Research On Single Phase To Ground Fault Location System Based On FPI And Petri NET

In China, the distribution network of voltage level of lOkV has long line and large coverage area, and a large part of the line is non control area,which can not get the fault information in a timely mannere. Single phase to ground fault is the most common type of fault in distribution network, which accounts for more than 75% of the total fault. Therefore, it is of great significance to establish the single phase to ground fault location system of distribution network for the rapid removal of fault,the safe and reliable operation of power system and the normal electricity consumption of users in the remote areas that have not realized the distribution automation.In order to realize the remote fault diagnosis of distribution line, the traditional fault passage indicator is improved to make it have the function of communication firstly. The main controller of the fault indicator is TMS320F2812 of the DSP series chip. The hardware mainly includes power module, signal acquisition module,wireless communication module and warning module; In the aspect of fault the communication layer based on GPRS and the monitoring layer. The faulcriterion,fault transient phase current is chosen as the judgment basis of single phase to ground fault, and the maximum modulus method is used which improve the reliability of fault passage indicator.Meanwhile, the single phase to ground fault location system is established based on the improved fault passage indicators. This fault location system is composed of three parts: the fault information layer composed of fault passage indicators on transmission lines, the communication layer based on GPRS and the monitoring layer.The fault information in fault information layer is uploaded to the monitoring layer through the communication layer. Monitoring layer uses the ability of parallel reasoning of Petri network full, adopts the fault location algorithm based on Petri net to realize the fault location and identification rapidly; considering FPI's failure to operate and misoperation, monitoring layer adopts fault location model based on fuzzy Petri net and fault reliability to obtain the reliability of every unit fault diagnosis domain.Finally, the simulation model of Petri network fault location system based on a feeder fault diagnosis domain is built by using MATLAB/Simulink and the PIPE that is simulation software of Petri net. The simulation results show that the single phase to ground fault location system can accurately identify the fault section and has certain practical value. It can provide some reference for the power line maintenance personnel to check the fault source, reduced their labor intensity, improve work efficiency to find fault source,and conducive to early resumption of electricity supply.