Patent ID: 7023109
Filing Date: 2006-04-04
Classification: H02J

Abstract:
1. An uninterruptible power supply unit for receiving AC power input and supplying AC power output, comprising: a power supply line including a first power supply line having first input and output terminals, and a second power supply line having second input and output terminals, a power supply switch interposed in the first power supply line for connecting and disconnecting the first power supply line, a parallel converter connected between the power supply switch and the first output terminal parallel to the first and second input and output terminals, a conductive path for connecting the first and second power supply lines between the power supply switch and the parallel converter, electrical power storage means connected to the parallel converter for storing electrical power, a series converter connected to the first power supply line in series between the parallel converter and the first output terminal for maintaining a voltage of the AC power output at the first output terminal at a predetermined value using the electrical power storage means as an energy source, voltage abnormality detection means connected to the first and second input terminals for detecting an abnormality of the AC power input at the first and second input terminals, and controlling means connected to the power supply switch, the parallel converter and the voltage abnormality detection means for controlling the power supply switch and the parallel converter in response to a result detected by the voltage abnormality detection means, said controlling means, when the voltage abnormality detection means detects no abnormality, controlling the power supply switch to connect the first power supply line and controlling the parallel converter so that the electrical energy stored in the electrical power storage means has a predetermined value, and when the voltage abnormality detection means detects the abnormality, controlling the power supply switch to disconnect the first power supply lines and the parallel converter.