Control method of light storage integrated system, control terminal and storage medium

Abstract

This invention provides a control method, control terminal, and storage medium for an integrated photovoltaic-storage system. The integrated photovoltaic-storage system includes a photovoltaic module; the photovoltaic module includes a photovoltaic component and a first DC-DC converter; the photovoltaic component is connected to a DC bus via the first DC-DC converter; when the first DC-DC converter is not operating, the first DC-DC converter contains a current path from its input to its output; the control method includes: acquiring the operating mode of the photovoltaic module and the voltage of the DC bus; if the photovoltaic module is in a curtailment mode and the DC bus voltage is greater than a preset voltage, then controlling the output power of the photovoltaic module to be non-zero, so that the DC bus voltage does not exceed the preset voltage. This invention does not completely curtail light after the photovoltaic module enters a curtailment mode, but rather partially curtails light, preventing the DC bus voltage from becoming too high, reducing device stress, and improving the system's safety and reliability.

Description

Technical Field

[0001] This invention relates to the field of power grid technology, and in particular to a control method, control terminal and storage medium for an integrated photovoltaic-storage system. Background Technology

[0002] The rational and rapid development of renewable energy is an important way to solve my country's energy shortage and environmental pollution problems. Solar photovoltaic power generation has been widely used due to its advantages such as being pollution-free, sustainable, having a large total capacity, and being widely distributed. Integrated photovoltaic and energy storage systems reduce the impact on the grid connection and improve the reliability of photovoltaic grid connection by configuring energy storage modules of a certain capacity on the photovoltaic system.

[0003] In existing technologies, when there is abundant sunshine at noon, a large number of photovoltaic modules are connected to the grid, which can easily lead to excess energy in the grid and cause the photovoltaic modules to enter a "curtailment" mode (drive shut down, output power is 0). When the photovoltaic modules enter the "curtailment" mode, the DC bus voltage is raised, the stress on the devices increases, and the safety and reliability of the system are seriously affected. Summary of the Invention

[0004] This invention provides a control method, control terminal, and storage medium for an integrated photovoltaic and energy storage system, in order to solve the problem in the prior art where photovoltaic modules enter a "curtailment" mode, causing the DC bus to be raised and affecting system safety.

[0005] In a first aspect, embodiments of the present invention provide a control method for an integrated photovoltaic and energy storage system. The integrated photovoltaic and energy storage system includes: a photovoltaic module; the photovoltaic module includes: a photovoltaic component and a first DC-DC converter; the photovoltaic component is connected to a DC bus via the first DC-DC converter; when the first DC-DC converter is not operating, the first DC-DC converter includes a current path from its input terminal to its output terminal; the control method includes:

[0006] Obtain the operating mode of the photovoltaic module and the voltage of the DC bus;

[0007] If the photovoltaic module is in the curtailment mode and the DC bus voltage is greater than the preset voltage, the output power of the photovoltaic module will be controlled to be non-zero, so that the DC bus voltage is not greater than the preset voltage.

[0008] In a second aspect, embodiments of the present invention provide a control terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the control method for the integrated photovoltaic and energy storage system as described in the first aspect or any possible implementation of the first aspect.

[0009] Thirdly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the control method for an integrated photovoltaic and energy storage system as described in the first aspect or any possible implementation of the first aspect.

[0010] This invention provides a control method, control terminal, and storage medium for an integrated photovoltaic and energy storage system. The method includes: acquiring the operating mode of the photovoltaic module and the voltage of the DC bus; if the photovoltaic module is in a curtailment mode and the DC bus voltage is greater than a preset voltage, then controlling the output power of the photovoltaic module to be non-zero, so that the DC bus voltage does not exceed the preset voltage. In this embodiment, when the photovoltaic module enters a curtailment mode and exceeds the preset voltage, the photovoltaic module is controlled to partially curtail light, maintaining the photovoltaic module's control over the DC bus voltage, preventing the DC bus voltage from being raised too high, reducing device stress, and improving the system's safety and reliability. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a topology diagram of a photovoltaic module;

[0013] Figure 2 This is a schematic diagram of the characteristic curves of a photovoltaic module;

[0014] Figure 3 This is a flowchart illustrating the implementation of a control method for an integrated photovoltaic and energy storage system provided in an embodiment of the present invention.

[0015] Figure 4 This is a topology diagram of an integrated photovoltaic and energy storage system provided in an embodiment of the present invention;

[0016] Figure 5 This is a schematic diagram of the structure of the control device of the integrated photovoltaic and energy storage system provided in the embodiment of the present invention;

[0017] Figure 6 This is a schematic diagram of the control terminal provided in an embodiment of the present invention. Detailed Implementation

[0018] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments will be described below in conjunction with the accompanying drawings.

[0020] Photovoltaics utilizes solar energy to generate electricity, and energy storage modules smooth out power fluctuations. When the sun is strong at midday, a large number of photovoltaic (PV) modules connected to the grid can cause grid instability. At this time, the grid does not want all PV modules to be connected, so some PV modules enter a curtailment mode. "Curtailment mode," as the name suggests, means that the electricity generated by the PV modules is abandoned, that is, the PV output current is zero. (Reference) Figure 1 The photovoltaic module 11 includes a photovoltaic module 111 and a first DC-DC converter 112. Figure 2 A characteristic curve of a photovoltaic module 111 is shown. The curve shows that the lower the output current of the photovoltaic module 111, the higher the output voltage. When the photovoltaic module 111 enters the curtailment mode, the output current of the photovoltaic module 111 is 0, and the output voltage of the photovoltaic module 111 is pulled up. Since the first DC-DC converter 112 typically uses a boost converter circuit, such as... Figure 1 As shown in the topology diagram of the Boost converter circuit, when the first DC-DC converter 112 is driven off, the input and output terminals of the first DC-DC converter 112 are connected through an inductor and a diode, and a current path exists. The output voltage is basically the same as the output voltage of the photovoltaic module 111, that is, the DC bus voltage is pulled up, which greatly increases the stress on the device and affects the safety and reliability of the system.

[0021] Based on the above, see Figure 3 The diagram illustrates the implementation flowchart of the control method for the integrated photovoltaic and energy storage system provided in this embodiment of the invention, which is described in detail below:

[0022] The photovoltaic-storage integrated system includes: a photovoltaic module 11; the photovoltaic module 11 includes: a photovoltaic module 111 and a first DC-DC converter 112; the photovoltaic module 111 is connected to a DC bus through the first DC-DC converter 112; when the first DC-DC converter 112 is not working, the first DC-DC converter 112 contains a current path from the input terminal to the output terminal; the above control method includes:

[0023] S101: Obtain the operating mode of photovoltaic module 11 and the voltage of the DC bus;

[0024] S102: If the photovoltaic module 11 is in the curtailment mode and the voltage of the DC bus is greater than the preset voltage, then control the output power of the photovoltaic module 11 to be non-zero, so that the voltage of the DC bus is not greater than the preset voltage.

[0025] In this embodiment of the invention, when the photovoltaic module 11 enters the curtailment mode, if the DC bus voltage is too high, the photovoltaic module 11 is controlled to partially curtail power, retaining a portion of the output power (i.e., the output power of the photovoltaic module 11 is not zero), so that the output current is not zero. Figure 2 As can be seen, the output voltage of photovoltaic module 111 decreases accordingly, ensuring that the voltage of the DC bus does not exceed the preset voltage, thus effectively improving the safety and reliability of the system.

[0026] Those skilled in the art will understand that photovoltaic module 11 typically employs MPPT (Maximum Power Point Tracking) control to output maximum power. In this embodiment of the invention, due to excess grid energy, grid connection of photovoltaic module 11 is not desired. Therefore, when controlling the output power of photovoltaic module 11 to be non-zero, it is desirable for the output power of photovoltaic module 11 to be as low as possible. Thus, MPPT control is not employed, and the minimum power output that ensures the DC bus voltage does not exceed a preset voltage is used to meet practical application requirements.

[0027] In this embodiment of the invention, when the power grid does not want the photovoltaic module 11 to be connected to the grid, it will issue a curtailment command. If the curtailment command is received, it can be determined that the photovoltaic module 11 has entered the curtailment mode.

[0028] In one possible implementation, S102 may include:

[0029] S1021: Determine the first rated output power of the current photovoltaic module 11 based on the preset voltage;

[0030] S1022: Control the photovoltaic module 11 to output according to the first rated output power.

[0031] Depend on Figure 2 It is known that the output power of photovoltaics is in a certain correspondence with the output voltage. Therefore, the first rated output power of the photovoltaic module 11 can be determined according to the preset voltage. When the photovoltaic module 11 is controlled to output according to the first rated output power, the output voltage of the photovoltaic module 11 is not greater than the preset voltage.

[0032] For example, the power value corresponding to the preset voltage can be found directly on the PU characteristic curve as the first rated output power, or the power value corresponding to a voltage slightly lower than the preset voltage can be selected as the first rated output power to ensure that the voltage of the DC bus is not greater than the preset voltage.

[0033] In one possible implementation, S1021 may include:

[0034] 1. Obtain current environment parameters;

[0035] 2. Determine the first rated output power of the photovoltaic module 11 based on the preset voltage and current environmental parameters.

[0036] Since the output power of photovoltaics is related to current environmental parameters, different irradiance and different temperatures correspond to different photovoltaic characteristic curves. Therefore, in this embodiment of the invention, the first rated power is determined based on a preset voltage combined with current environmental parameters. These current environmental parameters may include: current irradiance and current ambient temperature, etc.

[0037] For example, based on the current environmental parameters, obtain the corresponding PU characteristic curve, and find the power value corresponding to the preset voltage on the photovoltaic PU characteristic curve as the first rated output power.

[0038] Alternatively, the corresponding IU characteristic curve can be obtained based on the current environmental parameters, and the current corresponding to the preset voltage can be found on the IU characteristic curve. The first rated output power can then be calculated based on the preset voltage and the current corresponding to the preset voltage. This invention is not limited to the two methods described above.

[0039] In one possible implementation, after S102, the control method may further include:

[0040] S103: Real-time monitoring of changes in environmental parameters;

[0041] S104: If the change in environmental parameters is greater than the preset change, then the second rated output power of photovoltaic module 11 is determined based on the environmental parameters at the current moment and the preset bus voltage.

[0042] S105: Control the photovoltaic module 11 to output according to the second rated output power.

[0043] Because the environmental parameters (irradiance and ambient temperature) of the area where the photovoltaic module 11 is located change in real time—for example, when the irradiance or ambient temperature changes, the PU characteristic curve (or IU characteristic curve) of the photovoltaic module 11 changes, and the power corresponding to the preset voltage also changes—if the output of the photovoltaic module 11 is still controlled according to the first rated output power, the voltage of the DC bus may exceed the threshold. Therefore, in this embodiment of the invention, the change in environmental parameters is detected, and the output power of the photovoltaic module 11 is adjusted in real time, so that the voltage of the DC bus is controlled below the threshold, thereby improving the reliability of the system.

[0044] For example, when the change in irradiance is greater than a first preset change, the output power of the photovoltaic module 11 is adjusted. Or when the change in ambient temperature is greater than a second preset change, the output power of the photovoltaic module 11 is adjusted.

[0045] In one possible implementation, S102 may include:

[0046] S1023: Gradually increase the output power of photovoltaic module 11 according to the preset step size until the voltage of DC bus is not greater than the preset voltage.

[0047] In this embodiment of the invention, reference Figure 2 When the photovoltaic module 11 is not receiving light, the output current is 0 and the output power is 0. As the output power increases, the output voltage gradually decreases. In this embodiment of the invention, the first rated output power can be determined by steps S1021 to S1022, and the photovoltaic module 11 can be directly controlled to output according to the first rated output power. The adjustment is fast, but the adjustment is not precise enough. In this embodiment of the invention, the output power of the photovoltaic module 11 can also be gradually increased according to a preset step size, so that the voltage of the DC bus decreases steadily. This increases the adjustment time, but improves the stability and accuracy of the adjustment, and eliminates the need to calculate the first rated power, saving a complex calculation process.

[0048] In one possible implementation, refer to Figure 4 The integrated photovoltaic and energy storage system may further include: an energy storage module 12 and a bidirectional inverter module 13; the energy storage module 12 is connected to the DC bus; the input terminal of the bidirectional inverter module 13 is connected to the DC bus, and the second terminal of the bidirectional inverter module 13 is connected to the AC grid and the load 14 respectively; the above control method may further include:

[0049] S106: Obtain the actual output power of photovoltaic module 11, the power of load 14, and the charging power of energy storage module 12;

[0050] S107: Add the power of the load 14 to the charging power of the energy storage module 12 to obtain the power consumption, and subtract the actual output power of the photovoltaic module 11 from the power consumption to obtain the inverter power;

[0051] S108: Controls the bidirectional inverter module 13 to supply power to the DC bus according to the inverter power.

[0052] In this embodiment of the invention, the photovoltaic module 11 partially wastes power, and the portion with insufficient power is supplemented by the power grid, thus consuming the excess energy of the power grid and meeting the needs of practical applications.

[0053] The energy storage module 12 includes a battery and a second DC-DC converter. Details will not be elaborated here.

[0054] In one possible implementation, the control method described above may further include:

[0055] S109: If the output power of photovoltaic module 11 is not 0, then control the rated voltage of energy storage module 12 to be less than the rated DC output voltage of bidirectional inverter module 13, and the rated DC output voltage of bidirectional inverter module 13 to be less than the rated output voltage of photovoltaic module 11.

[0056] S1010: If the output power of photovoltaic module 11 is 0, then control the rated voltage of energy storage module 12 to be less than the rated DC output voltage of bidirectional inverter module 13.

[0057] When photovoltaic module 11 experiences partial solar power curtailment, to ensure that the energy output of photovoltaic module 11 is consumed, priority is given to powering photovoltaic module 11, followed by the power grid, and lastly, energy storage module 12. The power supply priority for each module is ensured by setting its rated output voltage.

[0058] When the output power of photovoltaic module 11 is 0, it means that photovoltaic module 11 has entered the curtailment mode, and the grid will give priority to power supply. The rated voltage of energy storage module 12 is less than the rated DC output voltage of bidirectional inverter module 13.

[0059] In one possible implementation, the control method described above may further include:

[0060] S1011: If the photovoltaic module 11 is in the curtailment mode and the voltage of the DC bus is not greater than the preset voltage, then control the photovoltaic module 11 to continue in the curtailment mode.

[0061] In this embodiment of the invention, if the photovoltaic module 11 enters the curtailment mode, but the voltage of the DC bus is not greater than the preset voltage and the stress on the device is within the acceptable range, then no action is required, and the curtailment mode can be maintained, with priority given to power supply from the grid.

[0062] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0063] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0064] Figure 5 A schematic diagram of the control device for the integrated photovoltaic and energy storage system provided in an embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0065] The photovoltaic-storage integrated system includes: a photovoltaic module 11; the photovoltaic module 11 includes: a photovoltaic module 111 and a first DC-DC converter 112; the photovoltaic module 111 is connected to a DC bus through the first DC-DC converter 112; when the first DC-DC converter 112 is not working, the first DC-DC converter 112 includes a current path from the input terminal to the output terminal; the aforementioned control device includes:

[0066] The first parameter acquisition module 21 is used to acquire the operating mode of the photovoltaic module 11 and the voltage of the DC bus.

[0067] The first power control module 22 is used to control the output power of the photovoltaic module 11 to be non-zero if the photovoltaic module 11 is in the curtailment mode and the voltage of the DC bus is greater than the preset voltage, so that the voltage of the DC bus is not greater than the preset voltage.

[0068] In one possible implementation, the first power control module 22 may include:

[0069] The power determination unit 221 is used to determine the first rated output power of the current photovoltaic module 11 based on the preset voltage.

[0070] The power output unit 222 is used to control the photovoltaic module 11 to output power according to the first rated output power.

[0071] In one possible implementation, the power determination unit 221 may be specifically used for:

[0072] 1. Obtain current environment parameters;

[0073] 2. Determine the first rated output power of the photovoltaic module 11 based on the preset voltage and current environmental parameters.

[0074] In one possible implementation, the control device may further include:

[0075] Environmental parameter monitoring module 23 is used to monitor changes in environmental parameters in real time;

[0076] The power adjustment module 24 is used to determine the second rated output power of the photovoltaic module 11 based on the environmental parameters at the current moment and the preset bus voltage if the change in environmental parameters is greater than the preset change.

[0077] The second power control module 25 is used to control the photovoltaic module 11 to output power according to the second rated output power.

[0078] In one possible implementation, the first power control module 22 may include:

[0079] The step adjustment unit 223 is used to gradually increase the output power of the photovoltaic module 11 according to a preset step size until the voltage of the DC bus is not greater than the preset voltage.

[0080] In one possible implementation, the integrated photovoltaic and energy storage system may further include: an energy storage module 12 and a bidirectional inverter module 13; the energy storage module 12 is connected to a DC bus; the input terminal of the bidirectional inverter module 13 is connected to the DC bus, and the second terminal of the bidirectional inverter module 13 is connected to the power grid and the load 14 respectively; the control device may further include:

[0081] The second parameter acquisition module 26 is used to acquire the actual output power of the photovoltaic module 11, the power of the load 14, and the charging power of the energy storage module 12.

[0082] The inverter power determination module 27 is used to add the power of the load 14 to the charging power of the energy storage module 12 to obtain the power consumption, and subtract the actual output power of the photovoltaic module 11 from the power consumption to obtain the inverter power.

[0083] Inverter control module 28 is used to control bidirectional inverter module 13 to supply power to the DC bus according to the inverter power.

[0084] In one possible implementation, the control device may further include:

[0085] The first voltage setting module 29 is used to control the rated voltage of the energy storage module 12 to be less than the rated DC output voltage of the bidirectional inverter module 13 if the output power of the photovoltaic module 11 is not 0, and the rated DC output voltage of the bidirectional inverter module 13 is less than the rated output voltage of the photovoltaic module 11.

[0086] The second voltage setting module 210 is used to control the rated voltage of the energy storage module 12 to be less than the rated DC output voltage of the bidirectional inverter module 13 if the output power of the photovoltaic module 11 is 0.

[0087] In one possible implementation, the control device may further include:

[0088] The curtailment module 211 is used to control the photovoltaic module 11 to continue in the curtailment mode if the photovoltaic module 11 is in curtailment mode and the voltage of the DC bus is not greater than a preset voltage.

[0089] Figure 6 This is a schematic diagram of the control terminal provided in an embodiment of the present invention. Figure 6 As shown, the control terminal 5 in this embodiment includes a processor 50 and a memory 51. The memory 51 stores a computer program 52, and the processor 50 calls and runs the computer program 52 stored in the memory 51 to execute the steps in the control method embodiments of the various integrated optical and energy storage systems described above, for example... Figure 3The steps S101 to S102 are shown. Alternatively, the processor 50 is used to call and run the computer program 52 stored in the memory 51 to implement the functions of each module / unit in the above-described device embodiments, for example... Figure 5 The functions of modules 21 and 22 shown.

[0090] For example, computer program 52 can be divided into one or more modules / units, one or more of which are stored in memory 51 and executed by processor 50 to complete the present invention. One or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 52 in control terminal 5. For example, computer program 52 can be divided into... Figure 5 Modules / units 21 to 22 are shown.

[0091] The control terminal 5 can be a desktop computer, laptop, handheld computer, or cloud server, etc. The control terminal 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will understand that... Figure 6 This is merely an example of control terminal 5 and does not constitute a limitation on control terminal 5. It may include more or fewer components than shown, or combine certain components, or different components. For example, the control terminal may also include input / output devices, network access devices, buses, etc.

[0092] The processor 50 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0093] The memory 51 can be an internal storage unit of the control terminal 5, such as a hard disk or RAM of the control terminal 5. The memory 51 can also be an external storage device of the control terminal 5, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the control terminal 5. Furthermore, the memory 51 can include both internal and external storage units of the control terminal 5. The memory 51 is used to store computer programs and other programs and data required by the control terminal. The memory 51 can also be used to temporarily store data that has been output or will be output.

[0094] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0095] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0096] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0097] In the embodiments provided by this invention, it should be understood that the disclosed device / control terminal and method can be implemented in other ways. For example, the device / control terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0098] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0099] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0100] If an integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0101] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method for an integrated photovoltaic and energy storage system, characterized in that, The integrated photovoltaic and energy storage system includes: a photovoltaic module; the photovoltaic module includes: a photovoltaic component and a first DC-DC converter; the photovoltaic component is connected to a DC bus through the first DC-DC converter; when the first DC-DC converter is not working, the first DC-DC converter includes a current path from the input end to the output end, such that the output voltage of the first DC-DC converter follows the output voltage of the photovoltaic component; when the grid does not want the photovoltaic module to be connected to the grid, it sends a curtailment command, and the photovoltaic module receives the curtailment command and enters a curtailment mode; The control method includes: Obtain the operating mode of the photovoltaic module and the voltage of the DC bus; If the photovoltaic module is in a curtailment mode and the voltage of the DC bus is greater than a preset voltage, then the output power of the photovoltaic module is controlled to be non-zero, so that the voltage of the DC bus is not greater than the preset voltage. Controlling the output power of the photovoltaic module to be non-zero, so that the voltage of the DC bus is not greater than the preset voltage, includes: The first rated output power of the photovoltaic module is determined based on the preset voltage, and the output power of the photovoltaic module is controlled to increase from 0 to the first rated output power, so that the voltage of the DC bus is not greater than the preset voltage; or, the output power of the photovoltaic module is gradually increased according to a preset step size until the voltage of the DC bus is not greater than the preset voltage.

2. The control method for the integrated photovoltaic and energy storage system according to claim 1, characterized in that, The step of determining the first rated output power of the photovoltaic module based on the preset voltage includes: Get the current environment parameters; Based on the preset voltage and current environmental parameters, the first rated output power of the photovoltaic module is determined.

3. The control method for the integrated photovoltaic and energy storage system according to claim 2, characterized in that, After controlling the photovoltaic module to output power according to the first rated output power, the method further includes: Real-time monitoring of changes in environmental parameters; If the change in the environmental parameters is greater than the preset change, then the second rated output power of the photovoltaic module is determined based on the environmental parameters at the current moment and the preset voltage. The photovoltaic module is controlled to output power according to the second rated output power.

4. The control method for the integrated photovoltaic and energy storage system according to claim 1, characterized in that, The integrated photovoltaic and energy storage system further includes: an energy storage module and a bidirectional inverter module; the energy storage module is connected to the DC bus; the input terminal of the bidirectional inverter module is connected to the DC bus, and the second terminal of the bidirectional inverter module is connected to the power grid and the load respectively; the control method further includes: Obtain the actual output power of the photovoltaic module, the power of the load, and the charging power of the energy storage module; The power of the load is added to the charging power of the energy storage module to obtain the power consumption, and the actual output power of the photovoltaic module is subtracted from the power consumption to obtain the inverter power. The bidirectional inverter module is controlled to supply power to the DC bus according to the inverter power.

5. The control method for the integrated photovoltaic and energy storage system according to claim 4, characterized in that, The control method further includes: If the output power of the photovoltaic module is not 0, then the rated voltage of the energy storage module is controlled to be less than the rated DC output voltage of the bidirectional inverter module, and the rated DC output voltage of the bidirectional inverter module is less than the rated output voltage of the photovoltaic module. If the output power of the photovoltaic module is 0, then the rated voltage of the energy storage module is controlled to be less than the rated DC output voltage of the bidirectional inverter module.

6. The control method for the integrated photovoltaic and energy storage system according to any one of claims 1 to 5, characterized in that, The control method further includes: If the photovoltaic module is in the curtailment mode and the voltage of the DC bus is not greater than the preset voltage, then the photovoltaic module is controlled to continue in the curtailment mode.

7. A control terminal, characterized in that, It includes a processor and a memory, the memory being used to store computer programs, and the processor being used to call and run the computer programs stored in the memory to perform the steps of the control method for the integrated photovoltaic and energy storage system as described in any one of claims 1 to 6.

8. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the control method for the integrated photovoltaic and energy storage system as described in any one of claims 1 to 6.

Images