A Repeater Coil Based Wireless Power Transfer System Powering Multiple Gate Drivers of Series-Connected IGBTs

It is challenging to power a large number of gate drivers of the series-connected insulated gate bipolar transistors (IGBTs) in a high-voltage application because multiple isolated power supplies are needed. In this study, a novel wireless power transfer (WPT) system using repeater coils is designed to solve this problem. Every two repeater coils form a repeater unit, which transfers power to one load. With multiple repeater units in the system, multiple loads can obtain power simultaneously. To eliminate undesirable magnetic couplings between these coils, bipolar coils are used and the two bipolar coils in the same repeater unit are placed perpendicularly. It is derived that constant voltage can be obtained for all the loads, which is especially suitable for powering the IGBT's gate driver. Moreover, the variation of one load power will not affect others. The receiving circuit is designed to transform the received power to the DC voltage compatible with the driving circuits. An experimental setup with six loads has been constructed to validate the proposed WPT system.