有源电力滤波器(APF)电流检测算法使用低通滤波器(LPF)提取基波有功直流分量,直流分量的提取精度直接影响着指令电流信号的计算精度。提出一种应用数字递推最小二乘法(RIS)替代模拟LPF的电流检测新方法。RIS自适应滤波算法是在采样周期内对整体采样序列进行滤波器权系数最优化搜索,即对权系数迭代中的步长寻优,从而准确地跟踪输入信号的直流分量。新方法以瞬时无功功率理论为电流检测依据,利用坐标、三角变换矩阵根据电网三相瞬时电流计算出电流瞬时有功、无功交/直流分量。应用Matlab软件编写RLS自适应滤波算法程序进行仿真,结果表明APF由,流检测中采用教牢RTS自适应滤波提取育流分号的方法是可行、有效的。
The DC component of fundamental active power is extracted with LPF(Low Pass Filter) in the current detection of APF(Active Power Filter) and the extraction precision influences directly the calculation precision of reference current. A current detection method using digital RLS (Recursive Least Squares) to replace LPF simulation is presented. In the adaptive RLS filtering algorithm,the weight factor of filter is optimized to precisely follow the DC component of input signal for whole sampling sequences within the sampling period,namely the step length optimization of weight factor iteration. The new current detection algorithm is based on instantaneous reactive power theory,and the AC or DC component of active power and reactive power is calculated from the three-phase instantaneous currents using coordinate transformation and trigonometric function transformation. Simulations with Matlab demonstrate that,the proposed filtering scheme is feasible and valid for APF.