Taguchi's robust design optimisation of water‐cooled ISG motors considering manufacturing tolerances

Abstract

Electrical machines are widely used as a driving source for various applications because of their wide speed range, high efficiency, and torque density. Similar to any other machine, manufacturing tolerances occur when mass producing the motors. In particular, the tolerances of the shape of the motor or the residual flux density in the permanent magnet significantly affect the back-electromotive force (EMF), inductance etc. When the magnitude of the back-EMF is changed, the armature current must be changed to obtain the same torque. This consequently affects the loss of the motor, and hence leads to changes in efficiency. In particular, the loss changes cause thermal problems such as irreversible demagnetisation of the magnets and dielectric breakdown due to the increase in the temperature of the coils. Therefore, to reduce the inevitable manufacturing tolerance, a robust methodology should be assured. Here, the Taguchi's robust design is applied to an integrated starter-generator motor by using the signal-to-noise ratio to consider the coil temperature.

Robust Design of Induction Machines for High-Speed Electric Freight Locomotive Applications

“…For example, the tolerances for the remanent flux density of the PMs, the thickness and length of the PMs, and the thickness of the electrical steels are listed in the manufacturer's datasheet as 5%, 1%, and 8 to 10%, respectively [4]. Therefore, it is necessary to consider these uncontrolled tolerances in a proper and robust design [5].…”