改进相关系数法在介质损耗角测量中的应用研究

Improvement of correlation coefficient calculating algorithm for dielectric loss angle measurement

针对相关系数法计算介质损耗角时,谐波和直流分量对所测量值的计算结果影响较大的问题,提出了先对信号进行陷波处理,再用相关系数法计算介质损耗角的方法。仿真结果表明,该方法计算介质损耗角时的误差,较单独使用相关系数法时减少18%以上,克服了谐波及直流分量的影响,提高了相关系数法测量介质损耗角的精度。该改进方法测量介质损耗角更加准确,为绝缘在线监测系统测量电容型设备介质损耗角提供了科学准确的测量方法。

For measuring dielectric loss angle, the deficiency of using correlation coefficient calculating is analyzed and a new method of improving correlation coefficient calculating is presented,which has advantage of high precision, but without the influence of harmonics and dc component. This new method by firstly designing a notch filter to process the signal and secondly using the correlation coefficient calculating to calculate the dielectric loss angle, is testified to have a good effect on improving measuring accuracy through simulation results. The error of dielectric loss angle calculated by this way is reduced more than 18% than the former one. The improved method offers a reliable scientific measurement method for on-line monitoring system to measure dielectric loss angle of capacitive equipment.