Cogging torque reduction for permanent magnet structure of radial flux permanent magnet generator

Abstract

Recently, Permanent Magnet Generator has been widely used due to its ability of having simple structure yet high efficiency. A radial flux permanent magnet generator’s (RFPM) cogging torque leads to the decrease in output power. Generally, cogging torque is affected from the size of permanent magnet. This paper presents the techniques for cogging torque reduction and low torque ripple of RFPM design. This research used two methods to reduce the cogging torque which is the permanent magnet pole-arc ratio and also the permanent magnet structure. The cogging torque has been successfully reduced by increasing the permanent magnet pole-arc ratio and reducing the permanent magnet structure The best design configuration that can reduced the cogging torque by using pole-arc ratio is 0.49 pole-arc ratio which can reduce the cogging torque to 0.6986Nm. Moreover, for PM structure method 0.25 PM structure has been chosen as the best configuration since it can reduce the cogging torque to 0.2366Nm. This method able to reduce the cogging torque by 69.88%. Hence, both of these techniques are successfully reduced the cogging torque.