Inverter Control and its Effect on Copper Losses in Electrical Machines Equipped with Hairpin Winding

The electric drivetrain is considered as a closed loop system consisting of the controller, the inverter and the electrical machine in this contribution. Copper losses including AC and PWM effects are studied by using two different approaches for high accuracy or fast computation, based on the finite element method (FEM) and lookup tables (LUT) respectively. The influence of switching frequency and modulation method on both inverter and copper losses is analyzed. These losses are minimized by optimizing the inverter parameters in the speed-torque map. The inverter parameter's impact on the drive cycle energy loss is discussed. A permanent magnet excited synchronous machine equipped with hairpin winding is chosen as an exemplary machine.