Analysis on the Optimization of High-Frequency Performance for Optical Voltage Sensors Based on Pockels Effect

A novel closed-loop signal detection method is proposed to optimize the high-frequency performance of the optical voltage sensors (OVSs) based on Pockels effect. First, a timing sequence control method is introduced to accomplish the whole closed-loop process within one transit period of the optical propagation path, which can ensure the system high dynamic response with high-frequency signal input. Then, we investigate the frequency spectrum of closed-loop error, and design the signal processing before the closed-loop controller with a low pass filter to enhance the signal to noise ratio without reducing the system bandwidth. Furthermore, considering the optical parameter uncertainty and the unavoidable external disturbance, a closed-loop control algorithm is presented to optimize the steady state accuracy and dynamic performance of OVSs. The experimental results show that the closed-loop steady state accuracy of sine response, slope response, and acceleration measurement with the 20-kHz input signal are basically consistent with the static accuracy, and the relative measurement error of OVS is ±0.1% with the applied voltage over 100 V, which verify the effectiveness of the proposed detection scheme.