Feature Investigation of a New Dual-Stator Doubly Salient Brushless DC Generator With and Without Rotor-Yoke

In order to reduce the inherent voltage ripple and torque pulsation in variable reluctance machine, a new dual-stator doubly salient brushless DC machine(DS-BLDCM) is proposed and investigated in this paper. Configuration of the dual-stator DS-BLDCM with field winding is introduced, and basic operation principle of voltage ripple reduction is interpreted. A 24/16-16/24-pole DS-BLDCM is presented as case study. The field distribution, phase flux linkage and phase voltage are predicted, and output capability is analyzed and compared to that of conventional 24/16-pole doubly salient machine by finite element analysis(FEA). In view of the magnetic flux distribution, a dual-stator DS-BLDCM without rotor-yoke is further proposed, and the electromagnetic characteristic is preliminarily studied. The analysis results indicate that the voltage ripple can be effectively reduced with acceptable sacrifice of power density.