基于迭加原理的CVT暂态特性校正新方法

A New Method of Correcting Transient Characteristics of Capacitive Voltage Transformer Using Principle of Superposition

高压和超高压电力系统中广泛使用电容式电压互感器(CVT),但在电网短路时其暂态特性较差,变换误差很大。本文首次提出了一种基于迭加原理和CVT数字模型对其暂态特性进行校正的新方法,可在电网故障时为高压电网快速保护和测距装置提供准确的电压信号。文中给出的数字仿真结果,证明了本方法的有效性。

The capacitive voltage transformers （CVT） have been used widely in high voltage and ultrahigh voltage power systems, but CVT＇s transient impacts still puzzled many protection engineers up to now. In order to solve this problem, a method of digital emendation is proposed in the paper, which is employed to improve the CVT transient characteristics by using the digital signal technique based on the CVT model and the principle of superposition. The emended CVT output can be used as voltage inputs of microcomputer protective devices, fault location devices and others. Finally, the validity of the method proposed in the paper is proved by the result of digital simulation.