Open-loop optimization method based on the GRU and dual-grating demodulation principle for a PZT based optical voltage sensor

Distributed online monitoring of grid voltage is crucial for ensuring power quality, providing a foundational data layer for effective grid management. Piezoelectric grating optical voltage sensing presents a cost-effective solution with high bandwidth and long-distance transmission capabilities. This paper introduces an open-loop optimization approach that leverages the gate recurrent unit (GRU) and dual-grating demodulation principles to enhance the real-time response accuracy and extend the measurement range of piezoelectric-based optical voltage sensors. Experiments conducted within a 2.8 kV sensing range analyze the voltage response and spectral characteristics. After applying corrections, the sensor achieves a linearity of 99.93%, with a maximum deviation of 2.07% and a maximum hysteresis of 3.33%. This method significantly enhances real-time response accuracy and optimizes the utilization of the sensor’s nonlinear measurement range, advancing the application of optical voltage sensors in power grids.