An Indirect Testing Method for the Temperature-Rise of Multi-unit Permanent Magnet Synchronous Machines

Compared with traditional three-phase machine, multi-phase/multi-unit permanent magnet synchronous machine (PMSM) are more suitable for vehicle power system because that 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. Temperature-rise measurement is certainly a common demand of customers and manufacturers. The manufacturers have to optimize the product to be competitive, while the user wants to be sure that the motor is in accordance with the insulation temperature class limit. However, there are some problems existing in traditional direct temperature rise testing methods for the high-power PMSM, such as complexity of test systems, high testing cost, etc. In this paper, an indirect testing method for the temperature-rise of the multi-unit PMSM is proposed. With the use of a laboratory scale multi-unit PMSM prototype, the experimental comparison with conventional direct testing method validates the proposed method.