WO2021057075A1 - 优化器、光伏发电系统及光伏组件的iv曲线扫描方法 - Google Patents

优化器、光伏发电系统及光伏组件的iv曲线扫描方法 Download PDF

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Publication number
WO2021057075A1
WO2021057075A1 PCT/CN2020/094176 CN2020094176W WO2021057075A1 WO 2021057075 A1 WO2021057075 A1 WO 2021057075A1 CN 2020094176 W CN2020094176 W CN 2020094176W WO 2021057075 A1 WO2021057075 A1 WO 2021057075A1
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Prior art keywords
voltage
optimizer
photovoltaic
unit
segment
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PCT/CN2020/094176
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English (en)
French (fr)
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陈东
石磊
王朝辉
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华为技术有限公司
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to ES20869537T priority Critical patent/ES2961247T3/es
Priority to AU2020353609A priority patent/AU2020353609B2/en
Priority to EP20869537.9A priority patent/EP3907882B1/en
Priority to JP2021552869A priority patent/JP7301997B2/ja
Publication of WO2021057075A1 publication Critical patent/WO2021057075A1/zh
Priority to US17/404,407 priority patent/US20210376790A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/30—Electrical components
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S50/00—Monitoring or testing of PV systems, e.g. load balancing or fault identification
    • H02S50/10—Testing of PV devices, e.g. of PV modules or single PV cells
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
    • H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/30—Electrical components
    • H02S40/32—Electrical components comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/10—Control circuit supply, e.g. means for supplying power to the control circuit
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/30—Electrical components
    • H02S40/38—Energy storage means, e.g. batteries, structurally associated with PV modules
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers

Definitions

  • This application relates to the field of photovoltaic power generation technology, in particular to an optimizer, a photovoltaic power generation system, and an IV curve scanning method for photovoltaic components.
  • the optimizer is a power conversion device installed between the photovoltaic module and the inverter. It can eliminate the series-parallel mismatch of photovoltaic modules and reduce the probability of photovoltaic modules being bypassed. It also has the MPPT (Maximum Power Point) of a single photovoltaic module. Tracking, maximum power point tracking) function and IV curve scanning function.
  • MPPT Maximum Power Point
  • the photovoltaic power generation system can scan the IV curve of the photovoltaic modules online through the optimizer.
  • the optimizer scans the IV curve, it needs to control the output voltage of the photovoltaic module to change from the open circuit voltage to a lower voltage or even 0V, and obtain the output current value corresponding to each voltage to obtain a complete IV curve.
  • the auxiliary power supply of the optimizer is usually powered by the output voltage of the photovoltaic module, when the output voltage of the photovoltaic module is low, the auxiliary power supply of the optimizer will be undervoltage, and the optimizer will stop working, thus failing to complete the complete IV curve scan. task.
  • the energy storage circuit is usually connected in parallel at the input end of the auxiliary power supply, and a unidirectional conduction circuit is connected in series before the energy storage circuit, so that when the output voltage of the photovoltaic module is low, the energy storage circuit can continue to be the auxiliary power supply Power supply to ensure that the optimizer completes the IV curve scan task.
  • the output voltage of the photovoltaic module can be changed step by step according to the set law. Therefore, a large-capacity energy storage circuit is required to ensure that the optimizer completes the IV curve scanning task.
  • a large-capacity energy storage circuit is not conducive to the optimized design of the volume and cost of the optimizer.
  • the embodiments of the present application disclose an optimizer, a photovoltaic power generation system, and an IV curve scanning method of photovoltaic modules that can reduce the capacity of the energy storage circuit and reduce the power fluctuation of the photovoltaic string.
  • an embodiment of the present application discloses an optimizer, which includes a conversion unit, a control unit, an auxiliary power supply, an energy storage unit, and a first unidirectional communication unit.
  • the auxiliary power supply, the energy storage unit and the first unidirectional conduction unit are all connected between the conversion unit and the control unit.
  • the input end of the conversion unit is connected to at least one photovoltaic component, and is used for power conversion of the connected photovoltaic component.
  • the control unit is electrically connected to the conversion unit, and is used to control the conversion unit.
  • the auxiliary power supply is used to provide a working voltage for the control unit.
  • the energy storage unit is used to provide electrical energy for the auxiliary power supply or the control unit.
  • the first unidirectional conduction unit is used to prevent the electric energy of the energy storage unit from falling as the voltage of the photovoltaic module drops.
  • the control unit is also used to perform IV curve scanning on each voltage segment when it is determined that the optimizer needs to perform the IV curve scanning task; wherein, each voltage segment is the output of the photovoltaic module corresponding to the optimizer.
  • the voltage is obtained in sections from the open circuit voltage to the preset minimum voltage, and the divided voltage sections are at least two.
  • the conversion unit can be a converter, such as a DC/DC converter;
  • the control unit can be an MCU (such as a single-chip microcomputer);
  • the auxiliary power supply can be a full-featured conversion circuit, for example, a conversion that can convert the input voltage to 12V or 5V Circuit;
  • the energy storage unit may be an energy storage circuit including a capacitor, a super capacitor or a battery;
  • the first unidirectional conduction unit may be a unidirectional conduction circuit including at least one diode.
  • the control unit when the control unit determines that the optimizer needs to perform an IV curve scanning task, it performs IV curve scanning on each voltage segment. Since each voltage segment is obtained by segmenting the output voltage of the photovoltaic module corresponding to the optimizer from the open-circuit voltage to the preset minimum voltage, and the divided voltage segments are at least two, and when the voltage value is lower, The optimizer will be restarted when the voltage segment is scanned for the IV curve, so that the energy storage unit can be recharged during this period, and the output voltage of the photovoltaic module will be adjusted to the current voltage segment, so only the energy storage unit with lower capacity is required Complete the complete IV curve scan task, thereby reducing the cost and volume of the optimizer.
  • control unit when the control unit receives the IV curve scan instruction sent by the host computer, it is determined that the optimizer needs to perform the IV curve scan task, that is, the IV curve scan task is executed when it is determined that there is a user demand, In this way, the needs of users can be more satisfied.
  • the conversion unit when the control unit scans the IV curve of each voltage segment, the conversion unit adjusts the output voltage of the photovoltaic module to the value of one of the two end points of the voltage segment. Voltage value. Among them, there is an intersection between two adjacent voltage segments. In this way, a complete and continuous IV curve scan from the open circuit voltage to the preset minimum voltage can be realized.
  • the two end points of one of the voltage sections are the open circuit voltage and the threshold voltage of the photovoltaic module, and the voltage section is defined as the first voltage section; wherein, the threshold voltage of the photovoltaic module is less than the auxiliary voltage.
  • the minimum required voltage for power supply operation; the threshold voltage of the photovoltaic component to the preset minimum voltage is divided into at least two voltage segments. In this way, it can be ensured that a complete IV curve scan can be achieved using a lower capacity energy storage unit, which is beneficial to reduce the volume and cost of the optimizer.
  • the minimum required voltage for the operation of the auxiliary power supply refers to the minimum output voltage output by the photovoltaic module for the auxiliary power supply to work normally.
  • the lowest output voltage of the photovoltaic module can be directly supplied to the auxiliary power supply for normal operation, or it can be supplied to the auxiliary power supply for normal operation after transformation (such as boosting or step-down).
  • the threshold voltage of the photovoltaic module is less than the minimum required voltage for auxiliary power supply operation means that the voltage difference between the threshold voltage of the photovoltaic module and the minimum required voltage for auxiliary power supply operation is within a preset range, and the preset range depends on the energy storage unit
  • the energy that can be provided, that is, the preset range is the voltage that the energy storage unit continues to supply when the output of the photovoltaic component is less than the minimum output voltage that can be used for the auxiliary power supply to work normally, and the photovoltaic component drops during this time.
  • the first voltage section is divided into at least two voltage sections. In this way, the total output power fluctuations of multiple optimizers when performing the IV curve scanning task at the same time can be made smaller.
  • the auxiliary power supply is electrically connected to the control unit; the energy storage The unit is connected in parallel to the input end of the auxiliary power supply; the first unidirectional conduction unit is connected in series between the input end of the conversion unit and the energy storage unit, or the first unidirectional conduction unit is connected in series to all Between the output terminal of the conversion unit and the energy storage unit.
  • the first unidirectional conduction unit includes at least one diode.
  • the energy storage unit includes at least one capacitor, or at least one super capacitor, or at least one battery.
  • the first unidirectional conduction unit is connected in series between the input end of the conversion unit and the energy storage unit; the optimizer further includes a second unidirectional conduction unit; the second The unidirectional conduction unit is connected in series between the output terminal of the conversion unit and the energy storage unit, thereby improving the energy storage capacity of the energy storage unit in response to different working conditions.
  • the second unidirectional conduction unit includes at least one diode.
  • the input terminal of the auxiliary power source is electrically connected to the input terminal of the conversion unit, or the input terminal of the auxiliary power source is electrically connected to the output terminal of the conversion unit.
  • the first unidirectional conduction unit is connected in series between the output terminal of the auxiliary power supply and the energy storage unit.
  • the energy storage unit is electrically connected to the control unit. In this way, when the optimizer performs the IV curve scanning task, the energy storage unit only supplies power to the control unit, thereby improving the utilization rate of the capacity of the energy storage unit.
  • the auxiliary power supply can also turn off some circuits that are not related to the IV curve scanning function to reduce power loss and increase the power supply time of key circuits.
  • an embodiment of the present application discloses a photovoltaic power generation system, which includes a plurality of photovoltaic components and an inverter.
  • the photovoltaic power generation system further includes a plurality of optimizers as described in the first aspect; wherein, the input end of each optimizer is connected to at least one photovoltaic module, and the output ends of the plurality of optimizers are connected in series to form a string and are connected to the inverter The converter is connected.
  • the voltage segment currently being scanned by at least one optimizer is different from the voltage segment currently being scanned by other optimizers. the same.
  • an embodiment of the present application discloses an IV curve scanning method of a photovoltaic module, which is applied to a photovoltaic power generation system, and the photovoltaic power generation system includes a plurality of photovoltaic modules.
  • the IV curve scanning method of the photovoltaic module includes:
  • the IV curve scanning is performed on each divided voltage segment.
  • the performing IV curve scanning on each of the divided voltage segments specifically includes: when performing IV curve scanning on each voltage segment, adjusting the output voltage of the photovoltaic module to the voltage segment The voltage value of one of the two terminals.
  • the two end points of one of the voltage sections are the open circuit voltage and the threshold voltage of the photovoltaic module, and the voltage section is defined as the first voltage section; wherein, the threshold voltage of the photovoltaic module is less than the auxiliary voltage.
  • the minimum required voltage for power supply operation; the threshold voltage of the photovoltaic component to the preset minimum voltage is divided into at least two segments.
  • the first voltage section is divided into at least two voltage sections.
  • the voltage segment currently being scanned by at least one optimizer is different from the voltage segment currently being scanned by other optimizers. the same.
  • an embodiment of the present application discloses a computer-readable storage medium, in which program instructions for IV curve scanning are stored, and the program instructions are used to execute the photovoltaic system described in the third aspect after being called.
  • the IV curve scanning method of the component is not limited to:
  • Fig. 1 is a schematic structural diagram of a photovoltaic power generation system provided by an embodiment of the application.
  • Fig. 2 is a schematic block diagram of an optimizer in an embodiment of the application.
  • Fig. 3 is a schematic diagram of voltage segments of photovoltaic modules in an embodiment of the application.
  • Fig. 4 is a schematic diagram of voltage segments of photovoltaic modules in another embodiment of the application.
  • Fig. 5 is a functional block diagram of an optimizer in another embodiment of the application.
  • Fig. 6 is a functional block diagram of the optimizer in still another embodiment of the application.
  • Fig. 7 is a functional block diagram of an optimizer in another embodiment of the application.
  • Fig. 8 is a functional block diagram of an optimizer in another embodiment of the application.
  • FIG. 9 is a flowchart of a method for scanning the IV curve of a photovoltaic module in an embodiment of the application.
  • the present application provides a photovoltaic power generation system, an optimizer applied in the photovoltaic power generation system, and an IV curve scanning method for photovoltaic components.
  • the optimizer can perform IV curve scanning on the photovoltaic module to detect whether the photovoltaic module is defective or damaged.
  • FIG. 1 is a functional block diagram of a photovoltaic power generation system 200 according to an embodiment of the application.
  • the photovoltaic power generation system 1000 includes a plurality of optimizers 100, a plurality of photovoltaic modules 300 and an inverter 500.
  • the photovoltaic module 300 is used to convert solar energy into electrical energy.
  • the input end of each optimizer 100 is connected to at least one photovoltaic module 300, and the output ends of multiple optimizers 100 are connected in series to form a string and then connected to the inverter 500.
  • the photovoltaic power generation system 1000 may include multiple strings.
  • the optimizer 100 is used to optimize the output power of the photovoltaic module 300 connected to it, so as to ensure that the output power of the photovoltaic power generation system 1000 is maximized.
  • the optimizer 100 can also be used to scan the IV curve of the photovoltaic module 300 connected to it to detect whether the photovoltaic module 300 connected to it is defective or damaged.
  • I refers to current
  • V refers to voltage.
  • the IV curve can also indicate the current power generation capacity, working conditions and other information of the photovoltaic module 300.
  • the inverter 500 is used to convert the DC power output by the photovoltaic module 300 into AC power and output it to the grid 2000.
  • a combiner box (not shown) can be added between the optimizer 100 and the inverter 500, and the AC side of the inverter 500 can be connected to a step-up transformer (not shown) and then connected to the power grid 2000. It can be determined according to the specific application environment, and there is no specific limitation here.
  • the photovoltaic power generation system 1000 further includes a communication host (not shown), which is used to communicate with the optimizer 100 and obtain the electrical parameters of the optimizer 100 through communication.
  • the communication host may be an independent device, or may be integrated in other devices of the photovoltaic power generation system 1000, for example, integrated in the inverter 500, the combiner box, the grid-connected box, or one of the optimizers.
  • the communication host communicates with the optimizer through wireless communication (such as WiFi, Lora, Zigbee, etc.) or PLC communication.
  • each optimizer 100 includes a conversion unit 10, a control unit 20, an auxiliary power supply 30, an energy storage unit 40 and a first unidirectional communication unit 50.
  • the input end of the conversion unit 10 is connected to at least one photovoltaic module 300 and serves as the input end of the optimizer 100.
  • the output terminal of the conversion unit serves as the output terminal of the optimizer 100, and the output terminals of a plurality of optimizers 100 are connected in series to form a string.
  • the conversion unit 10 is a DC/DC conversion unit, which can work in a power conversion mode for power conversion of the DC power of the photovoltaic module 300 at the input end, and then output the converted DC power to the output end ; Or, it can work in the pass-through mode, connecting the input end and the output end directly.
  • the DC/DC conversion unit can be configured according to the specific application environment, for example, a buck circuit, a boost circuit, or a buck-boost circuit.
  • the conversion unit 10 When the conversion unit 10 works in the power conversion mode, it is mainly used to perform Maximum Power Point Tracking (MPPT) on the electrical energy of the photovoltaic module 300 at the input end. In addition, it can also work in slow-start, power-limited mode, etc. Among them, the slow start (also called soft start) is used in the start-up phase of the conversion unit 10 to smoothly run from the standby mode to the power conversion mode, for example, from the standby mode to the maximum power at a rate of 0.2A/s of the input current change rate. Point current.
  • MPPT Maximum Power Point Tracking
  • the limited power mode is used to reduce the output power when the operating state of the conversion unit 10 itself is close to the critical value (for example, the output voltage reaches the critical value, the ambient temperature reaches the critical value), so as to protect the conversion unit 10 itself, or when an externally issued Reduce the output power after the power limit mode command.
  • the critical value for example, the output voltage reaches the critical value, the ambient temperature reaches the critical value
  • the control unit 20 is electrically connected to the conversion unit 10 for controlling the conversion unit 10.
  • the control unit 20 is also used to collect the working state parameters of the conversion unit 10, where the working state parameters of the conversion unit 10 include but are not limited to information such as the input voltage, input current, output voltage, and output current of the conversion unit 10.
  • the auxiliary power source 30, the energy storage unit 40 and the first unidirectional conduction unit 50 are connected between the conversion unit 10 and the control unit 20.
  • the auxiliary power supply 30 is electrically connected to the control unit 20 for providing the control unit 20 with a working voltage. It can be understood that the auxiliary power supply 30 may also be used to supply power to other functional circuits in the optimizer 100.
  • the control unit 20 may be a single-chip microcomputer.
  • the control unit 20 may include multiple signal acquisition ports, communication ports, multiple control ports, and so on.
  • the energy storage unit 40 is connected in parallel to the input end of the auxiliary power source 30 to provide electrical energy for the auxiliary power source 30.
  • the energy storage unit 40 includes at least one energy storage capacitor, or at least one super capacitor, or at least one battery.
  • the first unidirectional conduction unit 50 is connected in series between the input end of the conversion unit 10 and the energy storage unit 40 to prevent the electric energy of the energy storage unit 40 from following the photovoltaic module 300 when the optimizer 100 performs the IV curve scan of the photovoltaic module 300 The voltage drops and drops.
  • the first unidirectional conduction unit 50 includes at least one diode.
  • the anode of the diode is electrically connected to the anode of the input terminal of the conversion unit 10, and the cathode of the diode is connected to the auxiliary power supply.
  • the anode of the input end of 30 is electrically connected; or, the cathode of the diode is electrically connected to the cathode of the input end of the conversion unit 10, and the anode of the diode is electrically connected to the cathode of the input end of the auxiliary power source 30; or, the The anode of the diode is electrically connected to the anode of the output terminal of the conversion unit 10, and the cathode of the diode is electrically connected to the anode of the input terminal of the auxiliary power source 30; or, the cathode of the diode is electrically connected to the output terminal of the conversion unit 10
  • the negative electrode is electrically connected, and the anode of the diode is electrically connected to the negative electrode of the input terminal of the auxiliary power source 30.
  • control unit 20 is configured to perform IV curve scanning for each voltage segment when it is determined that the optimizer 100 needs to perform an IV curve scanning task.
  • each voltage segment is obtained by segmenting the output voltage of the photovoltaic module 300 corresponding to the optimizer 100 from the open circuit voltage to the preset minimum voltage, and the divided voltage segments are at least two, that is, the optimizer
  • the output voltage of the photovoltaic module 300 corresponding to 100 is divided into N voltage segments from the open circuit voltage to the preset minimum voltage.
  • N is a positive integer greater than or equal to 2.
  • the preset minimum voltage may be 0V or a certain value close to 0V, which is not specifically limited here.
  • control unit 20 when the control unit 20 receives an IV curve scan instruction sent by a host computer (such as an inverter), it is determined that the optimizer 100 needs to perform an IV curve scan task. In other embodiments, it can also be detected autonomously. When it is detected that the current state of the optimizer 100 meets the preset state, it is determined that the optimizer 100 needs to perform the IV curve scanning task.
  • a host computer such as an inverter
  • the conversion unit 10 adjusts the output voltage of the photovoltaic module 300 to be between the two end points of the voltage segment. The voltage value of one of the endpoints.
  • control unit 20 when the control unit 20 scans the IV curve of each voltage segment, it can change the output voltage of the photovoltaic module 300 from an end point (starting point) of the voltage segment through the conversion unit 10 according to a preset rule. To the other end point (end point). Wherein, the starting voltage of each voltage section is greater than the ending voltage, or the starting voltage of each voltage section is smaller than the ending voltage, or the starting voltage of some voltage sections is greater than the ending voltage and the starting voltage of the remaining voltage sections is smaller than the ending voltage.
  • the preset rule is at least one of: a voltage drop rule with a fixed voltage difference, or a parabolic voltage drop rule, or a voltage drop rule with a fixed duty cycle change rate.
  • the parabolic voltage drop law specifically refers to the rapid drop near the preset minimum voltage of the photovoltaic module, and the slower drop near the maximum power point voltage and open circuit voltage; the voltage drop law of the fixed duty cycle change rate It means that the control duty cycle of the optimizer 100 changes from the initial situation with a fixed step. For example, the control duty cycle starts from 0 and increases to 1 with a fixed step of 0.01.
  • the two end points of one of the voltage segments are the open circuit voltage and the threshold voltage V1 of the photovoltaic module 300 respectively, and the voltage segment is defined as the first voltage segment.
  • the threshold voltage of the photovoltaic assembly 300 is less than the minimum required voltage for the auxiliary power supply 30 to work, and the threshold voltage to the preset minimum voltage is divided into at least two voltage segments. In this way, it can be ensured that a complete IV curve scan can be achieved using a lower capacity energy storage unit, which is beneficial to reduce the volume and cost of the optimizer.
  • the working voltage of the auxiliary power source 30 may be directly provided by the photovoltaic module 300, or may be provided by the photovoltaic module 300 after being boosted or stepped down by the conversion unit 10. Therefore, the minimum required voltage for the auxiliary power source 30 to work refers to the photovoltaic module 300 The output minimum output voltage for the auxiliary power supply 30 to work normally.
  • the minimum output voltage of the photovoltaic module 300 can be directly provided to the auxiliary power supply 30 (as shown in Figure 2) to supply the auxiliary power supply 30 for operation, or after transformation (as shown in Figure 5) It is provided to the auxiliary power source 30 to supply the auxiliary power source 30 to work normally.
  • the threshold voltage of the photovoltaic module 300 is less than the minimum required voltage for the operation of the auxiliary power supply 30 means that the voltage difference between the threshold voltage of the photovoltaic module 300 and the minimum required voltage for the operation of the auxiliary power supply 30 is within a preset range, and the preset range depends on
  • the energy that can be provided by the energy storage unit 40 that is, the preset range is when the output of the photovoltaic module 300 is less than the lowest output voltage for the auxiliary power supply 30 to work normally, the energy storage unit 40 continues to supply power, and at that time The voltage dropped by the inner photovoltaic module 300.
  • the output voltage of the photovoltaic module 300 is greater than the minimum required voltage for the auxiliary power supply 30 most of the time; when the output voltage of the photovoltaic module 300 is lower than the minimum required voltage for the auxiliary power supply 30 to operate
  • the energy storage unit 40 provides electrical energy to the auxiliary power supply 30; when the capacity of the energy storage unit 40 is low, the auxiliary power supply 30 will be undervoltage after a short period of time, which is optimized
  • the device 100 stops working and only completes the IV curve scan whose voltage value is as low as the threshold voltage V1. Among them, the threshold voltage V1 is less than the minimum required voltage for the auxiliary power supply 30 to work.
  • the optimizer 100 restarts, and controls the output voltage of the photovoltaic module 300 to quickly decrease to the voltage value V1 of one of the two end points of the second segment to perform an IV curve scan on the second voltage segment.
  • the first unidirectional conduction The unit 50 is positively cut off, and the energy storage unit 40 provides power to the auxiliary power source 30, and the optimizer 100 completes the second segment IV curve scan from the threshold voltage V1 to a certain value V2. Among them, V2 is less than V1. And so on, until the Nth segment IV curve scan to the preset lowest voltage is completed. Thus, the optimizer 100 completes the complete IV curve scanning task.
  • the optimizer 100 performs the IV curve scanning task on the connected photovoltaic module 300 and controls the output voltage of the photovoltaic module 300 to decrease, if the optimizer 100 does not include the first unidirectional conduction unit 50 and the energy storage unit 40 , The input voltage of the auxiliary power source 30 will drop as the output voltage of the photovoltaic module 300 drops, and stop working when the output voltage of the photovoltaic module 300 is less than the minimum required voltage for the auxiliary power source 30 to work, causing the optimizer 100 to fail to complete the photovoltaic module.
  • the voltage value of the output voltage of the component 300 is lower than the IV curve scanning task of the minimum required voltage for the auxiliary power supply 30 to work.
  • the optimizer 100 since the optimizer 100 includes the first unidirectional conduction unit 50 and the energy storage unit 40, when the optimizer 100 controls the output voltage of the photovoltaic module 300 to drop below the minimum required voltage for the auxiliary power supply 30 to work , The first unidirectional conduction unit 50 is positively cut off, thereby preventing the electric energy of the energy storage unit 40 from falling following the decrease of the output voltage of the photovoltaic assembly 300.
  • the output voltage of the photovoltaic module 300 is divided into at least two voltage segments from the threshold voltage to the preset minimum voltage, and the control unit 20 performs IV curve scanning on each voltage segment, and then uses a smaller capacity energy storage
  • the unit 40 can ensure that the optimizer 100 completes the complete IV curve scanning task.
  • the control unit 20 performs IV curve scanning on each voltage segment when it is determined that the optimizer 100 needs to perform an IV curve scanning task. Since each voltage segment is obtained by segmenting the output voltage of the photovoltaic module 300 corresponding to the optimizer 100 from the open circuit voltage to the preset minimum voltage, and the divided voltage segments are at least two, and the voltage value is compared The optimizer will be restarted when the low voltage section performs IV curve scanning, so that the energy storage unit 40 can be recharged during this period, and the output voltage of the photovoltaic module 300 will be adjusted to the current voltage section, so only a storage with a lower capacity is required. The energy unit 40 can complete the complete IV curve scanning task, thereby reducing the cost and volume of the optimizer 100.
  • the first voltage section is further divided into at least two voltage sections. Specifically, as shown in Fig. 4, “paragraph 1” in Fig. 3 is divided into paragraph 1’, paragraph 2’, ..., paragraph M’, where M’ is an integer greater than or equal to 2.
  • the IV curve scan is performed on the 1'th segment, the 2'th segment,...the Nth segment respectively.
  • the voltage segment currently being scanned by at least one optimizer 100 is different from the voltage segment currently being scanned by other optimizers 100. In the same way, the final total output power fluctuation of the string can be made smaller.
  • the number of photovoltaic modules 300 connected to each optimizer 100 is the same, and the characteristics are the same or similar, and multiple optimizers 100 are connected in series to form a string. If the optimizer 100 of the same string performs the IV curve scanning task at the same time, and each optimizer 100 adopts the same, single-segment IV curve scanning method to control the output voltage of the photovoltaic module 300, the total output power curve of the string will be approximately It is a multiple of the power curve in Figure 4, and the total output power has great fluctuations, which in turn affects the normal operation of the subsequent circuit.
  • each optimizer 100 may segment the output voltage of the corresponding photovoltaic module 300 respectively, and these segments may be the same or different.
  • these segments are different.
  • the optimizer 100 of the same string performs the IV curve scanning task at the same time, at a certain moment, one optimizer 100 performs the first stage IV curve scanning, and the other optimizer 100 performs the second stage IV curve scanning, and then optimizes again.
  • the device 100 performs the third segment IV curve scan, and so on; among them, the first segment, the second segment, the third segment...the Nth segment can be the same or different.
  • the definition that the two voltage segments are the same voltage segment is defined as if and only if the terminal voltage values of the two voltage segments are the same. If at this moment, the voltage segments of the IV curve scan performed by each optimizer 100 are more evenly distributed in the entire range from the open circuit voltage to the preset minimum voltage, for example, the first segment is 25 to 33V, and the second segment is 20 to 29V, The third segment is 15-25V, etc., and the output power of each optimizer 100 will be more evenly distributed in the entire range from the highest power point to the zero power point. At a later moment, since the segments of the IV curve scan of each optimizer 100 will continue to be evenly distributed, the output power of each optimizer 100 will also be evenly distributed, thereby making the final total output power of the string The fluctuation is small.
  • the segmentation of the output voltage of the photovoltaic module 300 is relatively flexible and free. For the voltage range higher than the threshold voltage V1, it is better to divide it into several segments rather than one segment, because this voltage range is larger and the corresponding power range is also larger, and more voltage segments correspond to more power segments. This facilitates the selection of segments, thereby reducing total output power fluctuations. That is, when the optimizer 100 of the same string performs the IV curve scanning task at the same time, the segments of each optimizer 100 at the beginning should be selected evenly, so that The fluctuation of the total output power of the string is reduced more obviously.
  • the difference from the optimizer 100 in FIG. 2 is that the first unidirectional conduction unit 50 is connected in series between the output terminal of the conversion unit 10 and the energy storage unit 40.
  • the working voltage of the auxiliary power source 30 is provided by the output voltage of the photovoltaic module 300 after being transformed by the transformation unit 10.
  • the first unidirectional conduction unit 50 includes at least one diode.
  • each optimizer 100 further includes a second unidirectional conduction unit 60, and the second unidirectional conduction unit 60 is connected in series with the conversion unit. Between the output terminal of 10 and the energy storage unit 40, the energy storage capacity of the energy storage unit 40 in response to different working conditions can be improved.
  • the second unidirectional conduction unit 60 includes at least one diode.
  • the input terminal of the auxiliary power source 30 is electrically connected to the input terminal of the conversion unit 10, or the input terminal of the auxiliary power source 30 is electrically connected to the output terminal of the conversion unit 10.
  • the first unidirectional conduction unit 50 is connected in series between the output end of the auxiliary power source 30 and the energy storage unit 40, and the energy storage unit 40 is electrically connected to the control unit 20.
  • the energy storage unit 40 only supplies power to the control unit 20, thereby improving the utilization rate of the capacity of the energy storage unit 40.
  • the auxiliary power supply 30 can also turn off some circuits that are not related to the IV curve scanning function to reduce power loss and increase the power supply time of key circuits.
  • the present application also provides an IV curve scanning method of a photovoltaic module.
  • the IV curve scanning method of the photovoltaic module is applied to the photovoltaic power generation system 1000 shown in FIG. 1.
  • the IV curve scanning method of the photovoltaic module includes the following steps.
  • step S101 the output voltage of the photovoltaic module corresponding to the optimizer is divided into at least two voltage segments from the open circuit voltage to the preset minimum voltage.
  • the optimizer 100 divides the output voltage of the corresponding photovoltaic module from the open circuit voltage to the preset minimum voltage into at least two voltage segments.
  • the upper computer (such as the inverter 500) may also divide the output voltage of the photovoltaic module 300 corresponding to the optimizer 100 from the open circuit voltage to the preset minimum voltage into at least two voltage segments. Specific restrictions.
  • step S102 when it is determined that the optimizer needs to perform the IV curve scanning task, the IV curve scanning is performed on each of the divided voltage segments.
  • control unit 20 when the control unit 20 receives an IV curve scan instruction sent by a host computer (such as an inverter), it is determined that the optimizer 100 needs to perform an IV curve scan task. In other embodiments, it can also be detected autonomously, and when it is detected that the current state of the optimizer 100 meets the preset state, it is determined that the optimizer 100 needs to perform the IV curve scanning task.
  • a host computer such as an inverter
  • performing IV curve scanning on each of the divided voltage segments includes: when performing IV curve scanning on each voltage segment, adjusting the output voltage of the photovoltaic module 300 to The voltage value of one end of the two segment points of the voltage segment.
  • control unit 20 when the control unit 20 scans the IV curve of each voltage segment, it can change the output voltage of the photovoltaic module 300 from an end point (starting point) of the voltage segment through the conversion unit 10 according to a preset rule. To the other end point (end point). Wherein, the starting voltage of each voltage section is greater than the ending voltage, or the starting voltage of each voltage section is smaller than the ending voltage, or the starting voltage of some voltage sections is greater than the ending voltage and the starting voltage of the remaining voltage sections is smaller than the ending voltage.
  • the preset rule is at least one of: a voltage drop rule with a fixed voltage difference, or a parabolic voltage drop rule, or a voltage drop rule with a fixed duty cycle change rate.
  • the two end points of one of the voltage segments are the open circuit voltage and the threshold voltage V1 of the photovoltaic module 300 respectively, and the voltage segment is defined as the first voltage segment.
  • the threshold voltage of the photovoltaic assembly 300 is less than the minimum required voltage for the auxiliary power supply 30 to work, and the threshold voltage of the photovoltaic assembly 300 to the preset minimum voltage is divided into at least two voltage segments.
  • the threshold voltage of the photovoltaic module 300 is less than the minimum required voltage for the operation of the auxiliary power supply 30 means that the voltage difference between the threshold voltage of the photovoltaic module 300 and the minimum required voltage for the operation of the auxiliary power supply 30 is within a preset range, and the predetermined range
  • the set range depends on the energy that the energy storage unit 40 can provide, that is, the preset range is when the output of the photovoltaic module 300 is less than the lowest voltage for the auxiliary power supply 30 to work normally, the energy storage unit 40 continues to supply power, and the The voltage dropped by the photovoltaic module 300 during this time.
  • the first voltage segment is divided into at least two voltage segments.
  • the voltage segment currently being scanned by at least one optimizer 100 is different from the voltage segment currently being scanned by other optimizers 100.
  • the IV curve scanning method of photovoltaic modules can be implemented in hardware or firmware, or can be stored in, for example, Read-Only Memory (ROM), Random Access Memory (Random Access Memory, for short).
  • Software or computer code in computer-readable storage media such as RAM), floppy disk, hard disk, or magneto-optical disk, or can be stored as original on a remote recording medium or non-transitory machine-readable medium, downloaded through the network, and stored in a local record
  • the computer code in the medium, so that the method described here can utilize a general-purpose computer or a special processor or in programmable or special hardware such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA) to be stored in the record
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • a computer, processor, microprocessor, controller, or programmable hardware includes memory components, such as RAM, ROM, flash memory, etc., when the computer, processor, or hardware implements the processing methods described herein, the storage When fetching and executing software or computer code, the memory component can store or receive the software or computer code.
  • the execution of the code converts the general-purpose computer into a dedicated computer for executing the processing shown here.
  • the computer-readable storage medium may be a solid-state memory, a memory card, an optical disc, and the like.
  • the computer-readable storage medium stores program instructions and is called by the optimizer of the present application to execute the above-mentioned IV curve scanning method of the photovoltaic module.

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Abstract

一种优化器、光伏发电系统及光伏组件的IV曲线扫描方法，该光伏发电系统（1000）包括多个光伏组件（300）、多个优化器（100）及逆变器（500）。每个优化器的输入端与至少一个光伏组件相连，多个优化器的输出端串联形成组串后与逆变器相连。优化器包括变换单元（10）、用于对变换单元进行控制的控制单元（20）。优化器还包括连接于变换单元及控制单元之间的辅助电源（30）、储能单元（40）及第一单向导通单元（50）。控制单元用于对各个电压段分别进行IV曲线扫描；其中，各个电压段为将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压进行分段得到，且所分得的电压段至少为两个。该光伏发电系统可以降低优化器的成本以及体积。

Description

优化器、光伏发电系统及光伏组件的IV曲线扫描方法
本申请要求于2019年09月23日提交中国专利局、申请号为201910901754.7、申请名称为“优化器、光伏发电系统及光伏组件的IV曲线扫描方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光伏发电技术领域，尤其涉及优化器、光伏发电系统及光伏组件的IV曲线扫描方法。
背景技术
优化器是一种安装在光伏组件和逆变器之间的功率变换装置，可以消除光伏组件的串并联失配，降低光伏组件被旁路的概率，并具有单个光伏组件的MPPT(Maximum Power Point Tracking，最大功率点跟踪)功能和IV曲线扫描功能。
为了对光伏组件进行检测以判断其是否存在缺陷或损坏，光伏发电系统可以通过优化器在线对光伏组件进行IV曲线扫描。当优化器进行IV曲线扫描时，需要控制光伏组件的输出电压从开路电压变化至一个较低电压乃至0V，并获取各个电压对应的输出电流值，从而得到完整的IV曲线。然而，由于优化器的辅助电源通常由光伏组件的输出电压供电，当光伏组件的输出电压较低时，优化器的辅助电源将欠压，优化器将停止工作，从而无法完成完整的IV曲线扫描任务。
现有技术中，通常在辅助电源的输入端并联储能电路，并在储能电路前串联单向导通电路，以使得当光伏组件的输出电压较低时，可以由储能电路继续为辅助电源供电，进而确保优化器完成IV曲线扫描任务。然而，由于IV曲线扫描过程需要花费一定时间，才能使光伏组件的输出电压能够一步一步的按照设定的规律变化，因此，需要较大容量的储能电路才能确保优化器完成IV曲线扫描任务，而较大容量的储能电路将不利于优化器的体积和成本的优化设计。
发明内容
本申请实施例公开了一种能够降低储能电路容量，并降低光伏组串功率波动的优化器、光伏发电系统及光伏组件的IV曲线扫描方法。
第一方面，本申请实施例公开一种优化器，包括变换单元、控制单元、辅助电源、储能单元及第一单向导通单元。其中，辅助电源、储能单元及第一单向导通单元均连接于所述变换单元与所述控制单元之间。所述变换单元的输入端与至少一个光伏组件相连，用于对所连接的光伏组件进行功率变换。控制单元与所述变换单元电连接，用于对所述变换单元进行控制。所述辅助电源用于为所述控制单元提供工作电压。所述储能单元用于为所述辅助电源或者控制单元提供电能。所述第一单向导通单元用于防止所述储能单元的电能随着所述光伏组件电压的下降而下降。所述控制单元还用于在确定所述优化器需要执行IV曲线扫描任务时，对各个电压段分别进行IV曲线扫描；其中，所述各个电压段为将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压进行分段得到，且所分得的电压 段至少为两个。
其中，变换单元可以是变换器，例如DC/DC变换器；控制单元可以是MCU(如单片机)；辅助电源可以是一个功能齐全的变换电路，例如，可以将输入电压转换为12V或5V的变换电路；储能单元可以是包括电容、超级电容或者电池的储能电路；第一单向导通单元可以是包括至少一个二极管的单向导通电路。
本申请实施例中的优化器，所述控制单元在确定优化器需要进行IV曲线扫描任务时，对各个电压段分别进行IV曲线扫描。由于各个电压段为将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压进行分段得到，且所分得的电压段至少为两个，而在对电压值较低的电压段进行IV曲线扫描时会重启优化器，使得在此期间储能单元得以重新充电，并且光伏组件的输出电压会被调节至当前的电压段，因此仅需容量较低的储能单元即可完成完整的IV曲线扫描任务，从而降低了优化器的成本以及体积。
在一种实施方式中，当所述控制单元接收到上位机发送的IV曲线扫描指令时，确定所述优化器需要执行IV曲线扫描任务，即当确定有用户需求时才执行IV曲线扫描任务，如此，可以更加满足用户的需求。
在一种实施方式中，所述控制单元在对每个电压段进行IV曲线扫描时，通过所述变换单元将所述光伏组件的输出电压调节至该电压段两个端点之中的一个端点的电压值。其中，相邻的两个电压段之间存在交集。如此，可以实现完整的且连续的从开路电压至预设最小电压的IV曲线扫描。
在一种实施方式中，其中一个电压段的两个端点分别为所述光伏组件的开路电压和阈值电压，且定义该电压段为第一电压段；其中，所述光伏组件的阈值电压小于辅助电源工作的最低需求电压；所述光伏组件的阈值电压至所述预设最小电压被划分为至少两个电压段。如此，可以保证使用较低容量的储能单元即可实现完整的IV曲线扫描，有利于降低优化器的体积和成本。
其中，所述辅助电源工作的最低需求电压是指，光伏组件输出的可供辅助电源正常工作的最低输出电压。该光伏组件的最低输出电压可以直接供给辅助电源正常工作，也可经过变换(如升压或者降压)后供给辅助电源正常工作。光伏组件的阈值电压小于辅助电源工作的最低需求电压是指，光伏组件的阈值电压与辅助电源工作的最低需求电压之间的压差在预设范围内，而该预设范围取决于储能单元所能提供的能量，即该预设范围为当该光伏组件的输出小于可供辅助电源正常工作的最低输出电压时，由储能单元继续供电，并在该时间内光伏组件下降的电压。
在一种实施方式中，所述第一电压段被划分为至少两个电压段。如此，可以使得多个优化器在同时执行IV曲线扫描任务时的总输出功率波动较小。
在一种实施方式中，为了保证在光伏组件的输出电压小于辅助电源工作的最低需求电压时，优化器能够完成IV曲线扫描任务，所述辅助电源与所述控制单元电连接；所述储能单元并联在所述辅助电源的输入端；所述第一单向导通单元串联于所述变换单元的输入端和所述储能单元之间，或者，所述第一单向导通单元串联于所述变换单元的输出端和所述储能单元之间。其中，所述第一单向导通单元包括至少一个二极管。所述储能单元包括至少一个电容，或者，至少一个超级电容，或者，至少一个电池。
在一种实施方式中，所述第一单向导通单元串联于所述变换单元的输入端和所述储能单元之间；所述优化器还包括第二单向导通单元；所述第二单向导通单元串联于所述变换单元的输出端和所述储能单元之间，进而可以提高储能单元应对不同工作情况时的储能能力。
其中，所述第二单向导通单元包括至少一个二极管。
在一种实施方式中，所述辅助电源的输入端与所述变换单元的输入端电连接，或者，所述辅助电源的输入端与所述变换单元的输出端电连接。所述第一单向导通单元串联于所述辅助电源的输出端与所述储能单元之间。所述储能单元与所述控制单元电连接。如此，当优化器进行IV曲线扫描任务时，储能单元仅为控制单元供电，从而提高了储能单元容量的利用率。此外，辅助电源还可以关闭与IV曲线扫描功能无关的部分电路，以降低电能的损耗，提高关键电路的供电时间。
第二方面，本申请实施例公开一种光伏发电系统，包括多个光伏组件以及逆变器。所述光伏发电系统还包括多个第一方面所述的优化器；其中，每个优化器的输入端与至少一个光伏组件相连，多个优化器的输出端串联形成组串后与所述逆变器相连。
在一种实施方式中，当同一组串内的多个所述优化器同时进行IV曲线扫描任务时，至少一个优化器当前正在进行扫描的电压段与其他优化器当前正在进行扫描的电压段不相同。
第三方面，本申请实施例公开一种光伏组件的IV曲线扫描方法，应用于光伏发电系统中，所述光伏发电系统包括多个光伏组件。所述光伏组件的IV曲线扫描方法，包括：
将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压分成至少两个电压段；
在确定所述优化器需要执行IV曲线扫描任务时，对所分的各个电压段分别进行IV曲线扫描。
在一种实施方式中，所述对所分的各个电压段分别进行IV曲线扫描，具体包括：在对每个电压段进行IV曲线扫描时，将所述光伏组件的输出电压调节至该电压段两个端点之中的一个端点的电压值。
在一种实施方式中，相邻的两个电压段之间存在交集。
在一种实施方式中，其中一个电压段的两个端点分别为所述光伏组件的开路电压和阈值电压，且定义该电压段为第一电压段；其中，所述光伏组件的阈值电压小于辅助电源工作的最低需求电压；所述光伏组件的阈值电压至所述预设最小电压被划分为至少两段。
在一种实施方式中，所述第一电压段被划分为至少两个电压段。
在一种实施方式中，当同一组串内的多个所述优化器同时进行IV曲线扫描任务时，至少一个优化器当前正在进行扫描的电压段与其他优化器当前正在进行扫描的电压段不相同。
第四方面，本申请实施例公开一种计算机可读存储介质，所述可读存储介质中存储有 IV曲线扫描的程序指令，所述程序指令用于供调用后执行第三方面所述的光伏组件的IV曲线扫描方法。
附图说明
为了说明本申请实施例或背景技术中的技术方案，下面将对本申请实施例或背景技术中所需要使用的附图进行说明。
图1为本申请一实施例提供的光伏发电系统的结构示意图。
图2为本申请一实施例中的优化器的原理框图。
图3为本申请一实施例中的光伏组件的电压分段示意图。
图4为本申请另一实施例中的光伏组件的电压分段示意图。
图5为本申请另一实施例中的优化器的原理框图。
图6为本申请再一实施例中的优化器的原理框图。
图7为本申请又一实施例中的优化器的原理框图。
图8为本申请又一实施例中的优化器的原理框图。
图9为本申请一实施例中的光伏组件的IV曲线扫描方法的流程图。
具体实施方式
本申请提供一种光伏发电系统、应用于光伏发电系统中的优化器以及光伏组件的IV曲线扫描方法。其中，所述优化器可以对光伏组件进行IV曲线扫描，以检测光伏组件是否存在缺陷或损坏。下面结合附图，对本申请的实施例进行描述。
请参阅图1，其为本申请一实施例提供的光伏发电系统200的原理框图。如图1所示，所述光伏发电系统1000包括多个优化器100、多个光伏组件300以及逆变器500。其中，光伏组件300用于将太阳能转换成电能。每个优化器100的输入端与至少一个光伏组件300相连，多个优化器100的输出端串联形成组串后与逆变器500相连。可以理解，光伏发电系统1000可以包括多个组串。
优化器100用于对与其相连的光伏组件300的输出功率进行优化，以保证光伏发电系统1000输出功率最大化。优化器100还可以用于对与其相连的光伏组件300进行IV曲线扫描，以检测与其相连的光伏组件300是否存在缺陷或损坏。其中，I是指电流，V是指电压。此外，IV曲线还能指示光伏组件300当前的发电能力、工作状况等信息。
逆变器500用于将光伏组件300输出的直流电转换成交流电后输出至电网2000。在其他实施方式中，优化器100和逆变器500之间还可以增加汇流箱(图未示)，逆变器500的交流侧可以接升压变压器(图未示)再接电网2000，其可以依据具体应用环境而定，此处不做具体限定。
在一具体的实施方式中，光伏发电系统1000还包括一个通信主机(图未示)，用于与优化器100进行通信，通过通信获取优化器100的电参量。其中，通信主机可以是独立的设备，也可以集成在光伏发电系统1000的其它设备中，例如集成在逆变器500、汇流箱、并网箱或者其中一个优化器中。通信主机通过无线通信(如WiFi、Lora、Zigbee等)或者PLC通信与优化器进行通信。
请参阅图2，每个优化器100包括变换单元10、控制单元20、辅助电源30、储能单元40以及第一单向导通单元50。其中，变换单元10的输入端与至少一个光伏组件300相连，作为所述优化器100的输入端。变换单元的输出端作为优化器100的输出端，多个优化器100的输出端相串联以组成组串。
在一具体的实施例中，变换单元10为DC/DC变换单元，可以工作于功率变换模式，用于对输入端的光伏组件300的直流电能进行功率变换，再输出变换后的直流电能到输出端；或者，可以工作于直通模式，将输入端和输出端直接连通。在具体的实际应用中，DC/DC变换单元可以根据具体应用环境进行电路设置，例如设置buck电路、boost电路或者buck-boost电路等。
当变换单元10工作于功率变换模式时，主要用于对输入端光伏组件300的电能进行最大功率点跟踪(Maximum Power Point Tracking，MPPT)。除此，还可以工作于缓启动、限功率模式等。其中，缓启动(也叫软启动)用于变换单元10的启动阶段，平缓地从待机模式运行到功率变换模式，例如，从待机模式按照输入电流变化率0.2A/s的速度变化到最大功率点电流。限功率模式用于在变换单元10自身运行状态接近临界值时(例如输出电压达到临界值、环境温度达到临界值)降低输出功率，以对变换单元10自身进行保护，或者在接收到外部下达的限功率模式指令后降低输出功率。
控制单元20与变换单元10电连接，用于对变换单元10进行控制。此外，控制单元20还用于采集变换单元10的工作状态参数，其中，变换单元10的工作状态参数包括但不限于变换单元10的输入电压、输入电流、输出电压及输出电流等信息。
辅助电源30、储能单元40及第一单向导通单元50连接于变换单元10与所述控制单元20之间。
在一具体的实施方式中，如图2所示，辅助电源30与控制单元20电连接，用于为控制单元20提供工作电压。可以理解，辅助电源30还可以用于为优化器100内的其他功能电路供电。在本实施方式中，所述控制单元20可为单片机。所述控制单元20可包括多个信号采集端口、通信端口、多个控制端口等。
储能单元40并联在辅助电源30的输入端，用于为辅助电源30提供电能。在一具体的实施方式中，所述储能单元40包括至少一个储能电容，或者，至少一个超级电容，或者，至少一个电池。
第一单向导通单元50串联在变换单元10的输入端和储能单元40之间，用于防止在优化器100对光伏组件300进行IV曲线扫描时，储能单元40的电能跟随光伏组件300电压的下降而下降。在一具体的实施方式中，所述第一单向导通单元50包括至少一个二极管，例如，所述二极管的阳极与所述变换单元10的输入端正极电连接，所述二极管的阴极与辅助电源30的输入端正极电连接；或者，所述二极管的阴极与所述变换单元10的输入端负极电连接，所述二极管的阳极与所述辅助电源30的输入端负极电连接；或者，所述二极管的阳极与所述变换单元10的输出端正极电连接，所述二极管的阴极与所述辅助电源30的输入端正极电连接；或者，所述二极管的阴极与所述变换单元10的输出端负极电连接，所述二极管的阳极与所述辅助电源30的输入端负极电连接。
在一具体的实施方式中，所述控制单元20用于在确定优化器100需要进行IV曲线扫 描任务时，对各个电压段分别进行IV曲线扫描。其中，所述各个电压段为将该优化器100所对应的光伏组件300的输出电压从开路电压至预设最小电压进行分段得到，且所分得的电压段至少为两个，即将优化器100所对应的光伏组件300的输出电压从开路电压至预设最小电压分成N个电压段。其中，N为大于等于2的正整数。该预设最小电压可以是0V，也可以是接近0V的某一值，在此不做具体限定。
其中，在一实施方式中，当所述控制单元20接收到上位机(如逆变器)发送的IV曲线扫描指令时，确定优化器100需要执行IV曲线扫描任务。在其他实施方式中，还可以在自主检测，当检测到优化器100的当前状态符合预设状态时，确定优化器100需要执行IV曲线扫描任务。
具体地，在一实施方式中，所述控制单元20在对每个电压段进行IV曲线扫描时，通过所述变换单元10将所述光伏组件300的输出电压调节至该电压段两个端点之中的一个端点的电压值。
在一实施方式中，为了保证IV曲线扫描的连续性，相邻的两个电压段之间存在交集。如此，可以实现完整的连续的从开路电压至预设最小电压的IV曲线扫描。
需要说明的是，控制单元20在对各个电压段进行IV曲线扫描时，可以按照预设规律通过所述变换单元10将所述光伏组件300的输出电压从该电压段的一个端点(起点)变化至另一个端点(终点)。其中，每个电压段的起点电压大于终点电压，或者，每个电压段的起点电压小于终点电压，或者，部分电压段的起点电压大于终点电压而其余电压段的起点电压小于终点电压。
在一实施方式中，预设规律为：固定压差的电压下降规律，或者，抛物线的电压下降规律，或者，固定占空比变化率的电压下降规律中的至少一种。其中，该抛物线的电压下降规律具体是指在靠近光伏组件预设最小电压附近下降较快，而在靠近最大功率点电压和开路电压附近下降较慢；该固定占空比变化率的电压下降规律是指优化器100的控制占空比从初始情况以固定步长变化，比如该控制占空比从0开始，以固定的步长0.01增加到1。
下面结合图3对优化器100对所的各个电压段分别进行IV曲线扫描的过程进行详细介绍。
如图3所示，在一实施方式中，其中一个电压段的两个端点分别为光伏组件300的开路电压和阈值电压V1，且定义该电压段为第一电压段。其中，光伏组件300的阈值电压小于辅助电源30工作的最低需求电压，且阈值电压至所述预设最小电压被划分为至少两个电压段。如此，可以保证使用较低容量的储能单元即可实现完整的IV曲线扫描，有利于降低优化器的体积和成本。
可以理解，辅助电源30的工作电压可以由光伏组件300直接提供，也可以由光伏组件300经过变换单元10升压或者降压之后提供，因此，辅助电源30工作的最低需求电压是指光伏组件300输出的可供辅助电源30正常工作的最低输出电压，该光伏组件300的最低输出电压可以直接提供至辅助电源30(如图2)以供给辅助电源30工作，或者经过变换(如图5)后提供至辅助电源30以供给辅助电源30正常工作。光伏组件300的阈值电压小于辅助电源30工作的最低需求电压是指，光伏组件300的阈值电压与辅助电源30工作的最低需求电压之间的压差在预设范围内，而该预设范围取决于储能单元40所能提供的能量， 即该预设范围为当该光伏组件300的输出小于可供辅助电源30正常工作的最低输出电压时，由储能单元40继续供电，并在该时间内光伏组件300下降的电压。
当对第1段电压进行IV曲线扫描时，光伏组件300的输出电压大部分时间是大于辅助电源30工作的最低需求电压的；当光伏组件300的输出电压低于辅助电源30工作的最低需求电压时，第一单向导通单元50正向截止，由储能单元40为辅助电源30提供电能；当储能单元40的容量较低时，经过较短的时间后辅助电源30将欠压，优化器100停止工作，仅完成了电压值低至阈值电压V1的IV曲线扫描。其中，阈值电压V1小于辅助电源30工作的最低需求电压。随后优化器100重新启动，并且控制光伏组件300的输出电压快速降低至第2段两个端点之中一个端点的电压值V1以对第2电压段进行IV曲线扫描，此时第一单向导通单元50正向截止，由储能单元40为辅助电源30提供电能，优化器100完成从阈值电压V1至某一值V2的第2段IV曲线扫描。其中，V2小于V1。依次类推，直至完成至预设最低电压的第N段IV曲线扫描。从而使得优化器100完成完整的IV曲线扫描任务。
可以理解，当优化器100对所连接的光伏组件300进行IV曲线扫描任务，并控制光伏组件300的输出电压降低时，如果优化器100不包含该第一单向导通单元50和储能单元40，则辅助电源30的输入电压将跟随光伏组件300的输出电压下降而下降，并在光伏组件300的输出电压小于该辅助电源30工作的最低需求电压时停止工作，进而导致优化器100无法完成光伏组件300的输出电压的电压值低于辅助电源30工作的最低需求电压的IV曲线扫描任务。
而在本申请实施例中，由于优化器100包含第一单向导通单元50和储能单元40，当优化器100控制光伏组件300的输出电压降低至低于辅助电源30工作的最低需求电压时，第一单向导通单元50正向截止，进而防止储能单元40的电能跟随光伏组件300输出电压的下降而下降。同时，由于将光伏组件300的输出电压从阈值电压至所述预设最小电压分成至少两个电压段，并由控制单元20对各个电压段分别进行IV曲线扫描，进而采用较小容量的储能单元40即可保证优化器100完成完整的IV曲线扫描任务。
本申请实施例所公开的优化器100，所述控制单元20在确定优化器100需要进行IV曲线扫描任务时，对各个电压段分别进行IV曲线扫描。由于各个电压段为将该优化器100所对应的光伏组件300的输出电压从开路电压至预设最小电压进行分段得到，且所分得的电压段至少为两个，而在对电压值较低的电压段进行IV曲线扫描时会重启优化器，使得在此期间储能单元40得以重新充电，并且光伏组件300的输出电压会被调节至当前的电压段，因此仅需容量较低的储能单元40即可完成完整的IV曲线扫描任务，从而降低了优化器100的成本以及体积。
在一实施方式中，所述第一电压段还被分成至少两个电压段。具体如图4所示，图3中的“第1段”被分成第1’段、第2’段、…第M’段，其中，M’为大于等于2的整数。当优化器100进行IV曲线扫描任务时，对第1’段、第2’段、…第N段分别进行IV曲线扫描。
在本实施方式中，当同一组串内的多个优化器100同时进行IV曲线扫描任务时，至少一个优化器100当前正在进行扫描的电压段与其他优化器100当前正在进行扫描的电压段 不相同，如此，可以使得该组串最终的总输出功率波动较小。
通常情况下，各个优化器100连接的光伏组件300的个数相同，特性相同或相近，多个优化器100串联形成组串。如果同一组串的优化器100同时进行IV曲线扫描任务，并且各个优化器100采用相同、单段的IV曲线扫描方法以控制光伏组件300的输出电压，则该组串的总输出功率曲线将约为图4中功率曲线的倍数，总输出功率存在极大的波动，进而影响后级电路的正常工作。
而在本申请实施例中，各个优化器100可以对所对应的光伏组件300的输出电压各自进行分段，这些分段可以相同也可以不同。当优化器100连接的光伏组件300的个数不同或特性不同时，这些分段则为不同。当同一组串的优化器100同时进行IV曲线扫描任务时，在某一时刻，某一优化器100进行第1段IV曲线扫描，另一优化器100进行第2段IV曲线扫描，再一优化器100进行第3段IV曲线扫描，依次类推；其中，第1段、第2段、第3段…第N段可以相同也可以不同。在本申请实施例中，两个电压段为相同电压段的定义为，当且仅当两个电压段的端点电压值相同。如果在该时刻，各个优化器100进行IV曲线扫描的电压段较为均匀的分布在开路电压至预设最小电压的整个范围内，例如第1段为25～33V，第2段为20～29V，第3段为15～25V等，则各个优化器100的输出功率也将较为均匀的分布在最高功率点至零功率点整个范围内。在其后的时刻，由于各个优化器100的IV曲线扫描的分段仍将延续性的均匀分布，则各个优化器100的输出功率也将均匀的分布，进而使得该组串最终的总输出功率波动较小。
需要说明的是，本申请实施例中，对光伏组件300的输出电压的分段较为灵活自由。对于高于阈值电压V1的电压范围，较宜分成若干段而非一段，因为这个电压范围较大且对应的功率范围也较大，电压分段较多则对应的功率分段也较多，有利于分段的选取，从而降低总输出功率波动，也即，同一组串的优化器100同时进行IV曲线扫描任务时，起始时刻各个优化器100的分段，较宜分布均匀的选取，从而使该组串总输出功率波动减小的更为明显。
请参阅图5，在一实施方式中，与图2中的优化器100不同的是，第一单向导通单元50的串联于变换单元10的输出端和储能单元40之间。在本实施方式中，所述辅助电源30的工作电压由光伏组件300的输出电压经变换单元10的变换后提供。该第一单向导通单元50包括至少一个二极管。
请参阅图6，在一实施方式中，与图2中的优化器100不同的是，每个优化器100还包括第二单向导通单元60，该第二单向导通单元60串联于变换单元10的输出端和储能单元40之间，进而可以提高储能单元40应对不同工作情况时的储能能力。
具体地，该第二单向导通单元60包括至少一个二极管。
请参阅图7和图8，在一实施方式中，辅助电源30的输入端与变换单元10的输入端电连接，或者，辅助电源30的输入端与变换单元10的输出端电连接。第一单向导通单元50串联于辅助电源30的输出端与储能单元40之间，储能单元40与控制单元20电连接。在本实施方式中，当优化器100进行IV曲线扫描任务时，储能单元40仅为控制单元20供电，从而提高了储能单元40容量的利用率。此外，辅助电源30还可以关闭与IV曲线扫描功能无关的部分电路，以降低电能的损耗，提高关键电路的供电时间。
请参阅图9，本申请还提供一种光伏组件的IV曲线扫描方法，该光伏组件的IV曲线扫描方法应用于图1所示的光伏发电系统1000中。所述光伏组件的IV曲线扫描方法包括如下步骤。
步骤S101，将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压分成至少两个电压段。
在一实施方式中，优化器100将所对应的光伏组件的输出电压从开路电压至预设最小电压分成至少两个电压段。在其他实施方式中，也可以是上位机(如逆变器500)将优化器100所对应的光伏组件300的输出电压从开路电压至预设最小电压分成至少两个电压段，在此不做具体限定。
步骤S102，在确定所述优化器需要执行IV曲线扫描任务时，对所分的各个电压段分别进行IV曲线扫描。
其中，在一实施方式中，当所述控制单元20接收到上位机(如逆变器)发送的IV曲线扫描指令时，确定优化器100需要执行IV曲线扫描任务。在其他实施方式中，还可以在自主检测，当检测到优化器100的当前状态符合预设状态时，确定优化器100需要执行IV曲线扫描任务。
具体地，在一实施方式中，所述对所分的各个电压段分别进行IV曲线扫描，具体包括：在对每个电压段进行IV曲线扫描时，将所述光伏组件300的输出电压调节至该电压段两个段点之中的一个端点的电压值。
在一实施方式中，为了保证IV曲线扫描的连续性，相邻的两个电压段之间存在交集。
需要说明的是，控制单元20在对各个电压段进行IV曲线扫描时，可以按照预设规律通过所述变换单元10将所述光伏组件300的输出电压从该电压段的一个端点(起点)变化至另一个端点(终点)。其中，每个电压段的起点电压大于终点电压，或者，每个电压段的起点电压小于终点电压，或者，部分电压段的起点电压大于终点电压而其余电压段的起点电压小于终点电压。
在一具体的实施方式中，预设规律为：固定压差的电压下降规律，或者，抛物线的电压下降规律，或者，固定占空比变化率的电压下降规律中的至少一种。
在一实施方式中，其中一个电压段的两个端点分别为光伏组件300的开路电压和阈值电压V1，且定义该电压段为第一电压段。其中，光伏组件300的阈值电压小于辅助电源30工作的最低需求电压，且光伏组件300的阈值电压至所述预设最小电压被划分为至少两个电压段。可以理解，光伏组件300的阈值电压小于辅助电源30工作的最低需求电压是指，光伏组件300的阈值电压与辅助电源30工作的最低需求电压之间的压差在预设范围内，而该预设范围取决于储能单元40所能提供的能量，即该预设范围为当该光伏组件300的输出小于可供辅助电源30正常工作的最低电压时，由储能单元40继续供电，并在该时间内光伏组件300下降的电压。
在一些实施方式中，所述第一电压段被分成至少两个电压段。当同一组串内的多个优化器100同时进行IV曲线扫描任务时，至少一个优化器100当前正在进行扫描的电压段与其他优化器100当前正在进行扫描的电压段不相同。
本说明书中各个实施例采用递进的方式描述，每个实施例重点说明的都是与其他实施 例的不同之处，各个实施例之间相同相似部分互相参见即可。对于实施例公开的方法而言，由于其与实施例公开的装置相对应，所以描述的比较简单，相关之处参见装置部分说明即可。
需要说明的是，对于前述的各个方法实施例，为了简单描述，故将其都表述为一系列的动作组合，但是本领域技术人员应该知悉，本申请并不受所描述的动作顺序的限制，因为依据本申请，某一些步骤可以采用其他顺序或者同时进行。
本申请实施例方法中的步骤可以根据实际需要进行顺序调整、合并和删减。
本申请提供的光伏组件的IV曲线扫描方法可以在硬件、固件中实施，或者可以作为可以存储在例如只读存储记忆体(Read-Only Memory，ROM)、随机存取存储器(Random Access Memory，简称RAM)、软盘、硬盘或磁光盘的等计算机可读存储介质中的软件或计算机代码，或者可以作为原始存储在远程记录介质或非瞬时的机器可读介质上、通过网络下载并且存储在本地记录介质中的计算机代码，从而这里描述的方法可以利用通用计算机或特殊处理器或在诸如专用集成电路(ASIC)或现场可编程门阵列(FPGA)之类的可编程或专用硬件中以存储在记录介质上的软件来呈现。如本领域能够理解的，计算机、处理器、微处理器、控制器或可编程硬件包括存储器组件，例如，RAM、ROM、闪存等，当计算机、处理器或硬件实施这里描述的处理方法而存取和执行软件或计算机代码时，存储器组件可以存储或接收软件或计算机代码。另外，当通用计算机存取用于实施这里示出的处理的代码时，代码的执行将通用计算机转换为用于执行这里示出的处理的专用计算机。
其中，所述计算机可读存储介质可为固态存储器、存储卡、光碟等。所述计算机可读存储介质存储有程序指令而供本申请的优化器调用后执行上述的光伏组件的IV曲线扫描方法。
以上所述，仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应以所述权利要求的保护范围为准。

Claims (18)

  1. 一种优化器，其特征在于，包括：
    变换单元，所述变换单元的输入端与至少一个光伏组件连接，用于对所连接的光伏组件进行功率变换；
    控制单元，与所述变换单元电连接，用于对所述变换单元进行控制；以及
    电连接于所述变换单元及所述控制单元之间的辅助电源、储能单元及第一单向导通单元；其中，所述辅助电源用于为所述控制单元提供工作电压；所述储能单元用于为所述辅助电源或者所述控制单元提供电能；所述第一单向导通单元用于防止所述储能单元的电能随着所述光伏组件电压的下降而下降；
    所述控制单元还用于对各个电压段分别进行电流电压IV曲线扫描；其中，所述各个电压段为将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压进行分段得到，且所分得的电压段至少为两个。
  2. 如权利要求1所述的优化器，其特征在于，所述控制单元对所分的每个电压段进行IV曲线扫描时，通过所述变换单元将所述光伏组件的输出电压调节至该电压段的两个端点之中的一个端点的电压值。
  3. 如权利要求1或2所述的优化器，其特征在于，相邻的两个电压段之间存在交集。
  4. 如权利要求1所述的优化器，其特征在于，所述分得的电压段中的第一电压段的两个端点值分别为所述光伏组件的开路电压和阈值电压的值；其中，所述光伏组件的阈值电压小于辅助电源工作的最低需求电压；所述光伏组件的阈值电压至所述预设最小电压被划分为至少两个电压段。
  5. 如权利要求4所述的优化器，其特征在于，所述第一电压段被划分为至少两个电压段。
  6. 如权利要求1所述的优化器，其特征在于，所述辅助电源与所述控制单元电连接；所述储能单元并联在所述辅助电源的输入端；
    所述第一单向导通单元串联于所述变换单元的输入端和所述储能单元之间；或者，所述第一单向导通单元串联于所述变换单元的输出端和所述储能单元之间。
  7. 如权利要求6所述的优化器，其特征在于，所述优化器还包括第二单向导通单元；所述第一单向导通单元串联于所述变换单元的输入端和所述储能单元之间；所述第二单向导通单元串联于所述变换单元的输出端和所述储能单元之间。
  8. 如权利要求1所述的优化器，其特征在于，所述辅助电源的输入端与所述变换单元的输入端电连接，或者，所述辅助电源的输入端与所述变换单元的输出端电连接；所述第一单向导通单元串联于所述辅助电源的输出端与所述储能单元之间；所述储能单元与所述控制单元电连接。
  9. 如权利要求6-8任一项所述的优化器，其特征在于，所述第一单向导通单元包括至少一个二极管。
  10. 如权利要求6-8任一项所述的优化器，其特征在于，所述储能单元包括至少一个电容，或者，至少一个超级电容，或者，至少一个电池。
  11. 一种光伏发电系统，包括多个光伏组件以及逆变器；其特征在于，所述光伏发电系统还包括多个如权利要求1至10任一项所述的优化器；其中，每个优化器的输入端与至少一个光伏组件相连，多个优化器的输出端串联形成组串后与所述逆变器相连。
  12. 如权利要求11所述的光伏发电系统，其特征在于，当同一组串内的多个所述优化器同时进行IV曲线扫描任务时，至少一个优化器当前正在进行扫描的电压段与其他优化器当前正在进行扫描的电压段不相同。
  13. 一种光伏组件的IV曲线扫描方法，应用于光伏发电系统中，所述光伏发电系统包括多个光伏组件；其特征在于，所述光伏组件的IV曲线扫描方法，包括：
    将该优化器所对应的光伏组件的输出电压从开路电压至预设最小电压分成至少两个电压段；
    对所分的各个电压段分别进行电流电压IV曲线扫描。
  14. 如权利要求13所述的IV曲线扫描方法，其特征在于，所述对所分的各个电压段分别进行IV曲线扫描，包括：在对每个电压段进行IV曲线扫描时，将所述光伏组件的输出电压调节至该电压段两个端点之中的一个端点的电压值。
  15. 如权利要求13或14所述的IV曲线扫描方法，其特征在于，相邻的两个电压段之间存在交集。
  16. 如权利要求13所述的IV曲线扫描方法，其特征在于，所述分得的电压段中的第一电压段的两个端点值分别为所述光伏组件的开路电压和阈值电压的值；其中，所述光伏组件的阈值电压小于辅助电源工作的最低需求电压；所述光伏组件的阈值电压至所述预设最小电压被划分为至少两个电压段。
  17. 如权利要求16所述的IV曲线扫描方法，其特征在于，所述第一电压段被划分为至少两个电压段。
  18. 如权利要求13所述的IV曲线扫描方法，其特征在于，当同一组串内的多个所述优化器同时进行IV曲线扫描任务时，至少一个优化器当前正在进行扫描的电压段与其他优化器当前正在进行扫描的电压段不相同。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113178894A (zh) * 2021-06-09 2021-07-27 阳光电源股份有限公司 一种光伏逆变器及其mpp扫描控制方法

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110677118B (zh) * 2019-09-23 2022-01-11 华为数字能源技术有限公司 优化器、光伏发电系统及光伏组件的iv曲线扫描方法
WO2021195929A1 (zh) * 2020-03-31 2021-10-07 华为技术有限公司 光伏组串的参数曲线扫描方法、变换器及光伏发电系统
US11843349B2 (en) 2021-05-10 2023-12-12 Michael Gostein In-situ I-V measurement of a module in a PV array
CN114337541B (zh) * 2022-01-07 2024-04-12 阳光电源股份有限公司 一种光伏组件的iv扫描方法、光伏系统
US20230231389A1 (en) * 2022-01-14 2023-07-20 Solaredge Technologies Ltd. Power System Including a Power Storage
CN115037247B (zh) * 2022-08-10 2022-11-25 深圳市首航新能源股份有限公司 一种光伏i-v扫描方法、装置及光伏系统
CN117411160B (zh) * 2023-12-14 2024-04-16 江苏天合清特电气有限公司 储能供电系统、方法及储能系统
CN117811092B (zh) * 2024-02-29 2024-05-14 锦浪科技股份有限公司 一种基于无线通讯的光伏优化器系统的启动方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106712716A (zh) * 2017-02-10 2017-05-24 阳光电源股份有限公司 一种光伏组件的iv曲线扫描方法及优化器
CN107196604A (zh) * 2017-05-26 2017-09-22 阳光电源股份有限公司 一种光伏发电系统及其组件iv曲线扫描方法
CN108418549A (zh) * 2018-03-07 2018-08-17 阳光电源股份有限公司 光伏组件iv曲线同步扫描方法、装置以及光伏发电系统
JP2019040434A (ja) * 2017-08-25 2019-03-14 オムロン株式会社 太陽電池のｉ−ｖカーブの計測機能を有するパワーコンディショナ
CN110677118A (zh) * 2019-09-23 2020-01-10 华为技术有限公司 优化器、光伏发电系统及光伏组件的iv曲线扫描方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8878563B2 (en) * 2011-10-13 2014-11-04 Steven Andrew Robbins System and apparatus for arc detection and location in solar arrays
JP6546203B2 (ja) * 2015-02-10 2019-07-17 株式会社東芝 電力変換装置の制御装置、制御プログラム及び電力変換装置
CN104967406B (zh) * 2015-05-05 2016-12-14 中检集团南方电子产品测试（深圳）股份有限公司 一种光伏组件阵列直流发电特性的测量仪器及其测量方法
CN107450646B (zh) * 2017-09-30 2018-12-07 北京东方计量测试研究所 太阳电池伏安特性控制电路
JP2019161813A (ja) * 2018-03-12 2019-09-19 オムロン株式会社 評価装置及びパワーコンディショナ
CN109861644B (zh) * 2018-12-24 2020-07-07 阳光电源股份有限公司 光伏组件故障诊断方法、边缘计算处理装置和逆变器
CN109818495B (zh) * 2019-03-14 2020-05-22 阳光电源股份有限公司 组串逆变器及其升压斩波电路控制方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106712716A (zh) * 2017-02-10 2017-05-24 阳光电源股份有限公司 一种光伏组件的iv曲线扫描方法及优化器
CN107196604A (zh) * 2017-05-26 2017-09-22 阳光电源股份有限公司 一种光伏发电系统及其组件iv曲线扫描方法
JP2019040434A (ja) * 2017-08-25 2019-03-14 オムロン株式会社 太陽電池のｉ−ｖカーブの計測機能を有するパワーコンディショナ
CN108418549A (zh) * 2018-03-07 2018-08-17 阳光电源股份有限公司 光伏组件iv曲线同步扫描方法、装置以及光伏发电系统
CN110677118A (zh) * 2019-09-23 2020-01-10 华为技术有限公司 优化器、光伏发电系统及光伏组件的iv曲线扫描方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3907882A4

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113178894A (zh) * 2021-06-09 2021-07-27 阳光电源股份有限公司 一种光伏逆变器及其mpp扫描控制方法
CN113178894B (zh) * 2021-06-09 2024-04-12 阳光电源股份有限公司 一种光伏逆变器及其mpp扫描控制方法

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