Torque ripple minimization of an IPMSG with fractional-slot, concentrated-winding using uncontrolled rectifier-connected boost converter control

This paper presents a technique to reduce electromagnetic torque ripple of an IPMSG with fractional-slot, concentrated-winding which is connected to a rectifier and a boost converter. Firstly, the generator was controlled using DC current control of the boost converter. The generator torque ripple with this conventional method was found as 29.7% of rated torque which is significant to cause generator losses and drive train vibrations. Hence, a new control approach to reduce the ripple was proposed. The proposed strategy directly controls the electromagnetic torque of the generator using a rotor position based torque estimator. The new method was able to reduce torque ripple to 7.6% of the rated torque. The generator was controlled at rated speed and rated current with each of methods mentioned above for the analysis. The improvement was experimentally verified using a 4kW prototype fractional-slot, concentrated-wound IPMSG.