Design and Experimental Evaluations of 5kW-Surface Permanent Magnet Vernier Machines

Abstract

This paper presents experimental evaluations of 5kW-level Surface Permanent Magnet Vernier Machines (SPMVM). The SPMVM has a feature of high-torque with low current loading, and thus has a possibility to achieve high torque and high efficiency at once, which is difficult with the conventional permanent magnet machines. Following to a brief explanation about the design of the prototype machines, experimental results are brought about, which show good agreements between the designed and measured characteristics. The experiments reveal that the SPMVM inherently has relatively low power factor, which is below 0.6 this case. It is also confirmed that the cogging torque becomes about 2 to 3% of the rated torque because of slight magnetic unbalances in the prototypes. As a conclusion, the most attractive features of the SPMVM are high torque density and low power loss, and thus the SPMVM is suitable for the applications that require high torque constantly, and that the weight or volume limitations are strict. © 2002, The Institute of Electrical Engineers of Japan. All rights reserved.