基于频率自适应广义积分控制器选择性谐波电流控制策略

Selective Harmonic Current Control Strategy Based on Frequency Adaptive Generalized Integrators

为提高有源电力滤波器的补偿性能,提出一种基于频率自适应广义积分控制器的电流控制策略。在两相静止坐标系下,对基波和某些指定次谐波分别设置对应的广义积分控制器,利用其无穷大开环增益和频率选择特性,实现谐波电流的无静差和选择性跟踪补偿。控制器采用直接离散域设计,避免数字化过程引入控制器性能偏差或偏谐。广义积分控制器频率自适应策略是通过保持基波周期采样点数恒定方式实现,保证电网频率波动情况下,控制器仍能对各次谐波实现高增益和选择性。实验结果验证所提出控制策略的有效性。

To improve the compensation performance of three-phase shunt active power filter （APF）, a novel current control strategy is proposed based on frequency adaptive generalized integrators （GI）. The method employs an array of generalized integrators, one for the fundamental, and one for each harmonic, implemented in stationary frame. Because of the characteristics of the GI of the infinite open loop gain and high selectivity, zero steady-state error and selective compensation of harmonics are achieved. The proposed controller is designed directly in Z-domain in order to eliminate the unexpected loss of gain and detuning of GI during digitalization processing. The frequency adaptive of the GI is realized by keeping the number of samples per fundamental fixed, and high compensation precision at the each harmonics in the presence of grid frequency variation is achieved. The effectiveness of the control scheme proposed is verified completely by experimental results.