| 摘要 |
PURPOSE: To suppress the harmonic resonance current generated by switching operation actively by causing at least a resistor, a diode, a capacitor, and a switching circuit to constitute a power converter, and providing a feedback circuit for feeding energy back from the main circuit. CONSTITUTION: A power converter has a damping resistor RD1 connected between a snubber capacitor CS1 and a diode DR1, and a damping resistor RD2 connected between a snubber capacitor CS4 and a diode DR2. When PWM control is performed by this circuit, harmonic resonance current generated in a loop starting from a positive-side DC power source VDP passing a neutral- point diode DN1, and returning to the positive-side DC power source from a regenerative capacitor CR1 via the snubber capacitor CS1, the damping resistor RD1, and the diode DR1, is suppressed by the damping resistor RD1. Accordingly, it becomes possible to suppress the harmonic resonance curent generated at every switching, and to reduce thermal losses caused by the skin effect of the buses and the wiring of the main circuit. |
