Research On The Fault Location System For Phase-to-ground Fault In Power Distribution Network And Its Implementation

In our country, the lines in the power distribution network are long, much branched and complex.So failures happens on them frequently. At present, the fault location system based on fault indicator is able to realize fault location quickly, and it has a high degree of automation.However, sometimes the fault indicator refuses to act when there is a single-phase earthed fault in the distribution network, because of the difficulty of detecting the characteristic current and refusing to move. Therefore, in this paper, a new method of fault location for distribution network is proposed in this paper to improve the correct rate of the fault indicator.And this method can effectively improve the accuracy of the indication fault.In addition, MATLAB is used to analyze the fault phase judgment,the selection of the investment, the self starting criterion and the sensitivity influencing factors. And it will increase its sensitivity and anti-interference ability.In this paper,I have designed the control system of the new fault location me thod for distribution network.And the single chip microcomputer which is called S TM32F103BVT6 is set as the main control chip.I designed the data acquisition,ma n-machine interface, power conversion circuits, serial communication circuits and o ther circuits, and put forward the measures of anti-interference in the design proce ss.It will minimize the influence of the problem on the fault location due to the hardware of the control device.Finally, we carried out the further tests of the device by using dynamic simulation experiments,Our main test was the function logic, the system characteristic waveform and the correct rate of fault indicator in the dynamic simulation system. The results show that the device can adapt to the environment of the simulation in the dynamic simulation laboratory.After that, we conducted the artificial single phase grounding fault test of10 kV distribution line in Qujing Power Supply Bureau. Compared with the traditional method of transient fault indicator, the correct rate 30.23% higher and the error rate decreased by 9.8%.It shows that this new method of fault location in distribution network has good practical application effect.