The Study on Improving Reluctance Torque and Preventing Irreversible Demagnetization by Modified the Shape of Conventional Ferrite Flux-Concentrated Motor

Abstract

In recent years, most electric motors have been replaced by permanent magnet synchronous motors to improve efficiency. However, the production of rare earth-earth magnets, a key material for electric motors, is concentrated in certain countries, so the price is high. Therefore, it should be replaced by an electric motor that uses non-rare earth magnets, but this is also not easy due to the low performance of non-rare earth magnets. Therefore, most motors using non-rare earth are made of spoke type to compensate for low magnetic flux density. But, Spoke-type Permanent Magnet Synchronous Motor (Spoketype PMSM) still have many problems. Although the Spoke-type PMSM produced high magnetic flux density with low magnetic flux magnets, its performance is still lower than that of an electric motor using rare earth magnets. and spoke type PMSM is vulnerable to irreversible demagnetization. In this paper solved the above problem by dividing the magnet in half and inserting the iron core in the q-axis path. The idea proposed in this paper increased the reluctance torque, thereby improving the overall torque. In addition, the irreversible demagnetization was reduced by passing the magnetic flux through the iron core.