Sliding mode controlled multiphase buck converter with interleaving and current equalization

This paper presents a sliding mode control design of a multiphase power converter. The use of multiphase converters and an appropriate phase shift result in chattering reduction to the desired level at a given switching frequency in the so called “ripple cancellation” or “harmonic cancellation”. Additionally, this strategy considers sliding mode as a suitable substitute for Pulse Width Modulation because of the benefits in sliding mode control, i.e. the possibility of achieving desired system responses regardless of parameter changes. A 4-phase buck converter prototype was built and the controller was programmed in an FPGA. Experimental results show that chattering reduction, robust output regulation and phase current equalization are achieved, thus validating the proposed approach.