Cogging Torque Minimization Using Skewed and Separated Magnet Geometries

Dalcali A., KURT E., Celik E., ÖZTÜRK N.

JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, vol.23, no.1, pp.223-230, 2020 (ESCI) identifier


In the study, analytical design, analysis and optimization of a 2.5 kW 14-pole, 84-slot permanent magnet synchronous generator (PMSG) have been performed. The performance characteristics of this PMSG such as efficiency, torque, cogging torque and magnetic flux density are assessed. Then, 3D model of the respective generator is acquired to examine the effect of magnet geometry on the cogging torque produced. In that context, the effects of splitted and skewed magnet structures are examined. In the first design, the magnet is modelled with one piece and the rms value of the cogging torque is found as 436.75 mNm. In the second case, a certain skewed slit is made alongside the magnet and that yields a slightly reduced cogging torque of 434.58 mNm. In the other design, the magnet of the first design is divided into two sub-parts, which are then combined together in a skewed fashion. Thus, the value of cogging torque is found as 159.60 mNm. Eventually, by making two certain slits on the last model, cogging torque is further depressed down to 89.95mNm. It is concluded from the obtained results that the last design contributes an improvement in the value of cogging torque up to 80% compared to the initial design.