Digital repetitive controlled three-phase PWM rectifier

In this paper, a digital repetitive control (RC) strategy is proposed to achieve zero tracking error for constant-voltage constant-frequency (CVCF) pulse width modulation (PWM) converters. The proposed control scheme is of plug-in structure: a plug-in digital repetitive controller plus a conventional controller (e.g., PD controller). The design of the plug-in repetitive learning controller is systematically developed. The stability analysis of overall system is discussed. A repetitive controlled three-phase reversible PWM rectifier is given as an application example. Near unit power factor and constant output do voltage are ensured under parameter uncertainties and load disturbances. Simulation and experimental results are provided to testify the effectiveness of the proposed control scheme.