A Novel Converter Topology for a Primary-Side Controlled Wireless EV Charger With a Wide Operation Range

Abstract

The full-bridge commonly employed in the primary of an SAE J2954 compliant inductive power transfer (IPT) based wireless electric vehicle (EV) charger possesses many challenges. To alleviate these issues, expensive switches, and extra components are employed together with secondary-side regulation. As an alternative, this article proposes a new topology, termed integrated boost multilevel converter (IBMC). An IBMC consists of series-connected half-bridge submodules (SMs) in each arm, and the dc supply is connected to each arm through a dc inductor. When an IBMC is used as the primary converter, its ability to generate a boosted multilevel output voltage, enables it to regulate the power flow efficiently over a wide load/coupling range without requiring a secondary-side regulator. This article focuses on the operating principles of this new IBMC under steady-state conditions and discusses a modulation scheme that can be used to regulate the power flow while balancing the SM voltages. The benefits of the IBMC is experimentally validated using an SAE J2954 WPT2/Z2 compliant prototype. This prototype used an IBMC built with low-cost switching devices on the primary-side to regulate the power flow to 7.7 kW as the coupling factor changed between 0.11 and 0.25 while maintaining the system efficiency between 90.4% and 91.9%.