# US 2014/0152107 A1 · Photovoltaic power generation system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152107 A1 - Document ID: US20140152107A1 - Status: Published application - Kind: A1 - Application number: 14/235,286 - Filed: 2012-08-01 - Published: 2014-06-05 - Earliest claimed: 2011-08-01 - Assignees: Tokyo Institute of Technology - Inventors: Ryuichi Shimada - Web page: https://patentgrep.com/patent/US20140152107A1 ## CPC - H02J 1/12: Parallel operation of DC sources having power converters with further DC sources without power converters - G05F 1/67: to the maximum power available from a generator, e.g. from solar cell - H02S 50/00: Monitoring or testing of PV systems, e.g. load balancing or fault identification - H02S 50/10: Testing of PV devices, e.g. of PV modules or single PV cells (testing of semiconductor devices during manufacturing {H10P74/00}) - Y02E 10/56: Power conversion systems, e.g. maximum power point trackers - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - G05F: SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES - H02S: GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES (obtaining electrical energy from radioactive sources G21H1/12; light sensitive inorganic semiconductor devices H10F; light sensitive organic semiconductor devices H10K30/00; thermoelectric devices H10N10/00; pyroelectric devices H10N15/00) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract [Problem] An object of the present invention is to provide a photovoltaic power generation system that performs the MPPT control with respect to respective panels and minimizes the power loss due to the power conversion. [Means for Solving the Problem] The photovoltaic power generation system according to the present invention performs an MPPT control for each photovoltaic panel by charging the lacking voltage or current. The power charge section connected in series or parallel to each panel charges the lacking voltage or current being caused by the non-uniformity of light quantities of the photovoltaic panels or temperatures. ## Claims ### Claim at position 1 -13. (canceled) ### Claim 14 A photovoltaic power generation system which generates a DC power at a string composed by connecting plural photovoltaic panels in parallel and said photovoltaic panels, converts said DC power by a power converter connected to said string and supplies it to a load, wherein: said respective photovoltaic panels comprising a voltage detection section for detecting a voltage value generated in said photovoltaic panel and a power detection section for detecting an energy generated in said photovoltaic panel; further comprising power charge sections connected to said photovoltaic panels in series and a maximum power point tracking (MPPT) control section for controlling a voltage value charged by said power charge section; wherein said power charge section comprises a DC power source for power charge, a charge power adjustment section for adjusting a voltage for charging, and a power measurement section for measuring a charged energy; and wherein said MPPT control section controls said respective photovoltaic panels so as to have a voltage at a maximum power point of said respective photovoltaic panels, and controls said charge power adjustment section so that a net output power Wnet (W1−W2) which is a difference between an energy (W1) at said maximum power point and a charge energy (W2) measured by said power measurement section becomes maximum. ### Claim 15 (depends on 14) The photovoltaic power generation system according to claim 14, wherein said MPPT control section controls voltages of said respective photovoltaic panels by controlling said charge power adjustment section with a feedback control so that said net output power Wnet which is said difference between said energy (W1) at said maximum power point and said charge energy (W2) measured by said power measurement section becomes maximum. ### Claim 16 (depends on 14) The photovoltaic power generation system according claim 14, wherein said DC power source for charge power is provided one in said respective power charge section in common. ### Claim 17 (depends on 14) The photovoltaic power generation system according to claim 14, wherein said charge power adjustment section includes a DC/DC up- or down-converter circuit. ### Claim 18 (depends on 17) The photovoltaic power generation system according to claim 17, wherein said DC/DC up- or down-converter circuit includes an isolation transformer. ### Claim 19 (depends on 14) The photovoltaic power generation system according to claim 14, wherein keeping voltages of said photovoltaic panels with a feedback control so as to have a voltage at a maximum power point constantly by making said charge power adjustment section connected in series be a bootstrap circuit which boosts itself by using a part of current generated in said photovoltaic panel according to a DC/DC down-converter circuit for generating a low voltage, by using said part of currents generated in said photovoltaic panels instead of said DC power source for power charge. ### Claim 20 (depends on 14) The photovoltaic power generation system according to claim 14, wherein said MPPT control section has functions for detecting, determining and memorizing a voltage as a voltage (Vmax) at a maximum power point wherein a net output power Wnet is maximum, by continuously changing voltages of said photovoltaic panels by controlling said charge power adjustment section, and wherein said net output power Wnet is a difference between said output power (W1) from the photovoltaic panel and a charge energy (W2) measured by said power measurement section. ### Claim 21 (depends on 14) The photovoltaic power generation system according to claim 14, wherein said MPPT control section controls, with respect to said respective photovoltaic panels, in such a way as to scan said charge energy (W2) with a time-sharing sequence, to memorize said voltage (Vmax) of said photovoltaic panels that a net output power Wnet which is a difference between said energy (W1) generated at that time in said photovoltaic panels and said charge energy (W2) becomes maximum, and to keep the voltage (Vmax) till a next scanning of the photovoltaic panels. ### Claim 22 (depends on 14) The photovoltaic power generation system according to claim 14, wherein said power detection section and said voltage detection section are built in said photovoltaic panel. ### Claim 23 (depends on 14) The photovoltaic power generation system, wherein having a photovoltaic array connected said plural strings claimed in claim 14 in series. ### Claim 24 (depends on 14) The photovoltaic power generation system, comprising said string claimed in claim 14, or a photovoltaic array composed by connecting said strings in series or parallel, and a power conditioner for supplying a power to a load by converting a DC output from said string or said photovoltaic array, wherein said power conditioner comprises a maximum power point tracking (MPPT) section, and wherein said MPPT control section does not perform a power charge operation for one or plural photovoltaic panel(s) within said string or said photovoltaic array, and a power decreasing caused by not performing said power charge operation is supplemented by a MPPT function of said power conditioner. ### Claim 25 A photovoltaic power generation system which generates a DC power at a string composed by connecting plural photovoltaic panels in series and said photovoltaic panels, converts said DC power by a power converter connected to said string and supplies it to a load, wherein: said respective photovoltaic panels comprising a voltage detection section for detecting a voltage value generated at said photovoltaic panel and a power detection section for detecting an energy generated in said photovoltaic panel; further comprising power charge sections connected to said photovoltaic panels in parallel and a maximum power point tracking (MPPT) control section for controlling a current value charged by said power charge section; wherein said power charge section comprises a DC power source for power charge, a charge power adjustment section for adjusting a current for charging, and a power measurement section for measuring a charged energy; and wherein said MPPT control section controls said respective photovoltaic panels so as to have a voltage at a maximum power point of said respective photovoltaic panels, and controls said charge power adjustment section such that a net output power Wnet (W1−W2) which is a difference between an energy (W1) at said maximum power point and a charge energy (W2) measured by said power measurement section becomes maximum. ### Claim 26 (depends on 25) The photovoltaic power generation system according to claim 25, wherein said MPPT control section controls voltages of said respective photovoltaic panels by controlling said charge power adjustment section with a feedback control so that said net output power Wnet which is said difference between said energy (W1) at said maximum power point and said charge energy (W2) measured by said power measurement section becomes maximum. ### Claim 27 (depends on 25) The photovoltaic power generation system according to claim 25, wherein said DC power source for charge power is provided one in said respective power charge section in common. ### Claim 28 (depends on 25) The photovoltaic power generation system according to claim 25, wherein said charge power adjustment section includes a DC/DC up- or down-converter circuit. ### Claim 29 (depends on 28) The photovoltaic power generation system according to claim 28, wherein said DC/DC up- or down-converter circuit includes an isolation transformer. ### Claim 30 (depends on 25) The photovoltaic power generation system according to claim 25, wherein said MPPT control section has functions for detecting, determining and memorizing a voltage as a voltage (Vmax) at a maximum power point wherein a net output power Wnet is maximum, by continuously changing voltages of said photovoltaic panels by controlling said charge power adjustment section, and wherein said net output power Wnet is a difference between said output power (W1) from a photovoltaic panel and a charge energy (W2) measured by said power measurement section. ### Claim 31 (depends on 25) The photovoltaic power generation system according to claim 25, wherein said MPPT control section controls, with respect to said respective photovoltaic panels, in such a way as to scan said charge energy (W2) with a time-sharing sequence, to memorize said voltage (Vmax) of said photovoltaic panels that a net output power Wnet which is a difference between said energy (W1) generated at that time in said photovoltaic panels and said charge energy (W2) becomes maximum, and to keep the voltage (Vmax) till a next scanning of the photovoltaic panels. ### Claim 32 (depends on 25) The photovoltaic power generation system according to claim 25, wherein said power detection section and said voltage detection section are built in said photovoltaic panel. ### Claim 33 (depends on 25) The photovoltaic power generation system, wherein having a photovoltaic array connected said plural strings claimed in claim 25 in parallel. ### Claim 34 (depends on 25) The photovoltaic power generation system, comprising said string claimed in claim 25, or a photovoltaic array composed by connecting said strings in series or parallel, and a power conditioner for supplying a power to a load by converting a DC output from said string or said photovoltaic array, wherein said power conditioner comprises a maximum power point tracking (MPPT) section, and wherein said MPPT control section does not perform a power charge operation for one or plural photovoltaic panel(s) within said string or said photovoltaic array, and a power decreasing caused by not performing said power charge operation is supplemented by a MPPT function of said power conditioner.