Optimal design of a direct-driven permanent magnet synchronous wind generator

Low-speed high-torque direct-drive permanent magnet (LSHTPM) synchronous machines, which are characterized by large dimensions and weight, have huge potential for wind power generation. Despite to this fact, before the manufacture process of these machines, optimal design should be done to reduce the material costs and maximize power density and efficiency. In this paper, t he attention is focused on an optimal design of a 1.5MW direct-drive wind generator which is done in this research. The relationships between main dimensions of the machine and its power density, efficiency are investigated. In addition, a novel analytical optimization method is used to find optimal aspect ratio and split ratio to maximize power density and efficiency. The influences of electrical and magnetic load on the optimal aspect ratio and split ratio are also explored. Other parameters and results that may have major influence on the main dimensions such as pole number, slot width, and etc. are carried out and also discussed.