A low loss permanent magnet brushless DC motor utilizing tape wound amorphous iron

An axial-field permanent magnet brushless DC motor which utilizes tape-wound amorphous iron is proposed. Simplified waveforms and performance equations for this type of machine are presented. The machine equations and waveforms are verified with a proof-of-concept machine. No-load iron losses are compared with manufacturers´ data, and full-load iron losses are also presented. Output torques for rectangular and trapezoidal current waveforms are measured and compared, and explanations for the differences are proposed. Machine designs from a computer program which demonstrate the possible benefits for this type of machine are presented. It is suggested that this type of machine could be considerably more efficient than induction machines and, additionally, cost competitive when a variable-speed drive is already a system requirement.<>