1.China Southern Power Grid Research Institute;2.Guangxi Power Grid Co., Ltd. Electric Power Research Institute
Since most of the traditional measurement methods for the ground parameters of the distribution network are mainly aimed at the accurate measurement of the ground capacitance of the distribution network, the measurement of the leakage resistance to the ground is not accurate, and it cannot eliminate the harmonic elimination resistance and voltage during the measurement of the ground parameters. The influence of the internal impedance of the transformer causes a large error in the measurement result; at the same time, the traditional measurement method cannot be widely applied to the situation of different system grounding methods, and the actual application is relatively inconvenient. To this end, this paper proposes a method for measuring the leakage resistance of the distribution network to ground based on zero sequence voltage regulation, and selects a suitable tap tap grounding on a special Y/△ connection grounding transformer with tap taps external to the distribution network , Obtain a smaller zero-sequence voltage, measure the zero-sequence current of the system at this time, and calculate the leakage resistance of the system to ground by calculating the voltage and current values ??obtained. The PSCAD/EMTDC simulation software is used to simulate and analyze the proposed ground leakage resistance measurement method. The measurement results obtained have small errors and are suitable for different system wiring methods. This indicates that the method has high measurement accuracy, wide applicability, and is safe and economical. , Easy to use.