换流阀触发光纤故障分析与电场仿真

由于光纤具有抗电磁干扰，高带宽，高绝缘等特性，在换流阀通讯和晶闸管触发中，占据重要的地位。针对换流阀触发光纤故障的现场实例，本文首先通过对光纤故障点处宏观及微观的形貌分析，确定了光纤故障类型为局部放电，随后利用有限元法对换流阀屏蔽罩及光纤进行了等比例建模及电场计算，分析了光纤故障点处出现局部放电的原因。结果表明，当光纤轴向电阻率分布不均匀时，易与相邻光纤发生局部放电；当光纤在安装过程中，没有被光纤盖板钳制电位时，光纤与盖板之间极易发生局部放电。本文结果可为换流阀触发光纤的安装提供一定的技术支持。

Fault Analysis and Electric Field Simulation of Converter Valve Optical Fiber

Due to the characteristics of anti-electromagnetic interference, high bandwidth and high insulation, optical fiber plays an important role in converter valve communication and thyristor trigger. Based on the factual example of the optical fiber fault, the optical fiber fault type is determined as partial discharge by analyzing the macroscopic and microscopic morphology of the optical fiber fault point, firstly. Then, the proportional models of converter valve shield and optical fiber are build by using the finite element method, and the electric field distribution is calculated. The causes of partial discharge at the optical fiber fault point are analyzed. The results show that when the axial resistivity distribution of the optical fiber is uneven, partial discharge is easy to occur with the adjacent optical fiber. When the optical fiber is not clamped by the optical fiber cover plate during installation, partial discharge is very easy to occur between the optical fiber and the cover plate. The results of this paper can provide some technical support for the installation of optical fiber.