220kV电子式电压互感器带电校验系统研究

电子式电压互感器(EVT)的常规校验方法为离线校验,这需要复杂的停电操作并带来较大的经济损失。文中研究了220 k V EVT带电校验系统,包括标准通道、被校通道和基于PC机的校验系统。提出自适应全相位DFT电参量提取算法,精确计算电网频率,自适应调整DFT运算点数,将非同步采样近似为同步采样。设计了一套电容标准器全绝缘举升接入装置,通过无线遥控实现标准互感器带电接入,并进行安全性仿真分析。试验表明,该系统比差小于0.05%,角差小于2',且可保证标准互感器安全接入与退出,满足0.2级电子式互感器在线校验要求。

Research on on-site calibration system of 220kV electronic voltage transformer

The normal calibration method of electronic voltage transformer (EVT) is offline calibration, and it requirescomplex outage switching operations which will bring large economic losses .This paper studies on-site calibrationsystem of 220 kV electronic voltage transformer, including standard channel, calibration channel and calibrationsystem based on PC.An adaptive full-phase DFT algorithm is proposed to calculate electric parameters accurately , extractthe frequency of the grid accurately, adjust the DFT operation points, and approximate the non-synchronous samplingto synchronous sampling.In this paper, a set of standard capacitor fully insulated lifting access device is de -signed, which is operated by wireless remote control , and the security simulation analysis is carried out.Test showsthat the system ratio error is less than 0.05% and phase error is less than 2′, and it ensures the security of capacitorstandard's access and exit, which meets the requirement of 0.2 class electronic transformer online calibration system.