Conventional EV Chargers Use Large, Costly LFTs Dependent on Copper and Iron, Raising Efficiency Concerns
Researchers at the Indian Institute of Science (IISc), in collaboration with Delta Electronics India, have developed a new power converter design that promises to make electric vehicle (EV) fast-charging more efficient, compact, and cost-effective.
One of the biggest hurdles in the growth of EV adoption is the lack of reliable fast-charging stations capable of delivering over 1MW of power—enough to run about 1,000 homes. Conventional chargers rely on line frequency transformers (LFTs), which are bulky, expensive, and heavily dependent on copper and iron. They also require multiple power conversion stages, increasing both cost and energy loss.
CHB-Based Multiport DC Converter
The IISc team has designed a cascaded H-bridge (CHB)-based multiport DC converter that directly connects to the medium-voltage AC grid. By eliminating the need for bulky transformers, the system reduces energy losses and simplifies charging infrastructure.
The results, published in the journal IEEE Transactions on Industrial Electronics, show that the new design improves efficiency by 3–5% compared to conventional systems. “Even small efficiency gains at the megawatt scale translate into significant energy savings and lower material costs,” said Kaushik Basu, Associate Professor at IISc and the corresponding author of the study.
Dual Functionality and Grid Support
The bidirectional design of the converter allows not only charging of EVs but also storing energy locally in batteries. This stored power can then be used during peak demand periods or fed back to the grid in emergencies, making charging hubs potential local power stabilisers. According to IISc, such systems could support hospitals, essential services, or entire neighbourhoods during outages.
Green and Scalable Technology
The converter is also compatible with renewable energy sources like solar, enabling a cleaner charging ecosystem. Its compact, transformer-free design cuts down on copper and iron usage, making it environmentally friendlier and more sustainable for large-scale deployment.
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Beyond EV Charging
While developed for EV infrastructure, researchers believe the design could be applied in data centres, railway traction systems, and wind energy setups—all sectors that demand high-efficiency power conversion.With India targeting 30% EV adoption by 2030, this breakthrough from IISc could play a critical role in scaling fast-charging infrastructure, reducing costs, and driving sustainable mobility.
