Design of Large PM-Generators for Wind Power Applications

Abstract

This report describes generator design for wind power applications. It explains a modern design procedure which uses both analytical and numerical analysis. The numerical analysis uses finite element analysis and in this report it is performed in Comsol. The report is done in cooperation with the industrial company, SmartMotor AS.

A new Matlab-based script is developed in order to handle the winding layout of distributed windings which will be used in the finite element analysis. The script saves the designer valuable time. A new method that uses Fourier analysis for calculating iron losses for the analyzed geometry is suggested. It is concluded that the Fourier analysis is an incorrect approach as it returns not plausible losses. The new method could however be used without a Fourier analysis. It is concluded that this method is more accurate and less time consuming compared to the method that was used before.

In recent papers concentrated windings have been suggested to be more suitable for wind power applications than the conventional distributed windings. In this report distributed winded and concentrated winded generators have been designed and simulated. The results from these simulations are the basis of the comparison. The comparison uses key performance indicators for each machine, which will give an overview of how well the machines perform. In this report it is concluded that both generators offer equal performance regarding voltage waveform and vibrations. The concentrated winded generator does however allow easier manufacturing, better efficiency and shorter length. It is superior in terms of torque per weight. It is therefore concluded that the concentrated winded generator is more suitable for wind power applications.