电容式CVT电压补偿电路研究

Research on Capacitive CVT Voltage Compensation Circuit

电容式电压互感器(CVT)动态性能较差,容易造成继电保护的误动作,此外,CVT的频率响应并不平滑,带宽也有限,使得其不适用于系统谐波测量。在此提出了一种降低CVT电压畸变和校正CVT动态响应及其稳态响应的新方法,设计了一种电子电路来模拟CVT瞬态过程,最终输出的CVT电压和设计电路电压的总和畸变相当低。该方法不依赖于负载和与CVT相连的铁磁谐振抑制电路。将所提方法的CVT百分比误差与动态补偿方法进行比较,仿真结果验证了该方法的有效性和准确性。

Capacitive voltage transformer(CVT)has poor dynamic performance and is prone to malfunction of relay protection.In addition,the frequency response of CVT is not smooth and bandwidth is limited,making it unsuitable for system harmonic measurement.A new method for reducing CVT voltage distortion and correcting CVT dynamic re-sponse and its steady-state response is proposed.An electronic circuit is designed to simulate the CVT transient process.The sum of the output CVT voltage and the design circuit voltage is quite low.This method does not rely on the load and the ferromagnetic resonance suppression circuit connected to the CVT.The CVT percentage error of the proposed method is compared with the dynamic compensation method.The simulation results verify the effectiveness and accuracy of the proposed method.