A New Hybrid Brushless DC Motor/Generator without Permanent Magnet

The Brushless DC (BLDC) motor is a simple robust machine which has found application over a wide power and speed of ranges in different shapes and geometry. This paper briefly reviews the fundamentals behind the motor and also the different types of BLDC motors with different geometries and then presents a new configuration for BLDC motor/generator, which does not use a permanent magnet in the rotor. The proposed novel motor/generator consists of two magnetically dependent stator and rotor sets (layers), where each stator set includes nine salient poles with windings wrapped around them while, the rotor comprises of six salient poles. The magnetic field passes through a guide to the rotor then the stator and finally completes its path via the motor housing. This is a three phase motor/generator and every stator and rotor pole arcs are about 30 o . A new power electronic converter is also presented. This topology provides bidirectional control of the current for each motor phase independently. This control scheme permits the motor to operate with any number of phases at any time. In this converter, four power switches in the form of a bridge connection for each motor phase has been utilized therefore, the motor can operate by switching different sequences for the current direction in each motor phase windings and also offers the choice of having any number of phases to be on at any time. A proto-type motor/generator and the drive circuit have been built and tested in the laboratory and the numerical and experimental results are presented. Due to the ruggedness of the proposed motor/generator in comparison with the conventional and brushless dc motors used for automobile applications, this unit looks very promising for use as an integrated motor generator for hybrid vehicle.

[1]  L. Tutelea,et al.  PM-assisted reluctance synchronous motor/generator (PM-RSM) for mild hybrid vehicles: electromagnetic design , 2004, IEEE Transactions on Industry Applications.

[2]  S. J. Wang,et al.  A new type single-phase spindle motor for HDD and DVD , 1999 .

[3]  Duane C. Hanselman,et al.  Brushless Permanent-Magnet Motor Design , 1994 .

[4]  J. E. Gilliam,et al.  Brushless Permanent-Magnet and Reluctance Motor Drives , 1990 .

[5]  Nabeel A. O. Demerdash,et al.  Modeling of effects of skewing of rotor mounted permanent magnets on the performance of brushless DC motors , 1991 .

[6]  O. Wasynczuk,et al.  Analysis and Modeling of a Single-Phase Brushless DC Motor Drive System , 1989, IEEE Power Engineering Review.

[7]  Ali Emadi,et al.  Low-Voltage Switched Reluctance Machine Based Traction Systems for Lightly Hybridized Vehicles , 2001 .

[8]  M. Ehsani,et al.  Advantages of switched reluctance motor applications to EV and HEV: design and control issues , 1998, Conference Record of 1998 IEEE Industry Applications Conference. Thirty-Third IAS Annual Meeting (Cat. No.98CH36242).

[9]  Hamid A. Toliyat,et al.  A new topology for unipolar brushless DC motor drive with high power factor , 2003 .

[10]  Nabeel A. O. Demerdash,et al.  Three-dimensional finite element analysis of permanent magnet brushless DC motor drives-status of the state of the art , 1996, IEEE Trans. Ind. Electron..

[11]  A. Kusko,et al.  Definition of the brushless DC motor , 1988, Conference Record of the 1988 IEEE Industry Applications Society Annual Meeting.

[12]  Robert L. Steigerwald,et al.  Development of a Unipolar Converter for Variable Reluctance Motor Drives , 1987, IEEE Transactions on Industry Applications.

[13]  K. Matsuoka,et al.  Automatic design method of brushless DC motors for VCRs , 1989 .

[14]  B. Fahimi,et al.  A switched reluctance machine-based starter/alternator for more electric cars , 2004, IEEE Transactions on Energy Conversion.

[15]  K.R. Rajagopal,et al.  FE analysis and CAD of radial-flux surface mounted permanent magnet brushless DC motors , 2005, IEEE Transactions on Magnetics.

[16]  R. Krishnan,et al.  A new power converter topology for PM brushless DC motor drives , 1998, IECON '98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.98CH36200).

[17]  R. Krishnan,et al.  A novel single switch per phase converter topology for four-quadrant PM brushless DC motor drive , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.