Considering Wind Speed Characteristics in the Design of a Coreless AFPM Synchronous Generator

Abstract

This paper presents an improved design procedure of a coreless Axial Flux Permanent Magnet Synchronous Generator (AFPMSG) for wind turbine application. An analytical design approach is proposed based on sizing equations and a nonlinear Magnetic Equivalent Circuit (MEC) model of AFPMSG. The reluctance of rotor back iron core is separated into two parts, which are calculated through the nonlinear iterative algorithm. An optimal design of the coreless AFPMSG is performed using Partial Swarm Optimization (PSO) method in order to increase the Annual Energy Yield (AEY) of the generator. The statistical model of wind speed distribution and wind turbine characteristic are used for considering the generator performance over the whole operating wind speed range. In order to obtain the optimal values of design variables, the optimization procedure is provided for various number of pole pairs and coil numbers. The proposed procedure is used to design a double rotor-one coreless stator AFPMSG. Finally, 3-D Finite Element Analysis (FEA) is used to validate the design algorithm. Also, the generator performance is evaluated for different values of wind speed and load currents.