Trend AnalysisOther Engineering
Wireless Power Transfer Technology: Resonant Charging for Electric Vehicles in Motion
Wireless power transfer could eliminate the last major friction point of electric vehicles: plugging in. Recent advances in compensation topology, dynamic charging, and coil design are pushing wireless EV charging toward the efficiency and power levels needed for practical deployment.
By Sean K.S. Shin
This blog summarizes research trends based on published paper abstracts. Specific numbers or findings may contain inaccuracies. For scholarly rigor, always consult the original papers cited in each post.
Imagine electric vehicles that charge while driving---power transferred wirelessly from coils embedded in the road surface to a receiver on the vehicle's underside. This is not science fiction: dynamic wireless charging has been demonstrated at power levels exceeding 100 kW, and pilot projects are operating in Sweden, South Korea, and several U.S. states.
Wireless power transfer (WPT) for EVs uses resonant inductive coupling: a transmitter coil in the ground creates an oscillating magnetic field that induces current in a receiver coil on the vehicle. The "resonant" part is critical---by tuning transmitter and receiver circuits to the same resonant frequency, power transfer efficiency exceeds 90%, even across air gaps of 15-25 centimeters.
Why It Matters
Range anxiety and charging inconvenience remain the top barriers to EV adoption. Wireless charging addresses both: stationary wireless pads eliminate the need to handle heavy cables (especially valuable for autonomous vehicles, buses, and taxis), while dynamic wireless charging could dramatically reduce battery size requirements, lowering vehicle cost and weight. A vehicle that charges continuously while driving needs a much smaller battery than one that must store energy for the entire trip.
The Research Landscape
Compensation Topology Analysis
Latha, Irfan, and Koti Latha and Koti Reddy (2025), with 11 citations, provide an updated analysis of compensation topologies for wireless EV charging. The compensation circuit---capacitors and inductors that tune the system to resonance---determines efficiency, power transfer capability, and behavior under misalignment. Their analysis compares series-series, series-parallel, LCC-LCC, and newer double-sided LCC topologies, finding that LCC-LCC offers the best overall performance for EV applications.
Dynamic Wireless Charging
Kiddm and Saniei (2025) address the core challenge of dynamic wireless charging: maintaining efficient power transfer as a vehicle moves over sequential transmitter coils, encountering continuous misalignment changes. Their phase-shift control method maintains regulated charging current while restricting it within safe limits, even as the vehicle traverses between transmitter segments.
Coil Geometry Optimization
Yeole and Bhujbal (2025) systematically study how transmitter and receiver coil geometry affects power transfer efficiency. Coil shape (circular, rectangular, DD-bipolar), size, and turn count all influence coupling coefficient and misalignment tolerance. Their results provide design guidelines for coils that maximize efficiency across the range of alignments encountered in real parking and driving scenarios.
Onboard Power Electronics
Rai and Vakcharla (2024) present an interleaved boost converter integrated with the inductive power transfer receiver, offering wide-range voltage control and reduced current ripple. The onboard power electronics must convert the wirelessly received AC power to DC at the voltage and current required by the battery management system, and do so efficiently across varying coupling conditions.
Wireless vs. Wired EV Charging Comparison
<
| Parameter | Wired (Plug-in) | Wireless (Stationary) | Wireless (Dynamic) |
|---|
| Efficiency | 95-97% | 90-93% | 85-90% |
| Power level | Up to 350 kW | Up to 300 kW | Up to 200 kW |
| User convenience | Manual plug-in | Automatic (park-and-charge) | Continuous (drive-and-charge) |
| Infrastructure cost | Low-medium | Medium | Very high |
| Battery size impact | No reduction | No reduction | Significant reduction possible |
What To Watch
The first commercial dynamic wireless charging road segments are expected by 2027-2028. If costs can be reduced through economies of scale in coil manufacturing and standardized power electronics, dynamic charging could transform the economics of electric transportation---particularly for commercial fleets (buses, delivery vehicles, taxis) that operate on fixed routes and cannot afford extended charging stops.
Imagine electric vehicles that charge while driving---power transferred wirelessly from coils embedded in the road surface to a receiver on the vehicle's underside. This is not science fiction: dynamic wireless charging has been demonstrated at power levels exceeding 100 kW, and pilot projects are operating in Sweden, South Korea, and several U.S. states.
Wireless power transfer (WPT) for EVs uses resonant inductive coupling: a transmitter coil in the ground creates an oscillating magnetic field that induces current in a receiver coil on the vehicle. The "resonant" part is critical---by tuning transmitter and receiver circuits to the same resonant frequency, power transfer efficiency exceeds 90%, even across air gaps of 15-25 centimeters.
Why It Matters
Range anxiety and charging inconvenience remain the top barriers to EV adoption. Wireless charging addresses both: stationary wireless pads eliminate the need to handle heavy cables (especially valuable for autonomous vehicles, buses, and taxis), while dynamic wireless charging could dramatically reduce battery size requirements, lowering vehicle cost and weight. A vehicle that charges continuously while driving needs a much smaller battery than one that must store energy for the entire trip.
The Research Landscape
Compensation Topology Analysis
Latha, Irfan, and Koti Latha and Koti Reddy (2025), with 11 citations, provide an updated analysis of compensation topologies for wireless EV charging. The compensation circuit---capacitors and inductors that tune the system to resonance---determines efficiency, power transfer capability, and behavior under misalignment. Their analysis compares series-series, series-parallel, LCC-LCC, and newer double-sided LCC topologies, finding that LCC-LCC offers the best overall performance for EV applications.
Dynamic Wireless Charging
Kiddm and Saniei (2025) address the core challenge of dynamic wireless charging: maintaining efficient power transfer as a vehicle moves over sequential transmitter coils, encountering continuous misalignment changes. Their phase-shift control method maintains regulated charging current while restricting it within safe limits, even as the vehicle traverses between transmitter segments.
Coil Geometry Optimization
Yeole and Bhujbal (2025) systematically study how transmitter and receiver coil geometry affects power transfer efficiency. Coil shape (circular, rectangular, DD-bipolar), size, and turn count all influence coupling coefficient and misalignment tolerance. Their results provide design guidelines for coils that maximize efficiency across the range of alignments encountered in real parking and driving scenarios.
Onboard Power Electronics
Rai and Vakcharla (2024) present an interleaved boost converter integrated with the inductive power transfer receiver, offering wide-range voltage control and reduced current ripple. The onboard power electronics must convert the wirelessly received AC power to DC at the voltage and current required by the battery management system, and do so efficiently across varying coupling conditions.
Wireless vs. Wired EV Charging Comparison
<
| Parameter | Wired (Plug-in) | Wireless (Stationary) | Wireless (Dynamic) |
|---|
| Efficiency | 95-97% | 90-93% | 85-90% |
| Power level | Up to 350 kW | Up to 300 kW | Up to 200 kW |
| User convenience | Manual plug-in | Automatic (park-and-charge) | Continuous (drive-and-charge) |
| Infrastructure cost | Low-medium | Medium | Very high |
| Battery size impact | No reduction | No reduction | Significant reduction possible |
What To Watch
The first commercial dynamic wireless charging road segments are expected by 2027-2028. If costs can be reduced through economies of scale in coil manufacturing and standardized power electronics, dynamic charging could transform the economics of electric transportation---particularly for commercial fleets (buses, delivery vehicles, taxis) that operate on fixed routes and cannot afford extended charging stops.
References (8)
[1] Latha, B., Irfan, M. M., & Koti Reddy, B. (2025). WPT compensation topologies for EV charging. Discover Applied Sciences.
[2] Kiddm, W. A., Mortazavi, S., & Saniei, M. (2025). Dynamic Wireless Charging: Phase-Shift Control. IEEE Access.
[3] Yeole, D., Tate, L. D., & Bhujbal, P. U. (2025). Coil Geometry and Power Transfer Efficiency in RIPT. IEEE ICTMIM.
[4] Rai, A., Tummuru, N., & Vakcharla, V. R. (2024). Interleaved Boost Converter for Wireless Vehicle Charging. IEEE WPTCE.
Latha, B., Irfan, M. M., Reddy, B. K., & Basha, C. H. H. (2025). A novel enhancing electric vehicle charging: an updated analysis of wireless power transfer compensation topologies. Discover Applied Sciences, 7(4).
Ayad Kiddm, W., Mortazavi, S. S., Saniei, M., & Monadi, M. (2025). Enhancing Efficiency and Regulation Current in Dynamic Wireless Charging of Electric Vehicles: Phase-Shift Control Methods in Resonant Inductive Power Transfer Systems. IEEE Access, 13, 111317-111334.
Yeole, D. S., Tate, L. D., Bhujbal, P. U., & Bhise, P. V. (2025). Effect of Coil Geometry on Power Transfer Efficiency in Resonant Inductive Power Transfer (RIPT) for Electric Vehicle Charging. 2025 5th International Conference on Trends in Material Science and Inventive Materials (ICTMIM), 130-133.
Rai, A., Tummuru, N. R., & Ratnam Vakcharla, V. (2024). Interleaved Boost Converter Integrated Inductive Power Transfer System for Wireless Vehicle Charging Applications. 2024 IEEE Wireless Power Technology Conference and Expo (WPTCE), 7-11.