Optimum torque/current control of dual-PMSM Single-VSI drive

The paper deals with isotropic PM-brushless drives in configuration “single-inverter, dual-motor” operating with unbalanced load-torques. An innovative control algorithm is presented. It is suitable to minimize the resultant armature current needed to obtain an assigned resultant motor torque, whatever is the load unbalance. Simplified analytical expressions are given in order to quickly evaluate optimized reference currents with good approximation. From these reference values, a predictive feeding algorithm evaluates the reference voltage space-vector for the inverter supplying the two motors in parallel. Current and torque oscillation, torque/current ratio, dynamic response and stability are the mainly observed quantities. Effectiveness of proposed control techniques is highlighted.