HVDC直流场强仪相敏检波器分析与设计

地面合成电场是高压直流（HVDC）输电线路电磁环境的一个重要指标,测量该电场时需要同时测量其大小和极性。一般测量电场极性的方法是使用相敏检波器。传统的相敏检波器存在因相位不同步而导致检波误差较大的问题,影响了测量结果的准确性。本文从直流场强仪的原理出发,针对传统方式的弊端,设计了相敏检波器电路,基于该电路的工作原理分析了相位不同步所引起的检波误差,并采用全通滤波器补偿相位差。实验证明,该电路能够灵活、准确地补偿相位误差,从而解决传统设计方法中相位不同步的问题,实现了全波检波,进而分辨电场极性,满足了地面合成电场测量的需求。

Analysis and Design of Phase Sensitive Detector in HVDC Field Mill

Electric field detection is one of the most important items in HVDC electromagnetic environment detection.To solve the problem of distinguishing the polarity of this field,phase sensitive detector is used.In this paper,based on the theory of field mill,a new kind of phase sensitive detector is designed.The detecting error due to out phase is discussed,and all-pass filter is used to compensate the phase error.Experiment proved that this circuit can compensate the phase error accurately and flexibly,achieve full-wave detection,and make out the difference of positive and negative electric field.