Patent ID: 7652397

Claim:
A parallel-connected uninterruptible power supply system connected to a power source and a load, comprising: a power distribution circuit connected to the power source and the load and having a plurality of first connectors; a plurality of uninterruptible power supplies, each of which includes a controller, at least one second connector and a pull-down circuit, wherein the pull-down circuit is connected to the controller and the second connector; and a plurality of transmission lines, wherein each of which includes two ends and a pair of third connectors each disposed at one end, and wherein the third connector is connected with the first connector of the power distribution circuit and a second connector of an uninterruptible power supply; wherein the first connector, the second connector and the third connector respectively includes a plurality of first conducting structures and a plurality of second conducting structures, and when the second conducting structure of the third connector is detached from the second conducting structure of the first connector or from the second conducting structure of the second connector, a pull-down circuit of the corresponding uninterruptible power supply to which the third connector is connected sends a control signal to the controller to stop the operation of the corresponding uninterruptible power supply, such that the first conducting structure of the third connector is safely detached from the first connector or from the second connector and a malfunctioned uninterruptible power supply is removed from the parallel-connected uninterruptible power supply system for repair.