一种结合复三角函数和Hilbert变换的绝缘介质损耗测量方法

Dielectric Loss Factor Measurement Method Combined with Complex Triangle Function and Hilbert Transform

提出了一种结合复三角函数和Hilbert变换的绝缘介质损耗因数测量方法。将归一化工频电压信号和电流信号分别移相90°构成Hilbert变换对,再将两组复信号构造新的复三角信号模型,结合复三角函数和Hilbert变换特性,导出了tanδ的计算式,并给出了算法实现方法和硬件实现方案。仿真结果表明:该算法可有效解决由于频率波动引起的非同步采样和非整周期截断问题,tanδ实际测量的绝对误差小于0.000 03,具有较高的测量精度和抗干扰能力。

A kind of dielectric loss factor measurement method combined with Hilbert transform and com- plex triangle function was proposed. A Hilbert transform pair was built through a 90° phase-shift of pow- er frequency voltage and current signals, respectively. A new complex triangle signal model was construct- ed by the two signals. A formula for tariff was deduced based on the features of complex trigonometric and Hilbert transform, and a scheme for the algorithm and hardware implementation was given. The simu- lation results show that the algorithm can effectively solve the asynchronous sampling and non-integral pe- riod truncation problems caused by fluctuations of frequency. The absolute error of actual measuring tanδ is less than 0.00003, indicating a high measuring accuracy and anti-interference ability.