A new type of modular, direct drive permanent magnet generator for wind turbines has been patented. Windpower & Co (UK) Ltd built the first, credible size, variable speed generator to this concept. The testing of the highly unusual topology revealed four new types of loss mechanism which resulted in very low efficiency. There were also problems with noise, starting and cogging torque, thermal effects which tended to close the air gap and very high cost. Nevertheless, subsequent studies showed that the overall prospects remain good and efficiency should be high (about 96%) if the new parasitic losses can be eliminated and the other problems overcome. The research project will improve the predictive model, further evaluate the cause of one of the existing losses, exarnine and select the best ways of largely eliminating parasitic losses by innovative design and material use as well as reducing vibration, noise and starting torque, reducing the cost of power conditioning and developing a simple to use integrated wind turbine and generator controller. The results of the research will be tested on a MW scale generator test rig which will simulate all the working conditions of a wind turbine and measure the generator's overall efficiency and assess its power quality.
Funding SchemeEAW - Exploratory awards