Study of disk type corelss permanent magnet synchronous generator applied in ocean current energy system

The paper discusses the feasibility of a novel disk shape coreless permanent magnet synchronous generator (PMSG) applied in ocean current energy system (also called marine current energy), and presents the construction and model of the ocean current generator system. A prototype of 300W, 375r/min permanent magnet synchronous generator is designed based on such an application requirement. An outer-rotor design of the PMSG facilitates direct coupling of the generator to the ocean current turbine, while a coreless armature limits the resistive loss and improves the efficiency. The flux-density distribution is studied, with the aid of a finite element software package. An experiment of the performance of the disk type coreless PMSG is presented, for both constant-speed and variable-speed operation. The result has proved that the disk type coreless PMSG is appropriate for the ocean current energy system.