发电机中性点接地装置等效电路的分析

分析了发电机中性点经配电变压器二次侧接电阻和消弧线圈两种方式接地的等效电路对外加电源型单相接地保护导纳判据的影响 ,指出忽略配电变压器或消弧线圈的激磁阻抗和漏抗降低了判据的准确性。考虑相应参数的影响因素能够提高接地故障过渡电阻值的计算准确度 ,进一步提高保护的灵敏度。试验结果验证了接地装置参数的影响

Analysis on the equivalent circuit of grounding equipments at the neutral of power generator

This paper analyzes the effect of different equivalent circuits of grounding equipment at the neutral on the protection of ground fault by injecting signal, and points out that the accuracy of protection scheme using admittance is reduced if the leakage reactance and exciting impedance of grounding transformer or extinguishing coil ignored. The accuracy of calculating transient resistance and the sensitivity of protection can be improved by considering these parameters. The experimental results verify the influence of parameters of grounding equipment.