Experimental Verification of Dual Airgap PMVM Having Yokeless Rotor for Extended Speed Application

Abstract

Permanent magnet vernier machines (PMVM) are recently proven to be a good candidate for extended-speed operation in the constant power region. In this paper, a dual-airgap PMVM having a yokeless rotor has been presented for extended-speed operation. The PMVM model is designed with two stators and a sandwiched rotor without an iron yoke. To achieve the extended speed operation, the yokeless structure of dual airgap PMVM benefits from the increased inductance which makes it possible to operate at higher speeds. For this purpose, the prototype of this machine is built, and experimental testing is performed to verify its performance in a constant power region. Electromagnetic performance such as back EMF and output torque at high speeds are analyzed. The experimental results are compared with those obtained using finite element analysis which confirms the ability of dual airgap PMVM having a yokeless rotor to perform well at higher speeds in a constant power region.

Keywords

• Dual airgap PMVM
• radial type
• yokeless rotor
• extended speed operation
• finite element method
• experimental verification