谐波分析法介质损耗因数测量的误差分析

Error Analysis for the Dielectric Loss Factor Measurement Based on Harmonic Analysis

用谐波分析法进行介损测量时 ,很容易受到系统频率波动的影响 ,从而降低测量的准确度。本文在分析该算法误差机理的基础上得出了频率波动下引起测量误差的两个主要因素 :信号初相角的差异和谐波干扰 ,并据此提出了解析变换和低通滤波两种信号预处理方法。数值仿真表明改进的谐波分析算法具有良好的效果 。

The accuracy of the dielectric loss measurement based on harmonic analysis algorithm is greatly influenced by the frequency fluctuation. Based on theoretical analysis, it was shown that the effect of the initial phase angle and disturbance of harmonic wave are the two main reasons caused the errors of algorithm. In order to reduce measuring errors, the preprocessing method of the analytical transformation and the low pass filter applying to the input signals is proposed, and the better results with this new method are proved later by numerical simulation and practical test in field.