| 摘要 |
PURPOSE:To prevent the generation of abnormal currents by inter-winding magnetic coupling without mounting an AC reactor by bringing the voltage of each input winding to the same phase and bringing momentary voltage to the same voltage. CONSTITUTION:PWM system voltage type inverters 21a, 21b using self-arc- extinguishing type switching elements each supply input windings 4a, 4b for duplex winding type induction motors 4 directly with three-phase AC voltage Va, Vb having waveforms shown in the figures (a)-(b). Accordingly, since voltage having the same phase is fed to the input windings 4a, 4b-that is, momentary voltage is made the same at all times, there is inter-winding magnetic coupling, but abnormal currents do not flow, and an AC reactor may not be mounted. |
