基于卡尔曼滤波误差的电能质量扰动检测

检测电压或电流波形畸变时刻对扰动波形捕捉、电能质量扰动类型分类、暂态数据压缩等都有重要意义。为了更准确地检测电压或电流波形畸变发生时刻,提出了由线性卡尔曼滤波器的误差序列来实时检测电能质量扰动的时域方法。它根据误差序列的突然变化来确定扰动发生的时刻。此模型下卡尔曼滤波器增益系数K、误差协方差矩阵P与测量数据无关,可以离线计算,计算量小。基于PSCAD/EM TDC和M atlab的仿真表明此方法能准确定位电压跌落/上升及电容器投切等引起的暂态过程的起止时刻,并且对系统频率偏移有鲁棒性。误差序列的计算可以在两采样点之间完成,可用廉价的DSP芯片实现电能质量的实时检测。

Power Quality Disturbances Detection Based on Kalman Filter Residuals

It is meaningful to detect the transient points when voltage and/or current undergo(s) sudden changes for distorted waveforms capture,disturbance events classification,data compression and so on.Real-time disturbances detecting technique in time domain is proposed using the residual error sequence of linear Kalman filter.Since the gain coefficient K and the error covariance matrix P are constant which can be calculated off-line,the computing burden is reduced remarkably.The simulation results based on PSCAD/EMTDC and Matlab demonstrate that the approach can exactly determine the start and the end point of the transient caused by voltage sag/swell and capacitor switching.It is robust enough to system frequency variation within a certain range.The computation of error sequence can be accomplished between two samplings,and the technique can be used for on-line applications with low cost DSP.