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 impedance, 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.
