Being the uninterrupted power supply system where it possesses the uninterrupted power supply system and the multiple

摘要

PROBLEM TO BE SOLVED: To prevent erroneous charge mode determination and erroneous mode change in a "multi-system power receiving" uninterruptible power supply system having a common battery.;SOLUTION: The following three signals are input to a target-of-synchronization signal selection circuit 10: "inverter power feeding time" signal, "input-side multi-system mode" signal, and "rectifier operation" signal. In this example, it will be assumed that the "input-side multi-system mode" signal and the "rectifier operation" signal are at '1'. When in an inverter power feeding state, that is, the "inverter power feeding time" signal is at '1', a "bus voltage selection" signal is at '1' and a bus signal is selected as the signal to synchronize with. In the other cases (where the "inverter power feeding time" signal is at '0'), a straightforward voltage (commercial input) is selected as the signal to synchronize with.;COPYRIGHT: (C)2010,JPO&INPIT