Predictive Control of Five-leg Inverter Driving Dual PMSMs for Overcurrent Suppression

The five-leg inverter has been investigated widely as a low-cost solution for dual permanent magnet synchronous motors (PMSMs) drives. It installs a common leg between dual PMSMs and can be considered a fault-tolerant approach in the event of an open-circuit fault occurring within an inverter leg. For this topology, the overcurrent of the shared leg should be handled carefully since the confluence of phase current naturally amplifies the current peak. In this article, an enhanced model predictive control (MPC) scheme is presented to realize cooperative dual-PMSMs control, effective overcurrent elimination, lower computational burden, and fast transient response simultaneously. The master-slave structure and deadbeat control-based duty cycle partitioning scheme are adopted to eliminate the switching state conflict on the common leg and realize independent current controller construction. In addition, the relations of current phases of dual PMSMs are deduced, designed, and utilized to modify the reference current of the slave motor. As a result, the overcurrent component is contained in the cost function directly. Finally, the experimental tests of a dual-PMSM system are executed, and the results substantiate the effectiveness and superiority of the proposed algorithm.