A highly integrated drive inverter using DirectFETs and ceramic dc-link capacitors for open-end winding machines in electric vehicles

A highly integrated inverter for open-end winding machines is designed and build. This paper presents the design of a 6-phase full-bridge inverter for driving an open-end winding machine for electric vehicles. The inverter consists of six full-bridge phase modules that are arranged in a hexagonal shape inside the motor housing. DirectFETs with double-side cooling are used as switching elements. Each module has its own bank of ceramic capacitors. A low-inductive layout allows continuous operation in the nominal operating point at a dc-link voltage of 145V, which is extremely close to the breakdown voltage of the DirectFETs of 150V. In the nominal operating point with a dc-link voltage of 125V, a maximum efficiency of η = 97% is reached.