摘要
在高压电气设备介损角在线监测中,由于存在工频周期信号的非同步采样和截断现象,从而造成利用FFT算法计算介损角产生较大的误差。本文分析了非同步采样造成的FFT算法的泄漏效应,提出了一种基于相关Blackman窗的FFT介损角测量算法。该方法采用相关Blackman窗对系统电流与电压信号进行加权,然后利用频谱相位差校正法进行频谱校正以获得基波相位,最后根据电流与电压的基波相位差来计算出介损角。仿真结果表明该算法有效地克服了非同步采样和截断造成的介损角测量误差,并且能够大大降低信号频率波动、高次谐波对介损角测量精度的影响。
In on-line monitoring dielectric loss angle of high voltage electric equipment, the FFT algorithm brings significant errors because of asynchronous sampling and the truncation of power systems frequency signal. In this paper, leakage effect of FFT algorithm caused by asynchronous sampling is analyzed, a FFT algorithm of dielectric loss angle measurement based on correlation Blackman window is presented. Firstly, the power systems current and voltage signals are weighted by the correlation Blackman window. Then, the fundamental phase angles are calculat- ed with spectral phase difference correction method. Lastly, the dielectric loss angle is calculated by the phase difference of the fundamental current and voltage. The simulation results show that the proposed algorithm can effectively overcome dielectric loss angle measurement errors because of asynchronous sampling and the truncation of power systems frequency signal, and improve measurement accuracy of dielectric loss angle greatly under such conditions as power systems signal frequency fluctuation and higher harmonics.
出处
《电工电能新技术》
CSCD
北大核心
2015年第4期43-48,共6页
Advanced Technology of Electrical Engineering and Energy
关键词
介损角
FFT
非同步采样
泄漏效应
相关Blackman窗
频谱校正
dielectric loss angle
FFT
asynchronous sampling
leakage effect
correlation Blackman window
spectrum correction
