改善OVT内电场分布的介质包裹法

基于Pockels效应的光学电压传感器（Optical Voltage Transducer，OVT），运行中不可避免地存在震动、元器件连接的老化与热胀冷缩等问题，导致光学器件的相互位置产生偏移，进而影响电光晶体的内电场分布。文中以基于会聚偏光干涉原理的110 kV纵向调制的OVT为例，进行了仿真分析与实验研究，发现当入射光发生0.5的偏移或电光晶体发生1的偏移时，分别引入约0.107%和0.124%的电场积分误差。由于OVT必须满足0.2%的准确度要求，上述影响不容忽视。为此提出了介质包裹法，将Al2O3陶瓷包裹在电光晶体外部，使电场积分误差分别降低至0.001%和0.003%。实验与应用的情况表明，介质包裹法简单、实用、有效。

Medium enwrapping method for improving internal electric field distribution of OVT

There are some inevitable problems such as vibration, instable connection between the optical elements, hot expansion and cold contraction in the practical application of optical voltage transducer (OVT) based on Pockels effect. These factors cause the deviation between the optical elements, which affects the internal electric field distribution in the electro-optic crystal. The OVT based on convergent polarized light interference was adopted as an example. The simulation analysis and experimental research show that when the incident light has a 0.5 deviation or the BGO crystal has a 1 deviation, it leads to electric field integral errors of about 0.107% or 0.124%, respectively. As the OVT needs to guarantee the accuracy of 0.2%, the effect induced by the electric field integral errors cannot be ignored. Therefore, a new method of medium enwrapping was proposed and the alumina ceramic was selected as the medium to wrap out of the electro-optic crystal. So that the maximum electric field integral errors can be reduced to 0.001% or 0.003% respectively. The experimental result and its applications show that the medium enwrapping method is simple, practical and effective.