基于三角自卷积窗的介损角测量算法及应用

Dielectric Loss Angle Measurement Algorithm and Application Based on Triangular Self-Convolution Window

非同步采样条件下采用快速傅里叶变换(FFT)进行介损角测量时,频谱泄漏和栅栏效应造成的误差较大。本文提出了一种基于三角自卷积窗频谱相位差校正的介损角测量算法,介绍了其在高压电容型设备绝缘在线监测系统中的应用。三角自卷积窗具有良好的旁瓣性能,采用三角自卷积窗对信号进行加权能有效减少频谱泄漏对介损角测量的影响;基于三角自卷积窗的频谱校正算法不需求解高次方程,计算量小。在非同步采样情况下,通过对基波频率波动、采样频率变化、介损角真值变化、白噪声影响、谐波变化等情况下的介损角仿真测量实验和实际应用验证了本文算法的准确性和有效性。

With non-synchronization sampling, the spectral leakage and picket fence effect have great influence on the performance of dielectric loss angle measurement when using FFT. A phase difference revise algorithm for dielectric loss angle measurement is presented based on triangular self-convolution window （TSCW）, and the application in on-line dielectric loss angle monitoring of high voltage capacitive-type equipment is introduced in this paper. As the triangular self-convolution window has good side lobe behavior, the new algorithm can improve the accuracy of dielectric loss angle measurement by weighting the signal with TSCW. The simulation and application results, which include fundamental frequency fluctuation, changing of sampling frequency, real value of dielectric loss angle variance, white noise, changing of harmonic component verify the effectiveness and practicability of the algorithm.