基于滑动平均滤波的三相并网逆变器多谐振控制器

In order to reduce the influence of high-order harmonic and grid side background harmonic on the power quality of grid current of the three phases LCL grid-connected inverter, this paper presents a multi resonance controller based on moving average filter (MR-MAF). Firstly, the controller is designed according to the frequency domain characteristics of MAF, so that it possesses the similar structure with the proportional integral multi resonance (PIMR) controller through mathematical equivalent substitution. Then, by introducing two adjustable coefficients, the MR-MAF controller can obtain the flexible adjustment of the control performance. Finally, the validity and the effectiveness of the proposed method are verified by simulation and experimental results. The results show that, compared with the traditional PIMR controller, the MR-MAF controller can not only parallel multiple resonant terms with the same dynamic performance, but also has the better steady-state performance, and the harmonic content is reduced from 6.8% to 4%. Therefore, the controller has much lower complexity when suppressing wide frequency band harmonics, which can provide reference for improving the control performance of three-phase grid-connected inverters in the multi-harmonic condition.