Temperature-adaptive Smart Electric Vehicle Fast Charging System

While electric vehicles (EVs) are a significant step towards reducing carbon emissions, their full environmental benefits are realized only when they are powered by clean, renewable energy sources rather than existing fossil fuel-dependent power grids. The integration of renewable energy sources with EV charging infrastructure is crucial for sustainable electrified transportation. Solar photovoltaic (PV) systems, with abundant availability in India and ease of deployment, are a particularly promising solution for this. This paper proposes an off-grid 153 kW solar PV-powered EV fast charging station within solar carports to address the inadequate public EV charging infrastructure in India. The system comprises of a PV source with a unidirectional boost converter, an energy storage unit (ESU) managed by a bidirectional buck-boost converter to regulate its energy levels and a 60 kW EV fast charging point connected to the DC bus via a unidirectional buck converter. A novel battery cell temperature-adaptive fast charging mechanism is presented, which limits charging rates to ensure safe battery operating temperatures. This approach improves charging efficiency, enhances safety by preventing overheating, and extends battery life by protecting overall battery health. The control strategies of the system are designed to maximize solar power extraction and ensure stable operation under fluctuating loads and solar irradiance. The performance of the system is evaluated under different levels of solar irradiance and battery temperature conditions to assess its effectiveness.