Current sharing signal coupling/decoupling circuit for power converter systems
First Claim
1. A circuit for coupling/decoupling the current sharing signal terminal of a power converter module to an interconnecting bus in a power supply system including a plurality of current mode controlled power converter modules normally having their current sharing signal terminals connected to the interconnecting bus, the output terminals of said modules being connected in parallel to energize a common load, the circuit comprising:
- reference means for developing a reference voltage;
comparator means for comparing the voltage developed at the current sharing signal terminal of a corresponding power converter module to said reference voltage and operative to generate a control signal having a first signal state when a first predetermined difference indicative of normal operation of the module is detected between the compared voltages, and having a second signal state when a second predetermined difference indicative of a malfunctioning module is detected between the compared voltages; and
switching means responsive to said control signal and operative to connect said current sharing signal terminal to said interconnecting bus when said control signal is of said first signal state, and to disconnect said current sharing signal terminal from said interconnecting bus when said control signal is of said second signal state, whereby in the event said corresponding power converter module malfunctions, it will be effectively disconnected from the system.
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Accused Products
Abstract
An improved current sharing signal coupling/decoupling circuit for power converter systems, including the provision of an individual current sharing signal coupling/decoupling circuit for each module of a number of parallel connected modules, each circuit providing an interface between a module'"'"'s "current sharing signal" port and a common connection bus. The signal coupling/decoupling circuits also share a common ground noted in the disclosure as "current sharing signal ground". The signal coupling/decoupling circuit includes a comparator, a bi-directional switch and a variable voltage reference. The comparator senses the difference between the voltage on the common connection bus, the "common current sharing signal," less an amount set by the variable voltage reference circuit, and the voltage on the module current sharing signal port, the "module current sharing signal". If the module current sharing signal drops below the common current sharing signal, the comparator activates the bi-directional switch, disconnecting the module current sharing signal port from the common connection bus, allowing the remaining parallel connected modules to continue normal operation, thus providing a system that is tolerant of individual module faults. If n modules are the minimum number required to meet a system'"'"'s current output specification, then the use of n+1, n+2, . . . n+N modules with corresponding current coupling/decoupling circuits will allow for continued operation of the system in the event of failure of 1, 2, . . . N modules, the system reliability increasing with the number of modules in excess of n.
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Citations
18 Claims
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1. A circuit for coupling/decoupling the current sharing signal terminal of a power converter module to an interconnecting bus in a power supply system including a plurality of current mode controlled power converter modules normally having their current sharing signal terminals connected to the interconnecting bus, the output terminals of said modules being connected in parallel to energize a common load, the circuit comprising:
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reference means for developing a reference voltage; comparator means for comparing the voltage developed at the current sharing signal terminal of a corresponding power converter module to said reference voltage and operative to generate a control signal having a first signal state when a first predetermined difference indicative of normal operation of the module is detected between the compared voltages, and having a second signal state when a second predetermined difference indicative of a malfunctioning module is detected between the compared voltages; and switching means responsive to said control signal and operative to connect said current sharing signal terminal to said interconnecting bus when said control signal is of said first signal state, and to disconnect said current sharing signal terminal from said interconnecting bus when said control signal is of said second signal state, whereby in the event said corresponding power converter module malfunctions, it will be effectively disconnected from the system. - View Dependent Claims (2, 3, 4, 17, 18)
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5. A power supply system comprising:
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a plurality of current mode controlled power converter modules each having a current sharing signal terminal and a power output terminal, the power output terminals being connected together and adapted to power a common load; an interconnecting bus; and a plurality of current sharing signal coupling/decoupling circuits each of which is associated with one of said modules, each said circuit including reference means for developing a reference voltage; comparator means for comparing the voltage developed at the current sharing signal terminal of the associated power converter module to said reference voltage and operative to generate a control signal having a first signal state when a first predetermined difference indicative of normal operation of the associated module is detected between the compared voltages, and having a second signal state when a second predetermined difference indicative of a malfunctioning module is detected between the compared voltages; and switching means responsive to said control signal and operative to connect said current sharing signal terminal to said interconnecting bus when said control signal is of said first signal state, and to disconnect said current sharing signal terminal from said interconnecting bus when said control signal is of said second signal state, whereby in the event the associated power converter module malfunctions, it will be effectively disconnected from the system. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification