Control Method for Mono Inverter Dual Parallel Surface-Mounted Permanent-Magnet Synchronous Machine Drive System

This paper presents the control method for mono inverter dual parallel (MIDP) surface-mounted permanent-magnet synchronous motor (SPMSM) drive system. Unlike the MIDP induction machine drive system, MIDP SPMSM drive system suffers from the inherent instability due to the lack of slip. The proposed active damping control method refrains the system oscillation coming from the mechanical and electrical unbalances and enables the stable operation. This paper also presents the simple maximum torque per ampere control method for MIDP SPMSM drive system. Mathematically calculated optimal currents reduce the amplitude of the currents and improve the drive efficiency. To maximize the merits of the MIDP motor drive system, a sensorless algorithm is also applied. Experiments with the 600-W SPMSMs are executed to verify the feasibility of the proposed control method.