Design of low speed axial flux permanent magnet generators for marine current application

Abstract

The aim of this research work is to design, built and test low speed multi-pole permanent magnet generators for ocean energy conversion systems. Vertical axis drag/lift type ocean current turbines have low speed due to water speed of less than 1m/s. A low speed permanent magnet generator can be utilized to deliver low power that can be used to power- rated sea pods. The study focuses on the design of a permanent magnet generator, which is suitable for under water application and can generate electric power from the low speed marine currents (typically below 100rpm). This thesis explores different low speed permanent magnet generators and focuses on multi-pole direct driven axial flux permanent magnet Generator (AFPMG). AFPMG is suitable for direct coupled systems. Two types of AFPMG are designed and tested for several performance criterions. The prototyped AFPMGs are tested and the results are presented and discussed in this thesis. The first design produced 5.2V, 3.5W and the second design produced about 5.5V, 2W at 70 rpm. Both designs are simple in construction, economically viable and suitable for low electric power generation from ocean currents.