Analysis and Design of Loop Gains to Optimize the Dynamic Performance of Optical Voltage Sensor Based on Pockels Effect

A design method of loop gains is proposed for improving the fast dynamic tracking performance of optical voltage sensor (OVS) based on Pockels effect. The distribution principle of loop gains is investigated in theory according to the characteristics of closed-loop error of OVS. Based on the obtained distribution principle of loop gains, the hardware circuit and the control parameters of the controller are designed to improve the signal to noise ratio (SNR) of closed-loop error and the dynamic performance of OVS, respectively. The experimental results demonstrate that the system can achieve the high dynamic performance under the high detection precision: OVS can accurately track 13th harmonic with 1.57% measurement error and 4.24° phase error, and the long term steady accuracy of power frequency voltage is within ±0.1%. The experimental results validate the effectiveness of our new design method of loop gains.