Control methodology for single inverter, parallel connected dual induction motor drives for electric vehicles

The objective of this paper is to present a methodology for controlling the transient as well as steady state torque production from each rotor of a dual induction motor drive with parallel connected stator windings fed by a single power inverter. This type of drive topology is targeted towards electric vehicle applications where the expected benefits are: (1) a simple drive train design (no mechanical differential required); (2) traction control; and (3) lower cost and smaller size compared to a two inverter, two motor alternative. This paper includes the theoretical formulation of a suitable “dual motor” machine model from which the required control relations are derived. The control relations are similar in form to the single motor field-oriented control laws, but allow mean and differential drive torques to be directly controlled. Experimental test results demonstrate the transient torque splitting capabilities of the control but also indicate sensitivities to parameter variations