摘要
在高压电气设备介质损耗角在线监测中,DFT算法用于介质损耗角(介损角)测量时,系统频率的波动所造成的非同步采样将会产生泄露效应,从而会影响介损角测量精度。文章详细地分析了DFT算法非同步采样造成的泄露效应,提出了一种基于Hanning卷积窗的DFT介质损耗角测量算法。该算法采用Hanning卷积窗对电流和电压信号进行加权,利用频谱相位差校正法进行频谱校正以获得基波相位,根据电流与电压的基波相位差计算出介损角。通过仿真给出了该算法在电压频率波动和白噪声变化时计算所得介损角的变化情况,通过分析验证了该算法的有效性。
In on-line monitoring dielectric loss angle of high voltage electric equipment, used in dielectric loss angle measurement, and the leakage effect of asynchronous sampling fluctuation power system will affect the measuring accuracy. In this paper, the leakage DI;T algorithm is always caused by the frequency effect of DFT algorith.m caused by asynchronous sampling has been analyzed in detail and a DFT algorithm of dielectric loss angle measurement based on Hanning convolution window has been presented. The current and voltage signals are weighted by Hanning convolution window, and the fundamental phase angles are calculated through the spectral phase difference correction method. The dielectric loss angle is calculated by the phase difference of the fundamental current and voltage, Relative simulations provide the changes of the dielectric loss angle with the voltage frequency and white noise changing. The analysis on the resultS verify the validity of the algorithm.
出处
《电测与仪表》
北大核心
2014年第16期73-77,共5页
Electrical Measurement & Instrumentation
