Title :
Multilevel DC link inverter for brushless permanent magnet motors with very low inductance
Author :
Su, Gui-Jia ; Adams, Donald J.
Author_Institution :
Nat. Transp. Res. Center, Oak Ridge Nat. Lab., TN, USA
Abstract :
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.
Keywords :
air gaps; brushless machines; electric current control; inductance; insulated gate bipolar transistors; invertors; machine control; permanent magnet motors; power bipolar transistors; power semiconductor switches; switching circuits; IGBT limited switching frequency; IGBT switching devices; brushless permanent magnet motors; current regulation; current ripple; current ripples; design guidelines; ironless stator structure; long effective air gaps; low inductance; multilevel DC link inverter; operating principle; Air gaps; Brushless motors; Current control; Inductance; Induction motors; Insulated gate bipolar transistors; Inverters; Magnetic analysis; Permanent magnet motors; Stators;
Conference_Titel :
Industry Applications Conference, 2001. Thirty-Sixth IAS Annual Meeting. Conference Record of the 2001 IEEE
Conference_Location :
Chicago, IL, USA
Print_ISBN :
0-7803-7114-3
DOI :
10.1109/IAS.2001.955549
