DESIGN AND TEST OF OPTICAL VOLTAGE TRANSFORMER

The optical voltage transformer(OVT)based on Pockels effect of Bi4Ge3O12 crystal is developed. The structure of OVT and the principle of sensor are described in this paper. The temperature stability and time stability of sensor are tested. The accuracy of sensor is within the range from -0.4% to 0.4% while the temperature range is from 0C to +45C, and within the range from -0.3% to 0.3% while the time interval is 20 days. 220kV OVT prototype has passed the type tests such as accuracy, capability of insulator and the electromagnetic compatibility. The result shows that OVT prototype meets the expectant specification.