High accuracy optical voltage transformer with digital output based on coaxial capacitor voltage divider

The voltage transformer based on capacitor divider is susceptible to stray capacitance and Bi4Ge3O12 crystal is sensitive to temperature, which leads to the decrease of measurement precision. To solve these questions, a kind of temperature self-healing optical voltage transformer based on the coaxial capacitor is proposed in this paper. By using coaxial capacitor divider structure instead of the traditional capacitor divider structure, and using a reference light path to achieve the function of temperature self-healing, the measurement accuracy of the optical voltage transformer can be improved. The theoretical analysis, modeling and simulation of several key technologies of coaxial capacitance are presented. Simulation and experimental results show that the temperature self-healing optical voltage transformer based on coaxial capacitor structure meets the requirements of the 0.2 class accuracies.