Distribution Network With Distributed Power Supply Fault Location And Line Protection Device Research

With the rapid development of smart grids and the increasing demand of users,traditional power generation is facing a series of problems,such as the scarcity of non-renewable resources,environmental pollution and low efficiency of power generation.Distributed power supplies are gradually being connected to the distribution network because of their resource and environment friendly nature,low power consumption,high safety performance and good economy.However,the introduction of distributed power sources has led to changes in the power direction of fault currents in the distribution network,bringing challenges to traditional fault location techniques and line protection devices.In this context,the subject researches and designs a line protection device that integrates fault interval determination,line protection,telemetry remote data upload,human-machine interaction and communication functions,in addition to improving a matrix positioning algorithm based on line topology information and line fault information.Firstly,the overall structure of the line protection device is designed,the functional modules of the line protection device are clarified,and the two types of fault determination principles of the line protection device are introduced-the principle of phase-to-phase short circuit determination and the principle of zero sequence fault determination and the power parameter AC sampling algorithm.Thirdly,because the introduction of distributed generation changes the distribution structure of distribution network and the power direction of fault line,the traditional matrix location algorithm can no longer meet the changing needs of distribution network.This design improves a fault location algorithm based on the distribution line topology information matrix,and specifically explains the algorithm calculation process and fault location principle,The distribution system simulation model is built through the simulation software to verify the applicability of the fault location algorithm in different fault situations.Finally,the system is debugged with hardware and software modules and the protection function.The hardware debugging is to test whether there are hardware errors in the MCU board and IO board of the sectional switch controller system,the software debugging is to test whether each part of the functional module of the controller can complete the corresponding function,the protection function debugging is to test the action opening time of the sectional switch controller and thus determine whether it has the function of protecting The protection function is to test the opening time of the sectional switch controller and to determine whether it has the function to protect the distribution network lines.The test results show that the sampling error of the controller is within 0.5% of the data and the action opening time is within50 ms,which meets the relevant regulations of the national network standard.