Low cost cogging torque elimination at PMSM by power electronics control

Highest efficiency can be obtained by a Permanent Magnet Synchronous Machine (PMSM) drive. Simple and cost effective PMSM designs with automatically wound stator coils and therefore without stater skewing exhibit high cogging torque values coming from slot-tooth and magnet geometry. Skewing is the standard measure to avoid unfavorable cogging torques and it is usually done at rotor side with induction machines but cannot be realized at PMSM in the same way. This paper identifies cogging torque for a specific PMSM with automatically-wound stator without skewing and presents efficient solutions for a complete elimination of inherent cogging torque by advanced power electronics control and suitable power electronics hardware.