuous improvement of China's economic construction level.
文摘With the continuous development of China's economic construction, the construction of the State Grid system has made great progress under the promotion of science and technology. At present, intelligent substation is widely used and popularized in China's power industry because of its low cost, safety and efficiency. During the operation of intelligent substation, the operation efficiency, stability and reliability of relay protection equipment are the guarantee of its operation. Therefore, the research on the operation and maintenance of relay system equipment in intelligent substation is of great significance, and it is also the guarantee for the sustainable development and progress of intelligent substation.
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.
基金Project (No. E2005000039) supported by the Natural Science Foun-dation of Hebei Province, China
文摘The over-load protective relay is widely used directly affects the safe running of a motor. The reliability for motor protection. The reliability of the over-load protective relay testing and reliability analysis of the over-load protective relay is an important way to improve the reliability of products. In this paper, the reliability test method of the over-load protective relay is studied, and the reliability tests of the typical products are carried out on a reliability tester developed by authors. In terms of the testing results, the reliability analysis is finished. The failure reasons are found and the measures are put forward to improve the reliability of the products.
基金supported by the 2020 Infrastructure Engineering Technology Innovation Projectthe“Intelligent Substation”Supporting Technology Research Project(031200WS22200001)。
文摘The reliability analysis of vertically integrated protection devices is crucial for designing International Electrotechnical Commission(IEC)61850-based substations.This paper presents the hardware architecture of a four-inone vertically integrated device and the information transmission path of each function based on the functional information transmission chain of protection devices,measurement and control devices,merging units,and intelligent terminals.Additionally,a reliability analysis model of the protection device and its protection system is constructed using the fault tree analysis method while considering the characteristics of each module of the vertically integrated device.The stability probability of the protection system in each state is analyzed by combining the state-transfer equations of line and busbar protection with a Markov chain.Finally,the failure rate and availability of the protection device and its protection system are calculated under different ambient temperatures using a 110 kV intelligent substation as an example.The sensitivity of each device module is analyzed.
文摘The selectivity of short circuit protection of high voltage lines in coal mines cannot be realized by existing protection systems. To solve this problem, a scheme based on double layer Ether CAT and optical fiber interlock net was proposed. The system is mainly composed of double layer Ether CAT, optical fiber interlock net, ground monitoring station, underground control stations and integrated protection devices with Ether CAT communication interface and interlock interface. Double layer Ether CAT and optical fiber interlock net cooperate with each other, when one is interrupted, the other net carl realize selectivity of short circuit protection independently, Results of test show that the system can achieve selectivity of short circuit protection reliably, determine the fault location quickly, shorten troubleshooting time and improve safety and reliability of the power network in coal mines.
