An Indirect Testing Method for the Mechanical Characteristic of Multiunit Permanent-Magnet Synchronous Machines With Concentrated Windings

Compared with traditional three-phase machines, multiphase/multiunit permanent-magnet synchronous machines (PMSM) are more suitable for low-speed high-power applications because they provide higher output power, give better fault-tolerant ability, and require lower output ratings of a single inverter. Usually, to validate motor design and manufacturing quality, several tests must be performed. However, there are some problems existing in traditional testing methods for the high-power PMSM, such as complexity of test systems, high testing cost, insufficiency of test items, etc. In this paper, an indirect testing method for the mechanical characteristic of the multiunit PMSM is proposed. Through the proposed unit motor configuration, saturation considered inductance, speed-dependent losses, and other related parameters can be obtained with the proposed measuring strategy. Then, the mechanical characteristic of the multiunit PMSM can be eventually acquired based on these parameters. Finally, with the use of a laboratory-scale multiunit PMSM prototype, the experimental comparison with the conventional direct testing method validates the proposed method.