Development of Precise Capacitive Voltage Divider for Optical Voltage Transformer

In order to solve the enduring voltage problem of crystal materials in optical voltage transformers(OVT),a scheme is proposed based on distributed precise capacitive divider.The mathematical model of a high-voltage capacitive divider in power system is established in consideration of application environment of the transformer.Based on the relationship between the model and error characteristics of the capacitive divider,the impacts of error factors such as temperature changes,the stray capacitance and inter phase interference etc.to capacitive voltage dividers are particularly analyzed and synthesized.Based on above theory and error analysis method,a simulation is completed for 220 kV capacitor divider with the finite element software.The simulated results show that the accuracy of capacitive divider smaller than 0.1 percent if main capacitive value of capacitive divider is properly selected,which provides theoretical basis for designing capacitive divider.