Dynamic Wireless EV Charging Under Misalignment: A Study of Mitigation Technologies, Key Challenges, and Future Prospects

The dynamic wireless power transfer (DWPT) system is a technology that allows an EV to take in electrical energy while it is moving on energized sections of the roadway. This can minimize charging time interruptions and increase the driving range for vehicles, as well as enable high-use vehicle fleets to have a smaller traction battery. The operation of a DWPT system is, however, very sensitive to the relative position of the roadway transmitter and the receiver on the vehicle. Mutual inductance and reflected impedance may be changed by lateral displacement, movement of the transmitter segments, changes in ground clearance and angular misalignment. The changes can lead to resonance detuning, power fluctuation, higher stress on the power converter, as well as different leakage magnetic fields. This paper summarizes the progress in misalignment-tolerant DWPT systems in recent years, focusing on magnetic coupler structures, compensation networks, control techniques and standardization. It is possible to increase the coupling area using DD-type and quadrature couplers, and to enhance the robustness against the variations of the coupling, using a compensation network based on the LCC. Phase-shift control, predictive control and magnetic-field-shaping methods can be used to further improve operational stability. Past research indicates that the best systems utilize a combination of coupling-aware control and passive compensation and active regulation, not just one of the two mitigation strategies. The latest standards cover safety and interoperability of dynamic charging systems; SAE J2954 provides a reference for stationary wireless charging. There are still some key research needs to be addressed for cross-vendor dynamic testing, power quality during segment changes, foreign object detection, roadway durability, and bi-directional power transmission.