PV Integrated Single-Stage Isolated PFC Charger for Solar Panel Installed LEV

Surging appeal of light electric vehicles (LEVs) featuring rooftop solar photovoltaic (PV) panel is attracting masses and paving way for new research avenues, particularly in the realm of battery charging applications. However, there is limited literature on isolated integrated single-stage chargers that utilize both grid power and solar panels for charging LEVs, with a particular emphasis on reducing components and improving power quality (PQ). To bridge research gap and cater to the need for an on-board charger for solar-assisted LEVs, a dual-sourced isolated charger with several benefits over conventional topologies is detailed in this paper. It is derived from an isolated bridgeless SEPIC converter to accommodate an additional PV input. Solar PV input serves dual functionality by acting as a secondary power source and enhancing power quality of grid current, a feature not commonly seen in conventional PV-grid charging topologies. Charger’s design is aimed at reducing overall component count by reducing power processing stage and sharing components between each source. It results in a power circuit composed of 12 major components, encompassing all active and passive elements. Additionally, simultaneous and independent charging from each input, improved PQ indices of grid current, and swift maximum power point tracking (MPPT) of solar PV input are other necessary and desirable features of presented charger. Furthermore, zero voltage turn-on of semiconductor devices performing MPPT adds to efficiency improvement. Estimated efficiency of presented charger is 93.5% at full load. A separate control loop is designed for each input after thorough stability analysis and verifying plant Bode-plot using AC-sweep analysis in PSIM. A 650 W prototype is successfully tested under different dynamic conditions and yields 1.3% total harmonic distortion (THD) in grid current at rated conditions.