Boost-Cascaded-by-Buck Power Factor Correction Converter for Universal On-Board Battery Charger in Electric Transportation

A two-stage battery charger in battery operated electric vehicles (BEVs) and plug-in-hybrid electric vehicles (PHEVs) with wide output voltage range of 100-500 V is most suitable for all vehicle architectures. Existing battery chargers have a different limited range of output voltages of 36-48 V, 72-150 V and 200-450 V is achieved by varying the output voltage of DC/DC converters keeping a fixed voltage at DC link. A universal charger, which can address this wide range of battery pack voltages is suitable for all vehicle architectures. The most feasible way to meet this requirement of wide output voltage range is to vary the voltage at DC link with a fixed conversion voltage ratio at DC/DC converter. In this paper, we propose the use of cascaded converter in power factor correction (PFC) converters to achieve the wide DC link voltages for battery chargers. The primary focus of the paper is on the analysis and operation of boost-cascaded by buck (BoCBB) converter. The control implementation presented in the paper achieves a high input power quality, wide DC link voltages with universal input voltage ranges of 85-265 V. It also provides the degree of control freedom to operate even if the VNm (output voltage to the peak of Input) <; 0.5. Simulations of the proposed converter with 1 kW power rating are carried out in PSIM 11.0 software and the results with wide DC link voltage of 150-400 V are presented in the paper.