中电阻法小电流选线的RTDS测试可行性分析

Feasibility Analysis Using RTDS for Small Current Line Selection Based on Medium Resistance Method

建立了基于实时数字仿真仪(Real Time Digital Simulator,RTDS)的中电阻法小电流接地系统仿真平台,设置了不同类型的单相接地故障。利用中电阻法原理分析了仿真结果。分析表明,利用中电阻法可以克服消弧线圈等因素的影响,短暂增大故障电流,有利于选线装置正确选出故障线路,分析得出的结论与仿真情况一致,证明了该仿真平台对于中电阻法选线装置的检验有一定的适用性和可信度,从而证明了将RTDS用于对中电阻法选线装置的性能检验是可行的。

The correctness of single-phase grounded fault line selection device is very low because of the complex distribution network structure. The apparatus for fault line selecting based on medium resistance method is one of the types of facilities used for practical applications in the neutral un-effectual grounded system（ NUS）. In order to achieve continuous improvement and development of NUS,it is necessary to conduct a comprehensive testing on its line-selecting performance. This paper introduces the basic principle of the line selecting method based on medium resistance method,establishes a NUS simulation platform for medium resistance method based on RTDS,and different types of single-phase grounding fault are set up. Simulation results are analyzed by medium resistance method. The analysis shows that the influence of Peterson coil can be overcame by medium resistance method,this method can increase the fault current for a short time,and is good for the fault line selection. This conclusion is in agreement with the simulation. This demonstrates that the simulation platform has certain applicability and credibility for testing such apparatus,and proves that RTDS is feasible for the performance testing of such apparatus.