AC power supply apparatus and method for detecting instantaneous voltage fluctuation

摘要

PROBLEM TO BE SOLVED: To solve the problem that a lot of time is required until the instantaneous voltage fluctuation of a system power supply signal is detected in a conventional AC power supply device.SOLUTION: An AC power supply device includes: an inverter 13 for generating an AC power supply signal from a DC power supply signal, and for outputting the AC power supply signal to system wiring to which a power from a commercial system power supply SPS is supplied; an instantaneous voltage fluctuation detection part 30 for outputting a voltage fluctuation detection pulse signal S2, and for switching the duty ratio of the voltage fluctuation detection pulse signal S2 between a first duty ratio and a second duty ratio in accordance with the change of a magnitude relation between the effective value of a system power supply signal to be transmitted to the system wiring and a predetermined voltage fluctuation detection threshold; and a control part 11 for controlling an inverter 12, and for instructing the inverter 12 to change the output voltage of the AC power supply signal in accordance with the switching of the duty ratio of the voltage fluctuation detection pulse signal S2.SELECTED DRAWING: Figure 1