A power pulsation-free automatic activation strategy for the transmitting coils in dynamic wireless charging systems

Inductive power transfer (IPT) is a promising contactless charging technology for electric vehicles. In dynamic wireless power transfer (DWPT), energy is transferred while the vehicle moves, reducing charging stops and potentially enabling smaller onboard batteries. However, vehicle motion continuously changes the magnetic coupling and complicates transitions between consecutive transmitter sections. This thesis investigates a segmented DWPT system comprising consecutive short ground-side transmitters and one elongated vehicle-side receiver that can overlap adjacent sections. A position-dependent model is implemented in PLECS, and a sensorless strategy is developed to coordinate the synchronized activation of the initially inactive next transmitter section with the deactivation of the preceding section. The receiver side uses passive rectification. Before activation, the next transmitter is maintained in a controlled short-circuit sensing state. While the preceding transmitter supplies the receiver, the receiver current induces a measurable current in the next transmitter’s resonant branch. A second-order generalized-integrator phase-locked loop (SOGI-PLL) processes this current to obtain the phase and frequency information required for synchronized switching. The next transmitter is activated with a reduced current reference, which is increased smoothly during the handover, while the preceding transmitter is deactivated after its contribution has decreased sufficiently. The strategy requires no measurements of vehicle position, vehicle speed, or mutual inductance and no direct communication with the receiver. Time-domain PLECS simulations at the nominal vehicle speed of 5m/s verify induced-current sensing, synchronized activation, smooth current-reference transition, and coordinated deactivation. The transferred power remains continuous throughout the handover, without a zero-power interval or additional power oscillations caused by the transmitter changeover.