Cell surveillance monitor for a power converter

Claim 2

In an electrical power conversion system having at least one bridge converter, including a plurality of cells, connected to a load for supplying power thereto, circuitry for said converter for indicating failure of a cell within said bridge to conduct current properly comprising: a. current sensing means for each cell in said bridge, said current sensing means each outputting a first signal as long as its associated cell is conducting current properly; b. at least one detector, said detector monitoring the outputs of a number of said current sensing means and outputting a second signal when any one of said first signals is absent; and, c. means for supplying an inhibiting signal to said detector when said converter is supplying less current than a predetermined reference current to saId load whereby said detector is prevented from outputting said second signal.

Claim 3

The invention in accordance with claim 1 further including means responsive to said second signal to indicate that the detector is signaling a failure.

Claim 4

In an electric power conversion system having a plurality of bridges, each including a plurality of cells, connected to a load for supplying power thereto, circuitry for indicating failure of any of the cells in said bridges to conduct current properly comprising: a. current sensing means for each cell in said bridges, said current sensing means each outputting a first signal as long as its cell is conducting current properly; b. a plurality of detectors each associated with a prescribed number of said cells, each detector monitoring the outputs of its associated current sensing means and for outputting a second signal when any of said first signals is absent; c. logic circuit means connected to the outputs of a plurality of said detectors, said logic circuit means outputting further signals indicative of the number of said detectors signaling said failure; and, d. means for selectively supplying an inhibiting signal to each of said detectors when said bridges are supplying less current than a predetermined reference current to said load whereby each of said detectors is prevented from outputting a second signal.

Claim 5

In an electric power conversion system having a plurality of bridges, each including a plurality of cells, connected to a load for supplying power thereto, circuitry for indicating failure of any of the cells in said bridges to conduct current properly comprising: a. current sensing means for each cell in said bridges, said current sensing means each outputting a first signal as long as its cell is conducting current properly; b. a plurality of detectors each associated with a prescribed number of said cells, each detector monitoring the outputs of its associated current sensing means and for outputting a second signal when any of said first signals is absent; c. logic circuit means connected to the outputs of a plurality of said detectors, said logic circuit means outputting further signals indicative of the number of said detectors signaling said failure; and, d. means for selectively supplying an inhibiting signal to each of said detectors when said bridges are supplying less current than a predetermined reference current to said load whereby each of said detectors is prevented from outputting a second signal.

Claim 6

The electric power conversion system in accordance with claim 3 further including means responsive to the output of each detector for indicating when said detector is signaling a failure.

Claim 7

In an electric power conversion system having a plurality of bridge converters, each including a plurality of cells, connected to a load for supplying power thereto, circuitry for said converters for indicating failure of a cell within a bridge to conduct current properly comprising: a. current sensing means for each cell of a bridge, said current sensing means each outputting a first signal as long as its cell is conducting current properly; b. a detector, associated with each bridge, said detector monitoring the outputs of a number of said current sensing means and outputting a second signal when any of said first signals is absent; c. logic circuit means connected to the outputs of a plurality of said detectors, said logic circuit means outputting further signals indicative of the number of said detectors signaling said failure; and, d. means for supplying an inhibiting signal to each of said detectors when its associated bridge is supplying less current than a predetermined reference current to said load whereby such bridge is prevented from outputting a second signal.

Claim 8

In an electric power conversion system having a plurality of bridge converters, each including a plurality of cells, connected to a load for supplying power thereto, circuitry for said converters for indicating failure of a cell within a bridge to conduct current properly comprising: a. current sensing means for each cell of a bridge, said current sensing means each outputting a first signal as long as its cell is conducting current properly; b. a detector, associated with each bridge, said detector monitoring the outputs of a number of said current sensing means and outputting a second signal when any of said first signals is absent; c. logic circuit means connected to the outputs of a plurality of said detectors, said logic circuit means outputting further signals indicative of the number of said detectors signaling said failure; and, d. means for supplying an inhibiting signal to each of said detectors when its associated bridge is supplying less current than a predetermined reference current to said load whereby such bridge is prevented from outputting a second signal.

Claim 9

The electric power conversion system in accordance with claim 5 further including means responsive to the output of each detector for indicating when said detector is signaling a failure.

Claim 10

In an electric power conversion system having a plurality of bridges, each including a plurality of cells, connected to a load for supplying power thereto, circuitry for said bridges for indicating failure of any of the like cells in corresponding legs of said bridges to conduct current properly comprising: a. current sensing means for each cell in said bridges, said current sensing means each outputting a first signal as long as its cell is conducting current properly; b. a detector for the like cells in said legs of said bridges, each detector monitoring the outputs of said current sensing means for said cells and outputting a second signal when any of said first signals is absent; c. logic circuit means connected to the outputs of a plurality of said detectors, said logic circuit outputting further signals indicative of the number of said detectors signaling said failure; and, d. means for selectively supplying inhibiting signals to said detectors when said bridges are supplying less current than a predetermined reference current to said loaD whereby a detector is prevented from outputting a second signal.

Claim 11

In an electric power conversion system having a plurality of bridges, each including a plurality of cells, connected to a load for supplying power thereto, circuitry for said bridges for indicating failure of any of the like cells in corresponding legs of said bridges to conduct current properly comprising: a. current sensing means for each cell in said bridges, said current sensing means each outputting a first signal as long as its cell is conducting current properly; b. a detector for the like cells in said legs of said bridges, each detector monitoring the outputs of said current sensing means for said cells and outputting a second signal when any of said first signals is absent; c. logic circuit means connected to the outputs of a plurality of said detectors, said logic circuit outputting further signals indicative of the number of said detectors signaling said failure; and, d. means for selectively supplying inhibiting signals to said detectors when said bridges are supplying less current than a predetermined reference current to said loaD whereby a detector is prevented from outputting a second signal.

Claim 12

The electric power conversion system in accordance with claim 7 further including means responsive to the output of each detector for indicating which of said detectors are signaling said failure.