Patent ID: 6906435

Claim:
An interruptible power system comprising: two current conversion units coupled in parallel between an input AC voltage and a load, wherein each current conversion unit is composed of a rectifier and an inverter both connected in series, wherein the two rectifiers and the two inverters are further connected to form a cross configuration; at least one battery set coupled to output terminals of the two rectifiers; an input transformer coupled between the input AC voltage and input terminals of the two current conversion units; an output transformer coupled to output terminals of the two current conversion units; a static transform switch (STS) having two input terminals and one output terminal, wherein one of the two input terminals is coupled to an output terminal of the output transformer and the other input terminal is coupled to the input AC voltage through a by-pass switch, wherein the output terminal of the STS is coupled to the load; wherein when either the inverter or the rectifier is faulty in one of said current conversion modules, the other inverter or rectifier in the same module is still operated and controlled by the other current conversion module.