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
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
Several large-scale wind turbine tripping accidents occurred in Jiuquan wind power base in 2011.According to the on-site survey and analysis of these accidents related to relay protection,causes were found to be the c...Several large-scale wind turbine tripping accidents occurred in Jiuquan wind power base in 2011.According to the on-site survey and analysis of these accidents related to relay protection,causes were found to be the collection system defects and low correct operation rate of small current grounded line selectors of the unearthed neutral point collection system.By referring to both the characteristics of Jiuquan wind power base and arrangement of relay protection,the short-circuit features of wind power and its impacts on relay protection are analyzed.The collection system and the retrofit of the small current grounded line selector are improved by specific countermeasures.Finally,further research subjects are put forward.展开更多
The parameters of abnormal data are defined and their influence on the original data and Fourier Algorithm is studied. A formula is proposed to quantify how the abnormal data influences the amplitude calculated by Fou...The parameters of abnormal data are defined and their influence on the original data and Fourier Algorithm is studied. A formula is proposed to quantify how the abnormal data influences the amplitude calculated by Fourier Algorithm. Two simulation models are established in Matlab to study the influence of abnormal data on relay protection. The simulation results show that the abnormal data can make distance protection extend the fault’s influence and make over current protection start by error.展开更多
Research on reliability of relaying protection in smart substation not only has a positive effect on the rational configuration scheme of relaying protection in smart substation, but also can promote the stability and...Research on reliability of relaying protection in smart substation not only has a positive effect on the rational configuration scheme of relaying protection in smart substation, but also can promote the stability and safety of the overall operation of power system. There are many reliability strategies for relaying protection in smart substation. In practice, the key points of relaying protection should be clarified. Based on the reality, the protection configuration should be strengthened;the voltage limited delay should be used for protection, and the protection configuration scheme of actual lines should be paid attention to, so as to improve the reliability of relaying protection in smart substation and promote the realization of stable and sustainable development of power system and smart substation.展开更多
The intelligent substation relay protection facility is a fundamental element in construction of modern power system,based on the principles of flexibility,security and accuracy,and it can be divided into process laye...The intelligent substation relay protection facility is a fundamental element in construction of modern power system,based on the principles of flexibility,security and accuracy,and it can be divided into process layer and substation layer according to specific equipment.The former is suitable for individual sampling of disposable equipment,can be separated from the base station synchronization sampling,with the help of synchronous digital system and ping-pong algorithm to achieve synchronization of the overall sampling,that is to take the distribution protection components,through the separate transmission medium to realize the information transmission;the latter is for variable power plant components centralized backup protection,taking online real-time tuning technique.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
A simulation system for power grid with concentrated large-scale wind farm integration is established based on the electro-magnetic transient model of wind turbine equipped with doubly-fed induction generator (DFIG),w...A simulation system for power grid with concentrated large-scale wind farm integration is established based on the electro-magnetic transient model of wind turbine equipped with doubly-fed induction generator (DFIG),which is built by real-time digital simulator (RTDS).Using the hardware communication interface of RTDS,a closed-loop testing experiment is accomplished to study the impacts of large-scale wind farms on the existing relay protection devices for wind farm outgoing transmission line.This paper points out problems existing in current relay protection devices as follows:fault phase selector can select unwanted phase due to the changes of fault features caused by special network connection of wind farms;blocking condition for distance protections needs to be re-examined due to the weak power-feed characteristics of wind farms;and power frequency parameter based relay protection devices cannot accurately operate due to the special transient voltage and current characteristics of wind farms during fault period.Results lay the foundation for improving the performances of the existing relay protection device and developing new principle 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
In this paper, refusal of operation and the degree of constraint violation are considered as one part of the objective function for optimizing the protection relay setting coordination of over current relays in power ...In this paper, refusal of operation and the degree of constraint violation are considered as one part of the objective function for optimizing the protection relay setting coordination of over current relays in power systems; a new expression of objective function in this optimization problem is proposed. To combine the advantages of both Tabu search （TS） and evolutionary algorithms （EAs）, a new niche-based evolutionary Tabu search algorithm （named NETS） is presented to solve this optimization problem. Moreover, in two cases of power networks, comparisons between NETS and two published algorithms are given. Experimental results show the expression of the objective function for protection relay setting is feasible and reasonable, and the proposed algorithm NETS exhibits a good performance.展开更多
A compound relay protection operation criterion is proposed based on Kirchhoff’s Current Law and abnormal data detecting algorithm. The abnormal data detecting algorithm are proposed after deep research on the abnorm...A compound relay protection operation criterion is proposed based on Kirchhoff’s Current Law and abnormal data detecting algorithm. The abnormal data detecting algorithm are proposed after deep research on the abnormal data properties. The current transformer status monitoring system and current phase angle detecting system is introduced. A simulation model containing different power sources and loads is established in Matlab. The simulation results show that this compound criterion can work quickly and reliably in all conditions.展开更多
With the rapid development of the smart grid, it is necessary to do good corresponding work in relaying protection so as to meet the overall requirements of the smart grid better. So we must focus on the state divisio...With the rapid development of the smart grid, it is necessary to do good corresponding work in relaying protection so as to meet the overall requirements of the smart grid better. So we must focus on the state division, risk analysis and fault diagnosis methods in the relaying protection system, in the basis of fully understanding the advantages and disadvantages of relaying protection system, and then improve the problems existing of relaying protection system at this stage according to the actual situation. This paper aims at the overview of analysis on state evaluation of relaying protection systems.展开更多
As the false trips of remote protection relays are among the main reasons behind cascading blackouts, it is critical to design reliable relay protection. Even though common protection schemes on traditional power syst...As the false trips of remote protection relays are among the main reasons behind cascading blackouts, it is critical to design reliable relay protection. Even though common protection schemes on traditional power systems have been investigated for a few decades, cascading failures in recent years indicate more research needed in this area. Consequently, researchers have proposed agent-based methods on the Smart Grid （SG） to address this issue. However, these existing agent-based methods simply use TCP protocol without considering real-time communication requirements （such as bandwidth and delay）. To deal with this issue, several methods for efficient network resource management are proposed. Furthermore, these existing methods do not consider the potential issues in practical communication networks, which may result in delay violation and trigger relay false trips. We have discussed simple backup solutions in the previous work. In this paper, in addition to network efficiency, we focus on improving the system reliability by exploring known power system information and minimizing the chances of false trips of important remote relays, e.g., defining power line priorities based on their importance. Moreover, to further improve the. system reliability, we also in- vestigate the peer-to-peer protection approaches to address the single point of failure of centralized control center.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
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
Since opening of the Korean high-speed railway in 2004,the rate of electrification has been increasing rapidly,and safety of the supply of AC railways has become very important.And the digital protection relays in rai...Since opening of the Korean high-speed railway in 2004,the rate of electrification has been increasing rapidly,and safety of the supply of AC railways has become very important.And the digital protection relays in railway feeding system need more attention with the expansion of unmanned SSs(substations)and digital SSs.For accident prevention,it is necessary to develop accurate modeling and simulation technology for railway feeding devices of electric railway.And it is also important to continuously improve test methods and develop excellent relay algorithms and apply them to the protection system to prepare for unexpected accidents.In this study,after reduced modeling the AC railway power supply system using PSCAD/EMTDC(Power Systems Computer Aided Design/Electromagnetic Transient DC Analysis),the results were compared and verified with the numerical calculation using the symmetric coordinate method.It also presents a method of using the verified results for simulation and education for various railway accidents.This study result will be used for the construction of new lines as well as existing lines in the future railway business.展开更多
This paper presents the main results on the use of conventional protection hardware to protect a Half Wavelength Transmission Line, or shortly AC-Link, for possible occurrence of three-phase and single-phase fault dur...This paper presents the main results on the use of conventional protection hardware to protect a Half Wavelength Transmission Line, or shortly AC-Link, for possible occurrence of three-phase and single-phase fault during energization maneuver. Lines of these dimensions do not exist today, but in countries of continental size they could be an interesting alternative to HVDC transmission, since the AC-Link has less dependence on Power Electronics technology. The studies on performance and relay settings were implemented using the RTDS real-time simulator. It is important to note that the AC-Link protection for the energization maneuver can be performed with existing hardware on conventional relays.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
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
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.
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.
基金supported by National High Technology Research and Development Program of China(863Program)(No.2011AA05A104)
文摘Several large-scale wind turbine tripping accidents occurred in Jiuquan wind power base in 2011.According to the on-site survey and analysis of these accidents related to relay protection,causes were found to be the collection system defects and low correct operation rate of small current grounded line selectors of the unearthed neutral point collection system.By referring to both the characteristics of Jiuquan wind power base and arrangement of relay protection,the short-circuit features of wind power and its impacts on relay protection are analyzed.The collection system and the retrofit of the small current grounded line selector are improved by specific countermeasures.Finally,further research subjects are put forward.
文摘The parameters of abnormal data are defined and their influence on the original data and Fourier Algorithm is studied. A formula is proposed to quantify how the abnormal data influences the amplitude calculated by Fourier Algorithm. Two simulation models are established in Matlab to study the influence of abnormal data on relay protection. The simulation results show that the abnormal data can make distance protection extend the fault’s influence and make over current protection start by error.
文摘Research on reliability of relaying protection in smart substation not only has a positive effect on the rational configuration scheme of relaying protection in smart substation, but also can promote the stability and safety of the overall operation of power system. There are many reliability strategies for relaying protection in smart substation. In practice, the key points of relaying protection should be clarified. Based on the reality, the protection configuration should be strengthened;the voltage limited delay should be used for protection, and the protection configuration scheme of actual lines should be paid attention to, so as to improve the reliability of relaying protection in smart substation and promote the realization of stable and sustainable development of power system and smart substation.
文摘The intelligent substation relay protection facility is a fundamental element in construction of modern power system,based on the principles of flexibility,security and accuracy,and it can be divided into process layer and substation layer according to specific equipment.The former is suitable for individual sampling of disposable equipment,can be separated from the base station synchronization sampling,with the help of synchronous digital system and ping-pong algorithm to achieve synchronization of the overall sampling,that is to take the distribution protection components,through the separate transmission medium to realize the information transmission;the latter is for variable power plant components centralized backup protection,taking online real-time tuning technique.
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.
基金supported by the Special Fund of the National Basic Research Program of China (973 Program) (No.2009CB219704)
文摘A simulation system for power grid with concentrated large-scale wind farm integration is established based on the electro-magnetic transient model of wind turbine equipped with doubly-fed induction generator (DFIG),which is built by real-time digital simulator (RTDS).Using the hardware communication interface of RTDS,a closed-loop testing experiment is accomplished to study the impacts of large-scale wind farms on the existing relay protection devices for wind farm outgoing transmission line.This paper points out problems existing in current relay protection devices as follows:fault phase selector can select unwanted phase due to the changes of fault features caused by special network connection of wind farms;blocking condition for distance protections needs to be re-examined due to the weak power-feed characteristics of wind farms;and power frequency parameter based relay protection devices cannot accurately operate due to the special transient voltage and current characteristics of wind farms during fault period.Results lay the foundation for improving the performances of the existing relay protection device and developing new principle 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Supported by the National Natural Science Foundation of China (50677046, 60573168)
文摘In this paper, refusal of operation and the degree of constraint violation are considered as one part of the objective function for optimizing the protection relay setting coordination of over current relays in power systems; a new expression of objective function in this optimization problem is proposed. To combine the advantages of both Tabu search （TS） and evolutionary algorithms （EAs）, a new niche-based evolutionary Tabu search algorithm （named NETS） is presented to solve this optimization problem. Moreover, in two cases of power networks, comparisons between NETS and two published algorithms are given. Experimental results show the expression of the objective function for protection relay setting is feasible and reasonable, and the proposed algorithm NETS exhibits a good performance.
文摘A compound relay protection operation criterion is proposed based on Kirchhoff’s Current Law and abnormal data detecting algorithm. The abnormal data detecting algorithm are proposed after deep research on the abnormal data properties. The current transformer status monitoring system and current phase angle detecting system is introduced. A simulation model containing different power sources and loads is established in Matlab. The simulation results show that this compound criterion can work quickly and reliably in all conditions.
文摘With the rapid development of the smart grid, it is necessary to do good corresponding work in relaying protection so as to meet the overall requirements of the smart grid better. So we must focus on the state division, risk analysis and fault diagnosis methods in the relaying protection system, in the basis of fully understanding the advantages and disadvantages of relaying protection system, and then improve the problems existing of relaying protection system at this stage according to the actual situation. This paper aims at the overview of analysis on state evaluation of relaying protection systems.
文摘As the false trips of remote protection relays are among the main reasons behind cascading blackouts, it is critical to design reliable relay protection. Even though common protection schemes on traditional power systems have been investigated for a few decades, cascading failures in recent years indicate more research needed in this area. Consequently, researchers have proposed agent-based methods on the Smart Grid （SG） to address this issue. However, these existing agent-based methods simply use TCP protocol without considering real-time communication requirements （such as bandwidth and delay）. To deal with this issue, several methods for efficient network resource management are proposed. Furthermore, these existing methods do not consider the potential issues in practical communication networks, which may result in delay violation and trigger relay false trips. We have discussed simple backup solutions in the previous work. In this paper, in addition to network efficiency, we focus on improving the system reliability by exploring known power system information and minimizing the chances of false trips of important remote relays, e.g., defining power line priorities based on their importance. Moreover, to further improve the. system reliability, we also in- vestigate the peer-to-peer protection approaches to address the single point of failure of centralized control center.
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.
基金the Ministry of Land,Infrastructure and Transport's Research Project on Railway Technology-Project(20RTRP-B146034-03)。
文摘Since opening of the Korean high-speed railway in 2004,the rate of electrification has been increasing rapidly,and safety of the supply of AC railways has become very important.And the digital protection relays in railway feeding system need more attention with the expansion of unmanned SSs(substations)and digital SSs.For accident prevention,it is necessary to develop accurate modeling and simulation technology for railway feeding devices of electric railway.And it is also important to continuously improve test methods and develop excellent relay algorithms and apply them to the protection system to prepare for unexpected accidents.In this study,after reduced modeling the AC railway power supply system using PSCAD/EMTDC(Power Systems Computer Aided Design/Electromagnetic Transient DC Analysis),the results were compared and verified with the numerical calculation using the symmetric coordinate method.It also presents a method of using the verified results for simulation and education for various railway accidents.This study result will be used for the construction of new lines as well as existing lines in the future railway business.
文摘This paper presents the main results on the use of conventional protection hardware to protect a Half Wavelength Transmission Line, or shortly AC-Link, for possible occurrence of three-phase and single-phase fault during energization maneuver. Lines of these dimensions do not exist today, but in countries of continental size they could be an interesting alternative to HVDC transmission, since the AC-Link has less dependence on Power Electronics technology. The studies on performance and relay settings were implemented using the RTDS real-time simulator. It is important to note that the AC-Link protection for the energization maneuver can be performed with existing hardware on conventional relays.
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.
