Uninterruptible polyphase AC power supply

摘要

An uninterruptible polyphase AC power supply equalizes an electric power taken out from a polyphase AC power source, even if unbalanced load is connected to output. The uninterruptible AC power supply comprizes a polyphase balanced phase shifter generating one control signal in synchronous with one phase of the AC power source and other control signals each having a prescribed phase difference with respect to said former control signal, a phase comparator comparing phases of said respective control signals with those of output voltage of the uninterruptible AC power supply to output correction signals whch minimize the phase difference between them, a plurality of phase shifters for signal phase to which are respectively supplied said control signals as well as said correction signal in the corresponding phases to generate invertor control signals in the corresponding phases, and a means for supplying the invertor control signals being the outputs of said respective phase shifters for single phase to the invertors in the corresponding phases.