Resonant-repetitive combined control for stand-alone power supply units

This paper investigates a combined Resonant-Repetitive (RR) control structure for a three phase four leg DC/AC converter power supply. The RR control configuration is composed by a resonant controller tuned at the system fundamental frequency working in conjunction with a plug-in type repetitive controller. The resonant part of the control scheme is used for system stabilization purposes and for fine regulation of the fundamental frequency; the repetitive part of the scheme is implemented for fine regulation at the system harmonic frequencies. The proposed control configuration is used to regulate the power supply output voltage providing very good tracking of the output voltage reference even in the presence of a non-linear load. Experimental validation from a 40 kVA converter prototype is presented to validate the operation of the proposed converter and control.