| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To dispense with complicated operation for prevention of the bias magnetism of a transformer and besides, lessen the undervoltage in the switching from a commercial power source to an uninterruptible power supply system. <P>SOLUTION: An output voltage detector 10 detects the voltage waveform on the load side in every half cycle, and stores in advance this voltage waveform on load side in a voltage waveform memory 11 on load side; and an output voltage waveform command operating part 12 makes the detected waveform of the output voltage detector an output voltage command as it is at normality of a commercial power source. When power abnormality occurs, it sets the voltage waveform stored in the voltage waveform memory on load side as an output voltage command in a half cycle. It includes a step of adjusting the amplitude of output voltage with the effective value of the output as a coefficient, calculating and adjusting the amount of undervoltage from the integrated value of the output, setting the integrated value in advance, and setting the reference integrated value in advance. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
