Deterministic and artificial intelligence approaches in optimizing permanent magnet generators for wind power applications

This paper presents the design procedure of a permanent magnet generator fo r a 20 kW wind turbine prototype. This work has been developed in the frame of a research project funded by the General Secretariat for Research and T echnology of Greece concerning the design and construction of a gear-less w ind turbine for both autonomous and interconnected operation with the elect rical grid. in wind power applications, multipole permanent magnet generato rs have become very attractive especially in small ratings. Developments in magnetic materials, on the other hand, enabled remanence levels up to 1.2 T by using convenient Nd-Fe-B magnets resulting in competitive design of "p eripheral" type generator structures. Such a design tends to replace the tr aditional "internal" configurations involving ferrites. The magnet cost rem ains the most important concern in medium scale applications that is why th e present paper is mainly devoted to the permanent magnet material optimiza tion. The method involves a preliminary design stage based on standard formulae i n a first step and the introduction of a two-dimensional finite element cod e into an optimization procedure in a second step, in order to investigate the optimal shape design problem. A neural network approach has been applie d in a third step in order to be compared with the deterministic technique, (C) 2001 Elsevier Science B.V. All rights reserved.