电子式电压互感器中的相位补偿研究

Phase Compensation Scheme for Electronic Voltage Transformer

针对基于电容分压原理的电子式电压互感器的相位误差,提出了相位补偿方案。分析了二次分压电阻引入相位误差的大小,设计了组合相位补偿电路对该相位误差进行补偿。研究分析了相位补偿电路在不同工作点时随频率和温度的变化特性,结果表明,通过选取合适的单元移相电路工作点,使移相电路对频率的依赖性最小、受温度的影响也最小。该相位补偿技术已成功应用于电子式电压互感器。其型式试验结果表明,互感器的整体性能在-40～40℃时,比差和角差准确度达到了0.2级的要求。

Aiming at the phase error of the electronic voltage transformer（EVT） with capacitive divider, a phase compensation scheme was proposed. By analyzing the quantity of the phase error induced by secondary resistive divider, a combined phase compensation eireuit was designed to compensate this phase error. The performance variation of the phase compensation circuit with frequency and temperature at different operation point was investigated, and the result showed that appropriate operation point of the phase compensation circuit significantly reduced the effects of frequency and temperature. This phase compensation technology has been used successfully in EVT. The type tests showed that the magnitude error and the phase error of EVT reached IEC level 0.2 under the temperature ranging from -40 ℃ to 40 ℃.