三相PWM逆变器鲁棒重复控制策略

摘要

A robust repetitive control ( RRC) strategy is proposed for three-phase CVCF PWM (pulse-width modulation) inverters to improve waveform control performance, I. E. , fast dynamic response, good robustness, low steady-errors, etc. First, robust control theory was adopted to model two uncertainties; after that, one fictitious complex uncertainty △k was introduced to replace long delay cell z-N+m in repetitive controller, then a repetitive controller was integrated into designing robust feedback controller. Experimental results demonstrate that RRC controlled three-phase constant-voltage constant-frequency pulse-width modulation inverter can produce high quality output voltages with low total harmonic distortion and high tracking accuracy even in the presence of rectifier loads. It has fast dynamic response, and good robustness under load disturbances and parameter variations.%为了提高三相CVCF PWM逆变器波形的控制性能(同时具有动态响应快、稳定误差小和鲁棒性好等优点),提出了鲁棒重复控制策略.首先采用鲁棒控制理论对两类不确定建模；然后引进一个虚拟的复不确定△k代替重复控制器中的长延迟环节z -N+m,将重复控制器集成到鲁棒反馈控制器设计之中形成鲁棒重复控制方案.实验结果表明,采用鲁棒重复控制策略控制的三相逆变器,即使在非线性负载情况下也能保证输出电压的THD含量低、跟踪精度高、响应快；并且在参数变化和负载突变扰动的情况下,仍具有良好的鲁棒性.