Reducing Cogging Forces in a Linear Generator for Ocean.

An increased awareness of the environment and the growing energy needs of countries like China and India have accelerated the search for sustainable alternatives to fossil fuel energy sources. Generating electricity from ocean waves is a viable alternative. This is because the energy densities are sufficient to supplement the grid and thus make it economically viable. The seasonal supply profile also matches the demand profile. There are currently many different devices operating on different principles, the most promising of these is the oscillating body device using a linear generator. Linear generators are able to convert linear motion into electrical energy without the need for intermediate gears, screws or crank shafts. This increases the overall efficiency and makes the device more reliable. Static force simulations were done on a novel linear generator design. The generator combines the duel air-gap of a double sided topology with the encapsulation of the magnetic field in a tubular topology. This results in an increased force density, but also large cogging forces. The topic of this thesis is to find suitable methods of reducing the cogging forces.

Rael Schmulian completed his Bachelors and Masters degree in Electrical Engineering at the University of the Witwatersrand in South Africa. His masters research was focused on optimising the design of an ocean wave linear generator. He is now exploring a new avenue of research, in an attempt to find viable household renewable energy solutions.