光学电压传感器分压结构的缺陷及改进方法

现有的光学电压传感器多基于光功率检测模式，其测量范围与测量灵敏度受到电光晶体半波电压的限制。纵向调制的多片晶体叠层结构可以解决半波电压限制的问题，但仅适用于1 000 kV电压等级。此外，仿真结果表明这一结构中晶体内的电场分布极不均匀，受震动与热胀冷缩等因素的影响，光路或晶体的相互位置易产生偏移而引入积分电压误差。文中以110 kV电压等级为例，对多片晶体叠层结构进行了改进，简化了传感系统的结构，并将MgTiO₃陶瓷按照一定的要求安装在锗酸铋(BGO)晶体的外部以改善晶体的内电场分布，可以把积分电压误差从0.275%降低至0.01%以下。改进后的结构可用于各种电压等级。最后，通过实验验证了新方法的有效性。

Defects and Improvement Methods of Voltage Division Structure of Optical Voltage Sensor

The measurement mode of existing optical voltage sensor is mostly based on optical power detection, so its measurement range and sensitivity are limited by the half-wave voltage of electro-optic crystal. The multi-segmented Pockels sensor can fix the problem of limitation of the half-wave voltage, but only for 1 000 kV voltage level. In addition, from the simulations the electric field distribution in the crystal is un-uniform and the optical path and crystal slices are deviated easily by vibration and thermal expansion and contraction in this configuration, which results in measurement error. Therefore, the multi-segmented structure is improved at 110 kV voltage level. The sensing system is simplified and the MgTiO₃ ceramic is used to wrap around the crystal to improve the electric field distribution in the crystal, so that the error reduces from 0. 275% to 0. 01% or less. The improved structure is applicable to various voltage levels. Finally, the validity of the proposed method is verified by the experiment.