利用模间干涉原理的电压互感器仿真

为了满足电力工业发展对高压电压互感器的要求,设计一种新型的光纤电压互感器成为国内外的研究热点,故在理论分析光纤内光模场分布特点后用MATLAB仿真研究了光纤的模间干涉现象,给出了理想情况下LP01模和LPe1v1en模之间干涉光强的分布与光纤轴向长度变化之间的关系;在分析了石英晶体的压电特性基础上,提出了一种采用石英晶体逆压电效应和椭圆芯保偏光纤模间干涉原理的电压互感器设计方案,给出了相应的数学模型;通过仿真研究,得到了该方案的线性测量范围及调节方法。该设计方案光路结构简单,抗干扰能力强,是光学电压互感器设计的一种新思路。

Simulation of Voltage Transducer Using Interference Between Modes

In order to satisfy the demands of high voltage transducer in modern power industry,designing a novel optic fiber high voltage transducer is focused on.The mode field distribution characteristic of optic fiber is analyzed theoretically.The interference phenomenon between modes in optic fiber is simulated with MATLAB.It shows that the light intensity of two output lobes from optic fiber exchanges with each other.This intensity variation is typically sinusoidal with respect to phase difference between two modes.A three-dimensional simulation result figure of relationship between interference of LP01 and LPeven11 mode and the axial length variety in ideal fiber is plotted.After analyzing the quartz crystal's characteristic,a novel scheme of voltage transducer based on interference between modes and converse piezoelectric effect of quartz crystal is put forward.This scheme sandwiches three optic fiber wrapped quartz crystal cylinders with four pieces of metal electrodes, and the high voltage is applied on the metal electrode.The quartz crystal cylinder is cut with bottom and top circle surface perpendicular to a two-fold axis of quartz crystal.After the mathematic model of the transducer is deduced,a mathematic result for evaluating the linear range and adjusting method is given.In the method,a PZT is introduced to adjust the static phase difference between LP01 and LPeven11 mode in fiber.This scheme has some advantages,such as simple light path,immunity to circumstance disturbance,low cost,wide bandwidth,without danger of exploding,etc.This configuration is a new technique for high voltage transducer's design.