Hye-Won Choi, "전기 자동차 충전기용 다상 인터리브드 벅 컨버터의 레그별 전류 균등 분배 기법," 아주대학교 공학석사 학위 논문, 2021. > Paper

A current-balancing strategy for a multileg interleaved DC/DC converter with a reduced number of current sensors for electric-

vehicle chargers is proposed in this paper. There are imbalances between the leg currents of multileg DC/DC converters, which are

caused by the difference between the leg impedances and the driver delay. Each of the leg current sensors must achieve current

balancing. However, the conventional strategy is burdensome due to its high cost and volume. To mitigate these issues, the

proposed balancing strategy effectively balances leg currents using fewer current sensors than the number of legs. The proposed

strategy was verified by various simulation and experimental results.

This thesis proposes current balancing strategy of multi-leg interleaved buck converters based chargers for electric vehicle (EV). The

EV chargers have been increasing the power capacity using the multi-leg converters. There are imbalances between the leg currents

of multi-leg DC/DC converters, which are caused by the difference of the leg impedances, delay of the gate driver, and error of the

sensors. Each of the leg current sensors must achieve current balancing for the reliability of the converter. The conventional

strategies for the current balancing strategies are burdensome due to its high cost and volume. To mitigate these issues, the

proposed balancing strategy effectively balances leg currents using fewer current sensors than the number of legs. The proposed

strategy is based on DC-link current sensing and involves calculating each of the leg currents to generate a new duty ratio. In all

of the duty ratios, the leg currents achieve balancing by supplementing the minimum current sensors. The effectiveness of the

proposed current balancing strategy was validated by the simulation and experimental results.