Research Projects

India is planning to achieve electric vehicle use of 30% by 2030. The target is to establish 4 lakh charging stations by 2026. EV charging infrastructure in the country must support high-power fast charging of e-buses and e-Trucks in near future. This project proposal aims to indigenously develop the converters and systems required for high power (250 kW) fast DC charging of heavy electric vehicles such as high end electric cars, buses and trucks. High-power off-board chargers are generally connected to a medium-voltage AC grid (e.g., 11 kV) through a low-frequency 50 Hz or 60 Hz transformer. This requires significant infrastructure upgrades that includes the need for 11-33kV power connections with each charger requiring its own separate 11 kV power connection and substation. Therefore, this project proposes direct medium voltage (11 kV) AC interface for the chargers without a low frequency transformer. The required isolation of the vehicle side is provided through high frequency transformer based converters using the Solid State Transformer (SST) concept. The proposed charger architecture can be extended to charging parks where multiple such high power chargers will be fed from a common medium voltage AC-DC interface reducing the cost significantly. As an initial prototype two high power chargers (250 kW) fed from a common AC-DC medium voltage converter will be developed. They will be able to charge either two different vehicles independently or a single large vehicle with proper coordination delivering a charging power up to 500 kW. In India, conductive chargers are currently used to charge a vehicle. There are safety hazards due to human interference. Integrating a wireless charging system into electric vehicle eliminates the need for human interference between vehicle and charger. Therefore, this project also aims to develop a high power density static wireless charging system of about 50kW operating with a frequency of 100 khz. To enhance the power capacity, polyphase couplers will be employed. Also a tripolar polarized pad structure will be used for placing of coils on both sides. With this structure the problem of misalignment can be solved. Deployment of high power EV charging parks in large scale can have detrimental effect on the voltage frequency stability and power quality of the distribution grid. This project intends to analyze these effects and come up with recommendation for safe operation of high power EV charging parks and suitable financial incentives for their adherence. In this regard optimal operation and pricing strategy will be investigated. The technical and economic viability of integrating renewable energy sources / battery storage systems with EV charging stations and their effectiveness in providing ancillary grid services will also be explored.