A novel three-phase primary-side control topology for high-power IPT system

There is a recognised need for developing multi-phase inductive power transmission (IPT) systems to shorten the charging time in the wireless charging field. Researchers have not treated the converter needed to drive the multi-phase coils in much detail. This paper proposes a three-phase integrated boost multilevel converter (TP-IBMC) based on a multi-phase IPT system. There are advantages of multi-level converters and the boost function in TP-IBMC. Using a digitized modulation scheme, it can output a square wave voltage with variable amplitude to regulate the power in the primary. The TP-IBMC includes three bridge arms (a, b, c), each of which contains a DC inductor to achieve energy storage and multiple sub-modules to realize variable levels. The number of sub-modules can be increased or decreased. This paper establishes a three-phase IPT model considering the mutual inductance between phases and discusses the capacitor voltage balancing strategy. A primary-side control IPT simulation model compliant with the SAE J2954 WPT 3 standard is built to verify that TP-IBMC can regulate output power through a digitised modulation scheme, under the fluctuations of coupling factor (i.e., 0.14 - 0.31) and battery voltage (i.e., 280 V - 420 V).