An optimal control strategy based on a discrete energy function, for single-phase AC/DC converters used in plug-in electric vehicles

Abstract

This paper presents a novel digital control scheme for a power factor correction boost converter based on a discrete energy function. It is shown in this paper that the dynamics of the power factor correction AC/DC boost converter can be significantly improved by implementing a very simple yet novel optimal control scheme, which is superior to the conventional controller for the AC/DC power factor correction boost converters used in plug-in electric vehicles. In the proposed control scheme, first an energy function is introduced, which represents the discrete energy of the error signals, then the control law is designed based on the discrete energy function. In order to verify the performance of the proposed controller, it is examined on a digitally controlled 3KW boost PFC operating at 100 kHz switching frequency. Experimental results show that the proposed controller results in low current harmonics and significantly faster output voltage transient responses as compared to the one for conventional control schemes.