基于并联滤波器的电压闪变检测

Detection of voltage flicker based on parallel filter

依据最小方差原则和梯度下降方法,经过旋转变换,得到二维线性自适应跟踪器,组成频点和带宽可任意设定的一致指数稳定的并联梳状ⅡR滤波器,分析其频率特性。该滤波器可提取电力信号中的已知频率的谐波和间谐波,获得基波幅值的准确跟随。再用另一个并联滤波器分析基波幅值跟随信号,提取基波电压的恒定值和多个波动分量,对电压波动进行加权滤波、平方、平滑滤波后得到瞬时视感度。算法抑制了间谐波造成的平方解调法检测闪变度的误差,具有较好的均值统计意义下的抗干扰性能。通过仿真比较说明了算法的有效性。

The frequency characteristic of a linear uniformly and exponentially stable parallel comb IIR filter with adjustable frequencies and bandwidths is presented, which is composed of two-dimension adaptive trackers derivedby circumrotation transform from Least Mean Square and Grads Descent Algorithm. When it is used to ana- lyze power signal with harmonics and inter-harmonics of known frequencies, every components and their amplitudes can be closely tracked. The constant and fluctuations of voltage can be detected when the tracked fundamental amplitudeis further analyzed by another comb filter. The instantaneous flicker sensation level is calculated after the fluctuations is weighting filtered, squared, and smoothed. The error of severity flicker obtained by square demodula- tor caused by inter-harmonics is reduced in proposed algorithm, and good anti-jamming performance is achieved in mean statistic. The performance is verified by comparative simulations.