Optical storage direct current coupling control circuit and related device

Abstract

The embodiment of the present application provides a kind of light storage direct current coupling control circuit and related device, wherein circuit includes: DC-AC module, DC-DC module and control module.Control module is used to calculate the alternating voltage and direct current voltage under multiple different bus voltage set values according to the actual output power of photovoltaic system and the output power demand value of DC-AC module, alternating voltage is the alternating side output voltage when DC-AC module reaches maximum conversion efficiency, direct current voltage is the charging voltage of energy storage module when DC-DC module reaches maximum conversion efficiency;According to different bus voltage set values and alternating voltage and direct current voltage under different bus voltage set values, determine the target bus voltage value, target alternating voltage value and target direct current voltage value when energy storage module reaches maximum charging power, and control multiple photovoltaic systems, DC-AC module and DC-DC module correspond to target bus voltage value, target alternating voltage value and target direct current voltage value output.

Description

Technical Field

[0001] This application relates to the field of energy storage device technology, and in particular to a photovoltaic-energy storage DC coupling control circuit, method, photovoltaic-energy storage DC coupling control system, readable storage medium, and computer program product. Background Technology

[0002] With the development of new energy technologies, various power generation technologies have advanced rapidly in recent years. Among them, photovoltaic (PV) power generation has received widespread attention due to its advantages such as low pollution. To ensure stable output of PV power, PV-storage systems have emerged. A PV-storage system includes a PV system and energy storage modules. When the PV system generates too much power, the energy storage modules can be charged; when the PV system generates too little power, the energy storage modules can be discharged, ensuring a stable output of PV power to the grid and thus guaranteeing the stable operation of the grid.

[0003] A photovoltaic-storage DC-coupled system is a type of photovoltaic-storage system. In related technologies, when the photovoltaic-storage DC-coupled system generates too much electricity to charge the energy storage module, the MPPT (Maximum Power Point Tracking) unit performs scheduling control based on its own optimal efficiency conversion point to enable the photovoltaic system to supply power to the energy storage module. However, this scheduling control scheme is based on a single MPPT and therefore cannot meet the energy storage needs of the energy storage module. Summary of the Invention

[0004] This application provides a photovoltaic-storage DC coupling control circuit, method, photovoltaic-storage DC coupling control system, readable storage medium, and computer program product to solve the problem that the scheduling and control schemes of related technologies cannot meet the energy storage requirements of energy storage modules.

[0005] On one hand, this application provides a photovoltaic-storage DC coupling control circuit, comprising:

[0006] The DC-AC module has its DC side connected to multiple photovoltaic systems via a DC bus, and its AC side connected to the power grid.

[0007] The DC-DC module has its first end connected to the DC bus and its second end connected to the energy storage module.

[0008] The control module is connected to the DC-AC module, DC-DC module and multiple photovoltaic systems respectively. It is used to obtain the actual output power of the photovoltaic system and the output power demand value of the DC-AC module. Based on the actual output power and the output power demand value, it calculates the AC voltage and DC voltage when the output power of the DC-AC module reaches the output power demand value under multiple different bus voltage settings. The AC voltage is the AC side output voltage when the DC-AC module reaches the maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module when the DC-DC module reaches the maximum conversion efficiency.

[0009] The control module is also used to determine the target bus voltage, target AC voltage, and target DC voltage values ​​when the energy storage module reaches its maximum charging power, based on different bus voltage settings and AC and DC voltages under different bus voltage settings, and to control multiple photovoltaic systems, DC-AC modules, and DC-DC modules to output the target bus voltage, target AC voltage, and target DC voltage values ​​respectively.

[0010] The photovoltaic-storage DC-DC coupling control circuit provided in this application calculates the AC and DC voltages required to achieve the output power demand of the DC-AC module under multiple different bus voltage settings. The AC voltage is the AC-side output voltage required for the DC-AC module to reach its maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module required for the DC-DC module to reach its maximum conversion efficiency. Based on the different bus voltage settings and the AC and DC voltages under those settings, the circuit determines the target bus voltage, target AC voltage, and target DC voltage values ​​required for the energy storage module to reach its maximum charging power. It then controls multiple photovoltaic systems, DC-AC modules, and DC-DC modules to output corresponding values. This approach considers the DC-DC module, photovoltaic system, and DC-AC module together, ensuring that the photovoltaic system supplies power to the energy storage device as much as possible while meeting the basic energy requirements of the power grid. This solves the problem that related technologies' dispatch control schemes often fail to meet the energy storage requirements of the energy storage module.

[0011] Optionally, the control module is also used to calculate the charging power of the energy storage module at different bus voltage settings based on the output power demand value, the actual output power, different bus voltage settings, and the AC and DC voltages under different bus voltage settings, so as to obtain multiple candidate charging powers.

[0012] The control module is also used to select the maximum candidate charging power from multiple candidate charging power, and to obtain the bus voltage setting value, AC voltage and DC voltage when the maximum candidate charging power is reached. The bus voltage setting value, AC voltage and DC voltage when the maximum candidate charging power is reached correspond to the target bus voltage value, target AC voltage value and target DC voltage value.

[0013] The above scheme obtains multiple candidate charging powers through traversal calculations and selects the largest charging power from them. The operation is simple and convenient. It provides a selection scheme for the optimal solution under a finite number of parameters, which helps to realize the optimal scheduling scheme control of the photovoltaic-storage DC coupling system and can meet the energy storage needs of the energy storage module to the greatest extent.

[0014] Optionally, the control module is also used to calculate the charging power of the energy storage module at different bus voltage settings based on the output power demand value, the actual output power, different bus voltage settings, and the AC and DC voltages under different bus voltage settings.

[0015] The control module is also used to process different bus voltage settings and AC voltage, DC voltage and charging power under different bus voltage settings to obtain the fitting relationship between the bus voltage settings, AC voltage, DC voltage and charging power, so as to calculate the target bus voltage value, target AC voltage value and target DC voltage value when the maximum charging power is achieved based on the fitting relationship.

[0016] The above scheme fits the relationships of various parameters, and can obtain the maximum charging power of the energy storage module when the conversion efficiency of each equipment module of the photovoltaic-storage DC coupling system is reasonable, as well as the output voltage parameters of the DC-DC module, DC-AC module and multiple photovoltaic systems when the maximum charging power is reached, so as to meet the energy storage needs of the energy storage module to the greatest extent.

[0017] Optionally, the control module is also used to obtain the maximum conversion efficiency of the DC-AC module when the output power of the DC-AC module reaches the output power demand value under different bus voltage settings, based on the output power demand value and multiple different bus voltage settings.

[0018] The control module is also used to calculate the AC voltage under different bus voltage settings, which is the AC side voltage that enables the DC-AC module to achieve maximum conversion efficiency.

[0019] The above scheme provides a specific method for obtaining the maximum conversion efficiency of the DC-AC module and the corresponding AC side output voltage under different bus voltage settings. It realizes the optimal solution calculation of the output voltage of the DC-AC module under different bus voltage settings, and provides data reference for subsequent system-based scheduling control.

[0020] Optionally, the control module is also used to obtain the maximum conversion efficiency of the photovoltaic system under different bus voltage settings based on the actual output power of the photovoltaic system and multiple different bus voltage settings;

[0021] The control module is also used to calculate the remaining power of the DC bus under different bus voltage settings based on the actual output power of the photovoltaic system, the maximum conversion efficiency of the photovoltaic system, the maximum conversion efficiency of the DC-AC module, and the AC voltage under different bus voltage settings.

[0022] The control module is also used to obtain the maximum conversion efficiency of the DC-DC module under different bus voltage settings based on different bus voltage settings and the remaining power of the DC bus under different bus voltage settings.

[0023] The control module is also used to calculate the DC voltage under different bus voltage settings, which is the charging voltage of the energy storage module when the DC-DC module achieves maximum conversion efficiency.

[0024] The above scheme provides a method for obtaining the charging voltage of the energy storage module when the DC-DC module achieves maximum conversion efficiency under different bus voltage settings. It realizes the optimal solution calculation of the output voltage of the DC-DC module under different bus voltage settings, and provides data reference for subsequent system-based scheduling control.

[0025] Optionally, the photovoltaic-storage DC coupling control circuit may also include a data acquisition module;

[0026] The acquisition module, connected to the control module, is used to acquire and transmit the current and voltage values ​​of the photovoltaic system.

[0027] The control module is also used to calculate the actual output power of the photovoltaic system based on the current and voltage values ​​of the photovoltaic system.

[0028] The above scheme calculates the actual output power of the photovoltaic system by setting up a data acquisition module and based on the acquired current and voltage values ​​of the photovoltaic system, providing data reference for subsequent system-based scheduling and control.

[0029] On the other hand, this application also provides a photovoltaic-storage DC-coupled control method, applied to a photovoltaic-storage DC-coupled control system, wherein the photovoltaic-storage DC-coupled control system is connected to a DC-AC module, a DC-DC module, and multiple photovoltaic systems respectively; the method includes:

[0030] Obtain the actual output power of the photovoltaic system and the output power requirement of the DC-AC module;

[0031] Based on the actual output power and the output power demand, calculate the AC voltage and DC voltage when the output power of the DC-AC module reaches the output power demand under multiple different bus voltage settings. The AC voltage is the AC side output voltage when the DC-AC module reaches its maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module connected to the DC-DC module when the DC-DC module reaches its maximum conversion efficiency.

[0032] Based on different bus voltage settings and the AC and DC voltages under different bus voltage settings, determine the target bus voltage, target AC voltage, and target DC voltage values ​​that enable the energy storage module to reach its maximum charging power.

[0033] Control multiple photovoltaic systems, DC-AC modules, and DC-DC modules to output target bus voltage, target AC voltage, and target DC voltage respectively.

[0034] Optionally, determining the target bus voltage, target AC voltage, and target DC voltage values ​​to enable the energy storage module to reach its maximum charging power, based on different bus voltage settings and the AC and DC voltages under different bus voltage settings, may include:

[0035] Based on the output power demand, actual output power, different bus voltage settings, and AC and DC voltages under different bus voltage settings, the charging power of the energy storage module at different bus voltage settings is calculated to obtain multiple candidate charging powers.

[0036] Select the maximum candidate charging power from multiple candidate charging power options;

[0037] Obtain the bus voltage setpoint, AC voltage, and DC voltage when the maximum candidate charging power is reached. The bus voltage setpoint, AC voltage, and DC voltage when the maximum candidate charging power is reached correspond to the target bus voltage value, target AC voltage value, and target DC voltage value.

[0038] Optionally, determining the target bus voltage, target AC voltage, and target DC voltage values ​​to enable the energy storage module to reach its maximum charging power, based on different bus voltage settings and the AC and DC voltages under different bus voltage settings, may include:

[0039] Based on the output power demand, actual output power, different bus voltage settings, and AC and DC voltages under different bus voltage settings, calculate the charging power of the energy storage module at different bus voltage settings.

[0040] The different bus voltage settings and the AC voltage, DC voltage and charging power under different bus voltage settings are processed to obtain the fitting relationship between the bus voltage settings, AC voltage, DC voltage and charging power;

[0041] The target bus voltage, target AC voltage, and target DC voltage at maximum charging power are calculated based on the fitting relationship.

[0042] Optionally, based on the actual output power and the required output power, the AC voltage required to achieve the required output power for the DC-AC module under multiple different bus voltage settings can be calculated, which may include:

[0043] Based on the output power demand value and multiple different bus voltage settings, the maximum conversion efficiency of the DC-AC module is obtained when the output power of the DC-AC module reaches the output power demand value under different bus voltage settings.

[0044] Calculate the AC voltage under different bus voltage settings. The AC voltage is the AC side voltage that enables the DC-AC module to achieve maximum conversion efficiency.

[0045] Optionally, based on the actual output power and the output power demand, the DC voltage under multiple different bus voltage settings can be calculated, which may include:

[0046] Based on the actual output power of the photovoltaic system and multiple different bus voltage settings, the maximum conversion efficiency of the photovoltaic system under different bus voltage settings is obtained;

[0047] Based on the actual output power of the photovoltaic system, and the maximum conversion efficiency of the photovoltaic system, the maximum conversion efficiency of the DC-AC module, and the AC voltage under different bus voltage settings, calculate the remaining power of the DC bus under different bus voltage settings.

[0048] Based on different bus voltage settings and the remaining power of the DC bus under different bus voltage settings, the maximum conversion efficiency of the DC-DC module under different bus voltage settings is obtained;

[0049] Calculate the DC voltage under different bus voltage settings. The DC voltage is the charging voltage of the energy storage module when the DC-DC module achieves maximum conversion efficiency.

[0050] Optionally, the photovoltaic-storage DC coupling control system is also connected to the acquisition module to obtain the actual output power of the photovoltaic system, and may include:

[0051] The receiver module collects the current and voltage values ​​of the photovoltaic system.

[0052] The actual output power of the photovoltaic system is calculated based on the current and voltage values ​​of the photovoltaic system.

[0053] In another aspect, this application also provides a photovoltaic-storage DC coupling control system, including a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the steps of the photovoltaic-storage DC coupling control method as described above.

[0054] Furthermore, this application also provides a photovoltaic-storage DC coupling control system configured to perform the steps of the photovoltaic-storage DC coupling control method as described above.

[0055] In another aspect, this application also provides a readable storage medium on which a program or instruction is stored, and when the program or instruction is executed by a processor, it implements the steps of the aforementioned optical-storage DC-DC coupling control method.

[0056] In another aspect, this application also provides a computer program product that can be executed by a processor to implement the steps of the aforementioned optical-storage DC-DC coupling control method.

[0057] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0058] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0059] Figure 1 This is a schematic diagram of the structure of the photovoltaic-storage DC coupling system involved in the embodiments of this application.

[0060] Figure 2 This is a schematic diagram of the structure of a photovoltaic-storage DC coupling control circuit provided in an optional embodiment of this application.

[0061] Figure 3 This is a schematic diagram of the structure of a photovoltaic-storage DC coupling control circuit provided in another optional embodiment of this application.

[0062] Figure 4 This is a schematic flowchart of a photovoltaic-storage DC coupling control method provided in an optional embodiment of this application.

[0063] Figure 5 This is a schematic flowchart of a photovoltaic-storage DC coupling control method provided in another optional embodiment of this application.

[0064] Figure 6 This is a schematic diagram of the structure of a photovoltaic-storage DC-DC coupling control system provided in an optional embodiment of this application.

[0065] The accompanying drawings are not drawn to scale.

[0066] Marker explanation:

[0067] Photovoltaic system 10, DC-AC module 20, DC-DC module 30, energy storage module 40, control module 50, data acquisition module 60. Detailed Implementation

[0068] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0070] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0071] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0072] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0073] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0074] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0075] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0076] In the field of new energy, power batteries serve as the primary power source for electrical devices (such as vehicles, ships, or spacecraft), while energy storage batteries serve as the charging source for these devices; the importance of both is self-evident. As an example, and not a limitation, in some applications, power batteries can refer to the batteries within electrical devices, and energy storage batteries can refer to the batteries within charging devices. For ease of description, both power batteries and energy storage batteries will be referred to as batteries in the following text.

[0077] In the field of photovoltaic power generation, batteries can be used as energy storage modules to form a photovoltaic-storage system together with the photovoltaic system. This photovoltaic-storage system can provide a stable AC voltage to the power grid.

[0078] In this system, when the photovoltaic (PV) system generates too much power, the battery, acting as an energy storage module, can be charged; when the PV system generates too little power, the battery assists the PV system in providing a stable voltage output to the grid. Therefore, battery-like energy storage modules have important applications in PV power generation. Of course, this energy storage module can also be composed of other components or systems with energy storage capabilities, such as supercapacitors.

[0079] Please refer to Figure 1 , Figure 1 This is an optional architecture design diagram of the photovoltaic-storage DC coupling system involved in this application, which is included in the aforementioned photovoltaic-storage system.

[0080] This photovoltaic-storage DC-DC coupling system may include a DC-DC (Direct Current-Direct Current) module 30, a DC-AC (Direct Current-Alternating Current) module 20, an energy storage module 40, and multiple photovoltaic systems 10. The multiple photovoltaic systems 10 can convert solar energy into electrical energy, and then output a DC bus voltage through their output terminals. The DC side of the DC-AC module 20 can be connected to the output terminals of the multiple photovoltaic systems 10 via a DC bus, and the AC side of the DC-AC module 20 is connected to the power grid. The DC-DC module 30 may be a bidirectional DC-DC module 30, with its first terminal connected to the output terminal of the photovoltaic system 10 and its second terminal connected to the energy storage module 40.

[0081] In some optional examples, a transformer can also be provided. The AC side of the DC-AC module 20 can be connected to the input terminal of the transformer, and the output terminal of the transformer can be connected to the power grid, so that the final output AC voltage is adapted to the grid voltage. The energy storage module 40 can be an energy storage element such as a battery and / or a supercapacitor.

[0082] The photovoltaic system 10 mentioned above may include photovoltaic panels and MPPT (Maximum Power Point Tracking) units, and the photovoltaic panels in multiple photovoltaic systems 10 constitute a photovoltaic array.

[0083] In related technologies, the MPPT unit can perform maximum power point tracking through voltage and current detection to obtain its own optimal efficiency conversion point. Based on this optimal efficiency conversion point, it schedules and controls the input of the DC-DC module 30, ensuring that the DC-DC module 30 charges the energy storage module 40 according to its own efficiency point under a given input condition. In other words, the control strategy in related technologies often considers the optimal efficiency of a single module. In this case, the photovoltaic system 10 charges the energy storage module 40 with relatively little electricity, which is insufficient to meet the energy storage needs of the energy storage module 40.

[0084] To address the aforementioned issues, this application... Figure 1 Based on the structure shown, a photoelectric storage DC-DC coupling control circuit is provided. Please refer to the following: Figure 1 and Figure 2 ,in Figure 2 This is a schematic diagram of an optional circuit structure for a photovoltaic-storage DC coupling control circuit. In one optional embodiment, the photovoltaic-storage DC coupling control circuit includes: a DC-AC module 20, a DC-DC module 30, and a control module 50.

[0085] It should be noted that, in addition to the connection structure already described above, the photovoltaic-storage DC coupling control circuit also includes a control module 50, which can be connected to the DC-DC module 30, the DC-AC module 20, and multiple photovoltaic systems 10. For example, the control module 50 can be connected to the DC-DC module 30, the DC-AC module 20, and multiple photovoltaic systems 10 via a CAN (Controller Area Network) bus.

[0086] based on Figure 1 and Figure 2 As shown in the structure, the DC side of the DC-AC module 20 and the first terminal of the DC-DC module 30 can be connected to a DC bus, and multiple photovoltaic systems can be connected via the DC bus. The DC-AC module 20 can convert the DC voltage obtained from the DC bus into AC power, which is then transmitted to the power grid via the AC side of the DC-AC module 20. When the electricity generated by the multiple photovoltaic systems 10 exceeds the electricity consumed by the power grid, the DC-DC module 30 can convert the DC voltage obtained from the DC bus after being connected to the DC bus to charge the energy storage module 40.

[0087] The aforementioned control module 50 can be an Energy Management System (EMS), or a dedicated control device / system with computing capabilities connected to the photovoltaic system 10, DC-DC module 30, and DC-AC module 20. For example, the control module 50 can be a cloud server, or a system combining an energy management device and a cloud server. The DC-AC module 20 can be a photovoltaic inverter. The control module 50 can schedule and control the DC-DC module 30, DC-AC module 20, and multiple photovoltaic systems 10 in the photovoltaic-storage DC-DC coupling system.

[0088] The control module 50 can acquire the actual output power of multiple photovoltaic systems 10 and the output power demand value of the DC-AC module 20, for example, the actual output power of each photovoltaic system 10 and the output power demand value of the DC-AC module 20. Based on the actual output power and the output power demand value, it calculates the AC voltage and DC voltage required to achieve the required output power value for the DC-AC module 20 under multiple different bus voltage settings. The AC voltage is the AC-side output voltage required for the DC-AC module 20 to achieve maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module 40 required for the DC-DC module 30 to achieve maximum conversion efficiency.

[0089] The control module 50 can also determine the target bus voltage value, target AC voltage value, and target DC voltage value when the energy storage module 40 reaches the maximum charging power based on different bus voltage setting values ​​and AC and DC voltages under different bus voltage setting values, and control multiple photovoltaic systems 10, DC-AC module 20, and DC-DC module 30 to output the target bus voltage value, target AC voltage value, and target DC voltage value respectively.

[0090] The control module 50 described above can acquire the electrical parameters of the photovoltaic system 10 and obtain the actual output power of the photovoltaic system 10 based on the acquired electrical parameters. These electrical parameters may include power, current, and voltage, etc.

[0091] The output power requirement of the DC-AC module 20 is an output power value that meets the energy demand of the power grid. This output power requirement is greater than or equal to the minimum power demand of the power grid, and its specific value can be set according to actual needs. For example, if the minimum power demand of the power grid is 250kW, then the output power requirement P... AC ≥250kW, for example, the output power requirement can be 250kW. This output power requirement is one of the output constraints of the photovoltaic-storage DC coupling system dispatch control, ensuring that the AC power output by the DC-AC module 20 meets the minimum power requirement of the power grid after dispatch control.

[0092] The aforementioned multiple different bus voltage setting values ​​are simulated bus voltage values ​​set by the control module 50. Their specific values ​​and quantities can be set according to actual needs. For example, 100 different bus voltage setting values ​​can be set.

[0093] The control scheme of this application will be explained below in conjunction with specific control principles.

[0094] Please refer to the following: Figure 1 and Figure 2Based on the architecture of the photovoltaic-storage DC-coupled system, an energy balance model for the entire system can be established. The energy balance model includes: the energy conservation formula satisfied by multiple photovoltaic systems 10, namely the following formula (1), and the energy conservation formula from the DC bus to the energy storage module 40 and the DC-AC module 20, namely the following formula (2).

[0095]

[0096] Where n is the total number of photovoltaic systems 10, α i Let P be the energy conversion efficiency (also known as MPPT conversion efficiency) of the i-th photovoltaic system 10 with respect to the DC bus output. pv-i Let P be the actual power generated by the i-th photovoltaic system 10. DC This refers to the DC bus power.

[0097] P DC =P Bat / α DC-Bat +P AC / α DC-AC (2)

[0098] Among them, P DC P represents the DC bus power. Bat For the charging power of energy storage module 40, α DC-Bat P represents the conversion efficiency of the DC-DC module 30 (also known as the energy conversion efficiency from the DC bus to the energy storage module 40). AC For the AC side power of DC-AC module 20, α DC-AC This refers to the conversion efficiency of the DC-AC module 20 (also known as the energy conversion efficiency from the DC bus to the grid).

[0099] In order to supply as much power as possible to the energy storage module 40 while meeting the basic power demand of the power grid (i.e., the output power of the AC side of the DC-AC module 20 must reach the required output power value), the charging power of the energy storage module 40 needs to be as large as possible. That is, the final adjustment and optimization target can be expressed in the form of formula (3).

[0100] z = max(P) Bat (3)

[0101] After substituting the parameters of formulas (1) and (2), formula (3) can be expressed as formula (4), that is:

[0102]

[0103] Among them, P Bat Let z be the charging power of energy storage module 40, z be the target for adjustment and optimization, i.e., the maximum charging power of energy storage module 40, and α be the charging power of energy storage module 40. iLet P be the energy conversion efficiency (also known as MPPT conversion efficiency) of the i-th photovoltaic system 10 with respect to the DC bus output. pv-i Let P be the actual power generated by the i-th photovoltaic system 10. AC The AC side power of DC-AC module 20 is the output power requirement value, α. DC-AC The conversion efficiency (also known as the DC bus to grid energy conversion efficiency) of DC-AC module 20 is α. DC-Bat The conversion efficiency of DC-DC module 30 (also known as the energy conversion efficiency from DC bus to energy storage module 40).

[0104] Therefore, based on formula (4), it can be found that when the actual output power of the photovoltaic system 10 and the output power demand of the DC-AC module 20 are known, how to maximize the charging capacity of the energy storage module 40 under the premise that the output power of the photovoltaic-storage DC coupling system meets the basic requirements of the power grid is to determine the reasonable conversion efficiency of multiple photovoltaic systems 10, DC-DC module 30 and DC-AC module 20 so that the charging power of the energy storage module 40 reaches the maximum charging power.

[0105] Therefore, before scheduling and control, multiple different bus voltage setpoints can be preset. Then, assuming the output bus voltage of the photovoltaic system 10 reaches each bus voltage setpoint and the output power of the DC-AC module 20 reaches the required output power, the output voltages corresponding to the maximum conversion efficiency of the DC-DC module 30 and the DC-AC module 20 can be calculated. It can be understood that the calculated output voltage at maximum conversion efficiency is the optimal solution for the relevant parameters of the DC-DC module 30 and the DC-AC module 20 in the photovoltaic-storage DC-coupled system, based on the actual output power of the photovoltaic-storage system and under the condition of satisfying output constraints.

[0106] Furthermore, based on multiple different bus voltage settings and the output voltages of the DC-DC module 30 and DC-AC module 20 associated with each bus voltage setting when they reach maximum efficiency, the charging power of the energy storage module 40 under multiple different bus voltage settings can be determined. Finally, the target bus voltage value, target AC voltage value, and target DC voltage value when the energy storage module 40 reaches its maximum charging power can be found. These determined target bus voltage values, target AC voltage values, and target DC voltage values ​​are the scheduling control parameters that maximize the charging power of the energy storage module 40 under reasonable conversion efficiency for multiple photovoltaic systems 10, DC-DC modules 30, and DC-AC modules 20.

[0107] Understandably, since multiple different bus voltage settings were initially assumed, and the optimal solutions for the relevant parameters of DC-DC module 30 and DC-AC module 20 were calculated accordingly, the target bus voltage values ​​of multiple photovoltaic systems 10 are the optimal solutions for the bus voltages of multiple photovoltaic systems 10 under the condition that the maximum charging power is determined and the optimal solutions for the output voltages of DC-DC module 30 and DC-AC module 20 when the energy storage module 40 reaches the maximum charging power (i.e., the target DC voltage and the target AC voltage).

[0108] Finally, the control module 50 can send the obtained target bus voltage value to multiple photovoltaic systems 10, send the obtained target DC voltage to the DC-DC module 30, and send the obtained target AC voltage to the DC-AC module 20, so that multiple photovoltaic systems 10 output according to the target bus voltage value, the DC-DC module 30 outputs according to the target DC voltage value, and the DC-AC module 20 outputs according to the target AC voltage value.

[0109] When the multiple photovoltaic systems 10, DC-DC module 30 and DC-AC module 20 reach the target bus voltage value, target DC voltage value and target AC voltage value respectively, the energy storage module 40 reaches the maximum charging power.

[0110] In some optional examples, when calculating the charging voltage of the energy storage module 40 to achieve maximum conversion efficiency for the DC-DC module 30 under different bus voltage settings, a power constraint can be set to ensure that the final calculated parameters simultaneously satisfy both the output constraint and the power constraint. This power constraint can be that the charging power of the energy storage module 40 during charging is less than or equal to the maximum charging power limit of the energy storage module 40, thereby ensuring that the charging voltage output by the DC-DC module 30 after dispatch control enables the energy storage module 40 to charge safely.

[0111] The technical solution of this application, based on the actual output power of multiple photovoltaic systems 10 and the output power demand of DC-AC module 20, calculates the output voltages of DC-DC module 30 and DC-AC module 20 at their maximum conversion efficiency under different bus voltage settings, through control module 50. This allows the acquisition of target bus voltage, target AC voltage, and target DC voltage when energy storage module 40 reaches its maximum charging power. Furthermore, it controls multiple photovoltaic systems 10, DC-AC module 20, and DC-DC module 30 to output according to the target bus voltage, target AC voltage, and target DC voltage. Therefore, it can balance the DC-DC module 30, photovoltaic system 10, and DC-AC module 20 from the perspective of the entire photovoltaic-storage DC coupling system, thereby finding the highest charging power at which all aspects of the entire photovoltaic-storage DC coupling system reach their optimal efficiency. This allows photovoltaic system 10 to supply as much power to energy storage devices as possible while meeting the basic energy demand of the grid, thus solving the problem that related technologies' scheduling and control schemes cannot meet the energy storage demand of energy storage module 40.

[0112] Please refer to Figure 3 , Figure 3 This is a schematic diagram of another embodiment of the photovoltaic-storage DC coupling control circuit proposed based on the above embodiments. In this embodiment, the photovoltaic-storage DC coupling control circuit further includes a data acquisition module 60.

[0113] The acquisition module 60 is connected to the control module 50. The acquisition module 60 can be used to acquire and transmit the current and voltage values ​​of the photovoltaic system 10.

[0114] The control module 50 can also be used to calculate the actual output power of the photovoltaic system 10 based on the current and voltage values ​​of the photovoltaic system 10.

[0115] It should be noted that the aforementioned acquisition module 60 may include a current sensor and a voltage sensor. The current sensor can detect the current of the photovoltaic system 10, and the voltage sensor can detect the voltage of the photovoltaic system 10. After the current sensor and voltage sensor respectively measure the current value and voltage value, the acquisition unit of the acquisition module 60 can send the electrical parameters measured by the sensors to the control module 50. In some alternative examples, a sampling resistor can also be set on the line where the photovoltaic system 10 is located to acquire the current value and voltage value of the photovoltaic system 10.

[0116] The control module 50 can multiply the current value and voltage value of the photovoltaic system 10 to obtain the actual output power of all photovoltaic systems 10, which is expressed by the following mathematical expression (5).

[0117] P pv-i=U pv-i *I pv-i (5)

[0118] In this embodiment of the application, by setting up the acquisition module 60 and calculating the actual output power of the photovoltaic system 10 based on the acquired current and voltage values ​​of the photovoltaic system 10, a data reference is provided for subsequent system-based scheduling and control.

[0119] Please continue reading. Figure 3 Based on the above embodiments, another embodiment of the photovoltaic-storage DC-DC coupling control circuit is proposed. In this embodiment, the control module 50 can be used to obtain the maximum conversion efficiency of the DC-AC module 20 when the output power of the DC-AC module 20 reaches the output power demand value under different bus voltage settings, according to the output power demand value and multiple different bus voltage settings.

[0120] The control module 50 can also be used to calculate the AC voltage under different bus voltage settings, where the AC voltage is the AC side voltage that enables the DC-AC module 20 to achieve maximum conversion efficiency.

[0121] Given that the output power of the DC-AC module 20 needs to reach the required output power value, the maximum conversion efficiency of the DC-AC module 20 under different bus voltage settings can be obtained by looking up a table.

[0122] It should be noted that the lookup table method obtains the maximum conversion efficiency under this condition by consulting the efficiency table of the DC-AC module 20. This efficiency table is related to the characteristics of the device itself and can be obtained through testing before the device leaves the factory. Based on the maximum conversion efficiency, the AC side output voltage of the DC-AC module 20 under this condition can be calculated.

[0123] In this embodiment, a specific method is given to obtain the maximum conversion efficiency of DC-AC module 20 and the corresponding AC side output voltage under different bus voltage settings. The optimal solution for the output voltage of DC-AC module 20 under different bus voltage settings is realized, providing data reference for subsequent system-based scheduling control.

[0124] Please continue reading. Figure 3 In another embodiment of the photovoltaic-storage DC coupling control circuit proposed in the above embodiments, the control module 50 can be used to obtain the maximum conversion efficiency of the photovoltaic system 10 under different bus voltage settings based on the actual output power of the photovoltaic system 10 and multiple different bus voltage settings.

[0125] The control module 50 can also be used to calculate the remaining power of the DC bus under different bus voltage settings based on the actual output power of the photovoltaic system 10, the maximum conversion efficiency of the photovoltaic system 10, the maximum conversion efficiency of the DC-AC module 20, and the AC voltage under different bus voltage settings.

[0126] The control module 50 can also be used to obtain the maximum conversion efficiency of the DC-DC module 30 under different bus voltage settings based on different bus voltage settings and the remaining power of the DC bus under different bus voltage settings.

[0127] The control module 50 can also be used to calculate the DC voltage under different bus voltage settings, where the DC voltage is the charging voltage of the energy storage module 40 when the DC-DC module 30 reaches its maximum conversion efficiency.

[0128] It should be noted that, given the actual output power of the photovoltaic system 10 and the set values ​​of the bus voltage of multiple photovoltaic systems 10, the maximum conversion efficiency of the photovoltaic system 10 under different bus voltage set values ​​can be obtained by looking up a table. This table lookup method involves an efficiency table for the photovoltaic system 10, which is similar to the efficiency table involved in the DC-AC module 20. The efficiency is related to the characteristics of the equipment itself, and the table can be obtained by referring to the aforementioned methods; further details will not be provided here.

[0129] Since the maximum conversion efficiency of the photovoltaic system 10 was obtained by looking up the table, the DC bus power under different bus voltage settings can be calculated using the aforementioned formula (1). Combining this with formula (2), where the DC bus power is known, the AC side power of the DC-AC module 20 is the output power requirement of the DC-AC module 20, and the maximum conversion efficiency of the DC-AC module 20 under different bus voltage settings was obtained in the aforementioned embodiment, the remaining power of the DC bus under different DC bus settings can be calculated. This remaining power is the input power at the first terminal of the DC-DC module 30, and is also P in formula (2). Bat / α DC-Bat .

[0130] Based on the above calculations, and having obtained the input power of the first terminal of the DC-DC module 30 at different bus voltage settings, the maximum conversion efficiency of the DC-DC module 30 at different bus voltage settings can be obtained by looking up a table. This table lookup method involves an efficiency table for the DC-DC module 30, which is similar to the efficiency table for the DC-AC module 20 and is related to the characteristics of the device itself. The table can be obtained by referring to the previous explanation, and will not be elaborated further here. Having obtained the maximum conversion efficiency of the DC-DC module 30 under different conditions, the optimal solution for the charging voltage provided by the second terminal of the DC-DC module 30 to the energy storage module 40 under these conditions can be calculated, i.e., the DC voltage under different conditions.

[0131] This application provides a method for obtaining the charging voltage of the energy storage module 40 when the DC-DC module 30 reaches its maximum conversion efficiency under different bus voltage settings. It realizes the optimal solution calculation of the output voltage of the DC-DC module 30 under different bus voltage settings, and provides data reference for subsequent system-based scheduling control.

[0132] Please refer to Figure 3 Based on the above embodiments, another embodiment of the photovoltaic-storage DC coupling control circuit is proposed. In this embodiment, the control module 50 can be used to calculate the charging power of the energy storage module 40 at different bus voltage settings based on the output power demand value, the actual output power, different bus voltage settings, and the AC and DC voltages under different bus voltage settings, and obtain multiple candidate charging powers.

[0133] In this embodiment, the remaining power of the DC bus at the bus voltage setting value can be obtained by using the output power demand value, the actual output power of the photovoltaic system 10, different bus voltage setting values ​​and AC voltage under different bus voltage setting values. Then, based on the remaining power of the DC bus and the maximum conversion efficiency of the DC-DC module 30 when obtaining the DC voltage under different bus voltage setting values, the charging power of the DC-DC module 30 finally output to the energy storage module 40 can be obtained according to formula (2).

[0134] The control module 50 can also be used to select the maximum candidate charging power from multiple candidate charging powers, and obtain the bus voltage setting value, AC voltage and DC voltage when the maximum candidate charging power is reached. The bus voltage setting value, AC voltage and DC voltage when the maximum candidate charging power is reached correspond to the target bus voltage value, target AC voltage value and target DC voltage value.

[0135] It should be noted that this embodiment provides a method for obtaining the maximum charging power and the corresponding target bus voltage, target AC voltage, and target DC voltage. The core idea is to use multiple different bus voltage settings preset by the control module 50 to calculate the DC voltage, AC voltage, and target charging power under multiple different bus voltage settings. Then, the parameters when the target charging power is at its maximum are found from the existing traversal results and used as the parameters of each module in the photovoltaic-storage DC coupling system for control.

[0136] This application embodiment obtains multiple candidate charging powers through traversal calculation and selects the largest charging power from them. The operation is simple and convenient. It provides a selection scheme for the optimal solution under a finite number of parameters, which helps to realize the optimal scheduling scheme control of the photovoltaic-storage DC coupling system and can meet the energy storage needs of the energy storage module 40 to the greatest extent.

[0137] Please refer to Figure 3 In another embodiment of the photovoltaic-storage DC coupling control circuit proposed based on the above embodiments, the control module 50 can be used to calculate the charging power of the energy storage module 40 at different bus voltage settings based on the output power demand value, the actual output power, different bus voltage settings, and the AC and DC voltages under different bus voltage settings.

[0138] The method for calculating the charging power of the energy storage module 40 at different bus voltage settings is similar to... Figure 6 The methods involved are the same, so I won't go into detail here.

[0139] The control module 50 can also be used to process different bus voltage settings and AC voltage, DC voltage and charging power under different bus voltage settings to obtain the fitting relationship between the bus voltage settings, AC voltage, DC voltage and charging power, so as to calculate the target bus voltage value, target AC voltage value and target DC voltage value when the maximum charging power is achieved based on the fitting relationship.

[0140] It should be noted that this embodiment provides a method for obtaining the maximum charging power and the corresponding target bus voltage, target AC voltage, and target DC voltage. The core idea is to use the control module 50 to pre-set multiple different bus voltage settings, calculate the DC voltage, AC voltage, and charging power under these different settings, and then fit the relationship between the charging power of the energy storage module 40 and the DC voltage, AC voltage, and bus voltage settings to obtain a fitting relationship. This fitting relationship can be a fitting equation or a fitting curve. Finally, based on this fitting relationship, the various DC voltage, AC voltage, and bus voltage settings at the maximum charging power can be obtained, which are then used as the target DC voltage, target AC voltage, and target bus voltage values.

[0141] This application embodiment fits the relationship between various parameters, and can obtain the maximum charging power of the energy storage module 40 when the conversion efficiency of each equipment module of the photovoltaic-storage DC coupling system is reasonable, as well as the output voltage parameters of the DC-DC module 30, DC-AC module 20 and multiple photovoltaic systems 10 when the maximum charging power is reached, so as to meet the energy storage needs of the energy storage module 40 to the greatest extent.

[0142] It should also be noted that in other optional examples, the optimal output voltage solution of each device that maximizes the charging power of the energy storage module 40 can be found by using methods such as gradient descent, based on different bus voltage settings and AC voltage, DC voltage and charging power under different bus voltage settings, so as to charge the energy storage module 40 as much as possible.

[0143] This application also provides a photovoltaic-storage DC coupling control method. In one optional embodiment, please refer to... Figure 1 , Figure 2 and Figure 4 This method is applied to a photovoltaic-storage DC-coupled control system (e.g., it could be...). Figure 2 The control module in the photovoltaic-storage DC coupling control system is connected to the DC-AC module, DC-DC module, and multiple photovoltaic systems within the photovoltaic-storage DC coupling system. The method includes:

[0144] Step 410: Obtain the actual output power of the photovoltaic system and the output power requirement of the DC-AC module.

[0145] Step 420: Based on the actual output power and the output power requirement, calculate the AC voltage and DC voltage at which the output power of the DC-AC module reaches the output power requirement under multiple different bus voltage settings. The AC voltage is the AC side output voltage at which the DC-AC module reaches its maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module connected to the DC-DC module at which the DC-DC module reaches its maximum conversion efficiency.

[0146] Step 430: Based on different bus voltage settings and the AC and DC voltages under different bus voltage settings, determine the target bus voltage, target AC voltage, and target DC voltage values ​​that enable the energy storage module to reach its maximum charging power.

[0147] Step 440: Control multiple photovoltaic systems, DC-AC modules and DC-DC modules to output the target bus voltage value, target AC voltage value and target DC voltage value respectively.

[0148] The multiple photovoltaic systems of this application can convert solar energy into electrical energy to output DC bus voltage. The DC side of the DC-AC module and the first terminal of the DC-DC module can be connected to the DC bus. The DC-AC module can convert the DC voltage obtained from the DC bus into AC power, which is then transmitted to the grid via the AC side of the DC-AC module. When the power generated by the multiple photovoltaic systems exceeds the power consumption of the grid, the DC-DC module, after being connected to the DC bus, can convert the DC voltage obtained from the DC bus to charge the energy storage module.

[0149] The aforementioned control module can be an Energy Management System (EMS), or a dedicated control device / system with computing capabilities connected to the photovoltaic system, DC-DC module, and DC-AC module. For example, it could be a cloud server, or a system combining similar energy management devices and cloud servers. The DC-AC module can be a photovoltaic inverter. The control module can schedule and control the DC-DC module, DC-AC module, and multiple photovoltaic systems within the photovoltaic-storage DC-DC coupling system.

[0150] The aforementioned control module can acquire the electrical parameters of the photovoltaic system and, based on these parameters, determine the actual output power of the photovoltaic system. These electrical parameters can include power, current, and voltage, among others.

[0151] The output power requirement of the DC-AC module is the output power value that meets the power grid's energy demand. This output power requirement is greater than or equal to the grid's minimum power requirement, and its specific value can be set according to actual needs. For example, if the grid's minimum power requirement is 250kW, then the output power requirement value P... AC≥250kW, for example, the output power requirement can be 250kW. This output power requirement is one of the output constraints of the photovoltaic-storage DC-DC coupling system dispatch control, ensuring that the AC power output by the DC-AC module meets the minimum power requirement of the power grid after dispatch control.

[0152] The aforementioned multiple different bus voltage settings are simulated bus voltage values ​​set by the control module. Their specific values ​​and quantities can be set according to actual needs. For example, 100 different bus voltage settings can be set.

[0153] The specific control principle of this method has been explained in the aforementioned photovoltaic-storage DC-coupled control circuit, and will not be repeated here. Therefore, based on the aforementioned control principle, it can be seen that, given the actual output power of the photovoltaic system and the output power requirements of the DC-AC module, the key is to maximize the charging capacity of the energy storage module while ensuring that the output power of the photovoltaic-storage DC-coupled system meets the basic requirements of the power grid. This means determining the reasonable conversion efficiency of multiple photovoltaic systems, DC-DC modules, and DC-AC modules to maximize the charging power of the energy storage module.

[0154] Therefore, before scheduling and control, multiple different bus voltage setpoints can be preset. Then, assuming the photovoltaic system's output bus voltage reaches each setpoint and the DC-AC module's output power meets the required output power, the output voltages corresponding to the maximum conversion efficiency of the DC-DC and DC-AC modules can be calculated. It can be understood that the calculated output voltage at maximum conversion efficiency is the optimal solution for the relevant parameters of the DC-DC and DC-AC modules in the photovoltaic-storage DC-coupled system, based on the actual output power of the photovoltaic-storage system and under the condition of satisfying output constraints.

[0155] Furthermore, based on multiple different bus voltage settings and the output voltages of the DC-DC and DC-AC modules associated with each bus voltage setting when they reach maximum efficiency, the charging power of the energy storage module at multiple different bus voltage settings can be determined. Finally, the target bus voltage, target AC voltage, and target DC voltage when the energy storage module reaches its maximum charging power can be found. These determined target bus voltage, target AC voltage, and target DC voltage are the scheduling control parameters that maximize the charging power of the energy storage module under reasonable conversion efficiency for multiple photovoltaic systems, DC-DC modules, and DC-AC modules.

[0156] Understandably, since multiple different bus voltage settings were initially assumed, and the optimal solutions for the relevant parameters of the DC-DC and DC-AC modules were calculated accordingly, the target bus voltage settings for multiple photovoltaic systems are the optimal solutions for the bus voltages of multiple photovoltaic systems to achieve reasonable conversion efficiency, given the determination of the maximum charging power and the optimal solutions for the output voltages of the DC-DC and DC-AC modules when the energy storage module reaches its maximum charging power (i.e., the target DC voltage and the target AC voltage).

[0157] Ultimately, the control module can send the obtained target bus voltage value to multiple photovoltaic systems, send the obtained target DC voltage to the DC-DC module, and send the obtained target AC voltage to the DC-AC module, so that the multiple photovoltaic systems output according to the target bus voltage value, the DC-DC module outputs according to the target DC voltage value, and the DC-AC module outputs according to the target AC voltage value.

[0158] The energy storage module reaches its maximum charging power when multiple photovoltaic systems, DC-DC modules, and DC-AC modules reach the target bus voltage, target DC voltage, and target AC voltage, respectively.

[0159] In some optional examples, when calculating the charging voltage of the energy storage module to achieve maximum conversion efficiency under different bus voltage settings, a power constraint can be set to ensure that the final calculated parameters simultaneously satisfy both the output constraint and the power constraint. This power constraint can be that the charging power of the energy storage module is less than or equal to its maximum charging power limit, thereby ensuring that the charging voltage output by the DC-DC module after dispatch control enables safe charging of the energy storage module.

[0160] The technical solution of this application, based on the actual output power of multiple photovoltaic systems and the output power demand of the DC-AC module, calculates the output voltage corresponding to the maximum conversion efficiency of the DC-DC module and the DC-AC module when the output power of the DC-AC module reaches the output power demand value under different bus voltage settings. This allows the determination of the target bus voltage, target AC voltage, and target DC voltage when the energy storage module reaches its maximum charging power. Furthermore, it controls the output of multiple photovoltaic systems, DC-AC modules, and DC-DC modules according to the target bus voltage, target AC voltage, and target DC voltage values. Therefore, it can balance the DC-DC module, photovoltaic system, and DC-AC module from the perspective of the entire photovoltaic-energy storage DC coupling system, thereby finding the highest charging power when all aspects of the entire photovoltaic-energy storage DC coupling system reach their optimal efficiency points. This enables the photovoltaic system to supply as much power as possible to the energy storage devices while meeting the basic energy demand of the grid, thus solving the problem that the dispatch control schemes of related technologies cannot meet the energy storage demand of the energy storage module.

[0161] Please refer to Figure 5 , Figure 5 This is a flowchart illustrating another embodiment of the photovoltaic-storage DC-AC coupling control method proposed in the above embodiments. In this method, the energy management device is connected to the acquisition module. Step 410 above, obtaining the actual output power of the photovoltaic system and the output power requirement value of the DC-AC module, may include:

[0162] Step 510: Receive the current and voltage values ​​of the photovoltaic system collected by the acquisition module, and obtain the output power demand value of the DC-AC module.

[0163] Step 520: Calculate the actual output power of the photovoltaic system based on the current and voltage values ​​of the photovoltaic system.

[0164] It should be noted that the aforementioned acquisition module may include a current sensor and a voltage sensor. The current sensor can detect the current of the photovoltaic system, and the voltage sensor can detect the voltage of the photovoltaic system. After the current sensor and voltage sensor respectively measure the current value and voltage value, the acquisition module's acquisition unit can send the measured electrical parameters to the control module. In some alternative examples, a sampling resistor can also be set on the line where the photovoltaic system is located to acquire the current value and voltage value of the photovoltaic system.

[0165] The aforementioned control module can multiply the current and voltage values ​​of the photovoltaic system to obtain the actual output power of the photovoltaic system.

[0166] In this embodiment of the application, by setting up a data acquisition module and calculating the actual output power of the photovoltaic system based on the acquired current and voltage values, the actual output power of the photovoltaic system is obtained, providing data reference for subsequent system-based scheduling and control.

[0167] Furthermore, in another embodiment of the photovoltaic-storage DC coupling control method proposed in the above embodiments, step 410 includes:

[0168] Based on the output power demand value and multiple different bus voltage settings, the maximum conversion efficiency of the DC-AC module is obtained when the output power of the DC-AC module reaches the output power demand value under different bus voltage settings.

[0169] Calculate the AC voltage under different bus voltage settings. The AC voltage is the AC side voltage that enables the DC-AC module to achieve maximum conversion efficiency.

[0170] Based on the actual output power of the photovoltaic system and multiple different bus voltage settings, the maximum conversion efficiency of the photovoltaic system under different bus voltage settings is obtained.

[0171] Based on the actual output power of the photovoltaic system, and the maximum conversion efficiency of the photovoltaic system, the maximum conversion efficiency of the DC-AC module, and the AC voltage under different bus voltage settings, the remaining power of the DC bus under different bus voltage settings is calculated.

[0172] Based on different bus voltage settings and the remaining power of the DC bus under different bus voltage settings, the maximum conversion efficiency of the DC-DC module under different bus voltage settings is obtained.

[0173] Calculate the DC voltage under different bus voltage settings. The DC voltage is the charging voltage of the energy storage module when the DC-DC module achieves maximum conversion efficiency.

[0174] Given that the output power of the DC-AC module needs to reach the required output power value, the maximum conversion efficiency of the DC-AC module under different bus voltage settings can be obtained by looking up a table.

[0175] It should be noted that the lookup table method obtains the maximum conversion efficiency under this condition by consulting the efficiency table of the DC-AC module. This efficiency table is related to the characteristics of the device itself and can be obtained through testing before the device leaves the factory. Based on the maximum conversion efficiency, the AC output voltage of the DC-AC module under this condition can be calculated.

[0176] In this embodiment, a specific method is given to obtain the maximum conversion efficiency of the DC-AC module and the corresponding AC side output voltage under different bus voltage settings. The optimal solution for the output voltage of the DC-AC module under different bus voltage settings is calculated, providing data reference for subsequent system-based scheduling control.

[0177] It should also be noted that, given the actual output power of the photovoltaic system and the bus voltage settings of multiple photovoltaic systems, the maximum conversion efficiency of the photovoltaic system under different bus voltage settings can be obtained by looking up a table. This table lookup method involves a photovoltaic system efficiency table, which is similar to the efficiency table used in DC-AC modules and is related to the characteristics of the equipment itself. The acquisition of the table can be found above and will not be elaborated upon here.

[0178] Since the maximum conversion efficiency of the photovoltaic system was obtained by looking up the table, the DC bus power under different bus voltage settings can be calculated using the aforementioned formula (1). Combining this with formula (2), where the DC bus power is known, the AC side power of the DC-AC module is the output power requirement of the DC-AC module, and the maximum conversion efficiency of the DC-AC module under different bus voltage settings was obtained in the aforementioned embodiment, the remaining power of the DC bus under different DC bus settings can be calculated. This remaining power is the input power at the first terminal of the DC-DC module, which is also P in formula (2). Bat / α DC-Bat .

[0179] Based on the above calculations, and having obtained the input power of the DC-DC module's first terminal at different bus voltage settings, the maximum conversion efficiency of the DC-DC module at different bus voltage settings can be obtained through a lookup table method. This lookup table method involves an efficiency table for the DC-DC module, which is similar to the efficiency table for DC-AC modules and is related to the characteristics of the device itself. The table's acquisition can be referred to the previous explanation and will not be elaborated upon here. Having obtained the maximum conversion efficiency of the DC-DC module under different conditions, the optimal solution for the charging voltage provided by the second terminal of the DC-DC module to the energy storage module under these conditions can be calculated, i.e., the DC voltage under different conditions.

[0180] This application provides a method for obtaining the charging voltage of the energy storage module when the DC-DC module achieves maximum conversion efficiency under different bus voltage settings. It realizes the optimal solution calculation of the output voltage of the DC-DC module under different bus voltage settings, and provides data reference for subsequent system-based scheduling control.

[0181] In another embodiment of the photovoltaic-storage DC coupling control method proposed in the above embodiments, determining the target bus voltage value, target AC voltage value, and target DC voltage value for the energy storage module to reach its maximum charging power based on different bus voltage setpoints and the AC and DC voltages under different bus voltage setpoints may include:

[0182] Based on the output power demand, actual output power, different bus voltage settings, and AC and DC voltages under different bus voltage settings, the charging power of the energy storage module at different bus voltage settings is calculated to obtain multiple candidate charging powers.

[0183] Select the maximum candidate charging power from multiple candidate charging power options.

[0184] Obtain the bus voltage setpoint, AC voltage, and DC voltage when the maximum candidate charging power is reached. The bus voltage setpoint, AC voltage, and DC voltage when the maximum candidate charging power is reached correspond to the target bus voltage value, target AC voltage value, and target DC voltage value.

[0185] In this embodiment, the remaining power of the DC bus can be obtained by using the output power demand value, the actual output power of the photovoltaic system, different bus voltage setting values ​​and AC voltage under different bus voltage setting values, and then the charging power of the DC-DC module finally output to the energy storage module can be obtained according to formula (2) based on the remaining power of the DC bus and the maximum conversion efficiency of the DC-DC module when obtaining the DC voltage under different bus voltage setting values.

[0186] It should be noted that this embodiment provides a method for obtaining the maximum charging power and the corresponding target bus voltage, target AC voltage, and target DC voltage. The core idea is to use multiple different bus voltage settings preset by the control module, and to calculate the DC voltage, AC voltage, and target charging power under multiple different bus voltage settings. Then, the parameters when the target charging power is at its maximum are found from the existing traversal results, and these parameters are used as the parameters of each module in the photovoltaic-storage DC coupling system for control.

[0187] This application embodiment obtains multiple candidate charging powers through traversal calculation and selects the largest charging power from them. The operation is simple and convenient. It provides a selection scheme for the optimal solution under a finite number of parameters, which helps to realize the optimal scheduling scheme control of the photovoltaic-storage DC coupling system and can meet the energy storage needs of the energy storage module to the greatest extent.

[0188] Another embodiment of the photovoltaic-storage DC coupling control method can be proposed based on the above embodiments. In this embodiment, the target bus voltage value, target AC voltage value, and target DC voltage value for achieving the maximum charging power of the energy storage module are determined according to different bus voltage setpoints and the AC and DC voltages under different bus voltage setpoints. This may include:

[0189] Based on the output power demand, actual output power, different bus voltage settings, and AC and DC voltages under different bus voltage settings, calculate the charging power of the energy storage module at different bus voltage settings.

[0190] The different bus voltage settings and the AC voltage, DC voltage and charging power under different bus voltage settings are processed to obtain the fitting relationship between the bus voltage settings, AC voltage, DC voltage and charging power.

[0191] The target bus voltage, target AC voltage, and target DC voltage at maximum charging power are calculated based on the fitting relationship.

[0192] The method for calculating the charging power of the energy storage module at different bus voltage settings is similar to... Figure 6 The methods involved are the same, so I won't go into detail here.

[0193] It should be noted that this embodiment provides a method for obtaining the maximum charging power and the corresponding target bus voltage, target AC voltage, and target DC voltage. The core idea is to use a control module to pre-set multiple different bus voltage settings, calculate the DC voltage, AC voltage, and charging power under these settings, and then fit the relationship between the energy storage module's charging power and the DC voltage, AC voltage, and bus voltage settings to obtain a fitting relationship. This fitting relationship can be a fitting equation or a fitting curve. Finally, based on this fitting relationship, the various DC voltage, AC voltage, and bus voltage settings at maximum charging power can be obtained, which are then used as the target DC voltage, target AC voltage, and target bus voltage values.

[0194] This application embodiment fits relationships between various parameters, enabling the acquisition of the maximum charging power of the energy storage module at a reasonable conversion efficiency for each device module in the photovoltaic-storage DC coupling system, as well as the output voltage parameters of the DC-DC module, DC-AC module, and multiple photovoltaic systems when the maximum charging power is achieved. This maximizes the energy storage requirements of the energy storage module.

[0195] It should also be noted that in other optional examples, the optimal output voltage solution of each device that maximizes the charging power of the energy storage module can be found by using methods such as gradient descent, based on different bus voltage settings and AC voltage, DC voltage and charging power under different bus voltage settings, so as to charge the energy storage module as much as possible.

[0196] Figure 6 A schematic diagram of the hardware structure of an energy management device provided in an embodiment of this application is shown. The energy management device may include a processor 601 and a memory 602 storing computer program instructions.

[0197] Specifically, the processor 601 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0198] Memory 602 may include mass storage for data or instructions. For example, and not limitingly, memory 602 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 602 may include removable or non-removable (or fixed) media. Where appropriate, memory 602 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 602 is non-volatile solid-state memory.

[0199] In certain embodiments, the memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Thus, generally, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the methods according to one aspect of this disclosure.

[0200] The processor 601 reads and executes computer program instructions stored in the memory 602 to implement any of the optical-storage DC coupling control methods in the above embodiments.

[0201] In one example, the energy management device may also include a communication interface 603 and a bus 66. Wherein, as... Figure 6As shown, the processor 601, memory 602, and communication interface 603 are connected through bus 66 and complete communication with each other.

[0202] The communication interface 603 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0203] Bus 66 includes hardware, software, or both, that couples components of an image processing device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 66 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0204] The energy management device can execute the photovoltaic-storage DC coupling control method in the embodiments of this application, thereby realizing the photovoltaic-storage DC coupling control circuit and method described in conjunction with the above embodiments.

[0205] Furthermore, in conjunction with the photovoltaic-storage DC coupling control method in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any one of the photovoltaic-storage DC coupling control methods in the above embodiments.

[0206] In addition, this application also provides a computer program product, including a computer program, which, when executed by a processor, can implement the steps and corresponding content of the aforementioned method embodiments.

[0207] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no conflict in structure or control method. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A photovoltaic-storage DC-DC coupling control circuit, comprising: A DC-AC module, wherein the DC side of the DC-AC module is connected to multiple photovoltaic systems via a DC bus, and the AC side of the DC-AC module is connected to the power grid; A DC-DC module, wherein the first end of the DC-DC module is used to connect to the DC bus, and the second end of the DC-DC module is connected to the energy storage module; A control module, connected to the DC-AC module, the DC-DC module, and multiple photovoltaic systems, is used to acquire the actual output power of the photovoltaic system and the output power demand value of the DC-AC module. Based on the actual output power and the output power demand value, it calculates the AC voltage and DC voltage at which the output power of the DC-AC module reaches the output power demand value under multiple different bus voltage settings. The AC voltage is the AC side output voltage at which the DC-AC module reaches its maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module at which the DC-DC module reaches its maximum conversion efficiency. The control module is further configured to determine the target bus voltage value, target AC voltage value, and target DC voltage value when the energy storage module reaches its maximum charging power, based on different bus voltage setting values ​​and the AC voltage and DC voltage under different bus voltage setting values, and control multiple photovoltaic systems, the DC-AC module, and the DC-DC module to output the target bus voltage value, the target AC voltage value, and the target DC voltage value respectively.

2. The photovoltaic-storage DC coupling control circuit according to claim 1, wherein, The control module is used to calculate the charging power of the energy storage module at different bus voltage settings based on the output power demand value, the actual output power, different bus voltage settings, and the AC voltage and DC voltage under different bus voltage settings, and to obtain multiple candidate charging powers. The control module is further configured to select the maximum candidate charging power from the plurality of candidate charging powers, and obtain the bus voltage setting value, AC voltage and DC voltage when the maximum candidate charging power is reached, wherein the bus voltage setting value, AC voltage and DC voltage when the maximum candidate charging power is reached correspond to the target bus voltage value, the target AC voltage value and the target DC voltage value.

3. The photovoltaic-storage DC coupling control circuit according to claim 1, wherein, The control module is also used to calculate the charging power of the energy storage module at different bus voltage settings based on the output power demand value, the actual output power, different bus voltage settings, and the AC voltage and DC voltage under different bus voltage settings. The control module is further configured to process different bus voltage setting values ​​and the AC voltage, DC voltage and charging power under different bus voltage setting values ​​to obtain a fitting relationship between the bus voltage setting value, AC voltage, DC voltage and charging power, so as to calculate the target bus voltage value, the target AC voltage value and the target DC voltage value when the maximum charging power is achieved based on the fitting relationship.

4. The photovoltaic-storage DC coupling control circuit according to claim 1, wherein, The control module is also used to obtain, based on the output power demand value and multiple different bus voltage setting values, the maximum conversion efficiency of the DC-AC module when the output power of the DC-AC module reaches the output power demand value under different bus voltage setting values. The control module is also used to calculate the AC voltage under different bus voltage settings, wherein the AC voltage is the AC side voltage that enables the DC-AC module to achieve the maximum conversion efficiency.

5. The photovoltaic-storage DC coupling control circuit according to claim 4, wherein, The control module is also used to obtain the maximum conversion efficiency of the photovoltaic system under different bus voltage setting values ​​based on the actual output power of the photovoltaic system and multiple different bus voltage setting values; The control module is also used to calculate the remaining power of the DC bus under different bus voltage settings based on the actual output power of the photovoltaic system, the maximum conversion efficiency of the photovoltaic system, the maximum conversion efficiency of the DC-AC module, and the AC voltage under different bus voltage settings. The control module is also used to obtain the maximum conversion efficiency of the DC-DC module under different bus voltage settings based on different bus voltage settings and the remaining power of the DC bus under different bus voltage settings. The control module is also used to calculate the DC voltage under different bus voltage settings, wherein the DC voltage is the charging voltage of the energy storage module when the DC-DC module achieves maximum conversion efficiency.

6. The photovoltaic-storage DC coupling control circuit according to any one of claims 1 to 5, wherein, The photovoltaic-storage DC coupling control circuit also includes a data acquisition module; The acquisition module is connected to the control module and is used to acquire and transmit the current and voltage values ​​of the photovoltaic system. The control module is also used to calculate the actual output power of the photovoltaic system based on the current value and the voltage value of the photovoltaic system.

7. A photovoltaic-storage DC-DC coupling control method, applied to a photovoltaic-storage DC-DC coupling control system, wherein the photovoltaic-storage DC-DC coupling control system is connected to a DC-AC module, a DC-DC module, and multiple photovoltaic systems respectively; the method includes: Obtain the actual output power of the photovoltaic system and the output power requirement of the DC-AC module; Based on the actual output power and the output power requirement, the AC voltage and DC voltage are calculated respectively under multiple different bus voltage settings to make the output power of the DC-AC module reach the output power requirement. The AC voltage is the AC side output voltage when the DC-AC module reaches the maximum conversion efficiency, and the DC voltage is the charging voltage of the energy storage module connected to the DC-DC module when the DC-DC module reaches the maximum conversion efficiency. Based on different bus voltage settings and the AC and DC voltages under different bus voltage settings, determine the target bus voltage, target AC voltage, and target DC voltage values ​​that enable the energy storage module to reach its maximum charging power. The system controls multiple photovoltaic systems, DC-AC modules, and DC-DC modules to output the target bus voltage value, the target AC voltage value, and the target DC voltage value respectively.

8. The photovoltaic-storage DC coupling control method according to claim 7, wherein, The step of determining the target bus voltage value, target AC voltage value, and target DC voltage value for the energy storage module to reach maximum charging power based on different bus voltage setting values ​​and the AC voltage and DC voltage under different bus voltage setting values ​​includes: Based on the output power demand value, the actual output power, different bus voltage settings, and the AC voltage and DC voltage under different bus voltage settings, the charging power of the energy storage module at different bus voltage settings is calculated to obtain multiple candidate charging powers. Select the maximum candidate charging power from among the multiple candidate charging powers; Obtain the bus voltage setting value, AC voltage, and DC voltage when the maximum candidate charging power is reached. The bus voltage setting value, AC voltage, and DC voltage when the maximum candidate charging power is reached correspond to the target bus voltage value, the target AC voltage value, and the target DC voltage value.

9. The photovoltaic-storage DC coupling control method according to claim 7, wherein, The step of determining the target bus voltage value, target AC voltage value, and target DC voltage value for the energy storage module to reach maximum charging power based on different bus voltage setting values ​​and the AC voltage and DC voltage under different bus voltage setting values ​​includes: Based on the output power demand value, the actual output power, different bus voltage settings, and the AC voltage and DC voltage under different bus voltage settings, calculate the charging power of the energy storage module at different bus voltage settings; The AC voltage, DC voltage, and charging power under different bus voltage setting values ​​are processed to obtain the fitting relationship between the bus voltage setting value, AC voltage, DC voltage, and charging power. The target bus voltage, target AC voltage, and target DC voltage are calculated based on the fitting relationship to obtain the maximum charging power.

10. The photovoltaic-storage DC coupling control method according to claim 7, wherein, The step of calculating the AC voltage required to achieve the required output power for the DC-AC module under multiple different bus voltage settings, based on the actual output power and the required output power, includes: Based on the output power demand value and multiple different bus voltage setting values, the maximum conversion efficiency of the DC-AC module is obtained when the output power of the DC-AC module reaches the output power demand value under different bus voltage setting values. Calculate the AC voltage under different bus voltage settings, where the AC voltage is the AC side voltage that enables the DC-AC module to achieve the maximum conversion efficiency.

11. The photovoltaic-storage DC coupling control method according to claim 10, wherein, Based on the actual output power and the output power requirement, calculate the DC voltage under multiple different bus voltage settings, including: Based on the actual output power of the photovoltaic system and multiple different bus voltage setting values, the maximum conversion efficiency of the photovoltaic system under different bus voltage setting values ​​is obtained; Based on the actual output power of the photovoltaic system, and the maximum conversion efficiency of the photovoltaic system, the maximum conversion efficiency of the DC-AC module, and the AC voltage under different bus voltage settings, the remaining power of the DC bus under different bus voltage settings is calculated. Based on different bus voltage settings and the remaining power of the DC bus under different bus voltage settings, the maximum conversion efficiency of the DC-DC module under different bus voltage settings is obtained; Calculate the DC voltage under different bus voltage settings, where the DC voltage is the charging voltage of the energy storage module that enables the DC-DC module to achieve maximum conversion efficiency.

12. The photovoltaic-storage DC coupling control method according to any one of claims 7 to 11, wherein, The photovoltaic-storage DC coupling control system is also connected to the acquisition module, and the acquisition of the actual output power of the photovoltaic system includes: Receive the current and voltage values ​​of the photovoltaic system collected by the acquisition module; The actual output power of the photovoltaic system is calculated based on the current and voltage values ​​of the photovoltaic system.

13. A photovoltaic-storage DC coupling control system, comprising a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the photovoltaic-storage DC coupling control method as described in any one of claims 7 to 12.

14. A photovoltaic-storage DC-coupled control system configured to perform the steps of the photovoltaic-storage DC-coupled control method according to any one of claims 7 to 12.

15. A readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the optical-storage DC-DC coupling control method as described in any one of claims 7 to 12.

16. A computer program product, which can be executed by a processor to implement the steps of the photoelectric storage DC coupling control method as described in any one of claims 7 to 12.

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