Design and Optimization of a New TFPM Generator with Improved Torque Profile

Abstract

This paper aims to address the design, modelling and optimization procedure of electrical generators for direct drive wind turbine application by introducing a new transverse flux permanent magnet machine (TFPM). The proposed TFPM benefits from characteristics such as: using ferrite PMs instead of rare-earth PMs, fully utilization of PMs, employing only one PM per phase, and cancelling all the even order harmonics. Design algorithm of the TFPM for direct drive wind turbine application is proposed which employs 3-D magnetic equivalent circuit method instead of time consuming finite element analysis (FEA). The MEC method is developed by taking account of rotor movement, iron saturation effect and fringing flux. The MEC results are compared with FEA in terms of accuracy and processing time. In order to improve the TFPM torque characteristics, the Taguchi optimization method is employed and the rated torque along with torque ripple are improved significantly.