Parallel structure repetitive controller for CVCF three-phase PWM inverter

This paper presents a new parallel structure repetitive control (PSRC) scheme for constant-voltage constant-frequency (CVCF) pulse-width modulation (PWM) inverters to cancel output total harmonic distortion (THD). Compared with conventional repetitive control (CRC), parallel structure enables repetitive control to achieve much faster dynamic response without any loss of tracking accuracy or any added computation resources. Experimental results of a PSRC with six paralleled internal models (6-model RC) controlled CVCF three-phase PWM inverter show the validity and advantages of the proposed 6-model RC scheme.