基于改进重复控制器的三相四线逆变器设计

Design of Three-phase Four-leg Inverter Based on Modified Repetitive Controller

提出一种基于改进重复控制器(modified repetitive controller,MRC)的三相四线逆变器设计方法,能够有效抑制非线性负载对输出电压的扰动。为解决重复控制器稳定性和控制性能之间的矛盾,在其补偿环节增加自由度-零相位滤波器;以误差衰减速率和滤波器的复杂度为优化目标,以系统鲁棒稳定性为约束,给出基于微粒群优化方法的零相位滤波器优化设计,构建基于鲁棒优化零相位滤波器的MRC。该MRC的优化设计考虑了系统的未建模误差,具有鲁棒性,更便于工业应用。三相四线逆变器采用载波调制,最大化利用直流电压,无需复杂的数据处理,易于实现。理论分析和试验结果证明了三相四线逆变器的MRC及其优化设计方法的有效性和可行性。

A design method based on modified repetitive control （MRC） for three-phase four-leg inverter was proposed,which can effectively suppress the output voltage disturbances caused by non-linear loads.To make better tradeoff between the performance and robustness of repetitive control,a low-pass filter with zero-phase-shift is added in the compensation unit to increase the freedom of repetitive control.The zero-phase-shift filter is optimized with the target of higher error attenuation rate and less complexity for the filter design.Robust stability for the system is taken into account as the restriction,and particle swarm optimization （PSO） is employed to optimize the filter.At last,MRC based on optimal and robust filter with zero-phase-shift was designed.In the proposed controller,error from system modeling is taken into account,so the controller is of great robustness,and it is convenient to be applied in industry.Carrier modulation strategy is used in the modulation layer for three-phase four-leg inverter,which maximizes the utilization of the DC voltage,and no more complicated data process is necessary.The theoretical analysis and experimental results on a prototype verify the correctness and feasibility of the proposed design method.