Through insulating trance and the alternating current input filter from the

摘要

PROBLEM TO BE SOLVED: To provide an uninterruptibe power supply device and an input current control method therefor, capable of effectively eliminating the distortions of an input current caused by saturation of an input isolation transformer.;SOLUTION: This uninterruptibe power supply device includes: a converter 14 fed from an AC input power supply 1 through the isolation transformer 11; a DC filter for smoothing the DC output; and an inverter 17 which is fed to a load 3 by converting the output to AC. A first controller 36 regulates deviation between a DC voltage command and an input voltage of the inverter to output a DC current reference, generates a reference sine-wave synchronized with a phase and a frequency of the AC input power supply, adds a distorted current compensation reference to the reference sinwave to take it as the phase reference and multiplies the phase reference by the DC current reference to take it as an AC current reference. Moreover, a second controller 40 regulates the deviation between the AC current reference and the input current of the inverter to output an AC voltage reference, and supplies a gate pulse to a switching device for the converter, thus performing PWM control.;COPYRIGHT: (C)2007,JPO&INPIT