Fault Location For Distribution Network Based On Multi Information Source

With the arrival of industry 4.0,smart power grid has significantly changed its original operation mode.More and more intelligent equipment appears in substations at all levels.The emergence of these intelligent equipment is gradually transforming the distributed equipment and centralized monitoring of operators from the original manual inspection mode into the intelligent inspection mode,such as remote meter reading,remote control,remote fault location and so on.Distribution network is the most close to the unit of electricity consumption in the whole power system.Therefore,the safety,stability and continuous operation of distribution network will directly affect the productivity and economic benefits of the unit of electricity consumption.However,due to a variety of uncertain factors,such as natural environment change,human operation error,and old equipment damage,it is difficult to avoid the fault of the distribution network in 100 percent.After the fault occurs,how to remove the fault and restore power supply as soon as possible is the test of the comprehensive capacity of the power supply operating unit.In this process,fault location is the most important part of fault processing.The faster response sensitivity and higher accuracy of fault location system to fault can ensure the lower limit of fault processing speed to the greatest extent,laying a solid foundation for rapid fault treatment of distribution network.In this thesis,fault localization models are established for non-measurable and non-controllable areas in distribution network.The dynamic matrix algorithm combined with fault complaint calls is adopted to fast locate fault points in non-measurable and non-controllable areas.Especially for old urban areas where the distribution network were built earlier,the configuration of its intelligent components was not perfect.The dispatch and control center could only see the static wiring diagram of the power system and could not find the fault of the distribution network in time.By collecting the feedback information of users to judge the fault point of the distribution network,different root nodes according to different fault information are built.Compared with the traditional matrix algorithm with fixed root nodes,it greatly reduces the number and time of traversal,thus gaining time for fault repairing.For the malfunctions of measurement and control area,this thesis proposed a kind of fault localization models for power system based on weighted fuzzy Petri nets,where different WFPN models are established for different components respectively which includes transformer,buses and lines.By analyzing the status of protection and circuit breaker in SCADA,the possible point of failure can be inferred.Compared to the traditional Petri nets,our weighted fuzzy Petri net model will fuzzy the sampling values from 0,1 to [0,1].Moreover,for different input,different weights are given according to the associated with fault point of strength.The threshold of weights guarantees the exclusion of unreliable information,which facilitates our analysis of the failure,misoperation,and false alarm information.Finally,the Stateflow simulation tool of MATLAB is used to simulate the fault of a simple power distribution system.Simulation results show that the proposed fault location method of power system distribution network based on weighted fuzzy Petri net model has good accuracy and universality,and it is fault-tolerant to misreporting and variation of SCADA sampling information.Moreover,the simulation model is intuitive and simple to be modified.The maintenance and modification work of the complex and changeable system structure of distribution network is well handled.