Cost efficiency analysis of slow-speed slotless permanent magnet synchronous generator using different magnetic materials

This paper analyses the possibilities and cost-efficiency of using different magnetic materials on the rotor of a slow-speed slotless permanent magnet synchronous generator. The experimental tests were carried out using three different magnetic materials - SmCo, NdFeB and ferrite. Cost efficiency analysis of the tested generator concepts is based on magnetic material quantities, current market prices of those magnetic materials and generator output characteristics in case of the use of different magnetic materials on the rotor of the machine. The goal of the conducted study is to find the magnetic material with the best cost efficiency ratio to use on the rotor of the designed permanent magnet synchronous generator. The analysis shows that there are considerable alternatives to the most common NdFeB magnets. Test results and analysis are presented. Necessity of further study is pointed out.