Bridgeless Isolated Positive Output Luo Converter Based High Power Factor Single Stage Charging Solution for Light Electric Vehicles

Abstract

In order to overcome various limitations of conventional LEVs (Light Electric Vehicles) chargers such as high cost, high device count, low efficiency, large size, complex control, and complicated structure, an enhanced power quality single-stage isolated charging solution is put forward in this work. This charger configuration based on bridgeless isolated positive output (BLIPO) Luo converter establishes a high power factor (PF), distortions free, low cost, less device count, small size, and improved efficiency charging solution. It is noteworthy; the conventional Luo converter is modified to simplify the structure and to get positive polarity at the output side. The control of the charger to implement different charging modes i.e. constant current mode (CCM) and constant voltage mode (CVM), is accomplished by employing low sensing devices and simplified control circuitry. Furthermore, the size of magnetic component along with overall cost is reduced by considering discontinuous inductor current mode (DICM) design. The supply-side variations over a wide range and different loading conditions are considered while the selection and design of each component to enhance the safety and reliability feature of the charger. The overall design and performance are verified and a high power factor (HPF) distortion-free improved power quality charging is ensured during steady-state conditions and under various dynamics. Simulated results during supply voltage fluctuations and for different load conditions are provided for verification of performance of the charger.