Optimization of permanent magnet machines with respect to torque and audible noise

The electromagnetically generated audible noise of rotating electrical machines has gained considerable attention. The authors use the finite element technique to optimise a buried magnet permanent magnet machine with respect to audible noise and torque. The buried magnets are tangentially magnetized and set into radial slots in a steel rotor. The combination of such a motor and an inverter has all the characteristics required for an efficient low-speed drive system