# US 2014/0191583 A1 · Power balancing in a multi-phase system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191583 A1 - Document ID: US20140191583A1 - Status: Published application - Kind: A1 - Application number: 13/802,438 - Filed: 2013-03-13 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Enecsys Limited - Applicants: Enecsys Limited - Inventors: Lesley Chisenga; Aaron Jungreis; Paul Garrity - Web page: https://patentgrep.com/patent/US20140191583A1 ## CPC - H02J 3/26: Arrangements for eliminating or reducing asymmetry in polyphase networks - H02J 1/10: Parallel operation of DC sources - H02M 7/44: by static converters - Y02B 10/10: Photovoltaic [PV] - Y02E 10/56: Power conversion systems, e.g. maximum power point trackers - Y02E 40/50: Arrangements for eliminating or reducing asymmetry in polyphase networks - Y02P 80/20: using renewable energy - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Some embodiments of the invention provide a method for balancing the power output to each phase of a set of micro-inverters. The method of some embodiments is performed by a gateway, which receives output messages from a plurality of micro-inverters. The gateway identifies the phase of each micro-inverter and calculates the output of the plurality of micro-inverters to each power line of a multi-phase system. The gateway then sends control signals to the micro-inverters to control the output of each micro-inverter to maintain a balanced aggregate power output to each phase of the power grid. ## Claims ### Claim 1 A method for maintaining balanced energy transmissions between different phases of a multi-phase power system, the method comprising: for each phase of the multi-phase system, identifying a set of micro-inverters associated with the phase; calculating an aggregate power output for each phase of the multi-phase system; and controlling an individual power output of at least one micro-inverter of at least one set of micro-inverters in order to reduce the imbalance between the power outputs to each phase of the multi-phase power system. ### Claim 2 (depends on 1) The method of claim 1, wherein identifying a set of micro-inverters comprises: receiving a message from each micro-inverter; recording a received time of each message; and using received time of each message to determine the phase for each micro-inverter. ### Claim 3 (depends on 1) The method of claim 1, wherein controlling the individual power output of the at least one micro-inverter comprises sending a control signal to the micro-inverter over a communication system. ### Claim 4 (depends on 3) The method of claim 3, wherein the communication system is a wireless communication system. ### Claim 5 (depends on 1) The method of claim 1, wherein controlling the individual power output comprises setting a same threshold power output level for the at least one micro-inverter as for all of the micro-inverters in the same set of micro-inverters. ### Claim 6 (depends on 1) The method of claim 1, wherein controlling the individual power output of the at least one micro-inverter comprises setting a threshold output level for the micro-inverter that is different from the threshold output level of a micro-inverter in a different set of micro-inverters of another phase. ### Claim 7 (depends on 1) The method of claim 1, wherein controlling the individual power output comprises preventing the at least one micro-inverter from injecting power into the multi-phase power system. ### Claim 8 A multi-phase power system comprising: a plurality of sets of micro-inverters, each set of micro-inverters for injecting power into a power line of a particular phase of a multi-phase AC grid mains; a gateway for (i) receiving a set of information comprising the individual power output from each micro-inverter of the plurality of sets of micro-inverters, (ii) calculating an aggregate power output of each set of micro-inverters, and (iii) balancing the output to different phases of the multi-phase AC grid mains, the balancing comprising controlling the output of at least one micro-inverter of at least one set of micro-inverters. ### Claim 9 (depends on 8) The system of claim 8, further comprising at least one sensor for measuring the aggregate power output to the power line of the particular phase of the multi-phase AC grid mains. ### Claim 10 (depends on 8) The system of claim 8, wherein controlling the output of at least one micro-inverter comprises sending control signals to the at least one micro-inverter based on the set of information. ### Claim 11 (depends on 10) The system of claim 10, wherein the control signals comprise instructions to change the output of the at least one micro-inverter. ### Claim 12 (depends on 8) The system of claim 8, wherein balancing the output to the phases of the multi-phase power further comprises ensuring that the output to each phase of the multi-phase power grid is within a threshold value of the outputs to the other phases. ### Claim 13 (depends on 8) The system of claim 8, wherein the set of information comprises a value of at least one of voltage output, current output, and power output. ### Claim 14 (depends on 13) The system of claim 13, wherein the value is an average output over a period of time. ### Claim 15 (depends on 10) The system of claim 10, wherein the control signals comprise instructions to prevent a micro-inverter from injecting power into the multi-phase power system. ### Claim 16 (depends on 10) The system of claim 10, wherein each micro-inverter comprises (i) a wireless transmitter for transmitting the sets of information and (ii) a wireless receiver for receiving the control signals. ### Claim 17 A non-transitory machine readable medium comprising a program to be executed on at least one processing unit, the program comprising sets of instructions for: identifying, for each power line of a multi-phase AC grid mains, a set of micro-inverters that provides power to the power line; calculating an aggregate power output for each set of micro-inverters; and balancing the aggregate power output of each set of micro-inverters, the balancing comprising controlling the output of at least one micro-inverter of at least one set of micro-inverters. ### Claim 18 (depends on 17) The non-transitory machine readable medium of claim 17, wherein the program further comprises sets of instructions for receiving data from each set of micro-inverters. ### Claim 19 (depends on 17) The non-transitory machine readable medium of claim 17, wherein calculating an aggregate power output comprises receiving data from sensors from each phase of the AC grid mains. ### Claim 20 (depends on 17) The non-transitory machine readable medium of claim 17, wherein controlling the output of at least one micro-inverter comprises updating the output threshold for all of the micro-inverters providing power to a particular phase of the multi-phase system. ### Claim 21 A method for controlling power being injected into different power lines of a multi-phase power system, the method comprising: receiving messages from a plurality of micro-inverters, wherein each message is generated by a micro-inverter when a power line connecting the micro-inverter is at a particular phase of an AC cycle; identifying a first power line as a power line that is connected to a first micro-inverter transmitting the first message; calculating a timing differential between the first message received from the first micro-inverter and a second message received from the second micro-inverter; and identifying a second power line as a power line connected to a second micro-inverter based on the calculated timing differential. ### Claim 23 (depends on 21) The method of claim 21, wherein each micro-inverter generates a message when a power line connecting the micro-inverter is at a voltage peak of an AC cycle. ### Claim 24 (depends on 21) The method of claim 21, wherein each micro-inverter generates two messages in each AC cycle.