A Single-Stage High Step-Down Gain Modified Cuk-based HPF AC-DC Converter for LVEVs Chargers

A charger configuration, which is based on a modified Cuk converter, is demonstrated here for low-voltage electric vehicles (LVEVs). The topology presented in this work, is modified from the conventional Cuk-based converter, using a completely bridgeless structure, with the ability to provide a wide voltage step-down gain in a single stage between the supply AC voltage mains and the battery side. Moreover, the intermediate inductors in the presented charger configuration are designed for discontinuous inductor current mode, which helps in reducing the size of the magnetic components, facilitates inherent power factor correction at the input side, and reduces the switching losses incurred in the conducting devices. A simple control methodology is implemented for obtaining the desired charging profile at the battery side and also for power factor correction at the input. The charger presented in this work, provides good input side performance, with high power factor and low input current harmonic distortions, while being able to maintain a good charging profile at the battery end. Finally, the converter is simulated for a battery load of 450 W, 48V/100Ah, with a device switching frequency of 20kHz and the results of the same are presented in this paper.