Axial-Flux PM Machines: A New Class of Modular and Compact Electric Generators For Hydro Power Applications

The use of slotless axial-flux permanent magnet machines (AFPMs) as a new class of direct-drive electric generators for the hydropower application is discussed. The proposed hydrogenerator arrangement has special features such as compactness and modularity that are suitable particularly for the development of small-size and medium-size bulb-generator hydropower units. The leading characteristics of AFPMs designed for the hydropower application are given and it is shown that AFPMs allow substantial saving of machine active materials if compared with the conventional synchronous machines.