调制器调制系数对光纤电流互感器测量精度的影响

Effect of Modulator Modulation Coefficient on Measuring Accuracy of Fiber Optic Current Sensor

叙述了采用集成光学调制器的光纤电流互感器的工作原理。在此基础上分析了集成光学调制器调制系数随温度变化对光纤电流互感器测量精度的影响,对其产生的测量误差进行了仿真。在四态波调制的基础上,提出了对调制系数引起的调制通道增益变化进行补偿的反馈控制方法,有效降低了调制系数变化引起的测量误差。试验结果与理论分析一致,表明该方法有效。该方法同时还可以有效减小调制器调制系数随时间长期变化对光纤电流互感器测量精度的影响。

The operation principle of the fiber optic current sensor with an integrated optic modulator is dealt with. The effect of modulation coefficient variation of the integrated optic modulator with temperature on the measuring accuracy is analyzed, and the scale factor errors are simulated. Based on the four-state square wave modulation, a feedback control method of compensating for the modulation channel gain variation resulting from the modulation coefficient is proposed, which effectively reduces the scale factor errors arising from modulator coefficient changes. The effectiveness of the method is shown by the consistency of experimental results with theoretical analysis. Moreover, this feedback control method can reduce the effect of long-term changes with time on the measuring accuracy. This work is supported by Basic Scientific Research Program of Commission of Science, Technology and Industry for National Defense （No. C032007C001）, China Aerospace Science and Technology Corporation and State Grid Corporation of China.