基于保偏光纤模间干涉的光学电压互感器

Optical Voltage Transducer Based on Modular Interference in Polarization-maintaining Optic Fiber

为了满足高压及超高压电网对新型电压互感器的迫切需要,研究了一种基于保偏光纤模间干涉原理的高压电压互感器。用缠绕了保偏光纤的石英晶体圆柱作为电压传感头,被测电压通过石英晶体的逆压电效应来调制保偏光纤中2个低阶线性偏振模间的相位差,进而改变模间干涉输出光强的分布,通过探测模间干涉输出光强实现对被测高电压的测量。系统通过调整压电陶瓷的驱动电压使得模间干涉静态相位差为正交状态,并采取引入参考光路的方案剔除光源强度波动对测量精度的影响。实验研究结果表明,该互感器在额定被测电压附近能够达到0.2%的测量精度,能够同时反映被测高压的幅值和相位信息,满足高压测量领域对暂态变化的测量要求。

In order to satisfy the demands of high voltage transducer in high or extrahigh voltage power system,we studied an optical voltage transducer based on modular interference theory in polarization-maintaining optic fiber.The sensor head was designed with an optic-fiber-wrapped quartz crystal cylinder.The inverse piezoelectric effect of quartz crystal would modulate the modular phase difference of the polarization-maintaining optic-fiber so as to alter the distribution pattern of the modular interference output intensity.The high voltage applied on the quartz crystal was measured by detecting the modular interference output intensity which was modulated by the modular phase difference.In the transducer system,the static modular phase difference of modular interference was modulated to the quadrature status by adjusting the driving voltage on the PZT,and a reference arm was introduced to remove the light intensity fluctuations on the measurement accuracy.The experimental results show that the measurement accuracy of high voltage transducer based on modular interference is about 0.2% at the rated voltage.And the transducer can simultaneously acquire the amplitude and phase information of the high voltage,satisfying the transient demands of high voltage measurement domain.