| 摘要 |
PURPOSE: To set the input voltage of a PWM converter at an AC input voltage or less and to improve the power factor of an AC power supply by adding an effective current command signal and a reactive current command signal, outputting the current command signal, and performing the ignition control of the PWM converter in correspondence with the current command signal. CONSTITUTION: A reactive current command circuit 38 receives an AC power supply voltage Es and the detected signal of a current If flowing through a phase advancing capacitor 31 and outputs a reactive current command signal Sq, which has the same magnitude as the current If and the phase that is delayed 90 deg. with respect to the AC power supply voltage Es, to an adder 39. In the adder 39, an effective current command signal (the product of the AC power supply voltage Es and a voltage deviation signalΔV) and the reactive current command signal Sq are added, and a current command signal S is obtained. Then, the ignition of a PWM converter 21 is controlled in correspondence with the current command signal S. Thus, the input voltage of the PWM converter 21 can be set at the AC input voltage or less, and the power factor observed from the AC power source 1 can be set to 100%.
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