A Novel Brushless AC Doubly Salient Stator Slot Permanent Magnet Machine

A novel brushless ac, doubly salient, permanent magnet (PM) machine is proposed. It has the novel features of: 1) PMs placed in the stator slots (SSPM) to premagnetize only the stator on open circuit; 2) fail-safe capability during uncontrolled generator operation or winding short circuits; and 3) negligible cogging torque. The basic operating principle, electromagnetic performance, PM demagnetization, and the influence of leading design parameters on the machine losses and efficiency are investigated for the 12/10 stator/rotor pole machine. Finally, the performance of the proposed SSPM machine is predicted by 2-D finite-element analysis and is experimentally validated.