| 摘要 |
PURPOSE:To follow up the frequency quickly by deciding the direction for controlling the frequency based on the direction at the time when the phase difference passes 180 deg., controlling the frequency uniformly only in that direction, deciding the direction where the phase difference passes 0 deg. when both frequencies are close each other, and resetting the control based on a normal phase difference signal. CONSTITUTION:The synchronous control method for an uninterruptible power supply comprises a function for detecting that the output from a phase difference detecting function section 220 has passed 180 deg. and 0 deg. along with the passing direction thereof, and a function generating a signal for increasing/decreasing the frequency of power supply. The method further comprises a function for selecting an output between the section 220 and a setting function section 250 depending on the output from a decision function section 230. When an output from the section 220 passes 180 deg., any one set output is selected depending on the passing direction of output and the output frequency of one power supply is controlled. Control of the section 220 is reset depending on the passing direction of output therefrom when the output passes 0 deg.. |
