| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the number of parts and power loss of a single-phase AC uninterruptible power supply. <P>SOLUTION: A half bridge type AC-DC conversion circuit is composed of first and second FET switches S1, S2, first and second capacitors 7, 8, and a first reactor 6. A storage battery 12 is connected to a series circuit of the first and second capacitors 7, 8 in parallel. A half bridge type inverter composed of third and fourth FET switches S3, S4 is provided. An input switch 13 is connected between a first power supply terminal 1a and an interconnection point P1 of the first and second capacitors 7, 8. A load 2 is connected between a second power supply terminal 1b and an inverter output terminal 3. When the frequency of an AC power supply 1 is abnormal, the input switch 13 is turned OFF, the first to the fourth FET switches S1 to S4 are operated as a full bridge type inverter to feed a voltage of constant frequency to the load 2. At the power failure, a bypass switch 16 is turned ON. <P>COPYRIGHT: (C)2009,JPO&INPIT |
