Research On Communication Mechanism Of Single-phase Ground Fault Locating System In MV Power Distribution Network

The MV power distribution networks are usually adopting neutral ineffectively grounded mode which goes the name of little current grounded system. Because its current is little and the connection of branches in MV power distribution are complicated, single-phase ground fault locating has not been well resolved still now. When the fault location happened, fault phase to the ground voltage is lower and not-fault phase is higher, leading to the condition of the voltage of system is becoming asymmetric. But to our high joy, the line voltage is still symmetric. Therefore, the system can run one to two hours continuously with the single-phase ground fault. And if the fault last for a long time, PT may cause an explosion and insulator will flash out, which will expand the result and have a bad influence of the normal production and life of users. Therefore, rapid and accurate fault location is particularly urgent and important after single-phase ground fault happens.In accordance with the requirements of communication in distribution automation system, this paper compared and analyzed some communication modes which have been put to use, and then propose a single-phase ground fault locating communication mechanism based on GPRS after connect with respctive advantage and disadvantage of the communicatin mode. At first, this paper describe the GPRS technology and the related concepts. Combining with its own characteristics of GPRS, a briefly feasibility analysis is put forward. Secondly, the paper introduce the basic principle and the general strcture detailed of single-phase ground fault locating system in MV Power distribution networks. Besides, the paper decide to adopt the scheme of static IP address accessing mode through comprehensive compare of four different access solution, then design the entire system on the basis of this scheme. After the elaboration of the needs in single-phase ground fault locating system, the paper particularly describe from three parts of remote terminal, GPRS communication module and controlling center and elaborate GPRS wireless communication network, a defined communication protocol by myself, data frames, the data transmission basing on wireless network, the analysis of remote data and so on. Finally, the paper summarizes what have done and propose the prospect of it.