| Distribution networks play an important role in ensuring a continuous supply of electricity, which is closely linked with the thousands of families. With modern technology and the development of industrial production, the reliability of electricity supply has higher requirements. Therefore, to ensure reliable operation of distribution network is necessary.In China, most of the 6～66kV distribution systems adopt the non-effectively grounded mode. According to statistics, in the non-effectively grounded system, the single-phase grounding fault occurred in the highest rate with weak fault signals. So how to select the fault line according to the weak fault signals quickly and accurately has been a long-standing issue.Firstly, this article introduces how the voltage and current change regularly when a single-phase grounding fault occurs in the non-effectively grounded system. And then, it gives a brief introduction of several line selection methods based on the steady-state and transient, and chooses five of them after comparing and analyzing these methods. Afterwards, for different types of single-phase grounding fault, distribute a reasonable value for each method of the five, and so a new integrated approach for selecting the fault line comes about, which makes the fault line selection more reasonable, more accurate and more versatile. In addition, in the PSCAD / EMTDC simulation platform, set up a small distribution system model, compile some corresponding line selection algorithm process, and complete the relevant interface operation with MATLAB, and then carry out a large number of simulation studies of the single-phase grounding fault respectively under the pattern neutral are isolated or grounded via Peterson coil. Finally, it analyzes the results of the simulation and the line selection and verifies the accuracy and reliability of the synthesis for fault line selection, and put forward improvement and perfection response to the problems of the algorithm.In this paper, we observed the conditions of the outside line on the accuracy of the election, and proved that the integrated algorithm stability, versatility and feasibility through all cases of single-phase ground fault of the simulation. |
