站用变压器用电流互感器变比选择研究

Research on Transformation Ratio Selection of Current Transfer for Auxiliary Transformer

为了同时满足测量精度和继电保护整定的需求,站用变压器高压侧电流互感器变比选择常常面临困难。通过分析站用变压器保护的配置和整定原则,结合保护装置精确工作电流范围,计算出了电流互感器变比的上下限范围。在此基础上,通过分析电流互感器测量、保护绕组的变比关系得出了常用10 kV、35 kV站用变压器保护和测量的变比推荐值,以便工程实际应用。

In order to satisfy the requirements of measurement accuracy and relay protection setting simultaneously, the transformation ratio selection of current transformer in high voltage side of auxiliary transformer is a common problem faced in projects. Based on the research about the principle of relay protective configuration, the setting calculation of protection relaying and the precise work current range of protection devices, the upper and lower limits for the transformation ratio of current transformer are derived. And then, by analyzing the relationship between measuring winding and protection winding, the recommended transformation ratios of measuring winding and protection winding used in high voltage side of 10 kV and 35 kV auxiliary transformer are given for practical using.