Development of a New Permanent-Magnet BLDC Generator Using 12-Phase Half-Wave Rectifier

Six-phase double-star armature windings of a synchronous generator are essentially equivalent to 12-phase symmetrical windings displaced in turn by 30deg. This paper proposes and implements a new permanent-magnet brushless dc (BLDC) generator using 12-phase half-wave rectifier. Characteristic of output voltage is analyzed according to the star graph of slot potential, and the design constraints of armature windings are provided. Simulation models of 12-phase synchronous generator with half-wave rectifier and double-star synchronous generator with bridge rectifier are established separately. Field-circuit-coupled analysis is accomplished, and conducted modes of rectified diodes and output characteristic are obtained. It is shown that the current stress of diodes in 12-phase rectification system is less than half of that in double-star rectification system, and the output voltage fluctuation between the two different rectification systems is similar. Experimental results on prototype machine, which agree well with the simulation analysis, also verify the feature of the proposed BLDC generator system.