Flux maximization in wind turbine permanent magnet synchronous generator made of NdFeB permanent magnets

Abstract

The permanent magnets of the Permanent Magnet Synchronous Generator (PMSG) machine are made up of NdFeB alloy. The Neodymium-iron-boron (NdFeB) permanent magnets’ overall magnetic energy or energy product limits the maximum magnetic flux density value that can be achieved in the PMSG configuration. The generator shaft is made of stainless steel and has an electrical conductivity σ = 1.35 MS/m and relative permeability μr = 1. The flux is not well concentrated without optimizing the geometry of the NdFeB permanent magnets and rotoric slot opening. Therefore, optimization of NdFeB permanent magnet geometry and rotoric slot opening will maximize the linkage flux and mutual flux components and minimize leakage flux components of Permanent magnet synchronous generator. In this current research work, the goal is to maximize mutual flux and linkage flux while minimizing PMSG's leakage flux components at the same time by optimization of geometrical parameters of Permanent magnet synchronous generator using different optimization algorithms. In this work, finite element method is mapped by Radial Basis Function (RBF) neural network so that for any value of NdFeB permanent magnet length or rotoric slot opening, magnetic flux could be estimated immediately. In this present research work, an attempt has been made to determine the optimal values of geometric parameters, length of the NdFeB permanent magnet bm and slot opening of rotor bo for which the linkage flux and mutual flux are maximized and leakage flux is minimized. The values of permanent magnet length bm obtained using dynamic particle swarm optimization (DYPSO) and self-adaptive particle swarm optimization (ADPSO) are 28.5523 mm and 28.5524 mm respectively. The values of rotoric slot opening bo obtained using dynamic PSO and self-adaptive PSO are 18.587 mm and 18.587 mm respectively.