The Study Of Single-phase-to-ground Fault Section Location In Distribution Network Based On The PLC Technology

Neutral point non-effectively grounded system or neutral point earthed via arc-suppression coil is wildly adopted by medium-voltage power distribution network in our country. Single-phase grounded fault happens most frequently in the non-solidly earthed network with the probability up to 80 percent .When single-phase to earth fault occurs in a non-solidly earthed network, the fault current is small and the three phase line to line voltages are still symmetric since no short-circuit loop is formed, the load can keep on running for a period of time. But when the fault happened, the non-faulted phase voltage would increase and intermittent are grounding would lead arc over voltage, and the insulation would be damaged in long time running, therefore the system result in more serious phase-to-phase voltage. So single-phase to earth fault should be removed immediately. In case of the fault can’t be removed in time, the fault line and fault point should be detected quickly. The fault device should be removed as soon as possible after the necessary load transferring.Regarding the difficult problems started above, the thesis thoroughly researched and analyzed the stable and transient features of single-phase-to-ground fault in neutral non-effectively earthed system in theory, found the right fault features, put forward a fault section location algorithm, constructed a simple theoretical model to verify and simulation experiments with MATLAB. Then designed the overall system architecture of single-phase-to-ground Fault section location in distribution network Based on the PLC (Power Line Carrier) technology, introduced the basic structure of distribution network, the design of on-line monitoring and measuring module, distribution network carrier communication, as well as host control and processing system; Finally, put forward the system’s software processes.