A simple direct-frequency control of AC/DC three-phase Current Injection Series Resonant Converter (CISRC)

This paper presents a simple practical implementation of direct-frequency control for current injection series resonant converter (CISRC) to regulate the output voltage. Based on the control-to-output frequency response obtained from the small-signal model of the converter, a PI controller is proposed which provides robustness in relation to external disturbances and a good dynamic response of the output voltage. Controller design also involves a trade-off between reducing the output voltage ripple and maintaining the high quality input line current. Simulation and practical results are reported, confirming the validity of the proposed control technique.