Cost Reduction of a New Fault-Tolerant Halbach Permanent Magnet Machine Using Ferrite Magnet

In the permanent magnet (PM) machines, the Halbach PM (HPM) machine can offer higher performance than others, while they require more rare-earth PMs. Due to the high price of rare-earth PMs, such as NdFeB and SmCo magnets, the cost has become a serious drawback of the HPM machine. To overcome this disadvantage, a new fault-tolerant HPM (FTHPM) machine by mixing rare-earth PM and ferrite magnets is proposed in this paper. The proposed machine can be a good candidate for many applications because of low price and stable supply of ferrite magnets. Furthermore, the lumped parameter magnetic circuit method is used to analyze the proposed FTHPM machine. In addition, the finite element method is adopted to verify the effectiveness of the theoretical analysis.