Modelling and Control Solution of an E-axle for Third-Generation Electric Vehicles

This work studies the use of an e-axle based on a six-phase IPMSM. In addition, it has a dc bus with a cascade configuration. Moreover, a dc/dc converter is incorporated between the battery module and the six-phase inverter to provide the vehicle with fast charging capabilities, while avoiding the use of power semiconductors with high nominal voltages. In this scenario, the control algorithm must cope with the non-linearities of the machine by providing an accurate setpoint command for the entire torque and speed range of the inverter. Therefore, cross-coupling effects between the windings must be considered, and the voltage of the cascade link capacitors must be actively controlled and balanced. Given this, the authors propose a novel control approach that provides all these functionalities. The proposal has been experimentally validated on a full-scale prototype 70 kW electric drive, tested in a laboratory and an electric vehicle under real driving conditions.