Design and analysis of a new permanent magnet brushless DC machine

A new permanent magnet (PM) brushless DC machine with a unique feature of flux regulation is proposed in this paper. The originality is that the air-gap flux of the machine is generated by both the PM excitation and the specially controlled stator current under the same PM pole. The machine possesses advantageous characteristics of both the PM brushless DC machine and the DC series machine. The rotor configuration and principle of operation are so novel that the magnetic field distribution and performances of the machine are analyzed by use of a time-stepping finite element method. The theoretical calculation is also verified by experimental measurement.