# US 2012/0074787 A1 · Integrated photovoltaic source circuit combiner and protection subsystem > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0074787 A1 - Document ID: US20120074787A1 - Status: Published application - Kind: A1 - Application number: 12/892,285 - Filed: 2010-09-28 - Published: 2012-03-29 - Earliest claimed: 2010-09-28 - Assignees: Xantrex Technology Inc. - Inventors: Rick West - Web page: https://patentgrep.com/patent/US20120074787A1 ## CPC - H02H 7/20: for electronic equipment (for converters H02H7/10; for electric measuring instruments G01R1/36; for DC voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08) - H02H 3/05: with means for increasing reliability, e.g. redundancy arrangements {(for logic circuits H03K19/003)} - H02H 3/08: responsive to excess current (responsive to abnormal temperature caused by excess current H02H5/04) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract A combiner circuit and voltage protection circuit is disclosed. A plurality of photovoltaic sources is provided. A set of fuses, each having one side coupled to one of the plurality of photovoltaic sources is provided. A set of contacts, each having one side coupled to the other side of one of the fuses is provided. The other side of the contacts are coupled together to combine the output of the photovoltaic sources to an output interface, the output interface being coupled to the load. A set of diodes are each coupled to each of the set of fuses and form a current path around the set of contacts. A transistor is coupled to each of the diodes and the load interface. The transistor has an on state completing the flow of current through the diodes around the set of contacts to the load interface. ## Claims ### Claim 1 A system for combing the voltage output of multiple photovoltaic sources to a load, the system comprising: a plurality of photovoltaic sources; a set of contacts, each of the contacts having one side coupled to the one of the plurality of photovoltaic sources, wherein the other side of the contacts are coupled together to combine the output of the photovoltaic sources to an output interface, the output interface being coupled to the load; a set of diodes, each of the diodes coupled to each of the set of fuses and forming a current path around the set of contacts; and a transistor coupled to each of the diodes and the load interface, the transistor having an on state completing the flow of current through the diodes around the set of contacts to the load interface. ### Claim 2 (depends on 1) The system of claim 1 wherein the transistor is an insulated gate bi-polar transistor (IGBT). ### Claim 3 (depends on 1) The system of claim 1, further comprising: a current sensor coupled to the output interface; and a controller coupled to the current sensor, the transistor and the set of contacts, the controller controlling the opening and closing of the set of contacts. ### Claim 4 (depends on 3) The system of claim 3, wherein the controller detects an abnormal condition and opens the contacts while turning the transistor into an on state while the contacts are opening. ### Claim 5 (depends on 3) The system of claim 3, wherein the controller pulses the transistor and determines whether the transistor is in desaturation mode to measure the load. ### Claim 6 (depends on 1) The system of claim 1, further comprising a set of switches, each coupled to the other side of one of the set of fuses, the switches being switchable to isolate a particular fuse. ### Claim 7 (depends on 1) The system of claim 1, further comprising a second set of diodes coupled between the contacts and the transistor to allow current flow from the load interface around the set of contacts when the transistor is in the on state. ### Claim 8 (depends on 1) The system of claim 1, further comprising a set of fuses, each having one side coupled to one of the plurality of photovoltaic sources and another side coupled to one of the set of contacts. ### Claim 9 A method of protecting the components of a circuit combining the outputs of a plurality of voltage sources, the method comprising: attaching a contact to the output of each of the plurality of voltage sources; opening the contacts when an abnormal current level is detected on any of the outputs; and providing a current route around the contacts by closing a transistor for a period of time necessary to open the contacts. ### Claim 10 (depends on 9) The method of claim 9, wherein the transistor is an insulated gate bi-polar transistor (IGBT). ### Claim 11 (depends on 9) The method of claim 9, further comprising combining the contacts to form a combined output interface. ### Claim 12 (depends on 11) The method of claim 11, further comprising, sensing the current at the combined output interface and opening the contacts when an abnormal condition is detected from the sensed current. ### Claim 13 (depends on 11) The method of claim 11, further comprising pulsing the transistor and determining whether the transistor is in desaturation mode to measure a load coupled to the combined output interface. ### Claim 14 (depends on 9) The method of claim 9, wherein a set of fuses and a corresponding set of switches is coupled between the voltage sources and the corresponding contacts, each switch and corresponding contact being switchable to isolate a particular fuse. ### Claim 15 (depends on 9) The method of claim 9, further comprising providing a second set of diodes coupled between the contacts and the transistor to allow current flow from the load interface around the set of contacts when the transistor is in the on state. ### Claim 16 A machine readable medium having stored thereon instructions for allowing the interruption of power from a voltage source via a contact, a current path being formed via a diode and a transistor in an on state, comprising machine executable code which when executed by at least one machine, causes the machine to: open the contact when an abnormal current level is detected; and provide a current route around the contacts by closing the transistor for a period of time necessary to open the contact. ### Claim 17 (depends on 16) The machine readable medium of claim 16, wherein the transistor is an insulated gate bi-polar transistor (IGBT). ### Claim 18 (depends on 16) The machine readable medium of claim 16, wherein the contacts are combined to form a combined output interface. ### Claim 19 (depends on 18) The machine readable medium of claim 18, further comprising, sensing the current at the combined output interface and opening the contacts when an abnormal condition is detected from the sensed current. ### Claim 20 (depends on 18) The machine readable medium of claim 18, wherein the machine executable code further causes the machine to pulse the transistor and determine whether the transistor is in desaturation mode to measure a load coupled to the combined output interface. ### Claim 21 (depends on 16) The machine readable medium of claim 16, wherein a set of fuses and a corresponding set of switches is coupled between the voltage sources and the corresponding contacts, each switch and corresponding contact being switchable to isolate a particular fuse. ### Claim 22 (depends on 16) The machine readable medium of claim 16, wherein a second set of diodes is coupled between the contacts and the transistor to allow current flow from the load interface around the set of contacts when the transistor is in the on state.