WO2025255993A1 - 光储系统及其控制方法 - Google Patents

光储系统及其控制方法

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Publication number
WO2025255993A1
WO2025255993A1 PCT/CN2024/120848 CN2024120848W WO2025255993A1 WO 2025255993 A1 WO2025255993 A1 WO 2025255993A1 CN 2024120848 W CN2024120848 W CN 2024120848W WO 2025255993 A1 WO2025255993 A1 WO 2025255993A1
Authority
WO
WIPO (PCT)
Prior art keywords
circuit
energy storage
voltage
photovoltaic
bus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2024/120848
Other languages
English (en)
French (fr)
Inventor
曾贤杰
江海昊
张健民
史海旭
王磊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GD Midea Air Conditioning Equipment Co Ltd
Foshan Shunde Midea Electric Science and Technology Co Ltd
Original Assignee
GD Midea Air Conditioning Equipment Co Ltd
Foshan Shunde Midea Electric Science and Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by GD Midea Air Conditioning Equipment Co Ltd, Foshan Shunde Midea Electric Science and Technology Co Ltd filed Critical GD Midea Air Conditioning Equipment Co Ltd
Publication of WO2025255993A1 publication Critical patent/WO2025255993A1/zh
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—ELECTRIC POWER NETWORKS; 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
    • H02J3/28—Arrangements for balancing of the load in networks by storage of energy
    • H02J3/32—Arrangements for balancing of the load in networks by storage of energy using batteries or super capacitors with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—ELECTRIC POWER NETWORKS; 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 feeding a single network from two or more generators or sources in parallel; Arrangements for feeding already energised networks from additional generators or sources in parallel
    • 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 energy storage system application technology, and in particular to a photovoltaic energy storage system and its control method.
  • photovoltaic strings are connected to the DC bus via photovoltaic DC/DC circuits
  • energy storage modules are connected to the DC bus via energy storage DC/DC circuits
  • the power grid and load devices are connected to the DC bus via DC/AC circuits. Therefore, the bus voltage of the DC bus can reflect the energy balance of the system in the photovoltaic-storage system. Only when the energy flowing into and out of the DC bus is equal can the bus voltage remain stable.
  • this embodiment provides a photovoltaic energy storage system and its control method.
  • embodiments of this application provide a photovoltaic-storage system, including a photovoltaic string, an energy storage unit, and a load device.
  • the photovoltaic string is connected to a DC bus via a photovoltaic DC/DC circuit
  • the energy storage unit is connected to the DC bus via an energy storage DC/DC circuit
  • the load device and the power grid are connected to the DC bus via a DC/AC circuit.
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit are all used to detect the bus voltage of the DC bus and adjust their own operating state according to the voltage range in which the bus voltage is located.
  • the voltage range is set according to a voltage reference value and represents the energy balance state of the photovoltaic-storage system under the current bus voltage.
  • the photovoltaic energy storage system is provided with multiple voltage ranges, and the upper and lower bounds of each voltage range are obtained by adjusting based on the voltage reference value.
  • the voltage range includes a first voltage range, a second voltage range, a third voltage range, a fourth voltage range, and a fifth voltage range;
  • the first voltage range is from Udcr- ⁇ Udc to Udcr+ ⁇ Udc;
  • the second voltage range is from Udcr+ ⁇ Udc to Udcr+2 ⁇ Udc;
  • the third voltage range is greater than Udcr+2 ⁇ Udc;
  • the fourth voltage range is from Udcr-2 ⁇ Udc to Udcr- ⁇ Udc;
  • the fifth voltage range is less than Udcr-2 ⁇ Udc; wherein Udcr is the voltage reference value, and ⁇ Udc is the voltage adjustment value.
  • the optical storage system includes a dual-loop space vector pulse amplitude modulation circuit.
  • the dual-loop space vector pulse amplitude modulation circuit includes a conversion module, a voltage outer loop module, a current inner loop module, and a control module.
  • the conversion module is connected to the AC output terminal of the DC/AC circuit and is used to perform coordinate transformation on the acquired AC signal from the DC/AC circuit.
  • the voltage outer loop module is connected to the DC bus and is used to obtain a d-axis current reference through PI control based on the bus voltage and the bus voltage reference.
  • the current inner loop module is connected to the output terminal of the voltage outer loop module and the output terminal of the conversion module.
  • the control module is connected to the output terminal of the current inner loop module and is used to obtain compensation amounts for the operating parameters of the DC/AC circuit based on the d-axis voltage control signal and the q-axis voltage control signal, thereby adjusting the output power of the DC/AC circuit.
  • embodiments of this application also provide a control method for a photovoltaic energy storage system, applied to the photovoltaic energy storage system described in the first aspect, the control method comprising:
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit acquire the bus voltage of the DC bus;
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located.
  • the voltage range is set according to the voltage reference value and represents the energy balance state of the photovoltaic energy storage system under the current bus voltage.
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located, including: the DC/AC circuit operating in inverter mode; the DC/AC circuit adjusting its output power according to the compensation amount output by the dual closed-loop space vector pulse amplitude modulation circuit to maintain the bus voltage within the first voltage range; the photovoltaic DC/DC circuit operating in maximum power point tracking mode; and the energy storage DC/DC circuit adjusting its operating mode according to the amount of energy stored in the energy storage unit; wherein, the range of the first voltage range is from Udcr- ⁇ Udc to Udcr+ ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located, including: the DC/AC circuit operating in inverter mode; the photovoltaic DC/DC circuit operating in maximum power point tracking mode; and the energy storage DC/DC circuit determining the current charge of the energy storage unit, and operating in charging mode when the charge of the energy storage unit is less than the upper limit of rechargeable charge; wherein, the range of the second voltage range is from Udcr+ ⁇ Udc to Udcr+2 ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located, including: the DC/AC circuit operating in inverter mode; the photovoltaic DC/DC circuit reducing its output power; and the energy storage DC/DC circuit determining the current charge of the energy storage unit, and operating in charging mode when the charge of the energy storage unit is less than the upper limit of the rechargeable charge; wherein, the range of the third voltage range is greater than Udcr + 2 ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the control method further includes: if the power level of the energy storage unit is greater than the upper limit of the rechargeable power level, the energy storage DC/DC circuit stops charging the energy storage unit.
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located, including: the DC/AC circuit operating in rectification mode; the photovoltaic DC/DC circuit operating in maximum power point tracking mode; and the energy storage DC/DC circuit determining the current charge of the energy storage unit, and operating in discharge mode when the charge of the energy storage unit is greater than the lower discharge limit; wherein, the fourth voltage range is from Udcr-2 ⁇ Udc to Udcr- ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located, including: the DC/AC circuit operating in rectification mode and stopping the voltage supply to at least a portion of the load devices; the photovoltaic DC/DC circuit operating in maximum power point tracking mode; and the energy storage DC/DC circuit determining the current charge of the energy storage unit, and operating in discharge mode when the charge of the energy storage unit is greater than the lower discharge limit; wherein, the range of the fifth voltage range is less than Udcr-2 ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the DC/AC circuit stops the voltage supply to at least a portion of the load devices, including: the DC/AC circuit acquiring the priority of the load devices; and the DC/AC circuit stopping the voltage supply to the load devices in ascending order of priority.
  • the control method further includes: if the power level of the energy storage unit is less than the dischargeable lower limit power level, the energy storage DC/DC circuit stops discharging the energy storage unit.
  • Figure 1 is a structural framework diagram of a photovoltaic energy storage system provided in an embodiment of this application;
  • Figure 2 is a schematic diagram of five control modes of a photovoltaic energy storage system provided in an embodiment of this application;
  • Figure 3 is a voltage control block diagram of a dual closed-loop space vector pulse amplitude modulation circuit for bus voltage in a first voltage range provided by an embodiment of this application;
  • Figure 4 is a flowchart illustrating a control method for a photovoltaic energy storage system provided in an embodiment of this application
  • Figure 5 is a flowchart illustrating a method for controlling the bus voltage in a first range according to an embodiment of this application.
  • Figure 6 is a flowchart illustrating a method for controlling the bus voltage in a second range according to an embodiment of this application
  • Figure 7 is a flowchart illustrating a control method for bus voltage in a third interval according to an embodiment of this application.
  • Figure 8 is a flowchart illustrating a control method for controlling the energy storage unit's charge level when the bus voltage is in the second or third interval, according to an embodiment of this application.
  • Figure 9 is a flowchart illustrating a control method for bus voltage in the fourth range provided in an embodiment of this application.
  • Figure 10 is a schematic flowchart of a control method for bus voltage in the fifth interval provided by an embodiment of this application;
  • Figure 11 is a flowchart illustrating a control method for stopping the voltage supply to a load device according to an embodiment of this application.
  • “several” means one or more, “more than” means two or more, “greater than,” “less than,” and “exceeding” are understood to exclude the stated number, while “above,” “below,” and “within” are understood to include the stated number.
  • “first” and “second” in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
  • photovoltaic strings are connected to the DC bus via photovoltaic DC/DC circuits
  • energy storage modules are connected to the DC bus via energy storage DC/DC circuits
  • the power grid and load devices are connected to the DC bus via DC/AC circuits. Therefore, the bus voltage of the DC bus can reflect the energy balance of the system in the photovoltaic-storage system. Only when the energy flowing into and out of the DC bus is equal can the bus voltage remain stable.
  • embodiments of this application provide a photoelectric storage system and its control method, enabling communication systems to operate without relying on the photoelectric storage system. Under certain circumstances, it automatically triggers adjustments to energy output or input, thereby affecting the energy balance in the photovoltaic-storage system and achieving stable control of the bus voltage.
  • FIG. 1 is a structural framework diagram of an optical energy storage system provided in an embodiment of this application.
  • An embodiment of this application provides a photovoltaic-storage system, including a photovoltaic string 110, an energy storage unit 120, and a load device 130.
  • the photovoltaic string 110 is connected to a DC bus 160 via a photovoltaic DC/DC circuit 140
  • the energy storage unit 120 is connected to the DC bus 160 via an energy storage DC/DC circuit 150
  • the load device 130 and the power grid 180 are connected to the DC bus 160 via a DC/AC circuit 170.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 are all used to detect the bus voltage of the DC bus 160 and adjust their own operating state according to the voltage range in which the bus voltage is located.
  • the voltage range is set according to a voltage reference value and represents the energy balance state of the photovoltaic-storage system under the current bus voltage.
  • the photovoltaic-storage system consists of three main parts: a photovoltaic string 110, an energy storage unit 120, and a load device 130.
  • the photovoltaic string 110 can be composed of multiple photovoltaic circuit boards connected in series. Each photovoltaic panel can convert sunlight into direct current (DC). By superimposing the DC power generated by multiple photovoltaic circuit boards in series, the total output voltage and current are increased, thereby improving the output power and meeting the energy supply or storage needs of the photovoltaic system.
  • the photovoltaic string 110 is connected to a DC bus 160 via a photovoltaic DC/DC circuit 140.
  • the photovoltaic string 110 can effectively capture solar energy and convert it into usable electrical energy, while the photovoltaic DC/DC circuit 140 can convert the DC power generated by the photovoltaic string 110 into DC power suitable for the DC bus 160.
  • the energy storage unit 120 can be used to store and release electrical energy, and is typically composed of a series of batteries or other types of energy storage devices, such as lithium-ion batteries, sodium-sulfur batteries, and supercapacitors. When the electrical energy generated by the photovoltaic string 110 exceeds current demand, the excess electrical energy is stored, and the stored electrical energy is released when the system needs additional energy.
  • Energy storage unit 120 is connected to DC bus 160 via energy storage DC/DC circuit 150, which controls the flow of electrical energy between energy storage unit 120 and DC bus 160.
  • DC/AC circuit 170 is a DC-AC converter.
  • the electrical energy generated in photovoltaic string 110 is in DC form, but many residential and commercial applications require AC power for appliances and equipment.
  • DC/AC circuit 170 converts DC power to AC power by inverting it through a series of electronic components, such as transistors and capacitors. This allows the photovoltaic power generation system to be connected to the grid 180 or to supply AC loads in residential and commercial buildings. Simultaneously, DC/AC circuit 170 can also control the output AC parameters, such as voltage, frequency, and waveform, to ensure they meet the requirements of the receiving equipment.
  • Grid 180 can also rectify the AC power through DC/AC circuit 170 to supplement the supply to DC bus 160.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150 and the DC/AC circuit 170 detect the bus voltage, and according to the voltage of the DC bus 160, the photovoltaic DC/DC circuit 140 controls the output power of the photovoltaic, the energy storage DC/DC circuit 150 manages the energy flow between the energy storage unit 120 and the DC bus 160, controls the energy storage unit 120 to release the stored electrical energy, and the DC/AC circuit 170 controls the AC power to be rectified into DC power or controls the DC power to be inverted into AC power.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 adjust their operating states according to the voltage range of the bus voltage.
  • the voltage range is set according to the voltage reference value, which represents the energy balance state of the photovoltaic and energy storage system under the current bus voltage.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 enter different operating states.
  • the photovoltaic-storage system independently detects the bus voltage through the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170, and determines the voltage range of the bus voltage based on its magnitude. It then adjusts its own operating state accordingly. Since the bus voltage reflects the energy balance in the photovoltaic-storage system, the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 automatically adjust their operating states based on the voltage range of the bus voltage. This allows them to trigger adjustments to energy output or input independently without relying on the communication system of the photovoltaic-storage system, thereby affecting the energy balance in the system and achieving stable control of the bus voltage.
  • the voltage range of the DC bus 160 of the photovoltaic energy storage system is divided into five voltage ranges: the first voltage range, the second voltage range, the third voltage range, the fourth voltage range, and the fifth voltage range.
  • the five voltage ranges correspond one-to-one with the five working modes of the photovoltaic energy storage system: the first working mode, the second working mode, the third working mode, the fourth working mode, and the fifth working mode.
  • the photovoltaic energy storage system is configured with multiple voltage ranges, and the upper and lower bounds of each voltage range are based on a voltage reference value. The result was obtained through adjustments.
  • FIG. 2 is a schematic diagram of five control modes of a photovoltaic energy storage system provided in an embodiment of this application.
  • the voltage range includes a first voltage range, a second voltage range, a third voltage range, a fourth voltage range, and a fifth voltage range;
  • the first voltage range is from Udcr- ⁇ Udc to Udcr+ ⁇ Udc;
  • the second voltage range is from Udcr+ ⁇ Udc to Udcr+2 ⁇ Udc;
  • the range of the third voltage interval is greater than Udcr+2 ⁇ Udc;
  • the fourth voltage range is from Udcr-2 ⁇ Udc to Udcr- ⁇ Udc;
  • the range of the fifth voltage interval is less than Udcr-2 ⁇ Udc;
  • each voltage range has an upper and a lower bound, which are determined based on voltage reference values and system operating requirements. In practical applications, these voltage range settings can be adjusted according to the system's performance and stability requirements.
  • the voltage range of the DC bus 160 is adjusted by the voltage adjustment value, resulting in the following: when the bus voltage is in the first voltage range Udcr- ⁇ Udc to Udcr+ ⁇ Udc, the photovoltaic-storage system switches to the first operating mode; when the bus voltage is in the second voltage range Udcr+ ⁇ Udc to Udcr+2 ⁇ Udc, the photovoltaic-storage system switches to the second operating mode; when the bus voltage is in the third voltage range greater than Udcr+2 ⁇ Udc, the photovoltaic-storage system switches to the third operating mode; when the bus voltage is in the fourth voltage range Udcr-2 ⁇ Udc to Udcr- ⁇ Udc, the photovoltaic-storage system switches to the fourth operating mode; and when the bus voltage is in the fifth voltage range less than Udcr-2 ⁇ Udc
  • the system automatically triggers adjustments to energy output or input based on the voltage range of the bus voltage, thereby affecting the energy balance in the photovoltaic-storage system and achieving stable control of the bus voltage.
  • the photovoltaic-storage system can better cope with the impact of external factors such as grid fluctuations or load changes, thereby improving the system's stability and reliability.
  • FIG. 3 is a voltage control block diagram of a dual closed-loop space vector pulse amplitude modulation circuit for bus voltage in a first voltage range provided by an embodiment of this application.
  • the optical storage system includes a dual-loop space vector pulse amplitude modulation circuit.
  • the dual-loop space vector pulse amplitude modulation circuit includes a conversion module, a voltage outer loop module, a current inner loop module, and a control module.
  • the conversion module is connected to the AC output terminal of the DC/AC circuit and is used to perform coordinate transformation on the acquired AC signal from the DC/AC circuit.
  • the voltage outer loop module is connected to the DC bus and is used to obtain the d-axis current reference through PI control based on the bus voltage and the bus voltage reference.
  • the current inner loop module is connected to the output terminal of the voltage outer loop module and the output terminal of the conversion module.
  • the control module is connected to the output terminal of the current inner loop module and is used to obtain the compensation amount of the operating parameters of the DC/AC circuit based on the d-axis voltage control signal and the q-axis voltage control signal, so as to adjust the output power of the DC/AC circuit.
  • the transformation module is used for coordinate transformation, converting the acquired AC signal from the DC/AC circuit into a dq-axis coordinate system, obtaining the d-axis current feedback id and the q-axis current feedback iq.
  • the dq-axis coordinate system is a rotating coordinate system, where the d-axis is aligned with the rotor flux linkage axis, and the q-axis forms a 90-degree angle with the d-axis and is consistent with the rotor rotation direction.
  • the voltage outer loop module obtains the d-axis current reference value idref based on the feedback and given DC bus voltage through PI control.
  • the current inner loop module connects the output of the voltage outer loop module and the output of the transformation module. Based on the d-axis current feedback id and the d-axis current reference idref, it obtains the d-axis voltage control signal edpwm through PI control decoupling, and obtains the q-axis voltage control signal eqpwm based on the q-axis current feedback iq and the q-axis current reference iqref through PI control decoupling.
  • the SVPWM control module obtains the compensation values Sa, Sb, and Sc of the DC/AC circuit's operating parameters based on the d-axis voltage control signal edpwm and the q-axis voltage control signal eqpwm, and modulates the output power of the DC/AC circuit.
  • Kpu and Kiu are the proportional coefficient and integral coefficient of the bus voltage loop, respectively;
  • Kpid and Kiid are the proportional coefficient and integral coefficient of the d-axis current loop, respectively; and
  • Kpiq and Kiiq are the proportional coefficient and integral coefficient of the q-axis current loop, respectively.
  • the dual closed-loop space vector pulse amplitude modulation circuit converts the current of the three-phase AC ABC system into the current of the two-phase orthogonal dq system, obtains the bus voltage Ude and the bus voltage reference value Udcref on the d-axis, and calculates the corresponding d-axis active current based on the difference between the bus voltage Ude and the bus voltage reference value Udcref. Based on the calculated d-axis active current, the pulse amplitude modulation circuit applies the corresponding compensation amount to the DC/AC circuit 170 to adjust its output power.
  • FIG. 4 is a flowchart illustrating a control method for a photovoltaic energy storage system according to an embodiment of this application, this method is applied to the photovoltaic energy storage system described above and may include, but is not limited to, the following steps:
  • Step S410 The photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit obtain the bus voltage of the DC bus.
  • step S420 the photovoltaic DC/DC circuit, the energy storage DC/DC circuit, and the DC/AC circuit adjust their operating states according to the voltage range in which the bus voltage is located.
  • the voltage range is set according to the voltage reference value and represents the energy balance state of the photovoltaic-storage system under the current bus voltage.
  • the photovoltaic-storage system consists of three main parts: a photovoltaic string 110, an energy storage unit 120, and a load device 130.
  • the photovoltaic string 110 can be composed of multiple photovoltaic circuit boards connected in series. Each photovoltaic panel can convert sunlight into direct current (DC). By superimposing the DC power generated by multiple photovoltaic circuit boards in series, the total output voltage and current are increased, thereby improving the output power and meeting the energy supply or storage needs of the photovoltaic system.
  • the photovoltaic string 110 is connected to a DC bus 160 via a photovoltaic DC/DC circuit 140.
  • the photovoltaic string 110 can effectively capture solar energy and convert it into usable electrical energy, while the photovoltaic DC/DC circuit 140 can convert the DC power generated by the photovoltaic string 110 into DC power suitable for the DC bus 160.
  • the energy storage unit 120 can be used to store and release electrical energy, and is typically composed of a series of batteries or other types of energy storage devices, such as lithium-ion batteries, sodium-sulfur batteries, and supercapacitors. When the electrical energy generated by the photovoltaic string 110 exceeds current demand, the excess electrical energy is stored, and the stored electrical energy is released when the system needs additional energy.
  • Energy storage unit 120 is connected to DC bus 160 via energy storage DC/DC circuit 150, which controls the flow of electrical energy between energy storage unit 120 and DC bus 160.
  • DC/AC circuit 170 is a DC-AC converter.
  • the electrical energy generated in photovoltaic string 110 is in DC form, but many residential and commercial applications require AC power for appliances and equipment.
  • DC/AC circuit 170 converts DC power to AC power by inverting it through a series of electronic components, such as transistors and capacitors. This allows the photovoltaic power generation system to be connected to the grid 180 or to supply AC loads in residential and commercial buildings. Simultaneously, DC/AC circuit 170 can also control the output AC parameters, such as voltage, frequency, and waveform, to ensure they meet the requirements of the receiving equipment.
  • Grid 180 can also rectify the AC power through DC/AC circuit 170 to supplement the supply to DC bus 160.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150 and the DC/AC circuit 170 detect the bus voltage, and according to the voltage of the DC bus 160, the photovoltaic DC/DC circuit 140 controls the output power of the photovoltaic, the energy storage DC/DC circuit 150 manages the energy flow between the energy storage unit 120 and the DC bus 160, controls the energy storage unit 120 to release the stored electrical energy, and the DC/AC circuit 170 controls the AC power to be rectified into DC power or controls the DC power to be inverted into AC power.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 adjust their operating states based on the voltage range of the bus voltage.
  • the voltage range is set according to a voltage reference value, which represents the photovoltaic-energy storage system's operating state at the current bus voltage.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150 and the DC/AC circuit 170 enter different working states.
  • the method may include, but is not limited to, the following steps:
  • step S510 the DC/AC circuit operates in inverter mode.
  • the DC/AC circuit adjusts the output power according to the compensation amount output by the dual closed-loop space vector pulse amplitude modulation circuit so that the bus voltage is maintained within the first voltage range.
  • step S520 the photovoltaic DC/DC circuit operates in maximum power point tracking mode
  • step S530 the energy storage DC/DC circuit adjusts its operating mode according to the amount of electricity stored in the energy storage unit.
  • the first voltage range is from Udcr- ⁇ Udc to Udcr+ ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect the bus voltage and compare it with the upper and lower limits of each range.
  • the bus voltage is in the first voltage range, the bus voltage is stable, that is, the photovoltaic and energy storage system is in an energy balance state.
  • the photovoltaic and energy storage system enters the first working mode.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain the current working state and converts the DC power generated by the photovoltaic string 110 into voltage and current suitable for the DC bus 160.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain the current working state.
  • the DC/AC circuit 170 inverts the DC power to AC power to supply the grid 180 or the AC load of homes and commercial buildings.
  • closed-loop control allows the inverter to adjust the output voltage in real time according to the actual bus voltage, so as to keep the grid voltage stable within a suitable range, which helps to prevent voltage fluctuations from damaging other equipment and ensures the stable operation of the grid.
  • the photovoltaic energy storage system when the bus voltage is in the first voltage range, the photovoltaic energy storage system enters the first working mode.
  • the photovoltaic DC/DC circuit 140 maintains normal operation and continuously inputs the highest energy into the photovoltaic energy storage system. Since the energy storage unit 120 is in the off mode, the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain the current off mode.
  • the DC/AC circuit 170 inverts the DC power to AC power to supply the grid 180 or supply the AC load of homes and commercial buildings.
  • the method may include, but is not limited to, the following steps:
  • Step 610 The DC/AC circuit operates in inverter mode
  • Step 620 The photovoltaic DC/DC circuit operates in maximum power point tracking mode
  • Step 630 The energy storage DC/DC circuit determines the current power level of the energy storage unit, and operates in charging mode if the power level of the energy storage unit is less than the upper limit of the rechargeable power level.
  • the second voltage range is from Udcr+ ⁇ Udc to Udcr+2 ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect the bus voltage and compare it with the upper and lower limits of each range.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to operate normally and converts the DC power generated by the photovoltaic string 110 into voltage and current suitable for the DC bus 160.
  • the energy storage DC/DC circuit 150 controls...
  • the energy storage unit 120 switches to the energy storage mode, storing a portion of the DC power generated by the photovoltaic string 110 into the energy storage unit 120, reducing the DC power generated by the photovoltaic string 110 to within the adjustable range of the DC/AC circuit 170.
  • the bus voltage is in the first voltage range, and the photovoltaic-energy storage system enters the first working mode.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain normal operation
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain charging
  • the DC/AC circuit 170 inverts the remaining DC power to AC power to supply the grid 180 or the AC loads of homes and commercial buildings, thereby ensuring normal power supply.
  • the photovoltaic-storage system when the bus voltage is in the second voltage range, the photovoltaic-storage system is in an energy-sufficient state, storing the excess electrical energy supplied by the load device 130 and the grid 180 through the energy storage unit 120. This reduces the bus voltage without wasting energy, bringing the photovoltaic-storage system closer to a balanced state and improving the system's stability and reliability.
  • the photovoltaic energy storage system when the energy storage unit 120 has not reached its charging limit and the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect that the bus voltage is in the second voltage range, the photovoltaic energy storage system enters a second operating mode.
  • the photovoltaic DC/DC circuit 140 When the grid 180 and the AC load of residential and commercial buildings require maximum supply, the photovoltaic DC/DC circuit 140 is in MPPT mode, i.e., normal operating state, and continuously inputs the maximum energy to the photovoltaic energy storage system.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to store a portion of electrical energy, reducing the DC power generated by the photovoltaic string 110 to the maximum adjustable limit of the DC/AC circuit 170.
  • the bus voltage drops to the first voltage range, and the photovoltaic-storage system enters the first working mode.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain normal operation
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain the current charging state
  • the DC/AC circuit 170 inverts the DC power energy at the maximum adjustment limit into AC power energy suitable for supplying the power grid 180 or supplying households, thereby ensuring normal power supply.
  • the photovoltaic-energy storage system when the energy storage unit 120 has not reached its charging limit and the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect that the bus voltage is in the second voltage range, the photovoltaic-energy storage system enters a second operating mode.
  • the photovoltaic DC/DC circuit 140 is in MPPT mode, i.e., normal operating state, and continuously inputs the maximum energy to the photovoltaic-energy storage system.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to store a portion of electrical energy, reducing the DC power generated by the photovoltaic string 110 to meet the maximum adjustable limit of the DC/AC circuit 170.
  • the DC/AC circuit 170 switches to a current-limiting or shut-off state.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain normal operation
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain the current charging state
  • the DC/AC circuit 170 remains in the current-limiting or off state, converting the remaining DC power into AC power or shutting it off.
  • the method may include, but is not limited to, the following steps:
  • Step S710 The DC/AC circuit operates in inverter mode
  • Step S720 The photovoltaic DC/DC circuit reduces its output power
  • step S730 the energy storage DC/DC circuit determines the current power level of the energy storage unit, and operates in charging mode if the power level of the energy storage unit is less than the upper limit of the rechargeable power level.
  • the third voltage range is greater than Udcr + 2 ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value. It should be noted that there are two scenarios when the photovoltaic-storage system enters the third operating mode: First, the bus voltage is within the third voltage range, and the system directly enters the third operating mode. Second, when the energy storage unit 120 reaches its maximum rechargeable capacity and the photovoltaic DC/DC circuit 140, energy storage DC/DC circuit 150, and DC/AC circuit 170 detect that the bus voltage is within the second voltage range, the photovoltaic DC/DC circuit 140 is still operating normally, continuously inputting the maximum energy to the photovoltaic-storage system.
  • the DC/AC circuit 170 can only convert the maximum adjustable DC power into AC power, resulting in continuous redundancy in the photovoltaic-storage system.
  • the bus voltage continues to increase, gradually exceeding the second voltage range and reaching the third voltage range, thus the photovoltaic-storage system enters the third operating mode.
  • the photovoltaic-storage system when the bus voltage is in the third voltage range, the photovoltaic-storage system is in a state of excessive energy.
  • the output power is reduced by the photovoltaic DC/DC circuit 140, and the energy storage DC/DC circuit 150 stores electrical energy as an auxiliary, thereby reducing the bus voltage and bringing the photovoltaic-storage system towards a balanced state, thus improving the stability and reliability of the system.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect the bus voltage and compare it with the upper and lower limits of each range.
  • the bus voltage is in the third voltage range, i.e., the photovoltaic-energy storage system is in a state of sufficient energy and not within the adjustable range of the DC/AC circuit 170
  • the photovoltaic DC/DC circuit 140 reduces its output power.
  • the photovoltaic-energy storage system detects the energy storage unit 120.
  • the energy storage DC/DC circuit 150 can control the energy storage unit 120 to store energy until the bus voltage is reduced to the first voltage range or the energy storage unit 120 reaches its upper limit of rechargeable capacity and charging stops.
  • the energy storage DC/DC circuit 150 stops supplying energy to the energy storage unit 120, thereby preventing it from continuing to charge.
  • the photovoltaic DC/DC circuit 140 reduces the output power, and the bus voltage gradually decreases to the first voltage range. The photovoltaic-storage system enters the first working mode.
  • the photovoltaic DC/DC circuit 140 maintains the reduced power output state
  • the energy storage DC/DC circuit 150 controls the storage unit to maintain the status quo
  • the DC/AC circuit 170 inverts the DC power at the maximum adjustment limit into AC power suitable for supplying the power grid 180 or supplying households, thereby ensuring normal power supply.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to store energy and the photovoltaic DC/DC circuit 140 to reduce power, thereby lowering the bus voltage.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to stop charging, while the photovoltaic DC/DC circuit 140 continues to maintain low power to further reduce the bus voltage.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to stop charging.
  • FIG. 8 is a flowchart illustrating a control method for an energy storage unit reaching its upper limit when the bus voltage is in the second or third range, according to an embodiment of this application, the method may include, but is not limited to, the following steps:
  • Step S810 When the bus voltage is in the second or third range, determine that the energy storage unit has reached its upper limit.
  • step S820 the energy storage DC/DC circuit stops charging the energy storage unit.
  • the energy storage DC/DC circuit 150 can stop supplying power to the energy storage unit 120, thereby preventing it from continuing to charge.
  • exiting charging mode is an important safety function in energy storage systems. It can effectively prevent overcharging and protect the performance and safety of energy storage unit 120, helping to ensure the stability and reliability of the energy storage system during long-term operation.
  • the photovoltaic DC/DC circuit 140 when the energy storage unit 120 reaches its charging limit and the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect that the bus voltage is in the second voltage range, the photovoltaic DC/DC circuit 140 continuously inputs the maximum energy to the photovoltaic-energy storage system in MPPT mode, i.e., normal operation mode.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to exit the charging mode or maintain a non-charging state.
  • the DC/AC circuit 170 inverts the DC power at the maximum adjustment limit into AC power suitable for supplying the grid 180 or the household, thereby ensuring normal power supply.
  • the method may include, but is not limited to, the following steps:
  • Step 910 The DC/AC circuit operates in rectification mode
  • Step 920 The photovoltaic DC/DC circuit operates in maximum power point tracking mode
  • Step 930 The energy storage DC/DC circuit determines the current charge of the energy storage unit, and operates in discharge mode when the charge of the energy storage unit is greater than the lower discharge limit.
  • the fourth voltage range is from Udcr-2 ⁇ Udc to Udcr- ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the DC/AC circuit 170 when the DC/AC circuit 170 operates in rectification mode, it converts the DC power supplied by the grid 180 into AC power to increase the bus voltage. This helps maintain the stability of the photovoltaic-energy storage system and ensures the efficient utilization and transmission of energy. Simultaneously, when the charge of the energy storage unit 120 exceeds its discharge limit, the energy storage DC/DC circuit 150 operates in discharge mode, releasing the energy from the energy storage unit 120 to provide additional power to the photovoltaic-energy storage system, thus helping to maintain its operational stability.
  • the photovoltaic energy storage system is in a state of insufficient energy.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to release electrical energy to increase the bus voltage.
  • the DC/AC circuit 170 switches to rectification mode to rectify the AC power of the grid 180 into DC power to supply the load equipment 130 and maintain the operational stability of the photovoltaic energy storage system.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect the bus voltage and compare it with the upper and lower limits of each range.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to operate normally and converts the DC power generated by the photovoltaic string 110 into a voltage and current suitable for the DC bus 160.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to switch to the energy release mode and release the energy in the energy storage unit 120.
  • the DC/AC circuit 170 rectifies the AC power supplied by the grid 180 into DC power and raises the bus voltage to the first voltage range.
  • the bus voltage is in the first voltage range
  • the photovoltaic-storage system enters the first working mode
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain normal operation
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain discharge
  • the DC/AC circuit 170 rectifies the AC power supplied by the grid 180 into DC power to supply the loads of residential and commercial buildings, thereby ensuring normal power supply.
  • the method may include, but is not limited to, the following steps:
  • step S1010 the DC/AC circuit operates in rectification mode and stops the voltage supply to at least a portion of the load devices;
  • step S1020 the photovoltaic DC/DC circuit operates in maximum power point tracking mode
  • step S1030 the energy storage DC/DC circuit determines the current power of the energy storage unit, and operates in discharge mode when the power of the energy storage unit is greater than the lower limit of the dischargeable power.
  • the fifth voltage range is less than Udcr-2 ⁇ Udc, where Udcr is the voltage reference value and ⁇ Udc is the voltage adjustment value.
  • the photovoltaic-storage system enters the fifth operating mode: The first is when the bus voltage is in the fifth voltage range, in which case the photovoltaic-storage system directly enters the fifth operating mode; the second is when the energy storage unit 120 drops to the minimum discharge limit and the photovoltaic DC/DC circuit 140, energy storage DC/DC circuit 150, and DC/AC circuit 170 detect that the bus voltage is in the fourth voltage range.
  • the DC/AC circuit 170 adjusts the upper limit of the rectified AC power supplied by the grid 180 at its maximum. Since the photovoltaic DC/DC circuit 140 continues to input the maximum energy to the photovoltaic-storage system, the energy of the photovoltaic-storage system is still insufficient.
  • the bus voltage further decreases. This causes the photovoltaic-storage system to be unable to meet the voltage supply of the load device 130, gradually exceeding the fourth voltage range and reaching the fifth voltage range, thus the photovoltaic-storage system enters the fifth operating mode.
  • the photovoltaic energy storage system is in a state of severe energy shortage.
  • the supply demand is reduced, the photovoltaic energy storage system tends to a balanced state, and the stability and reliability of the photovoltaic energy storage system are improved.
  • the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect the bus voltage and compare it with the upper and lower limits of each range.
  • the photovoltaic-energy storage system controls a portion of the load devices 130 to shut down, thereby reducing the voltage supply to the load devices 130.
  • the photovoltaic-energy storage system detects the energy storage unit 120.
  • the energy storage DC/DC circuit 150 can control the energy storage unit 120 to release electrical energy until the bus voltage is raised to the first voltage range or the energy storage unit 120 reaches the lower limit of discharge capacity and stops discharging.
  • the energy storage DC/DC circuit 150 stops releasing electrical energy to the energy storage unit 120.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to work in MPPT mode, i.e., normal operation.
  • Some load devices 130 are turned off, the first voltage range changes, the bus voltage reaches the first voltage range, the photovoltaic-storage system enters the first working mode, the photovoltaic DC/DC circuit 140 maintains normal state, the energy storage DC/DC circuit 150 controls the storage unit to maintain a stopped charging state, and the DC/AC circuit 170 rectifies the AC power energy at the maximum adjustment limit into DC power energy, thereby ensuring normal power supply.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to release electrical energy and shut down the load device 130, thereby ensuring that the voltage supply meets the voltage requirements.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to stop discharging.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to stop discharging.
  • the method may include, but is not limited to, the following steps:
  • Step S1110 The DC/AC circuit obtains the priority of the load device
  • step S1120 the DC/AC circuit stops the voltage supply to the load device according to the priority from low to high.
  • the priority of load devices (130) is typically used to determine the order in which voltage supply is cut off. This ensures that critical equipment or systems receive priority power supply when power resources are limited or the grid (180) is unstable.
  • voltage supply can be dynamically adjusted to ensure rational resource utilization and sufficient power support for the most critical devices.
  • This intelligent energy management approach improves the reliability, stability, and efficiency of the photovoltaic-storage system while maximizing the satisfaction of the power needs of different devices. beg.
  • FIG. 12 is a flowchart illustrating a control method for an energy storage unit whose power reaches a lower limit when the bus voltage is in the fourth or fifth range, according to an embodiment of this application, the method may include, but is not limited to, the following steps:
  • Step S1210 When the bus voltage is in the fourth or fifth range, determine that the energy storage unit's power has reached the lower limit.
  • step S1220 the energy storage DC/DC circuit stops discharging the energy storage unit. It should be noted that when the photovoltaic-energy storage system is in the fourth operating mode and the system detects that the battery capacity of the energy storage unit 120 is less than 10%, the energy storage DC/DC circuit 150 can stop the energy storage unit 120 from releasing electrical energy, thereby preventing it from continuing to discharge.
  • the energy storage DC/DC circuit 150 will exit the discharge mode. This is to avoid over-discharge, prevent damage to the energy storage unit 120, and extend its service life.
  • the energy storage DC/DC circuit 150 when the energy storage unit 120 drops to the minimum discharge limit and the photovoltaic DC/DC circuit 140, the energy storage DC/DC circuit 150, and the DC/AC circuit 170 detect that the bus voltage is in the fourth voltage range, the photovoltaic DC/DC circuit 140 is in MPPT mode, i.e., normal operation state, and continuously inputs the maximum energy to the photovoltaic-energy storage system.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to exit the discharge mode or maintain a non-discharge state.
  • the DC/AC circuit 170 rectifies the DC power supplied by the grid 180 into suitable AC power, thereby ensuring normal power supply.
  • One embodiment of this application provides a photovoltaic-energy storage system that switches between different operating modes according to different bus voltage ranges.
  • the inverter, energy storage, and photovoltaic systems operate in different control modes. Stable control of the bus voltage can be achieved through the coordinated operation of each power unit in the system, including:
  • the photovoltaic energy storage system In the first operating mode, when the bus voltage is in the first voltage range, the photovoltaic energy storage system enters the first operating mode.
  • the photovoltaic DC/DC circuit 140 maintains normal operation and continuously inputs the maximum energy to the photovoltaic energy storage system. Since the energy storage unit 120 is in the off mode, the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain the current off mode.
  • the DC/AC circuit 170 inverts the DC power to AC power to supply the grid 180 or the load equipment 130.
  • the photovoltaic-storage system In the second operating mode, when the bus voltage is in the second voltage range, the photovoltaic-storage system enters the second operating mode.
  • the photovoltaic DC/DC circuit 140 is in MPPT mode, i.e., normal operating state, continuously inputting the maximum energy to the photovoltaic-storage system.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to store a portion of the electrical energy, reducing the DC power generated by the photovoltaic string 110 to the maximum adjustable limit of the DC/AC circuit 170.
  • the photovoltaic-storage system When the bus voltage drops to the first voltage range, the photovoltaic-storage system enters the first operating mode.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain normal operation
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain the current charging state
  • the DC/AC circuit 170 inverts the DC power at the maximum adjustable limit into a form suitable for supplying the grid 180 or the load equipment 130.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to exit the charging mode or maintain a non-charging state, which can effectively prevent overcharging and protect the performance and safety of the energy storage unit 120.
  • the photovoltaic DC/DC circuit 140 reduces its output power.
  • the conversion rate decreases.
  • the photovoltaic-storage system detects the energy storage unit 120.
  • the energy storage DC/DC circuit 150 can control the energy storage unit 120 to store energy until the bus voltage is reduced to the first voltage range or the energy storage unit 120 reaches its upper limit of rechargeable capacity, at which point charging stops.
  • the energy storage DC/DC circuit 150 stops supplying energy to the energy storage unit 120, thereby preventing it from continuing to charge.
  • the photovoltaic DC/DC circuit 140 reduces the output power, and the bus voltage gradually decreases to the first voltage range.
  • the photovoltaic energy storage system enters the first working mode.
  • the photovoltaic DC/DC circuit 140 maintains the reduced power output state
  • the energy storage DC/DC circuit 150 controls the storage unit to maintain the status quo
  • the DC/AC circuit 170 inverts the DC power at the maximum adjustment limit into a form suitable for supplying the power grid 180 or the load equipment 130.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to operate normally and converts the DC power generated by the photovoltaic string 110 into voltage and current suitable for the DC bus 160.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to switch to energy release mode, releasing the energy in the energy storage unit 120.
  • the DC/AC circuit 170 rectifies the AC power supplied by the grid 180 into DC power, raising the bus voltage to the first voltage range. At this time, the bus voltage is in the first voltage range, and the photovoltaic-storage system...
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to maintain normal operation
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to maintain discharge
  • the DC/AC circuit 170 rectifies the AC power supplied by the grid 180 into DC power to supply the load equipment 130.
  • the energy storage DC/DC circuit 150 controls the energy storage unit 120 to exit the discharge mode or maintain a non-discharge state, and the DC/AC circuit 170 rectifies the DC power supplied by the grid 180 into suitable AC power, thereby ensuring normal power supply.
  • the photovoltaic-storage system controls a portion of the load devices 130 to shut down, thereby reducing the voltage supply to the load devices 130.
  • the energy storage DC/DC circuit 150 can control the energy storage unit 120 to release electrical energy.
  • the photovoltaic DC/DC circuit 140 controls the photovoltaic string 110 to work in MPPT mode, i.e., normal operation state, shutting down a portion of the load devices 130.
  • the first voltage range changes, the bus voltage reaches the first voltage range, the photovoltaic-storage system enters the first operating mode, the photovoltaic DC/DC circuit 140 maintains normal state, the energy storage DC/DC circuit 150 controls the storage unit to maintain a stopped charging state, and the DC/AC circuit 170 rectifies the AC power at the maximum adjustable upper limit into DC power, thereby ensuring normal power supply.
  • the photovoltaic DC/DC circuit, energy storage DC/DC circuit, and DC/AC circuit in the photovoltaic-energy storage system can all independently detect the bus voltage and determine the voltage range of the bus voltage based on its magnitude. They then adjust their operating states accordingly based on the voltage range. Since the bus voltage reflects the energy balance state of the photovoltaic-energy storage system, the photovoltaic DC/DC circuit, energy storage DC/DC circuit, and DC/AC circuit automatically adjust their operating states based on the voltage range of the bus voltage. This allows them to trigger adjustments to energy output or input independently without relying on the communication system of the photovoltaic-energy storage system, thereby affecting the energy balance state of the system and achieving stable control of the bus voltage.
  • Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer.
  • communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

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Abstract

本申请公开一种光储系统及其控制方法，其中光储系统包括光伏组串(110)、储能单元(120)和负载设备(130)，光伏组串(110)通过光伏DC/DC电路(140)连接到直流母线(160)，储能单元(110)通过储能DC/DC电路(150)连接到直流母线(160)，负载设备(130)和电网通过DC/AC电路(170)连接到直流母线(160)；光伏DC/DC电路(140)、储能DC/DC电路(150)和DC/AC电路(170)均用于检测直流母线(160)的母线电压，并根据母线电压所处于的电压区间调整自身的工作状态；其中，电压区间按照电压参考值设定，且表征光储系统在当前母线电压下的能量平衡状态。

Description

光储系统及其控制方法
相关申请的交叉引用
本申请要求于2024年06月13日提交的申请号为202410769551.8、名称为“光储系统及其控制方法”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
本申请涉及光储系统应用技术领域，尤其涉及一种光储系统及其控制方法。
背景技术
光储系统中，光伏组串通过光伏DC/DC电路连接到直流母线、储能模块通过储能DC/DC电路连接到直流母线、电网和负载设备通过DC/AC电路连接到直流母线，因此直流母线的母线电压可以反映出光储系统中系统能量的平衡状态，只有流入和流出直流母线的能量相等，母线电压才能够保持稳稳定。
光储系统运行时，系统内各部分功率单元消耗或者释放的能量都不是一个固定值，这就需要通过直流母线电压信号对各部分功率单元进行合理控制，使得系统内部的能量尽可能保持平衡，维持母线电压稳定。当前通常通过通讯的方式来调整光伏DC/DC电路、储能DC/DC电路和DC/AC电路的工作状态来调节能量流动，从而维持母线电压稳定，然而这种方法依赖于通讯的可靠性和通讯速度，容易在动态情况下，母线电压波动大，甚至失控。
发明内容
为至少部分解决以上所述的技术问题之一，本实施例提供了一种光储系统及其控制方法。
第一方面，本申请的实施例提供了一种光储系统，包括光伏组串、储能单元和负载设备，所述光伏组串通过光伏DC/DC电路连接到直流母线，所述储能单元通过储能DC/DC电路连接到所述直流母线，所述负载设备和电网通过DC/AC电路连接到所述直流母线；所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路均用于检测所述直流母线的母线电压，并根据所述母线电压所处于的电压区间调整自身的工作状态；其中，所述电压区间按照电压参考值设定，且表征所述光储系统在当前母线电压下的能量平衡状态。
在一些实施例中，所述光储系统设置有多个所述电压区间，各个所述电压区间的上界值和下界值基于所述电压参考值进行调整得到。
在一些实施例中，所述电压区间包括第一电压区间、第二电压区间、第三电压区间、第四电压区间和第五电压区间；所述第一电压区间的范围为Udcr-ΔUdc到Udcr+ΔUdc；所述第二电压区间的范围为Udcr+ΔUdc到Udcr+2ΔUdc；所述第三电压区间的范围为大于Udcr+2ΔUdc；所述第四电压区间的范围为Udcr-2ΔUdc到Udcr-ΔUdc；所述第五电压区间的范围为小于Udcr-2ΔUdc；其中，Udcr为所述电压参考值，ΔUdc为电压调整值。
在一些实施例中，所述光储系统包括双闭环空间矢量脉冲幅度调制电路，所述双闭环空间矢量脉冲幅度调制电路包括变换模块、电压外环模块、电流内环模块和控制模块，所述变换模块连接所述DC/AC电路的交流输出端，用于对采集的所述DC/AC电路的交流电信号进行坐标转换，所述电压外环模块连接所述直流母线，用于根据所述母线电压和母线电压给定通过PI控制得到d轴电流给定，所述电流内环模块连接所述电压外环模块的输出端和所述变换模块的输出端，用于根据所述变换模块输出的d轴交流电流和所述d轴电流给定通过PI控制得到d轴电压控制信号，以及根据所述变换模块输出的q轴交流电流和q轴电流给定通过PI控制得到q轴电压控制信号，所述控制模块连接所述电流内环模块的输出端，用于根据所述d轴电压控制信号和所述q轴电压控制信号得到所述DC/AC电路的工作参数的补偿量，以调整所述DC/AC电路的输出功率。
第二方面，本申请的实施例还提供了一种光储系统的控制方法，应用于第一方面所述的光储系统，所述控制方法包括：
所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路获取所述直流母线的母线电压；以及
所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态；
其中，所述电压区间按照电压参考值设定，且表征所述光储系统在当前母线电压下的能量平衡状态。
在一些实施例中，在所述母线电压处于第一电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：所述DC/AC电路工作在逆变模式，所述DC/AC电路根据双闭环空间矢量脉冲幅度调制电路输出的补偿量调整输出功率，以使所述母线电压维持在所述第一电压区间内；所述光伏DC/DC电路工作在最大功率点跟踪模式；以及所述储能DC/DC电路根据所述储能单元的电量调整工作模式；其中，所述第一电压区间的范围为Udcr-ΔUdc到Udcr+ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
在一些实施例中，在所述母线电压处于第二电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：所述DC/AC电路工作在逆变模式；所述光伏DC/DC电路工作在最大功率点跟踪模式；以及所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量小于可充电上限电量的情况下，所述储能DC/DC电路工作在充电模式；其中，所述第二电压区间的范围为Udcr+ΔUdc到Udcr+2ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
在一些实施例中，在所述母线电压处于第三电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：所述DC/AC电路工作在逆变模式；所述光伏DC/DC电路降低输出功率；以及所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量小于可充电上限电量的情况下，所述储能DC/DC电路工作在充电模式；其中，所述第三电压区间的范围为大于Udcr+2ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
在一些实施例中，在所述储能DC/DC电路确定所述储能单元的当前电量之后，所述控制方法还包括：在所述储能单元的电量大于所述可充电上限电量的情况下，所述储能DC/DC电路停止对所述储能单元充电。
在一些实施例中，在所述母线电压处于第四电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：所述DC/AC电路工作在整流模式；所述光伏DC/DC电路工作在最大功率点跟踪模式；以及所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量大于可放电下限电量的情况下，所述储能DC/DC电路工作在放电模式；其中，所述第四电压区间的范围为Udcr-2ΔUdc到Udcr-ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
在一些实施例中，在所述母线电压处于第五电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：所述DC/AC电路工作在整流模式，并停止至少一部分所述负载设备的电压供给；所述光伏DC/DC电路工作在最大功率点跟踪模式；以及所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量大于可放电下限电量的情况下，所述储能DC/DC电路工作在放电模式；其中，所述第五电压区间的范围为小于Udcr-2ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
在一些实施例中，所述DC/AC电路停止至少一部分所述负载设备的电压供给，包括：所述DC/AC电路获取所述负载设备的优先级；以及所述DC/AC电路按照优先级从低到高停止所述负载设备的电压供给。
在一些实施例中，在所述储能DC/DC电路确定所述储能单元的当前电量之后，所述控制方法还包括：在所述储能单元的电量小于可放电下限电量的情况下，所述储能DC/DC电路停止对所述储能单元放电。
本申请的其它特征和优点将在随后的说明书中阐述，并且，部分地从说明书中变得显而易见，或者通过实施本申请而了解。本申请的目的和其他优点可通过在说明书、权利要求书以及附图中所特别指出的结构来实现和获得。
附图说明
图1是本申请的实施例提供的一种光储系统的结构框架图；
图2是本申请的实施例提供的一种光储系统的五种控制模式的示意图；
图3是本申请的实施例提供的一种母线电压在第一电压区间下双闭环空间矢量脉冲幅度调制电路的电压控制框图；
图4是本申请的实施例提供的一种光储系统的控制方法的流程示意图；
图5是本申请的实施例提供的一种母线电压处于第一区间的控制方法的流程示意图；
图6是本申请的实施例提供的一种母线电压处于第二区间的控制方法的流程示意图；
图7是本申请的实施例提供的一种母线电压处于第三区间的控制方法的流程示意图；
图8是本申请的实施例提供的一种母线电压处于第二或第三区间储能单元电量达到上限的控制方法的流程示意图；
图9是本申请的实施例提供的一种母线电压处于第四区间的控制方法的流程示意图；
图10是本申请的实施例提供的一种母线电压处于第五区间的控制方法的流程示意图；
图11是本申请的实施例提供的一种停止负载设备电压供给的控制方法的流程示意图；以及
图12是本申请的实施例提供的一种母线电压处于第四或第五区间储能单元电量达到下限的控制方法的流程示意图。
具体实施方式
为了使本申请的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本申请进行进一步详细说明。应当理解，此处所描述的具体实施例仅用以解释本申请，并不用于限定本申请。另外，说明书中所描述的特点、操作或者特征可以以任意适当的方式结合形成各种实施方式。同时，方法描述中的各步骤或者动作也可以按照本领域技术人员所能显而易见的方式进行顺序调换或调整。因此，说明书和附图中的各种顺序只是为了清楚描述某一个实施例，并不意味着是必须的顺序，除非另有说明其中某个顺序是必须遵循的。
在本申请的描述中，若干的含义是一个或者多个，多个的含义是两个以上，大于、小于、超过等理解为不包括本数，以上、以下、以内等理解为包括本数。如果有描述到第一、第二只是用于区分技术特征为目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量或者隐含指明所指示的技术特征的先后关系。
本文中为部件所编序号本身，例如“第一”、“第二”等，仅用于区分所描述的对象，不具有任何顺序或技术含义。而本申请所说“连接”、“联接”，如无特别说明，均包括直接和间接连接(联接)。
随着世界各国对节能减排和能源转型的不断推进，可再生能源发电技术已经受到越来越多的重视，其中，光储系统由于其技术成熟度以及经济性等因素被广泛应用于电力系统以及微型电网。
光储系统中，光伏组串通过光伏DC/DC电路连接到直流母线、储能模块通过储能DC/DC电路连接到直流母线、电网和负载设备通过DC/AC电路连接到直流母线，因此直流母线的母线电压可以反映出光储系统中系统能量的平衡状态，只有流入和流出直流母线的能量相等，母线电压才能够保持稳稳定。
光储系统运行时，系统内各部分功率单元消耗或者释放的能量都不是一个固定值，这就需要通过直流母线电压信号对各部分功率单元进行合理控制，使得系统内部的能量尽可能保持平衡，维持母线电压稳定。当前通常通过通讯的方式来调整光伏DC/DC电路、储能DC/DC电路和DC/AC电路的工作状态来调节能量流动，从而维持母线电压稳定，然而这种方法依赖于通讯的可靠性和通讯速度，容易在动态情况下，母线电压波动大，甚至失控。
基于此，本申请的实施例提供了一种光储系统及其控制方法，能够在不依靠光储系统的通讯系统的 情况下，自行触发调整能量输出或者输入，进而影响光储系统中的能量平衡状态，实现了母线电压的稳定控制。
下面结合附图对本申请的实施例提供的一种光储系统及其控制方法进行说明：
参照图1所示，图1是本申请的实施例提供的一种光储系统的结构框架图。
本申请的实施例提供了一种光储系统，包括光伏组串110、储能单元120和负载设备130，光伏组串110通过光伏DC/DC电路140连接到直流母线160，储能单元120通过储能DC/DC电路150连接到直流母线160，负载设备130和电网180通过DC/AC电路170连接到直流母线160；光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170均用于检测直流母线160的母线电压，并根据母线电压所处于的电压区间调整自身的工作状态；其中，电压区间按照电压参考值设定，且表征光储系统在当前母线电压下的能量平衡状态。
需要说明的是，光储系统由光伏组串110、储能单元120和负载设备130三个主要部分组成。其中，光伏组串110可以由多个光伏电路板串联组成，每个光伏电池板都能够将阳光转换为直流电能，通过串联多个光伏电路板产生的直流电能叠加起来，以增加总的输出电压和电流，提高输出功率，满足光伏系统供能或储能的需求。光伏组串110通过光伏DC/DC电路140连接到直流母线160，光伏组串110可以有效地捕获太阳能并将其转化为可用的电能，而光伏DC/DC电路140可以将光伏组串110所产生的直流电能转换为适合直流母线160的直流电能。储能单元120可以用于存储释放电能，通常由一系列电池或者其他类型的储能装置组成，如锂离子电池、钠硫电池、超级电容器等。在光伏组串110产生的电能超出当前需求时，将多余的电能存储起来，并在系统需要额外能量时释放存储的电能。储能单元120通过储能DC/DC电路150连接到直流母线160，储能DC/DC电路150控制储能单元120和直流母线160之间的电能流动。DC/AC电路170是直流电和交流电的转换电路，光伏组串110中产生的电能是直流形式的，但许多家庭和商业应用需要使用交流电来供电电器和设备，DC/AC电路170通过将直流电经过一系列的电子元件，如晶体管和电容器，进行逆变操作，将其转换为交流电。这样，光伏发电系统就可以连接到电网180或供应家庭、商业建筑的交流负载。同时，DC/AC电路170也可以控制输出的交流电参数，如电压、频率和波形，以确保其符合接收端设备的要求。电网180也可以通过DC/AC电路170整流为直流电，补充供给到直流母线160。
另外，通过光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并根据直流母线160的电压，光伏DC/DC电路140控制光伏的输出功率，储能DC/DC电路150管理储能单元120与直流母线160之间的能量流动，控制储能单元120释放储存电能，DC/AC电路170控制交流电整流为直流电或者控制直流电逆变交流电。
进一步的，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170调整自身的工作状态是根据母线电压处于的电压区间，电压区间按照电压参考值设定，电压参考值表征光储系统在当前母线电压下的能量平衡状态，母线电压在不同的电压区间，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170进入不同的工作状态。
可以理解的是，光储系统通过光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170独立检测母线电压，并根据母线电压的大小确定母线电压所处的电压区间，根据电压区间相应调整自身的工作状态，由于母线电压反映了光储系统中能量平衡状态，因此光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170基于母线电压所处的电压区间自动调整工作状态，能够在不依靠光储系统的通讯系统的情况下，自行触发调整能量输出或者输入，进而影响光储系统中的能量平衡状态，实现了母线电压的稳定控制。
在本申请的一个实施例中，光储系统设置直流母线160的电压区间分为五个电压区间，第一电压区间、第二电压区间、第三电压区间、第四电压区间和第五电压区间，同时五个电压区间分别一一对应光储系统的五种工作模式，第一工作模式、第二工作模式、第三工作模式、第四工作模式和第五工作模式。
在一些实施例中，光储系统设置有多个电压区间，各个电压区间的上界值和下界值基于电压参考值 进行调整得到。
可以理解的是，通过将电压范围划分为多个区间并调整其上下界，系统可以更有效地管理能量。根据实时的能量需求和供给情况，系统可以在不同的区间中切换，以最大程度地利用可用的能量并确保系统的稳定运行。
参照图2所示，图2是本申请的实施例提供的一种光储系统的五种控制模式的示意图。
在一些实施例中，电压区间包括第一电压区间、第二电压区间、第三电压区间、第四电压区间和第五电压区间；
第一电压区间的范围为Udcr-ΔUdc到Udcr+ΔUdc；
第二电压区间的范围为Udcr+ΔUdc到Udcr+2ΔUdc；
第三电压区间的范围为大于Udcr+2ΔUdc；
第四电压区间的范围为Udcr-2ΔUdc到Udcr-ΔUdc；
第五电压区间的范围为小于Udcr-2ΔUdc；
其中，Udcr为电压参考值，ΔUdc为电压调整值。
可以理解的是，每个电压区间都有一个上界值和一个下界值，这些值是根据电压参考值以及系统运行的要求来确定的。在实际应用中，这些电压区间的设置可以根据系统的性能和稳定性需求进行调整。
需要说明的是，基于电压参考值，即光储系统的平衡状态，通过电压调整值调整直流母线160的电压区间，从而得出：当母线电压处于第一电压区间Udcr-ΔUdc到Udcr+ΔUdc时，光储系统切换至第一工作模式；当母线电压处于第二电压区间Udcr+ΔUdc到Udcr+2ΔUdc时，光储系统切换至第二工作模式；当母线电压处于第三电压区间大于Udcr+2ΔUdc时，光储系统切换至第三工作模式；当母线电压处于第四电压区间Udcr-2ΔUdc到Udcr-ΔUdc时，光储系统切换至第四工作模式；当母线电压处于第五电压区间小于Udcr-2ΔUdc时，光储系统切换至第五工作模式。在不依靠光储系统的通讯系统的情况下，根据母线电压处于的电压区间，自行触发调整能量输出或者输入，进而影响光储系统中的能量平衡状态，实现了母线电压的稳定控制。
可以理解的是，通过根据电压参考值和调整值设置不同的电压区间，光储系统可以更好地应对电网180波动或负载变化等外部因素的影响，提高系统的稳定性和可靠性。
参照图3所示，图3是本申请的实施例提供的一种母线电压在第一电压区间下双闭环空间矢量脉冲幅度调制电路的电压控制框图。
在一些实施例中，光储系统包括双闭环空间矢量脉冲幅度调制电路，双闭环空间矢量脉冲幅度调制电路包括变换模块、电压外环模块、电流内环模块和控制模块，变换模块连接DC/AC电路的交流输出端，用于对采集的DC/AC电路的交流电信号进行坐标转换，电压外环模块连接直流母线，用于根据母线电压和母线电压给定通过PI控制得到d轴电流给定，电流内环模块连接电压外环模块的输出端和变换模块的输出端，用于根据变换模块输出的d轴交流电流和d轴电流给定通过PI控制得到d轴电压控制信号，以及根据变换模块输出的q轴交流电流和q轴电压给定通过PI控制得到q轴电压控制信号，控制模块连接电流内环模块的输出端，用于根据d轴电压控制信号和q轴电压控制信号得到DC/AC电路的工作参数的补偿量，以调整DC/AC电路的输出功率。
需要说明的是，变换模块用于进行坐标转换，将采集的DC/AC电路的交流电信号进行转换，将三项交流电转换为dq轴，得到d轴电流反馈id、q轴电流反馈iq，dq轴坐标系是一种旋转坐标系，其中d轴与转子磁链的轴对齐，q轴与d轴成90度角，并且与转子旋转方向一致。电压外环模块根据直流母线电压的反馈和给定通过PI控制得到d轴电流给定，即d轴有功电流的参考值idref。电流内环模块连接电压外环模块的输出端和变换模块的输出端，根据d轴电流反馈id和d轴电流给定idref通过PI控制解耦得到d轴电压控制信号edpwm，根据q轴电流反馈iq和q轴电流给定iqref通过PI控制解耦得到q轴电压控制信号eqpwm。控制模块SVPWM根据d轴电压控制信号edpwm和q轴电压控制信号eqpwm得到DC/AC电路的工作参数的补偿量Sa、Sb和Sc，调制DC/AC电路的输出功率
参照图3所示，Kpu和Kiu分别为母线电压环的比例系数和积分系数，Kpid和Kiid分别为d轴电流环的比例系数和积分系数，Kpiq和Kiiq分别为q轴电流环的比例系数和积分系数。
需要说明的是，双闭环空间矢量脉冲幅度调制电路将三相交流abc系统的电流转换为两相正交dq系统的电流，获取d轴上的母线电压Ude和母线电压参考值Udcref，根据母线电压Ude和母线电压参考值Udcref之间的差异，脉冲幅度调制电路会计算出相应的d轴有功电流，根据计算得到的d轴有功电流，脉冲幅度调制电路将相应的补偿量应用于DC/AC电路170，以调整其输出功率。当母线电压Udc高于母线电压参考值Udcref时，通过电流补偿，实际输入电网180电流参考值增加，则输入电网180的输出功率增加，使得母线电压值下降到参考值；当母线电压Udc低于电压参考值Udcref时，通过电流补偿，实际输入电网180网电流参考值减少，则输入电网180网输出功率减少，使得母线电压值上升到参考值，稳定供给电能给家用负载，从而确保系统在各种工作条件下都能够稳定运行，并且能够更好地适应电能变化和负载需求的波动。
可以理解的是，通过比较处理得到的电压信息，双闭环空间矢量脉冲幅度调制电路可以计算得到d轴有功电流的信息，用于调整DC/AC电路170的工作参数，以确保系统在不同工作状态下的稳定性和效率。根据计算得到的d轴有功电流信息，双闭环空间矢量脉冲幅度调制电路可以生成相应的补偿量，用于调整DC/AC电路170的输出功率，确保系统在各种工作负载下都能够提供稳定的电力输出，并实现对电网180的有效接入。
参照图4所示，图4是本申请的实施例提供的一种光储系统的控制方法的流程示意图，该方法应用于上文所述的光储系统，该方法可以包括但不限于以下步骤：
步骤S410，光伏DC/DC电路、储能DC/DC电路和DC/AC电路获取直流母线的母线电压；
步骤S420，光伏DC/DC电路、储能DC/DC电路和DC/AC电路根据母线电压所处于的电压区间调整自身的工作状态。
其中，电压区间按照电压参考值设定，且表征光储系统在当前母线电压下的能量平衡状态。
需要说明的是，需要说明的是，光储系统由光伏组串110、储能单元120和负载设备130三个主要部分组成。其中，光伏组串110可以由多个光伏电路板串联组成，每个光伏电池板都能够将阳光转换为直流电能，通过串联多个光伏电路板产生的直流电能叠加起来，以增加总的输出电压和电流，提高输出功率，满足光伏系统供能或储能的需求。光伏组串110通过光伏DC/DC电路140连接到直流母线160，光伏组串110可以有效地捕获太阳能并将其转化为可用的电能，而光伏DC/DC电路140可以将光伏组串110所产生的直流电能转换为适合直流母线160的直流电能。储能单元120可以用于存储释放电能，通常由一系列电池或者其他类型的储能装置组成，如锂离子电池、钠硫电池、超级电容器等。在光伏组串110产生的电能超出当前需求时，将多余的电能存储起来，并在系统需要额外能量时释放存储的电能。储能单元120通过储能DC/DC电路150连接到直流母线160，储能DC/DC电路150控制储能单元120和直流母线160之间的电能流动。DC/AC电路170是直流电和交流电的转换电路，光伏组串110中产生的电能是直流形式的，但许多家庭和商业应用需要使用交流电来供电电器和设备，DC/AC电路170通过将直流电经过一系列的电子元件，如晶体管和电容器，进行逆变操作，将其转换为交流电。这样，光伏发电系统就可以连接到电网180或供应家庭、商业建筑的交流负载。同时，DC/AC电路170也可以控制输出的交流电参数，如电压、频率和波形，以确保其符合接收端设备的要求。电网180也可以通过DC/AC电路170整流为直流电，补充供给到直流母线160。
另外，通过光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并根据直流母线160的电压，光伏DC/DC电路140控制光伏的输出功率，储能DC/DC电路150管理储能单元120与直流母线160之间的能量流动，控制储能单元120释放储存电能，DC/AC电路170控制交流电整流为直流电或者控制直流电逆变交流电。
进一步的，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170调整自身的工作状态是根据母线电压处于的电压区间，电压区间按照电压参考值设定，电压参考值表征光储系统在当前母线电压 下的能量平衡状态，母线电压在不同的电压区间，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170进入不同的工作状态。
参照图5所示，图5是本申请的实施例提供的一种母线电压处于第一区间的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤S510，DC/AC电路工作在逆变模式，DC/AC电路根据双闭环空间矢量脉冲幅度调制电路输出的补偿量调整输出功率，以使母线电压维持在第一电压区间内；
步骤S520，光伏DC/DC电路工作在最大功率点跟踪模式；
步骤S530，储能DC/DC电路根据储能单元的电量调整工作模式。
其中，第一电压区间的范围为Udcr-ΔUdc到Udcr+ΔUdc，Udcr为电压参考值，ΔUdc为电压调整值。
需要说明的是，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并将母线电压与各个区间的上界值和下界值对比，在母线电压处于第一电压区间的情况下，母线电压稳定，即光储系统处于能量平衡状态，光储系统进入第一工作模式，光伏DC/DC电路140控制光伏组串110为维持当前工作状态，并将光伏组串110所产生的直流电能转换为适合直流母线160的电压和电流，储能DC/DC电路150控制储能单元120维持当前工作状态，DC/AC电路170将直流电能逆变给交流电能，供给电网180或供应家庭、商业建筑的交流负载。
可以理解的是，闭环控制可以使逆变器根据母线电压的实际情况实时调整输出电压，以保持电网180电压稳定在合适的范围内，有助于防止电压波动对其他设备造成损害，并确保电网180的稳定运行。
在本申请一个实施例中，当母线电压处于第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140维持正常工作状态，持续为光储系统输入最高能量，由于储能单元120处于关闭模式，储能DC/DC电路150控制储能单元120维持当前关闭模式，DC/AC电路170将直流电能逆变给交流电能，供给电网180或供应家庭、商业建筑的交流负载。
参照图6所示，图6是本申请的实施例提供的一种母线电压处于第二区间的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤610，DC/AC电路工作在逆变模式；
步骤620，光伏DC/DC电路工作在最大功率点跟踪模式；
步骤630，储能DC/DC电路确定储能单元的当前电量，并在储能单元的电量小于可充电上限电量的情况下，储能DC/DC电路工作在充电模式。
其中，第二电压区间的范围为Udcr+ΔUdc到Udcr+2ΔUdc，Udcr为电压参考值，ΔUdc为电压调整值。
需要说明的是，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并将母线电压与各个区间的上界值和下界值对比，在母线电压处于第二电压区间的情况下，即光储系统处于能量充裕且不在DC/AC电路170可调节范围内，光伏DC/DC电路140控制光伏组串110为正常工作，并将光伏组串110所产生的直流电能转换为适合直流母线160的电压和电流，在储能单元120的电量小于可充电上限电量90％的情况下，储能DC/DC电路150控制储能单元120切换至储存电能模式，将一部分光伏组串110所产生的直流电能储存到储能单元120中，将光伏组串110所产生的直流电能降为符合DC/AC电路170可调节范围内，此时，母线电压处于第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140控制光伏组串110维持正常工作，储能DC/DC电路150控制储能单元120维持充电，DC/AC电路170将剩余的直流电能逆变给交流电能，供给电网180或供应家庭、商业建筑的交流负载，从而保证正常的供电。
可以理解的是，在母线电压处于第二电压区间的情况下，光储系统处于能量充裕状态，通过储能单元120将超出负载设备130和电网180供给的部分电能储存起来。在不浪费电能的同时，降低了母线电压，使光储系统趋向于平衡状态，提高系统的稳定性和可靠性。
在本申请的一个实施例中，在储能单元120未达到充电上限与光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压处于第二电压区间的情况下，光储系统进入第二工作模式，当电网180和家庭、商业建造的交流负载需要最大供给时，光伏DC/DC电路140在MPPT模式，即正常工作状态，持续为光储系统输入最高能量，储能DC/DC电路150控制储能单元120储存一部分电能，将光伏组串110所产生的直流电能降为符合DC/AC电路170可最大调节上限。此时，母线电压降为第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140控制光伏组串110维持正常工作，储能DC/DC电路150控制储能单元120维持当前充电状态，DC/AC电路170将最大调节上限的直流电能逆变为适合供给电网180或供应家庭的交流电能从而保证正常的供电。
在本申请的一个实施例中，在储能单元120未达到充电上限与光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压处于第二电压区间的情况下，光储系统进入第二工作模式，当电网180和家庭、商业建造的交流负载不需要最大供给或不需要供给时，光伏DC/DC电路140在MPPT模式，即正常工作状态，持续为光储系统输入最高能量，储能DC/DC电路150控制储能单元120储存一部分电能，将光伏组串110所产生的直流电能降为符合DC/AC电路170可最大调节上限，DC/AC电路170切换至限流或关闭状态。母线电压降为第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140控制光伏组串110维持正常工作，储能DC/DC电路150控制储能单元120维持当前充电状态，DC/AC电路170维持处于限流或关闭状态，将剩余的直流电能转变为交流电能或关闭。
参照图7所示，图7是本申请的实施例提供的一种母线电压处于第三区间的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤S710，DC/AC电路工作在逆变模式；
步骤S720，光伏DC/DC电路降低输出功率；
步骤S730，储能DC/DC电路确定储能单元的当前电量，并在储能单元的电量小于可充电上限电量的情况下，储能DC/DC电路工作在充电模式。
其中，第三电压区间的范围为大于Udcr+2ΔUdc，Udcr为电压参考值，ΔUdc为电压调整值。需要说明的是，光储系统进入第三工作模式的两种情况：第一种是母线电压处于第三电压区间，光储系统直接进入第三工作模式；第二种是当储能单元120达到可充电最大上限电量与光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压处于第二电压区间的情况下，由于光伏DC/DC电路140仍处于正常工作状态，持续为光储系统输入最高能量，又由于输入的最高能量大于DC/AC电路170可调节范围，DC/AC电路170只能将最大调节上限的直流电能逆变为交流电，从而导致光储系统中持续冗余，母线电压持续增大，逐渐超出第二电压区间，达到第三电压区间，光储系统也因此进入第三工作模式。
可以理解的是，在母线电压处于第三电压区间的情况下，光储系统处于能量过于充裕状态，通过光伏DC/DC电路140降低输出功率，通过储能DC/DC电路150存储电能作为辅助，降低了母线电压，使光储系统趋向于平衡状态，提高系统的稳定性和可靠性。
在本申请的一个实例中，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并将母线电压与各个区间的上界值和下界值对比，在母线电压处于第三电压区间的情况下，即光储系统处于能量充裕且不在DC/AC电路170可调节范围内，光伏DC/DC电路140降低输出功率，在光伏组串110所产生的直流电能转化为适合直流母线160的直流电能的过程中转化率降低，光储系统检测储能单元120，当储能单元120未达到可充电上限电量的情况下，储能DC/DC电路150可以通过控制储能单元120存储电能，直至降低母线电压至第一电压区间内或储能单元120达到可充电上限电量时停止充电；当储能单元120达到可充电上限电量的情况下，储能DC/DC电路150停止向储能单元120输送电能，从而阻止其继续充电。通过光伏DC/DC电路140降低输出功率，母线电压逐渐降低至第一电压区间内，光储系统进入第一工作模式，光伏DC/DC电路140维持降低功率输出状态，储能DC/DC电路150控制存储单元维持现状，DC/AC电路170将最大调节上限的直流电能逆变为适合供给电网180或供应家庭的交流电能，从而保证正常的供电。
可以理解的是，当母线电压处于第三电压区间，光储系统进入第三工作模式的情况下，储能单元120未达到可充电上限电量，通过储能DC/DC电路150控制储能单元120存储电能和光伏DC/DC电路140降低功率，从而降低母线电压。在降低母线电压的过程中，储能单元120达到可充电上限电量时，储能DC/DC电路150控制储能单元120停止充电，光伏DC/DC电路140继续维持低功率，降低母线电压；另外，在降低母线电压的过程中，储能单元120始终未达到可充电上限电量，在母线电压降至第一电压区间内时，储能DC/DC电路150控制储能单元120停止充电。
参照图8所示，图8是本申请的实施例提供的一种母线电压处于第二或第三区间储能单元电量达到上限的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤S810，当母线电压处于第二或第三区间，确定储能单元电量达到上限；
步骤S820，储能DC/DC电路停止对储能单元充电。
需要说明的是，当光储系统处于第二工作模式并且光储系统检测储能单元120的电池容量位于90％到100％区间时，储能DC/DC电路150可以停止向储能单元120输送电能，从而阻止其继续充电。
可以理解的是，退出充电模式是储能系统中的重要安全功能，能够有效预防过充情况的发生，并保护储能单元120的性能和安全，有助于确保储能系统在长期运行中保持稳定和可靠。
在本申请的一个实施例中，在储能单元120达到充电上限与光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压处于第二电压区间的情况下，光伏DC/DC电路140在MPPT模式，即正常工作状态，持续为光储系统输入最高能量，储能DC/DC电路150控制储能单元120退出充电模式或维持不充电状态，DC/AC电路170将最大调节上限的直流电能逆变为适合供给电网180或供应家庭的交流电能，从而保证正常的供电。
参照图9所示，图9是本申请的实施例提供的一种母线电压处于第四区间的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤910，DC/AC电路工作在整流模式；
步骤920，光伏DC/DC电路工作在最大功率点跟踪模式；
步骤930，储能DC/DC电路确定储能单元的当前电量，并在储能单元的电量大于可放电下限电量的情况下，储能DC/DC电路工作在放电模式。
其中，第四电压区间的范围为Udcr-2ΔUdc到Udcr-ΔUdc，Udcr为电压参考值，ΔUdc为电压调整值。
需要说明的是，在DC/AC电路170以整流模式运行时，将电网180供给的直流电转换为交流电，以提高母线电压，可以帮助维持光储系统的稳定性，并确保能源的有效利用和传输。同时，在储能单元120的电量大于可放电下限电量的情况下，储能DC/DC电路150会工作在放电模式，储能DC/DC电路150会将储能单元120中的电能释放出来，以提供额外的电能供给光储系统，帮助维持光储系统的运行稳定性。
可以理解的是，在母线电压处于第四电压区间的情况下，光储系统处于能量不足状态，通过储能DC/DC电路150控制储能单元120释放电能，提高母线电压，同时DC/AC电路170切换整流模式，将电网180的交流电能整流为直流电能，供给负载设备130，维持光储系统的运行稳定性。
在本申请的一个实施例中，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并将母线电压与各个区间的上界值和下界值对比，在母线电压处于第四电压区间的情况下，即光储系统处于能量不足，光伏DC/DC电路140控制光伏组串110为正常工作，并将光伏组串110所产生的直流电能转换为适合直流母线160的电压和电流，在储能单元120的电量大于可充电上限电量10％的情况下，储能DC/DC电路150控制储能单元120切换至释放电能模式，将储能单元120中的电能释放，DC/AC电路170将电网180供给的交流电能整流为直流电能，将母线电压提高至第一电压区间。此时，母线电压处于第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140控制光伏组串110维持正常工作，储能DC/DC电路150控制储能单元120维持放电，DC/AC电路170将电网180供给的交流电能整流为直流电能，供应家庭和商业建造的负载使用，从而保证正常的供电。
参照图10所示，图10是本申请的实施例提供的一种母线电压处于第五区间的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤S1010，DC/AC电路工作在整流模式，并停止至少一部分负载设备的电压供给；
步骤S1020，光伏DC/DC电路工作在最大功率点跟踪模式；
步骤S1030，储能DC/DC电路确定储能单元的当前电量，并在储能单元的电量大于可放电下限电量的情况下，储能DC/DC电路工作在放电模式；
其中，第五电压区间的范围为小于Udcr-2ΔUdc，Udcr为电压参考值，ΔUdc为电压调整值。
需要说明的是，光储系统进入第五工作模式的两种情况：第一种是母线电压处于第五电压区间，光储系统直接进入第五工作模式；第二种是当储能单元120降至可放电最低下限电量与光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压处于第四电压区间的情况下，DC/AC电路170以最大调节上限整流电网180供给的交流电，由于光伏DC/DC电路140持续为光储系统输入最高能量，光储系统能量仍不足，又由于储能单元120降至可放电最低下限电量，无法继续释放电能，母线电压进一步降低，导致光储系统无法满足于负载设备130的电压供给，逐渐超出第四电压区间，达到第五电压区间，光储系统也因此进入第五工作模式。
可以理解的是，在母线电压处于第五电压区间的情况下，光储系统处于能量严重不足的状态，通过关闭部分负载设备130，降低供给需求，使光储系统趋向于平衡状态，提高光储系统的稳定性和可靠性。
在本申请的一个实施例中，光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压，并将母线电压与各个区间的上界值和下界值对比，在母线电压处于第五电压区间的情况下，即光储系统处于能量不足且不在DC/AC电路170可调节范围内，光储系统控制一部分负载设备130关闭，从而降低负载设备130的电压供给，光储系统检测储能单元120，当储能单元120未达到可放电下限电量的情况下，储能DC/DC电路150可以通过控制储能单元120释放电能，直至提升母线电压至第一电压区间内或储能单元120达到可放电下限电量时停止放电；当储能单元120达到可放电下限电量的情况下，储能DC/DC电路150停止向储能单元120释放电能。通过光伏DC/DC电路140控制光伏组串110工作在MPPT模式，即正常工作状态，关闭部分负载设备130，第一电压区间发生变化，母线电压达到第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140维持正常状态，储能DC/DC电路150控制存储单元维持停止充电状态，DC/AC电路170将最大调节上限的交流电能整流为直流电能，从而保证正常的供电。
可以理解的是，当母线电压处于第五电压区间，光储系统进入第五工作模式的情况下，储能单元120未达到可放电下限电量，通过储能DC/DC电路150控制储能单元120释放电能和关闭负载设备130，从而使电压供给符合电压需求。在调整母线电压的过程中，储能单元120达到可放电下限电量时，储能DC/DC电路150控制储能单元120停止放电；另外，在调整母线电压的过程中，储能单元120始终未达到可放电下限电量，在母线电压降至第一电压区间内时，储能DC/DC电路150控制储能单元120停止放电。
需要解释的是，不同负载设备130接入光储系统中，导致电压参考值发生变化，从而导致五个电压区间的系数也发生变化。
参照图11所示，图11是本申请的实施例提供的一种停止负载设备电压供给的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤S1110，DC/AC电路获取负载设备的优先级；
步骤S1120，DC/AC电路按照优先级从低到高停止负载设备的电压供给。
需要说明的是，在光储系统中，为了有效管理能源分配和确保光储系统的稳定运行，通常会使用负载设备130的优先级来决定停止电压供给的顺序，确保关键设备或关键系统在电力资源有限或电网180状态不稳定时能够优先获得电力供应。通过实时监测光储系统中各个设备的电力需求和优先级，可以动态调整电压供给，确保资源的合理利用，并确保光储系统中最重要的设备获得足够的电力支持。这种智能的能源管理方式可以提高光储系统的可靠性、稳定性和效率，同时最大限度地满足不同设备的电力需 求。
参照图12所示，图12是本申请的实施例提供的一种母线电压处于第四或第五区间储能单元电量达到下限的控制方法的流程示意图，该方法可以包括但不限于以下步骤：
步骤S1210，当母线电压处于第四或第五区间，确定储能单元电量达到下限；
步骤S1220，储能DC/DC电路停止对储能单元放电。需要说明的是，当光储系统处于第四工作模式并且光储系统检测储能单元120的电池容量小10％时，储能DC/DC电路150可以停止储能单元120释放电能，从而阻止其继续放电。
可以理解的是，当储能单元120的电量降至可放电下限电量以下时，储能DC/DC电路150会退出放电模式。这是为了避免过度放电，以防止损害储能单元120并延长其使用寿命。
在本申请的一个实施例中，在储能单元120降至可放电最低下限电量与光伏DC/DC电路140、储能DC/DC电路150和DC/AC电路170检测母线电压处于第四电压区间的情况下，光伏DC/DC电路140在MPPT模式，即正常工作状态，持续为光储系统输入最高能量，储能DC/DC电路150控制储能单元120退出放电模式或维持不放电状态，DC/AC电路170将电网180供给的直流电能整流为适合交流电能，从而保证正常的供电。
在本申请的一个实施例中提供了一种光储系统，根据不同母线电压范围切换不同工作模式，不同工作模式下逆变、储能和光伏工作在不同的控制模式，可通过系统各功率单元协同实现母线电压的稳定控制，包括：
第一工作模式，当母线电压处于第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140维持正常工作状态，持续为光储系统输入最高能量，由于储能单元120处于关闭模式，储能DC/DC电路150控制储能单元120维持当前关闭模式，DC/AC电路170将直流电能逆变给交流电能，供给电网180或供应负载设备130。
第二工作模式，母线电压处于第二电压区间的情况下，光储系统进入第二工作模式，光伏DC/DC电路140在MPPT模式，即正常工作状态，持续为光储系统输入最高能量，储能DC/DC电路150控制储能单元120储存一部分电能，将光伏组串110所产生的直流电能降为符合DC/AC电路170可最大调节上限。母线电压降为第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140控制光伏组串110维持正常工作，储能DC/DC电路150控制储能单元120维持当前充电状态，DC/AC电路170将最大调节上限的直流电能逆变为适合供给电网180或供应负载设备130。
在储能单元120达到充电上限时，储能DC/DC电路150控制储能单元120退出充电模式或维持不充电状态，能够有效预防过充情况的发生，并保护储能单元120的性能和安全。
第三工作模式，在母线电压处于第三电压区间的情况下，即光储系统处于能量充裕且不在DC/AC电路170可调节范围内，光伏DC/DC电路140降低输出功率，在光伏组串110所产生的直流电能转化为适合直流母线160的直流电能的过程中转化率降低，光储系统检测储能单元120，当储能单元120未达到可充电上限电量的情况下，储能DC/DC电路150可以通过控制储能单元120存储电能，直至降低母线电压至第一电压区间内或储能单元120达到可充电上限电量时停止充电；当储能单元120达到可充电上限电量的情况下，储能DC/DC电路150停止向储能单元120输送电能，从而阻止其继续充电。通过光伏DC/DC电路140降低输出功率，母线电压逐渐降低至第一电压区间内，光储系统进入第一工作模式，光伏DC/DC电路140维持降低功率输出状态，储能DC/DC电路150控制存储单元维持现状，DC/AC电路170将最大调节上限的直流电能逆变为适合供给电网180或供应负载设备130。
第四工作模式，在母线电压处于第四电压区间的情况下，即光储系统处于能量不足，光伏DC/DC电路140控制光伏组串110为正常工作，并将光伏组串110所产生的直流电能转换为适合直流母线160的电压和电流，在储能单元120的电量大于可充电上限电量10％的情况下，储能DC/DC电路150控制储能单元120切换至释放电能模式，将储能单元120中的电能释放，DC/AC电路170将电网180供给的交流电能整流为直流电能，将母线电压提高至第一电压区间。此时，母线电压处于第一电压区间，光储系统 进入第一工作模式，光伏DC/DC电路140控制光伏组串110维持正常工作，储能DC/DC电路150控制储能单元120维持放电，DC/AC电路170将电网180供给的交流电能整流为直流电能，供应负载设备130。
在储能单元120降至可放电最低下限电量时，储能DC/DC电路150控制储能单元120退出放电模式或维持不放电状态，DC/AC电路170将电网180供给的直流电能整流为适合交流电能，从而保证正常的供电。
第五工作模式，在母线电压处于第五电压区间的情况下，即光储系统处于能量不足且不在DC/AC电路170可调节范围内，光储系统控制一部分负载设备130关闭，从而降低负载设备130的电压供给，储能DC/DC电路150可以通过控制储能单元120释放电能，通过光伏DC/DC电路140控制光伏组串110工作在MPPT模式，即正常工作状态，关闭部分负载设备130，第一电压区间发生变化，母线电压达到第一电压区间，光储系统进入第一工作模式，光伏DC/DC电路140维持正常状态，储能DC/DC电路150控制存储单元维持停止充电状态，DC/AC电路170将最大调节上限的交流电能整流为直流电能，从而保证正常的供电。
本申请的实施例提供的光储系统中的光伏DC/DC电路、储能DC/DC电路和DC/AC电路均可以独立检测母线电压，并根据母线电压的大小确定母线电压所处的电压区间，根据电压区间相应调整自身的工作状态，由于母线电压反映了光储系统中能量平衡状态，因此光伏DC/DC电路、储能DC/DC电路和DC/AC电路基于母线电压所处的电压区间自动调整工作状态，能够在不依靠光储系统的通讯系统的情况下，自行触发调整能量输出或者输入，进而影响光储系统中的能量平衡状态，实现了母线电压的稳定控制。
本领域普通技术人员可以理解，上文中所公开方法中的全部或某些步骤、系统可以被实施为软件、固件、硬件及其适当的组合。某些物理组件或所有物理组件可以被实施为由处理器，如中央处理器、数字信号处理器或微处理器执行的软件，或者被实施为硬件，或者被实施为集成电路，如专用集成电路。这样的软件可以分布在计算机可读介质上，计算机可读介质可以包括计算机存储介质(或非暂时性介质)和通信介质(或暂时性介质)。如本领域普通技术人员公知的，术语计算机存储介质包括在用于存储信息(诸如计算机可读指令、数据结构、程序模块或其他数据)的任何方法或技术中实施的易失性和非易失性、可移除和不可移除介质。计算机存储介质包括但不限于RAM、ROM、EEPROM、闪存或其他存储器技术、CD-ROM、数字多功能盘(DVD)或其他光盘存储、磁盒、磁带、磁盘存储或其他磁存储装置、或者可以用于存储期望的信息并且可以被计算机访问的任何其他的介质。此外，本领域普通技术人员公知的是，通信介质通常包含计算机可读指令、数据结构、程序模块或者诸如载波或其他传输机制之类的调制数据信号中的其他数据，并且可包括任何信息递送介质。
以上是对本申请的较佳实施进行了具体说明，但本申请并不局限于上述实施方式，熟悉本领域的技术人员在不违背本申请精神的前提下还可作出种种的等同变形或替换，这些等同的变形或替换均包含在本申请权利要求所限定的范围内。

Claims (13)

  1. 光储系统，包括光伏组串、储能单元和负载设备，其中，
    所述光伏组串通过光伏DC/DC电路连接到直流母线，所述储能单元通过储能DC/DC电路连接到所述直流母线，所述负载设备和电网通过DC/AC电路连接到所述直流母线；
    所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路均用于检测所述直流母线的母线电压，并根据所述母线电压所处于的电压区间调整自身的工作状态；以及
    所述电压区间按照电压参考值设定，且表征所述光储系统在当前母线电压下的能量平衡状态。
  2. 根据权利要求1所述的光储系统，设置有多个所述电压区间，其中各个所述电压区间的上界值和下界值基于所述电压参考值进行调整得到。
  3. 根据权利要求2所述的光储系统，其中，所述电压区间包括第一电压区间、第二电压区间、第三电压区间、第四电压区间和第五电压区间；
    所述第一电压区间的范围为Udcr-ΔUdc到Udcr+ΔUdc；
    所述第二电压区间的范围为Udcr+ΔUdc到Udcr+2ΔUdc；
    所述第三电压区间的范围为大于Udcr+2ΔUdc；
    所述第四电压区间的范围为Udcr-2ΔUdc到Udcr-ΔUdc；以及
    所述第五电压区间的范围为小于Udcr-2ΔUdc；
    其中，Udcr为所述电压参考值，ΔUdc为电压调整值。
  4. 根据权利要求1至3任一项所述的光储系统，还包括双闭环空间矢量脉冲幅度调制电路，其中，所述双闭环空间矢量脉冲幅度调制电路包括变换模块、电压外环模块、电流内环模块和控制模块，所述变换模块连接所述DC/AC电路的交流输出端，用于对采集的所述DC/AC电路的交流电信号进行坐标转换，所述电压外环模块连接所述直流母线，用于根据所述母线电压和母线电压给定通过PI控制得到d轴电流给定，所述电流内环模块连接所述电压外环模块的输出端和所述变换模块的输出端，用于根据所述变换模块输出的d轴交流电流和所述d轴电流给定通过PI控制得到d轴电压控制信号，以及根据所述变换模块输出的q轴交流电流和q轴电流给定通过PI控制得到q轴电压控制信号，所述控制模块连接所述电流内环模块的输出端，用于根据所述d轴电压控制信号和所述q轴电压控制信号得到所述DC/AC电路的工作参数的补偿量，以调整所述DC/AC电路的输出功率。
  5. 一种光储系统的控制方法，应用于权利要求1至4任一所述的光储系统，所述控制方法包括：
    所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路获取所述直流母线的母线电压；以及
    所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态；
    其中，所述电压区间按照电压参考值设定，且表征所述光储系统在当前母线电压下的能量平衡状态。
  6. 根据权利要求5所述的控制方法，其中，在所述母线电压处于第一电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：
    所述DC/AC电路工作在逆变模式，所述DC/AC电路根据双闭环空间矢量脉冲幅度调制电路输出的补偿量调整输出功率，以使所述母线电压维持在所述第一电压区间内；
    所述光伏DC/DC电路工作在最大功率点跟踪模式；以及
    所述储能DC/DC电路根据所述储能单元的电量调整工作模式；
    其中，所述第一电压区间的范围为Udcr-ΔUdc到Udcr+ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
  7. 根据权利要求5或6所述的控制方法，其中，在所述母线电压处于第二电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身 的工作状态，包括：
    所述DC/AC电路工作在逆变模式；
    所述光伏DC/DC电路工作在最大功率点跟踪模式；以及
    所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量小于可充电上限电量的情况下，所述储能DC/DC电路工作在充电模式；
    其中，所述第二电压区间的范围为Udcr+ΔUdc到Udcr+2ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
  8. 根据权利要求5至7任一项所述的控制方法，其中，在所述母线电压处于第三电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：
    所述DC/AC电路工作在逆变模式；
    所述光伏DC/DC电路降低输出功率；以及
    所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量小于可充电上限电量的情况下，所述储能DC/DC电路工作在充电模式；
    其中，所述第三电压区间的范围为大于Udcr+2ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
  9. 根据权利要求7或8所述的控制方法，在所述储能DC/DC电路确定所述储能单元的当前电量之后，还包括：
    在所述储能单元的电量大于所述可充电上限电量的情况下，所述储能DC/DC电路停止对所述储能单元充电。
  10. 根据权利要求5至9任一项所述的控制方法，其中，在所述母线电压处于第四电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：
    所述DC/AC电路工作在整流模式；
    所述光伏DC/DC电路工作在最大功率点跟踪模式；以及
    所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量大于可放电下限电量的情况下，所述储能DC/DC电路工作在放电模式；
    其中，所述第四电压区间的范围为Udcr-2ΔUdc到Udcr-ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
  11. 根据权利要求5至10任一项所述的控制方法，其中，在所述母线电压处于第五电压区间的情况下，所述光伏DC/DC电路、所述储能DC/DC电路和所述DC/AC电路根据所述母线电压所处于的电压区间调整自身的工作状态，包括：
    所述DC/AC电路工作在整流模式，并停止至少一部分所述负载设备的电压供给；
    所述光伏DC/DC电路工作在最大功率点跟踪模式；以及
    所述储能DC/DC电路确定所述储能单元的当前电量，并在所述储能单元的电量大于可放电下限电量的情况下，所述储能DC/DC电路工作在放电模式；
    其中，所述第五电压区间的范围为小于Udcr-2ΔUdc，Udcr为所述电压参考值，ΔUdc为电压调整值。
  12. 根据权利要求11所述的控制方法，其中，所述DC/AC电路停止至少一部分所述负载设备的电压供给，包括：
    所述DC/AC电路获取所述负载设备的优先级；以及
    所述DC/AC电路按照优先级从低到高停止所述负载设备的电压供给。
  13. 根据权利要求10至12任一项所述的控制方法，在所述储能DC/DC电路确定所述储能单元的当前 电量之后，还包括：
    在所述储能单元的电量小于可放电下限电量的情况下，所述储能DC/DC电路停止对所述储能单元放电。
PCT/CN2024/120848 2024-06-13 2024-09-24 光储系统及其控制方法 Pending WO2025255993A1 (zh)

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