| Abstract |
Variable speed drives have become popular solutions in many applications. Most research and development activities have been concentrated on converter-based speed variation of conventional squirrel-cage induction motors. New drives usually need not to be operated directly by the mains, or they are custom-design drives such as traction drives. In these application fields, competitors to the squirrel cage induction motor have appeared. Recent research has put an emphasis on reluctance motors, three phase and polyphase permanent magnet motors, and transversal flux motors. Siguificant improvements in motor size, weight, and cost can be achieved with regard to the induction motor. The purpose of this paper is to point out the properties of the complete drive systems including power electronics. In order to get a quantitative comparison with respect to the state-of-the-art, all motors mentioned above are dimensioned for a typical specification. Then the appropriate power electronics circuit is designed. It is shown that significant improvements in motor properties can be achieved. On the other hand, most new motor conceptions lead to higher requirements in power electronics. Each drive system offers advantages for special applications. In general purpose drives, the induction motor fed by a pulse width modulated voltage source inverter will probably continue its success, while demands such as high efficiency or low size and weight will ask for other solutions. |
