Outline design of a direct-drive low-speed brushless permanent-magnet generator for an ocean-going Bristol-cylinder type device

This paper describes the simple design rules that can be used to design direct-drive brushless generators for an ocean wave device. This is a very low speed device so the pole number and diameter is very large. While these machines may be large the pole pitch and axial length is low. The application is described and an air-gap wound design developed and simulated using analytical and finite element analysis techniques. A 248 pole design with surface rotor magnets is developed.