Model-Free Predictive Power Control for PWM Rectifiers under Asymmetrical Grids

Conventional model predictive power control (MPPC) features a simple concept and quick dynamic response. However, it relies heavily on the systemmodel its parameter accuracy. Furthermore, steady ripples are still high due to use of one voltage vector during period. Recently, model-free current (MFPCC) has been proposed in PWMrectifiers. Despite strong robustness, principle MFPCC cannot be directly applied control, because relationship between converter ismore complex. This paper first proposes basicmodel-free (MFPPC), which successfully extends ofMFPCC control. Subsequently, an improvedMFPPC is proposed, uses extended finite set vectors improve steady-state performance. by using online updated ultralocalmodel PWMrectifiers, problemof stagnant updating basic MFPPC solved. The ideal three-phase grid voltages symmetrical sinusoidal, but actual grids usually unsymmetrical. In this paper, proposedmethod asymmetrical adding appropriate compensated original references. compared conventionalMPPC. presented experimental results confirmthe effectiveness proposedmethods.