Fault Ride-Through （FRT） capabilities set up according to the grid codes may affect the performance of related protective elements during fault periods. Therefore, in this paper the coordination between the FRT capa...Fault Ride-Through （FRT） capabilities set up according to the grid codes may affect the performance of related protective elements during fault periods. Therefore, in this paper the coordination between the FRT capability and over-current protection of DFIG Wind Generators in MV networks is investigated. Simulation test cases using MATLAB-Simulink are implemented on a 365-MW wind farm in AL-Zaafarana, Egypt. The simulation results show the influence of the FRT capability on the protective relaying coordination in wind farms, showing that the FRT may work in situations where is were expected not to work, and then disabling the over-current protection, which should have worked in this situation.展开更多
Telephone occlusion method is a backup manual occlusion method during an urban rail transit signal equipment failure, which ensures that metro operated safely and orderly. Through the results of several telephone occl...Telephone occlusion method is a backup manual occlusion method during an urban rail transit signal equipment failure, which ensures that metro operated safely and orderly. Through the results of several telephone occlusion exercises, find out the shortcomings oftclcphone occlusion method and optimizing it.展开更多
The protection of distribution networks is facing new challenges from an increasing amount of DG （distributed generation）. Even though current technology provides satisfactory solutions to manage this new situation,...The protection of distribution networks is facing new challenges from an increasing amount of DG （distributed generation）. Even though current technology provides satisfactory solutions to manage this new situation, LOM （loss-of-mains protection） is still considered problematic. The solution proposed in this paper focuses on the use of a line differential protection relay. It inherently contains a suitable communication channel and provides absolutely selective protection for the feeder. Furthermore, it prevents the feeder relays from false tripping for faults on the neighboring feeder. The present trend in protection communication points towards the use of fiber optics. For line differential protection, this means a fast and high-capacity communication link which enables the implementation of many advanced protection functions. In addition, a solid foundation for such a communication link is offered by the new IEC 61850 standard and Ethernet technologies. The basic functionality of the line differential protection enables the operation of both the feeder protection and the DG protection for any fault on the feeder. Furthermore, basic LOM protection methods can be applied as backup protection for failures on the communication link.展开更多
文摘Fault Ride-Through （FRT） capabilities set up according to the grid codes may affect the performance of related protective elements during fault periods. Therefore, in this paper the coordination between the FRT capability and over-current protection of DFIG Wind Generators in MV networks is investigated. Simulation test cases using MATLAB-Simulink are implemented on a 365-MW wind farm in AL-Zaafarana, Egypt. The simulation results show the influence of the FRT capability on the protective relaying coordination in wind farms, showing that the FRT may work in situations where is were expected not to work, and then disabling the over-current protection, which should have worked in this situation.
文摘Telephone occlusion method is a backup manual occlusion method during an urban rail transit signal equipment failure, which ensures that metro operated safely and orderly. Through the results of several telephone occlusion exercises, find out the shortcomings oftclcphone occlusion method and optimizing it.
文摘The protection of distribution networks is facing new challenges from an increasing amount of DG （distributed generation）. Even though current technology provides satisfactory solutions to manage this new situation, LOM （loss-of-mains protection） is still considered problematic. The solution proposed in this paper focuses on the use of a line differential protection relay. It inherently contains a suitable communication channel and provides absolutely selective protection for the feeder. Furthermore, it prevents the feeder relays from false tripping for faults on the neighboring feeder. The present trend in protection communication points towards the use of fiber optics. For line differential protection, this means a fast and high-capacity communication link which enables the implementation of many advanced protection functions. In addition, a solid foundation for such a communication link is offered by the new IEC 61850 standard and Ethernet technologies. The basic functionality of the line differential protection enables the operation of both the feeder protection and the DG protection for any fault on the feeder. Furthermore, basic LOM protection methods can be applied as backup protection for failures on the communication link.
