Patent ID: 7898110
Filing Date: 2011-03-01
Classification: H02J

Abstract:
1. An on-line uninterruptible UPS system, comprising an AC-DC conversion circuit, a DC-AC conversion circuit and a backup battery circuit, characterized in that the backup battery circuit comprises one battery group and two switch devices, the two switch devices are connected in series, and then connected in parallel with the one battery group, the two switch devices are turned on complementarily to each other, the two ends of the one battery group are connected to a positive voltage output end and a negative voltage output end respectively, and a neutral line end is connected in between the two switch devices, wherein the backup battery circuit is operative to supply a voltage of the one battery group between the positive voltage output end and the neutral line when one of the two switch devices is turned on, and to supply the voltage of the one battery group between the negative voltage output end and the neutral line when the other of the two switch devices is turned on.