UNINTERRUPTED POWER SUPPLY SYSTEM Russian patent published in 1997 - IPC

FIELD: electrical engineering, power supply of important services with alternating current. SUBSTANCE: uninterrupted power supply system has n single-phase synchronous A. C. sources which are connected to load through unidirectional A. C. element. Each unidirectional element is fabricated in the form of four one-way electric keys of two types. Each two keys of different types are connected in parallel and are placed between one of poles of source and load, their controlling inputs are connected to other pole of source. In this case backward energy transfer from load to source while one of sources is disconnected or fails is prevented. EFFECT: enhanced reliability of power supply system. 4 cl, 2 dwg