A Hybrid Multiinput DC-DC Converter With Energy Storage Stage For Electric vehicle Application

A three-input DC–DC boost converter is proposed in this paper. The two unidirectional input power ports and a bidirectional port interface with the proposed converter to achieve a unified storage structure. This converter is interesting for hybridizing alternative energy sources such as photovoltaic source, battery1, and battery2. Supplying the output load, charging or discharging the battery2 can be made by the PV and the battery individually or simultaneously. The proposed structure utilizes only four power switches that are independently controlled with four different duty ratios. Utilizing those duty ratios, tracking the maximum power of the PV source, setting the battery1, controlling the battery2 power, and regulating the output voltage are provided. Depending on utilization state of the battery2, three different power operation modes are defined for the converter. In order to design the converter control system, small signal model is obtained in each operation mode. Due to interactions of converter control loops, separate closed controllers are designed with the help of decoupling network. The validity and control performance of the proposed converters are verified by simulation and experimental results under different operation conditions.