Bidirectional Grid-Side Power Management in DWPT Systems for EV Charging Applications

Abstract

Dynamic Wireless Power Transfer (DWPT) requires a pulsating power-profile input from the grid. In a typical Grid-to-Vehicle (G2V) infrastructure, this inherently transient loads on the grid side are usually in the range of tens to hundreds of kilowatts, which could impose significant stress or even cause instability at the grid on a large scale. Similarly, in a Vehicle-to-Grid (V2G) scenario, the vehicle would charge the grid, and the grid would become exposed to a similar profile of charging power. In this paper, a bidirectional converter topology and its control strategy are presented for grid-power management for bidirectional DWPT applications. A Supercapacitor (SC) based buffering unit is presented, capable of managing the grid-side power transients in a bidirectional DWPT environment. Compared to other existing methods, this topology does not require additional converter hardware. Moreover, grid-side electronics and cable ratings could be downscaled as the resulted peak current at the DWPT transmitter unit reduces significantly.