偏振器对比较式光学电流互感器性能的影响

使用偏振态分析工具,分析了偏振器性能--偏振度、消光比的不完善以及偏置角误差等因素对比较式光学电流互感器性能的影响.结果表明,由于双输入双输出的特殊传感头结构的采用,使得比较式OCT可以有效克服偏振度和消光比的不完善带来的不利影响,但是传感头的起偏器与检偏器之间的偏置角误差会对比较式OCT的性能产生较大的影响.可以采用改进工艺精确调整偏置角、增大参考直流磁场和软件修正等措施加以改进.对改进后的比较式OCT进行了实验,实验结果表明在50℃的温度变化范围内,互感器的误差变化量仅为0.7%,较之采用比较式补偿之前的误差变化量16%,温度性能得到了显著的提高.

Effects of Polarizer on Performance of Comparative Optical Current Transformer

The effects of polarization degree, extinction ratio and bias angle error of polarizer on performance of comparative Optical Current Transformer (OCT), were analyzed in detail by employing polarization analysis tools. The theoretical analysis result shows the comparative OCT can eliminate the influence of nonideal polarization degree and extinction ratio because of the sensor’s dual-input and dual-output structure, while the bias angle error brings great damage to the performance of the comparative OCT. This disadvantage can be decreased by adjusting position between polarizer and analyzer exactly and increasing reference DC magnetic field or correcting software. The experiment of comparative OCT is carried out, and the test result shows that the change of error of the comparative OCT is only 0.7% in the range of 50℃ temperature, while the change of error of an ordinary OCT is more than 16% before comparative compensation. Moreover, the temperature characteristic of comparative OCT is much more excellent.