一种高压电网电压行波信号的提取方法

行波信号的有效提取是高压电网行波保护和行波故障定位的前提，针对传统电容式电压互感器不能传变暂态高频信号的缺陷，提出了一种电压行波信号的提取方法。利用电容式电压互感器或电流互感器的套管末屏电容，设计了电压行波提取电路，考查了其频率响应特性。利用EMTDC分别仿真了提取电路对不同频率段、不同故障初始角和不同故障电阻的暂态电压信号提取响应，理论分析和仿真结果表明:该方法能够有效地提取暂态高频信号，正确反映一次侧特定频带的电压行波特征，很好地解决了行波保护或暂态量保护及故障定位中暂态电压行波提取的难题。

Method for Extracting Transient Voltage Travelling Wave Signal from High Voltage Power Grid

It is essential to efficiently extract travelling wave signal for travelling wave based protection and fault location.Because the conventional capacitive voltage transformer(CVT) is not able to accurately transmit transient high frequency signal,a method for extracting voltage travelling wave signal is proposed.Using the tip capacitance of CVT or current transformer,the circuit which extracts voltage travelling wave signal is designed and analyzed.The output responses of extraction circuit for different frequency bands,different fault inception angles and different grounding resistances are simulated respectively with EMTDC.Theoretical analysis and simulation results demonstrate that this method can efficiently extract transient high frequency signals and properly reflect the characteristics of voltage travelling wave of primary side within specified frequency band.