Plugging in is the obvious way to charge an EV, but it limits range and forces large, heavy batteries. Dynamic wireless power transfer (DWPT) proposes charging the vehicle while it moves, by embedding power-transmitting coils in the roadway that energise a receiver coil under the car — potentially allowing smaller batteries and near-unlimited range on electrified routes.
Working principle
The system uses magnetic resonant coupling. A transmitter coil in the road carries high-frequency AC, generating an oscillating magnetic field; a receiver coil on the vehicle picks it up by induction. Tuning both coils to the same resonant frequency with compensation capacitors dramatically improves efficiency across the air gap. For dynamic charging, segmented road coils energise in sequence as the vehicle passes over them.
| Method | Convenience | Challenge |
|---|---|---|
| Plug-in (conductive) | Manual, parked | Cables, range limits |
| Static wireless | Park & charge | Alignment, cost |
| Dynamic wireless | Charge while driving | Road cost, efficiency |
Key trade-offThe economics hinge on infrastructure cost vs. battery savings: electrifying even a fraction of highway lanes could let EVs carry far smaller batteries, but burying coils in roads is expensive.
Applications
- Electrified bus and taxi routes with in-motion charging
- Static wireless pads for fleets and home parking
- Logistics corridors and automated warehouse vehicles
References & further reading
- Kurs et al., “Wireless Power Transfer via Strongly Coupled Magnetic Resonances,” Science, 2007.
- Covic & Boys, “Inductive Power Transfer,” Proceedings of the IEEE, 2013.
- Mahesh et al., “Dynamic Wireless Charging of Electric Vehicles — A Review,” IEEE Access, 2021.