Machine integrated gearbox for electrical vehicles

The speed range that can be obtained with an electric machine is initially limited due to the finite supply voltage of the inverter. A winding reconfiguration method named dynamic machine operation is presented, capable of increasing the speed range and speed ratio by altering the configuration of the modular power electronics drive circuit as a function of the machine speed. An electric machine integrated equivalent of a gearbox for electric vehicles is realized in this manner. The theoretical analysis of the proposed dynamic machine operation principle is detailed and compared to conventional drive methods. Furthermore, the electric machine efficiency for different speed and torque levels is researched for each operating mode. Finally, the experimental verification demonstrates that the intended improvement of the speed range and speed ratio can be achieved.