In this paper, the integrated on-board battery charging system and its control method is introduced for a hybrid electric vehicles (HEVs). Integrated charging system consists of starter generator system, additional power relays and circuit. Depending on the states of power relays, the proposed charging system operates as two modes: 1) conventional starter system mode, 2) battery charging system mode. The usage of additional system components brings about the removal of conventional on-board charger (OBC) in HEV, thus, it means a decrease of the system volume, weight, and manufacturing cost in HEVs.
For a battery charging system modes, not only DC-link voltage control method and bi-directional current control method but also multiple harmonic currents reduction method is introduced. Through the proposed harmonic compensation method, the harmonics of different order are integrated as a unity variable in the synchronous reference frame. Compared to the conventional method which control each order harmonics individually, the proposed method can decrease the number of harmonic controller and simplicate the gain value selection of harmonic controller. The validity of proposed charging system and the effectiveness of proposed control methods are verified through the simulation and experimental results.
