| 摘要 |
PURPOSE: To obtain an uninterruptible power-supply apparatus by which the generation of a resonance phenomenon is suppressed effectively with reference to respective filter circuits which are connected, at two stages, to the output side of a power converter. CONSTITUTION: A first-stage filter circuit is formed of a reactor 3 and of a capacitor 4, and a second-stage filter circuit is formed of a transistor 5 and of a capacitor 6. The output voltage of a UPS apparatus is detected by a voltage detector 13, and it is fed back so as to be subtracted from a voltage reference Vref. The current of the capacitor 4 is detected by a current detector 11, and it is multiplied by a prescribed gain so as to be subtracted from the output of a voltage control circuit 15. Thereby, it is possible to obtain an effect similar to an effect that a damping resistance is added to the first-stage filter circuit. In addition, voltages of the capacitors 4, 6 are detected by a voltage detector 12 and the voltage detector 13, and they are multiplied by a prescribed gain so as to be subtracted from the output of the voltage control circuit 15. Thereby, it is possible to obtain an effect similar to an effect that a damping resistor is added to the second-stage filter circuit. |
