A Novel Stator PM Dual-mechanical-port Dual-electrical-port Machine

The brushless dual-mechanical-port dual-electrical-port (BLDD) machine has become a good candidate to replace conventional continuously variable transmission devices owing to its high compactness, high reliability and fast dynamic response, etc. However, the torque density of permanent magnet synchronous machine (PMSM) part in the BLDD machine is reduced by large effective airgap length. In this paper, a novel stator PM BLDD machine topology is proposed, in which consequent-pole Halbach magnets are placed at stator slot opening to construct the PMSM part. In this way, the effective airgap length is reduced, and the torque density is improved. The structure and operation principle of the proposed BLDD machine are first analyzed based on the flux modulation theory. Then, the operation characteristics and function of the proposed machine are verified by finite element analysis (FEA). Finally, the electromagnetic performances of the regular and proposed BLDD machines are compared.