배터리 충전기를 위한 DAB 컨버터의 전력회로 및 제어기 설계

Abstract

Among the high frequency DC-DC converters widely used as battery chargers, the DAB converter is a simple DC-DC converter that can be implemented using two full bridge converters and a transformer without additional elements. For switching control of the DAB converter, the SPS method is difficult to use for a battery charger due to low efficiency in light load. As a result, the DPS and TPS methods has been studied, but they also have some disadvantage in that the number of waveforms according to the combination of control variables is large, and thus many control variables exists difficult to control. In addition, The mode change between separate CC and CV controller may cause severe chattering and transient phenomena. In order to solve these shortcomings, in this paper SPS, DPS, and TPS were analyzed by related equations, and the switching methods are integrated into single control variable, thereby improving the converter efficiency and the THD of the transformer AC current. In addition, a new controller of the battery charging DAB converter is proposed to smooth the mode conversion between CC and CV by setting a new variable and to remove the DC current component of the transformer. Experimental circuits of the DAB converter were fabricated and their characteristics were verified.