Multilevel DC link inverter for brushless permanent magnet motors with very low inductance

Due to their long effective air gaps, permanent magnet motors tend to have low inductance. The use of ironless stator structure in present high power PM motors (several tens of kWs) reduces the inductance even further (<100 /spl mu/H). This low inductance imposes stringent current regulation demands for the inverter to obtain acceptable current ripple. An analysis of the current ripple for these low inductance brushless PM motors shows that a standard inverter with the most commonly used IGBT switching devices cannot meet the current regulation demands and will produce unacceptable current ripples due to the IGBT's limited switching frequency. This paper introduces a new multilevel DC link inverter, which can dramatically reduce the current ripple for brushless PM motor drives. The operating principle and design guidelines are included.

[1]  Gui-Jia Su,et al.  Design of a PM Brushless Motor Drive for Hybrid Electrical Vehicle Application , 2000 .

[2]  Pragasen Pillay,et al.  Modeling, simulation, and analysis of permanent-magnet motor drives. II. The brushless DC motor drive , 1989 .

[3]  I. Takahashi,et al.  A super high speed PM motor drive system by a quasi-current source inverter , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[4]  F. Crescimbini,et al.  PERFORMANCE OF CORELESS-WINDING AXIAL-FLUX PERMANENT-MAGNET GENERATOR WITH POWER OUTPUT AT 400 Hz - 3000 rev/min , 1997 .

[5]  D. J. Adams,et al.  A power line conditioner using cascade multilevel inverters for distribution systems , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[6]  K. T. Chau,et al.  A novel polyphase multipole square-wave permanent magnet motor drive for electric vehicles , 1994 .

[7]  K. T. Chau,et al.  A novel polyphase multipole square-wave permanent magnet motor drive for electric vehicles , 1993, Proceedings Eighth Annual Applied Power Electronics Conference and Exposition,.

[8]  Joachim Holtz,et al.  High-performance current regulation and efficient PWM implementation for low-inductance servo motors , 1999 .

[9]  Thomas A. Lipo,et al.  A hybrid multilevel inverter topology for drive applications , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.

[10]  Ezio Santini,et al.  Multi-stage axial-flux PM machine for wheel direct drive , 1995 .