Maximum power tracking method and device for photovoltaic modules

Abstract

The present application is applicable to the field of control technology, and provides a maximum power tracking method and device for a photovoltaic component. The method includes: obtaining a first output power value of the photovoltaic component at the current sampling moment, and a sampled power value of the photovoltaic component at the previous sampling moment; calculating a first power fluctuation coefficient of the photovoltaic component based on the first output power value and the sampled power value; obtaining a maximum reference voltage value corresponding to the global maximum power value of the photovoltaic component in the current environment when the first power fluctuation coefficient is greater than or equal to the first rated fluctuation coefficient; sending the maximum reference voltage value to the photovoltaic component as the operating reference voltage value, and the photovoltaic component is used to perform maximum power tracking according to the operating reference voltage value. The embodiment of the present application can enable the photovoltaic component to quickly track the maximum power value when the environment in which the photovoltaic component is located changes, thereby improving the speed at which the photovoltaic component tracks the maximum power value, thereby improving the working efficiency of the photovoltaic component.

Description

Technical Field

[0001] The present application belongs to the field of control technology, and in particular, relates to a maximum power tracking method and device for a photovoltaic module. Background Art

[0002] Currently, during the operation of a photovoltaic module, in order to ensure the working efficiency of the photovoltaic module, the photovoltaic module needs to track the maximum power value during operation so that the output power value of the photovoltaic module approaches the maximum value.

[0003] In the related art, when the external environment of the photovoltaic module changes, such as temperature change or light intensity change, the photovoltaic characteristic curve corresponding to the photovoltaic module will change accordingly, which will cause the photovoltaic module to be unable to quickly track the maximum power and affect the working efficiency of the photovoltaic module. Summary of the invention

[0004] The embodiments of the present application provide a maximum power tracking method and device for a photovoltaic module, which can increase the speed at which the photovoltaic module tracks the maximum power value when the environment in which the photovoltaic module is located changes.

[0005] In a first aspect, the present embodiment provides a maximum power tracking method for a photovoltaic component, including: obtaining a first output power value of the photovoltaic component at a current sampling moment, and a sampled power value of the photovoltaic component at a previous sampling moment; calculating a first power fluctuation coefficient of the photovoltaic component based on the first output power value and the sampled power value; when the first power fluctuation coefficient is greater than or equal to a first rated fluctuation coefficient, obtaining a maximum reference voltage value corresponding to a global maximum power value of the photovoltaic component under the current environment, and sending the maximum reference voltage value to the photovoltaic component as an operating reference voltage value, and the photovoltaic component is used to perform maximum power tracking according to the operating reference voltage value.

[0006] In a second aspect, an embodiment of the present application provides a maximum power tracking device for a photovoltaic assembly, the device being used to execute the method in the first aspect or any possible implementation of the first aspect. Specifically, the device may include a module for executing the maximum power tracking method for a photovoltaic assembly in the first aspect or any possible implementation of the first aspect.

[0007] In a third aspect, an embodiment of the present application provides a device, the device comprising a memory and a processor. The memory is used to store instructions; the processor executes the instructions stored in the memory, so that the device executes the maximum power tracking method of the photovoltaic assembly in the first aspect or any possible implementation of the first aspect.

[0008] In a fourth aspect, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium. When the instructions are executed on a computer, the computer executes the maximum power tracking method for photovoltaic components in the first aspect or any possible implementation of the first aspect.

[0009] In a fifth aspect, a computer program product comprising instructions is provided, which, when executed on a device, enables the device to execute the maximum power tracking method for photovoltaic components in the first aspect or any possible implementation of the first aspect.

[0010] In a sixth aspect, an embodiment of the present application provides a chip, including a processor, which is coupled to a memory and is used to execute a computer program or instruction stored in the memory to implement the maximum power tracking method of a photovoltaic component in the first aspect or any possible implementation of the first aspect.

[0011] In the seventh aspect, an embodiment of the present application provides a photovoltaic power supply structure, which includes: a photovoltaic component and a maximum power tracking device for the photovoltaic component, and the maximum power tracking device for the photovoltaic component is used to execute the maximum power tracking method for the photovoltaic component in the first aspect or any possible implementation of the first aspect.

[0012] In an eighth aspect, an embodiment of the present application provides an energy storage device, comprising a processor coupled to a memory, and configured to execute a computer program or instruction stored in the memory to implement a maximum power tracking method for a photovoltaic module in the first aspect or any possible implementation of the first aspect.

[0013] The maximum power tracking method of the photovoltaic assembly provided in the embodiment of the present application, by obtaining the first output power value at the current sampling moment and the sampled power value at the previous sampling moment, the first power fluctuation coefficient obtained can indicate the degree of environmental change at the current moment, when the external environment changes, the output power value of the photovoltaic assembly will also change, so the first power fluctuation coefficient increases accordingly, when the first power fluctuation coefficient is greater than or equal to the first rated fluctuation coefficient, it indicates that the current environment has changed significantly. In this case, the maximum power value determined before the environmental change is likely to have failed, so by re-obtaining the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly in the current environment, the maximum reference voltage value after the environmental change can be quickly determined, the output power value corresponding to the maximum reference voltage value in the current environment is closer to the maximum power value of the photovoltaic assembly than the output power value corresponding to the reference voltage value before the environmental change in the current environment, then the maximum reference voltage value can be sent to the photovoltaic assembly as the operating reference voltage value, so that the photovoltaic assembly performs maximum power tracking according to the operating voltage value, and then quickly tracks the maximum power value, which improves the speed of the photovoltaic assembly tracking the maximum power value when the external environment changes, so that the working efficiency of the photovoltaic assembly can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 is a schematic diagram of an equivalent circuit of a photovoltaic module provided in an embodiment of the present application;

[0016] Figure 2 Figure (a) is a schematic diagram of a photovoltaic characteristic curve between an output voltage value and an output power value provided in an embodiment of the present application;

[0017] Figure 2 Figure (b) is a schematic diagram of a photovoltaic characteristic curve between an output voltage value and an output current value provided in an embodiment of the present application;

[0018] Figure 3 It is a schematic diagram of the flow of the maximum power tracking method of the photovoltaic assembly provided in the embodiment of the present application;

[0019] Figure 4 is a flow chart of a maximum power tracking method for a photovoltaic module provided in another embodiment of the present application;

[0020] Figure 5is a schematic diagram of a process for obtaining a first operating reference voltage value provided in an embodiment of the present application;

[0021] Figure 6 is a schematic diagram of calculating and predicting output power values ​​provided in an embodiment of the present application;

[0022] Figure 7 It is a schematic diagram of a process for obtaining a reference voltage value corresponding to a global maximum power value of a photovoltaic module under a current environment provided by an embodiment of the present application;

[0023] Figure 8 It is a schematic diagram of a process for obtaining a reference voltage value corresponding to a global maximum power value of a photovoltaic module under a current environment provided by an embodiment of the present application;

[0024] Fig. 9 is a schematic diagram of a process for obtaining a reference voltage value corresponding to a global maximum power value of a photovoltaic module under a current environment provided by another embodiment of the present application;

[0025] Fig.10 1 is a schematic structural diagram of a maximum power tracking device 1000 for a photovoltaic module provided in an embodiment of the present application;

[0026] Fig.11 It is a schematic diagram of the structure of the device 1100 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0028] Figure 1 The equivalent circuit diagram of the photovoltaic module during operation is shown in FIG. 1 . According to the equivalent circuit, the relationship between the output voltage and output current of the photovoltaic module during operation can be obtained as shown in formula (1):

[0029]

[0030] Among them, I ph is the photocurrent value of the photovoltaic module; I d is the junction current value of the diode; R p is the parallel resistance; R s is the series resistance, I is the output current value of the photovoltaic module during operation, and U is the output voltage value of the photovoltaic module during operation.

[0031] Since in actual applications, the open circuit voltage value, short circuit current value, peak current value, and peak voltage value are usually provided by the manufacturer, the output current value of the photovoltaic module under standard irradiance and standard temperature can be expressed by formula (2):

[0032]

[0033] Among them, I sc is the short-circuit current value of the photovoltaic module, U oc is the open circuit voltage value, C1 and C2 are the unknown coefficients of the photovoltaic module, and e is the exponential function with e as the base.

[0034] Specifically, C1 and C2 can be calculated according to formula (3) and formula (4):

[0035]

[0036] Among them, I m is the peak current value of the PV module.

[0037]

[0038] Among them, U m is the peak voltage value of the photovoltaic module, and ln() is the logarithmic function with e as the base.

[0039] However, in actual applications of photovoltaic modules, it is necessary to consider the difference between the temperature in the actual environment and the temperature in the standard environment, and the difference between the irradiance in the actual environment and the irradiance in the standard environment. Therefore, the short-circuit current value, open-circuit voltage value, peak current value, and peak voltage value of the photovoltaic module can be re-determined according to formulas (5) to (8):

[0040]

[0041] U′ oc =U oc (1-γΔT)ln(1+βΔS) Formula (6)

[0042]

[0043] U′ m =U m (1-γΔT)ln(1+βΔS) Formula (8)

[0044] Among them, I′ sc is the short-circuit current value of the photovoltaic module under actual conditions, I sc is the short-circuit current value of the photovoltaic module under standard environment, S is the irradiance under standard environment, S refis the irradiance in the actual environment, ΔT is the difference between the temperature in the standard environment and the temperature in the actual environment, U′ oc is the open circuit voltage value of the photovoltaic module under actual conditions, U oc is the open circuit voltage of the photovoltaic module under standard environment, ΔS is the difference between the irradiance under standard environment and the irradiance under actual environment, I′ m is the peak current value of the photovoltaic module under actual conditions, I m is the peak current value of the photovoltaic module under standard conditions, U′ m is the peak voltage value of the photovoltaic module under actual conditions, U m It is the peak voltage value of the photovoltaic module under standard environment. The typical values ​​of α, β and γ are 0.0025, 0.5 and 0.00288 respectively.

[0045] According to formula (2) to formula (8), the relationship between the output voltage and output power of the photovoltaic module under the current environment can be described, and the result is: Figure 2 The photovoltaic characteristic curve a between the output voltage value (U) and the output power value (P) shown in Figure (a) 21 ,as well as Figure 2 The photovoltaic characteristic curve b between the output voltage value (U) and the output current value (I) shown in Figure (b) 21 .Depend on Figure 2 As can be seen from Figure (a) in the figure, different output voltage values ​​correspond to different output power values. Figure 2 As can be seen from Figure (b) in the figure, the output current value is usually larger when the voltage value is lower.

[0046] Therefore, in order to improve the working efficiency of photovoltaic modules, it is usually necessary to adjust the operating reference voltage value of the photovoltaic modules during the operation of the photovoltaic modules, so as to adjust the output voltage value of the photovoltaic modules so that the output power value of the photovoltaic modules reaches the maximum power value in the photovoltaic characteristic curve.

[0047] However, in the actual working process of photovoltaic modules, the external environment of photovoltaic modules may change at any time. For example, temperature changes or light intensity changes. When the temperature or light intensity changes, the photovoltaic characteristic curve of the photovoltaic module will also change accordingly. Take the sudden increase of light intensity as an example. Figure 2 As shown in Figure (a), before the light intensity increases, the operating reference voltage value of the photovoltaic module corresponds to the output voltage value U 22 , the maximum output power value P 21 When the light intensity of the environment where the photovoltaic module is located suddenly increases, the photovoltaic characteristic curve a 21 Will become the photovoltaic characteristic curve a 22In this case, the operating reference voltage value of the PV module does not change, so the output voltage value is still U 22 , however, the corresponding output power value P 22 It is no longer the maximum output power value of the photovoltaic module. In this case, the change of the environment in which the photovoltaic module is located will make it impossible for the photovoltaic module to quickly track the maximum power value again, resulting in a decrease in the working efficiency of the photovoltaic module.

[0048] In view of this, the present application proposes a maximum power tracking method for photovoltaic modules, so that the photovoltaic modules can quickly track the maximum power value when the environment changes. When the external environment changes, the speed at which the photovoltaic modules track the maximum power value and the working efficiency of the photovoltaic modules are improved.

[0049] The method provided in the embodiment of the present application can be executed by a first device, or by a chip in the first device (for example, a maximum power tracking device of a photovoltaic module). The first device can be a non-photovoltaic module, such as a server, an electronic device (for example, a mobile phone), or a photovoltaic module. When the first device is a non-photovoltaic module, the first device can communicate with the photovoltaic module.

[0050] Combine the following Figure 3 The maximum power tracking method of a photovoltaic module provided in an embodiment of the present application is introduced in detail.

[0051] The maximum power tracking method of a photovoltaic assembly provided in an embodiment of the present application includes:

[0052] S301. A first device obtains a first output power value of a photovoltaic component at a current sampling moment and a sampled power value of the photovoltaic component at a previous sampling moment.

[0053] Exemplarily, the first device can obtain the output current value of the photovoltaic component at the current moment through the output current value sampling device and the output voltage value of the photovoltaic component through the output voltage value sampling device, and determine the first output power value of the photovoltaic component at the current moment according to the output voltage value and output current value of the photovoltaic component at the current moment. The first device can obtain the output current value of the photovoltaic component at the previous sampling moment through the output current value sampling device and the output voltage value of the photovoltaic component at the previous sampling moment through the output voltage value sampling device, and determine the sampled power value of the photovoltaic component at the previous moment. Among them, the structure of the output current value sampling device and the output voltage value sampling device can adopt the structure in the prior art, which will not be repeated here.

[0054] Exemplarily, the output power value of the photovoltaic component at each sampling moment and the sampled power value of the photovoltaic component at the previous sampling moment may also be acquired by other devices and then fed back to the first device, which is not limited in the embodiment of the present application.

[0055] Exemplarily, the first output power value of the photovoltaic component at the current sampling moment and the sampled power value of the photovoltaic component at the previous sampling moment may also be obtained by inputting into the first device by the user, which is not limited in the embodiment of the present application.

[0056] S302: The first device calculates a first power fluctuation coefficient of the photovoltaic component according to the first output power value and the sampled power value.

[0057] Exemplarily, the first device may calculate the first power fluctuation coefficient of the photovoltaic component according to formula (9).

[0058]

[0059] Wherein, a is the first power fluctuation coefficient, P(k) is the first output power value sampled at the current moment, and P(k-1) is the sampled power value sampled at the previous sampling moment.

[0060] It should be understood that when the environment in which the photovoltaic component is located changes, the output power value of the photovoltaic component will also change. Therefore, the first power fluctuation coefficient obtained by calculation can be used to describe the degree of change in the environment in which the photovoltaic component is located at the current moment compared to the environment in which the photovoltaic component was located at the previous sampling moment. In other words, the first power fluctuation coefficient is used to describe the degree of change in the environment in which the photovoltaic component is located at the current moment compared to the environment in which the photovoltaic component was located at the previous sampling moment.

[0061] Alternatively, the above steps 301 and 302 may also be replaced by the following method: the first device obtains a first power fluctuation coefficient that is used to reflect the degree of change of the environment in which the photovoltaic component is located at the current moment compared to the environment in which the photovoltaic component was located at the previous sampling moment. That is, in order to control the photovoltaic component to perform maximum power tracking, the first device may directly obtain the first power fluctuation coefficient from other devices. In other words, the first fluctuation coefficient may also be calculated by other devices and then fed back to the first device.

[0062] S303: When the first power fluctuation coefficient is greater than or equal to the first rated fluctuation coefficient, the first device obtains a maximum reference voltage value corresponding to a global maximum power value of the photovoltaic assembly under the current environment.

[0063] It should be understood that when the first power fluctuation coefficient is greater than or equal to the first rated fluctuation coefficient, it means that the environment in which the photovoltaic component is located at the current moment has changed significantly compared to the environment in which the photovoltaic component was located at the previous sampling moment. In this case, the output power value corresponding to the current operating reference voltage value of the photovoltaic component has also changed significantly. Therefore, the maximum reference voltage value determined by the first device for the photovoltaic component before the environmental change is likely to have failed, and the output power value of the photovoltaic component may be reduced due to the environmental change. In order to enable the photovoltaic component to quickly track the maximum power value of the photovoltaic component, the first device can re-acquire the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic component in the current environment (i.e., after the environmental change).

[0064] Optionally, the first rated fluctuation coefficient may be a preset fluctuation coefficient.

[0065] S304: The first device sends the maximum reference voltage value as the operating reference voltage value to the photovoltaic component, and the photovoltaic component is used to perform maximum power tracking according to the operating reference voltage value.

[0066] Exemplarily, if the first device is a photovoltaic component, S304 specifically includes: the photovoltaic component operates according to the operating reference voltage value.

[0067] The maximum power tracking method of the photovoltaic assembly provided in the embodiment of the present application, by obtaining the first output power value at the current sampling moment and the sampled power value at the previous sampling moment, the first power fluctuation coefficient obtained can represent the degree of environmental change at the current moment. When the external environment changes, the output power value of the photovoltaic assembly will also change, so the first power fluctuation coefficient will increase accordingly. When the first power fluctuation coefficient is greater than or equal to the first rated fluctuation coefficient, it means that the current environment has changed significantly. In this case, the maximum power value determined before the environmental change is likely to have failed, so the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly in the current environment can be quickly determined by re-obtaining the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly in the current environment. The output power value corresponding to the maximum reference voltage value in the current environment is closer to the maximum power value of the photovoltaic assembly than the output power value corresponding to the reference voltage value before the environmental change in the current environment. The maximum reference voltage value can be sent to the photovoltaic assembly as the operating reference voltage value, so that the photovoltaic assembly performs maximum power tracking according to the operating voltage value. Accordingly, the maximum power value can be quickly tracked, which improves the speed of tracking the maximum power value of the photovoltaic assembly in the case of changes in the external environment, and improves the working efficiency of the photovoltaic assembly.

[0068] In a possible implementation of the present application, Figure 4As shown, after S302, the maximum power tracking method of the photovoltaic assembly provided by the present application further includes:

[0069] S305: When the first power fluctuation coefficient is less than the first rated fluctuation coefficient, the first device obtains a stability coefficient of the photovoltaic module.

[0070] As an example, S305 may be implemented in the following manner:

[0071] Method 1 can be:

[0072] Exemplarily, when the first power fluctuation coefficient is less than the first rated fluctuation coefficient, it means that the environment in which the photovoltaic module is located at the current moment has not changed significantly compared with the environment in which the photovoltaic module was located at the previous sampling moment. Therefore, the stability coefficient of the photovoltaic module can be calculated based on the first output power value and the sampled power value, where the stability coefficient of the photovoltaic module represents the degree of change of the output power value of the photovoltaic module within a certain period of time, and is used to determine whether the photovoltaic module has tracked the maximum power value.

[0073] Exemplarily, the calculation of the stability coefficient of the photovoltaic module by the first device according to the first output power value and the sampled power value can be implemented in the following manner: the first device can calculate the stability coefficient of the photovoltaic module according to formula (10).

[0074] b=P(k)-P(k-1) Formula (10)

[0075] Wherein, b is the stability coefficient, P(k) is the first output power value sampled at the current moment, and P(k-1) is the sampled power value sampled at the previous sampling moment.

[0076] Optionally, the first device obtaining the stability coefficient of the photovoltaic component may be that the first device obtains the stability coefficient of the photovoltaic component from other devices, that is, the stability coefficient is calculated by other devices and then fed back to the first device.

[0077] Method 2 can be:

[0078] In order to control the photovoltaic component to perform maximum power tracking, the first device can directly obtain the stability coefficient from other devices. In other words, the stability coefficient can also be calculated by other devices and then fed back to the first device.

[0079] S306: When the stability coefficient is greater than or equal to the rated stability coefficient, the first device obtains a second output power value of the photovoltaic component at a preset time interval.

[0080] It should be understood that according to Figure 2 The photovoltaic characteristic curve a shown in Figure (a) 21It can be seen that when the photovoltaic module tracks the maximum power value, the output power value of the photovoltaic module tends to be stable, that is, the difference between the output powers of the two samples is small, and the stability coefficient of the photovoltaic module is usually small. Therefore, when the stability coefficient is greater than or equal to the rated stability coefficient, it means that the output power value corresponding to the operating reference voltage value has not tracked the maximum power value of the photovoltaic module, so the operating reference voltage value of the photovoltaic module needs to be updated so that the photovoltaic module can track the maximum power value with the updated operating reference voltage value.

[0081] Before updating the operating reference voltage value of the photovoltaic component, in order to prevent the photovoltaic component from being unable to correctly track the maximum power value due to environmental changes, the first device can collect the second output power value of the photovoltaic component at a preset time interval.

[0082] Specifically, within the preset time interval, the operating reference voltage value does not change, and the preset time interval is smaller than the sampling period, that is, the operating reference voltage value corresponding to the first output power value is the same as the operating reference voltage value corresponding to the second output power value.

[0083] In some embodiments, when the stability coefficient is less than the rated stability coefficient, it indicates that the photovoltaic module has tracked the maximum power value. In order to prevent the output power value of the photovoltaic module from oscillating near the maximum power value, the value of the operating reference voltage value is not changed.

[0084] In summary, the stability coefficient in the embodiment of the present application is used to reflect whether the photovoltaic component tracks the maximum power value.

[0085] S307: The first device updates the operating reference voltage value of the photovoltaic component according to the first output power value and the second output power value to obtain a first operating reference voltage value.

[0086] S308: The first device sends a first operating reference voltage value to the photovoltaic component.

[0087] If the first device is a photovoltaic module, then S308 specifically includes: the photovoltaic module operates according to the first operating reference voltage value. In this step, after the first device sends the first operating reference voltage value to the photovoltaic module, the process returns to step S301.

[0088] In some embodiments of the present application, Figure 5 As shown, the process of S307 is specifically as follows: S1-S3:

[0089] S1. The first device calculates an absolute value of a power change of a photovoltaic module according to a first output power value and a second output power value.

[0090] In a possible implementation of the present application, the above S1 can be implemented in the following manner:

[0091] First, the first device calculates a predicted output power value of the photovoltaic component at a next sampling moment according to the first output power value and the second output power value.

[0092] Secondly, the first device calculates the absolute value of the power change of the photovoltaic component according to the first output power value and the predicted output power value.

[0093] Exemplarily, when calculating the predicted output power value of the photovoltaic component at the next sampling moment, the first device may calculate the predicted output power value of the photovoltaic component at the next sampling moment according to formula (11).

[0094]

[0095] Among them, P′(K+T) is the predicted output power value at the next sampling moment, is the second output power value, P(k) is the first output power value, n is greater than 1, and It is the same as the operating reference voltage value corresponding to P(k).

[0096] For example, when n is 2, when the predicted output power value P′(k+T) of the photovoltaic component at the next sampling moment is calculated according to formula (12), the predicted output power value of the photovoltaic component at the next sampling moment can be calculated according to formula (12).

[0097]

[0098] It should be understood that when n is 2, the time interval between the current sampling moment and the previous sampling moment is a cycle, and the preset time interval is half a cycle. The difference between the first output power value of the photovoltaic component at the current sampling moment and the second output power value of the photovoltaic component collected at the preset time interval is the change in the output power value of the photovoltaic component within the preset time interval. Since the operating reference voltage value does not change within the preset time interval, it is assumed that the change in the environment in which the photovoltaic component is located within the preset time interval is uniform. The first device can predict the output power value of the photovoltaic component at the next sampling moment based on the second output power value and the first output power value when the operating reference voltage value does not change, that is, the predicted output power value at the next sampling moment.

[0099] For example, Figure 6 As shown, curve a 61is the photovoltaic characteristic curve of the photovoltaic module at the current sampling moment. Taking the preset time interval as half a sampling period as an example, within the preset time interval, the reference operating voltage value of the photovoltaic module remains unchanged, so the output voltage value of the photovoltaic module is always U6. At the current sampling moment, the first output power value 1 is 70 kilowatts. If the light intensity of the environment where the photovoltaic module is located gradually increases within the preset time interval, and the speed of light intensity increase is uniform, after the preset time interval, the photovoltaic characteristic curve changes from curve a to curve b. 61 Becomes curve a 62 , the second output power value 2 is collected to be 75 kW. The predicted output power value 3 calculated according to formula (12) is 80 kW, where curve a 63 It is the photovoltaic characteristic curve of the photovoltaic component at the next sampling moment predicted when the operating reference voltage value of the photovoltaic component does not change. Furthermore, the predicted output power value 3 can be regarded as the output power value of the photovoltaic component at the next sampling moment when the operating reference voltage value of the photovoltaic component does not change.

[0100] For example, after the predicted output power value is obtained, the absolute value of the power change of the photovoltaic module can be calculated according to formula (13).

[0101] ΔP abs =|P′(k+T)-P(k)| Formula (13)

[0102] Among them, ΔP abs It is the absolute value of the power change of the PV module.

[0103] It should be understood that if the environment in which the photovoltaic component is located does not change within the preset time interval, since the operating reference voltage value also does not change within the preset time interval, the difference between the first output power value of the photovoltaic component at the current sampling moment and the second output power value of the photovoltaic component collected at the preset time interval is small, so that the predicted output power value is very close to the first output power value, so that the absolute value of the power change of the photovoltaic component is small; conversely, if the environment in which the photovoltaic component is located changes within the preset time interval, the difference between the first output power value of the photovoltaic component at the current sampling moment and the second output power value of the photovoltaic component collected at the preset time interval is large, so that the difference between the predicted output power value and the first output power value is large, so that the absolute value of the power change of the photovoltaic component is large.

[0104] S2. The first device compares the absolute value of the power change with the absolute value of the rated power change, and determines the voltage change value according to the comparison result.

[0105] Exemplarily, when the absolute value of the power change is greater than or equal to the absolute value of the rated power change, it means that within the preset time interval, the photovoltaic module is affected by the changes in the environment in which the photovoltaic module is located during the process of tracking the maximum power value, making the working state of the photovoltaic module unstable; conversely, when the absolute value of the power change is less than the absolute value of the rated power change, it means that within the preset time interval, the photovoltaic module is not affected by the changes in the environment in which the photovoltaic module is located during the process of maximum power tracking, and the working state of the photovoltaic module is stable.

[0106] In summary, when the absolute value of the power change is greater than or equal to the absolute value of the rated power change, the change in the environment where the photovoltaic module is located causes the photovoltaic characteristic curve of the photovoltaic module to change accordingly. After the change in the environment where the photovoltaic module is located, if the maximum power tracking method before the change in the environment where the photovoltaic module is located is still used, the photovoltaic module will not be able to quickly track the maximum power value. Therefore, the absolute value of the power change can be compared with the absolute value of the rated power change, and the voltage change value can be determined based on the comparison result, so that the photovoltaic module can track the maximum power value more quickly.

[0107] S3. The first device updates the operating reference voltage value of the photovoltaic component according to the voltage change value to obtain a first operating reference voltage value.

[0108] Exemplarily, after the voltage change value is determined, when the operating reference voltage value of the photovoltaic component is updated according to the voltage change value, the first reference voltage value can be calculated according to formula (14).

[0109] Uref=U′ref+Ustep formula (14)

[0110] Among them, Uref is the first operating reference voltage value, U′ref is the operating reference voltage value before updating, and Ustep is the voltage change value.

[0111] For example, taking the voltage change value as 1 volt and the operating reference voltage value before updating as 50 volts, the first device calculates the updated first operating reference voltage value as 51 volts according to formula (14).

[0112] For another example, taking the voltage change value as -1 volt and the operating reference voltage value before the update as 50 volts, the first device calculates the updated first operating reference voltage value as 49 volts according to formula (14).

[0113] In a possible embodiment of the present application, the method provided in the embodiment of the present application further includes before step S3: the first device obtains the first output voltage value of the photovoltaic component at the current sampling moment, and the sampled voltage value of the photovoltaic component at the previous sampling moment.

[0114] Exemplarily, the first device obtains the first output voltage value of the photovoltaic component at the current sampling moment and the sampled voltage value of the photovoltaic component at the previous sampling moment through the output voltage value sampling device.

[0115] Accordingly, when the first device compares the absolute value of the power change with the absolute value of the rated power change and determines the voltage change value according to the comparison result, it can be implemented in mode 3 or mode 4:

[0116] Method 3 can be:

[0117] When the absolute value of the power change is greater than or equal to the rated power change value, the first device determines the voltage change value according to the sampled power value, the first output voltage value, the sampled voltage value, and the second output power value.

[0118] Exemplarily, when the absolute value of the power change is greater than or equal to the rated power change value, the first device can determine the voltage change value according to formula (12) and formula (15), or formula (12) and formula (16).

[0119]

[0120] Ustep=[P′(k+T)-P(k-1)]×[U(k)-U(k-1)] Formula (16)

[0121] Among them, Ustep is the voltage change value, P′(k+T) is the predicted output power value at the next sampling moment, P(k-1) is the sampled power value, U(k) is the first output voltage value, and U(k-1) is the sampled voltage value.

[0122] It should be understood that when the absolute value of the power change is greater than or equal to the rated power change value, it means that the change in the environment in which the photovoltaic module is located has a certain impact on the output power of the photovoltaic module. Since the first device takes the change in the environment into consideration when obtaining the predicted output power value, in order to prevent the error in the calculated voltage change value caused by the environmental change, the voltage change value can be determined based on the sampled power value, the first output voltage value, the sampled voltage value, and the second output power value, so that the determined voltage change value will not cause an error in the calculated voltage change value due to the change in the environment in which the photovoltaic module is located.

[0123] Method 4 can be:

[0124] When the absolute value of the power change is less than the rated power change value, the first device determines the voltage change value according to the first output power value, the first output voltage value, the sampled power value and the sampled voltage value.

[0125] Exemplarily, when the absolute value of the power change is less than the rated power change value, the first device can determine the voltage change value according to formula (17) or formula (18).

[0126]

[0127] Ustep=[P(k)-P(k-1)]×[U(k)-U(k-1)] Formula (18)

[0128] Wherein, P(k) is the first output power value, P(k-1) is the sampled power value, U(k) is the first output voltage value, and U(k-1) is the sampled voltage value.

[0129] It should be understood that when the absolute value of the power change is less than the rated power change value, it means that the environment in which the photovoltaic component is located has no impact on the output power value of the photovoltaic component. Therefore, the first device can determine the voltage change value based on the first output power value, the first output voltage value, the sampled power value and the sampled voltage value.

[0130] In a possible embodiment of the present application, Figure 4 As shown, before step S305, the embodiment of the present application further includes S309 to S310:

[0131] S309: When the first power fluctuation coefficient is less than the first rated fluctuation coefficient, the first device obtains the current sampling number of the photovoltaic component.

[0132] When the first power fluctuation coefficient is less than the first rated fluctuation coefficient, it indicates that the change in the current environment of the photovoltaic module is small, so there is no need to re-obtain the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic module in the current environment. In this case, the current sampling number of the photovoltaic module can be obtained.

[0133] The current sampling number is the sampling number of the output current value acquisition device and the output voltage value acquisition device during a period when the first power fluctuation coefficient of the photovoltaic component is less than the first rated fluctuation coefficient.

[0134] S310: When the current sampling number is greater than or equal to the rated sampling number and the first output power value is less than the minimum operating power value of the photovoltaic component, the first device obtains the open circuit voltage value of the photovoltaic component at the current moment.

[0135] For example, since the output power value of the photovoltaic module is low when the light intensity is low, it is easy to cause the first power fluctuation coefficient to be greater than the first rated power fluctuation coefficient when calculating the first fluctuation coefficient of the photovoltaic module, so that the first device frequently obtains the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic module in the current environment, resulting in poor operating stability of the photovoltaic module.

[0136] In some implementations, when the current sampling number of the photovoltaic component is greater than or equal to the rated sampling number, and the first output power value is less than the minimum operating power value of the photovoltaic component, it means that the current environment of the photovoltaic component in this time period may have a low light intensity, resulting in a low output power value of the photovoltaic component in this time period.

[0137] It should be understood that in this case, the photovoltaic module is likely to have a low output voltage value due to low light intensity, thereby affecting the normal operation of the photovoltaic module. Therefore, when the current sampling number is greater than or equal to the rated sampling number, and the first output power value is less than the minimum operating power value of the photovoltaic module, the first device can obtain the open circuit voltage value of the photovoltaic module at the current moment to determine whether the photovoltaic module can continue to work.

[0138] Exemplarily, the open circuit voltage value of the photovoltaic module is a voltage value directly obtained by the output voltage value acquisition device when the photovoltaic module is not connected to a load under sunlight.

[0139] Exemplarily, after the first device obtains the current open circuit voltage value of the photovoltaic component, the embodiment of the present application further includes S311, or S312 to S313:

[0140] S311. When the open-circuit voltage value of the photovoltaic component at the current moment is less than or equal to the rated working voltage value, the first device outputs a stop working signal to the photovoltaic component, where the stop working signal is used to instruct the photovoltaic component to stop working.

[0141] Illustratively, since when the open-circuit voltage value of the photovoltaic module is less than or equal to the rated operating voltage value, the operating efficiency of the photovoltaic module will be too low, therefore when the open-circuit voltage value of the photovoltaic module at the current moment is less than or equal to the rated operating voltage value, the first device outputs a stop working signal to the photovoltaic module, and the stop working signal is used to instruct the photovoltaic module to stop working.

[0142] For example, if the rated working voltage is 10 volts, when the open circuit voltage of the photovoltaic component at the current moment is less than or equal to 10 volts, the first device outputs a stop working signal to the photovoltaic component, and the stop working signal is used to instruct the photovoltaic component to stop working.

[0143] S312. When the open-circuit voltage value of the photovoltaic component at the current moment is greater than the rated voltage value, the first device controls the photovoltaic component to enter a low-light protection mode, performs sampling in the low-light protection mode, and updates the operating reference voltage value of the photovoltaic component according to the power difference and voltage difference of the two samples to obtain a second operating reference voltage value.

[0144] It should be understood that when the open-circuit voltage value of the photovoltaic component at the current moment is greater than the rated voltage value, it means that the light intensity of the environment in which the photovoltaic component is currently located is low, but the photovoltaic component can still work normally. Therefore, the first device can control the photovoltaic component to enter the low-light protection mode and perform sampling in the low-light protection mode.

[0145] It should be understood that in the weak light protection mode, the output power of the photovoltaic module is less than the minimum operating power value, and in the weak light protection mode, the maximum power tracking method of the photovoltaic module is changed.

[0146] S313: The first device sends a second operating reference voltage value to the photovoltaic component.

[0147] Exemplarily, after obtaining the second operating reference voltage value, the first device may send the second operating reference voltage value to the photovoltaic component, and the photovoltaic component is configured to operate according to the second operating reference voltage value.

[0148] If the first device is a photovoltaic module, S313 specifically includes: the photovoltaic module operates according to the second operating reference voltage value.

[0149] In some embodiments of the present application, the first device in S312 updates the operating reference voltage value of the photovoltaic component according to the power difference and voltage difference of two samples by one of the methods 5 to 7:

[0150] Method 5 can be:

[0151] When the ratio of the power difference value and the voltage difference value of two samples is greater than the preset difference value, the operating reference voltage value of the photovoltaic assembly is increased by the first preset voltage value.

[0152] Specifically, the preset difference value may be 0. When the preset difference value is 0, when the ratio of the power difference value to the voltage difference value of two samples is greater than the preset difference value, it means that between the two samples, the sampled power value increases as the voltage value increases, or, between the two samples, the sampled power value decreases as the voltage value decreases. Figure 2 It can be analyzed from the photovoltaic characteristic curve in Figure (a) that the photovoltaic module has not yet tracked the maximum power value, so it is necessary to increase the operating reference voltage value so that the output voltage value of the photovoltaic module increases accordingly.

[0153] It should be understood that, specifically, when increasing the operating reference voltage value of the photovoltaic module, the operating reference voltage value of the photovoltaic module can be increased according to formula (19).

[0154] Uref=U'ref+Ustep formula (19)

[0155] Wherein, Uref is the updated operating reference voltage value, U'ref is the updated operating reference voltage value, and Ustep is the first preset voltage value.

[0156] For example, in the low-light protection mode, in order to reduce the complexity of calculation, Ustep may be determined to be 0.1 volt.

[0157] Method 6 can be:

[0158] When the ratio of the power difference value and the voltage difference value of two samples is smaller than the preset difference value, the operating reference voltage value of the photovoltaic assembly is reduced by the first preset voltage value.

[0159] Specifically, the preset difference value may be 0. When the preset difference value is 0, when the ratio of the power difference value to the voltage difference value of two samples is less than the preset difference value, it means that between the two samples, the sampled power value decreases as the voltage value increases, or, between the two samples, the sampled power value increases as the voltage value decreases. Figure 2 It can be analyzed from the photovoltaic characteristic curve in Figure (a) that the photovoltaic module has not yet tracked the maximum power value, so it is necessary to reduce the operating reference voltage value so that the output voltage value of the photovoltaic module decreases accordingly.

[0160] Specifically, when reducing the operating reference voltage of the photovoltaic module, the operating reference voltage value of the photovoltaic module can be reduced according to formula (20).

[0161] Uref=U'ref-Ustep formula (20)

[0162] Wherein, Uref is the updated operating reference voltage value, U'ref is the updated operating reference voltage value, and Ustep is the first preset voltage value.

[0163] Method 7 can be:

[0164] When the ratio of the power difference value and the voltage difference value of two samples is equal to the preset difference value, the operating reference voltage value of the photovoltaic component is not updated.

[0165] Specifically, the preset difference value may be 0. When the preset difference value is 0, if the ratio of the power difference value to the voltage difference value of two samples is equal to the preset difference value, it means that between the two samples, the sampled power value does not change as the voltage value increases, or, between the two samples, the sampled power value does not change as the voltage value decreases. Therefore, the photovoltaic module has tracked the maximum power value, and there is no need to update the operating reference voltage value.

[0166] It is worth mentioning that the above description only takes the preset difference value of 0 as an example. In actual applications, the preset difference value may also be 0.1 or other preset values.

[0167] In some embodiments of the present application, after updating the operating reference voltage value of the photovoltaic assembly according to the voltage difference and power difference of the two samples, the present application further includes: Figure 4 S314 in:

[0168] S314: The first device obtains an output power value of the photovoltaic component in a weak light protection mode.

[0169] Exemplarily, when obtaining the output power value of the photovoltaic component in the weak light protection mode, the output power value of the photovoltaic component in the weak light protection mode can be directly obtained and sent to the first device, or multiple groups of output power values ​​of the photovoltaic component in the weak light protection mode can be obtained and their average value can be sent to the first device.

[0170] In some embodiments of the present application, Figure 4 After S314, the embodiment of the present application further includes S315:

[0171] S315: When the output power value of the photovoltaic component in the weak light protection mode is greater than or equal to the rated minimum power value, the first device controls the photovoltaic component to exit the weak light protection mode.

[0172] For example, when the output power value of the photovoltaic component in the weak light protection mode is greater than or equal to the rated minimum power value, it means that the light intensity of the environment in which the photovoltaic component is currently located has become stronger, so the photovoltaic component does not need to continue to work in the weak light protection mode.

[0173] It should be understood that in order to prevent the photovoltaic assembly from frequently entering the weak light protection mode, the rated minimum power value is greater than the minimum operating power value.

[0174] For example, the minimum power value is set to 5 kilowatts, and the rated minimum power value is 7 kilowatts. When the output power value of the photovoltaic component in the weak light protection mode is greater than or equal to 7 kilowatts, it means that the light intensity of the environment in which the photovoltaic component is located is significantly enhanced. In this case, the first device controls the photovoltaic component to exit the weak light protection mode, and the photovoltaic component will not enter the weak light protection mode again due to the fluctuation of the output power value. In this step, after the first device controls the photovoltaic component to exit the weak light protection mode, it returns to execute step S301.

[0175] Exemplarily, in this step, when the output power value of the photovoltaic component in the weak light protection mode is less than the rated minimum power value, the first device returns to execute S310.

[0176] For example, when the output power value of the photovoltaic component in the weak light protection mode is less than the rated minimum power value, it means that the light intensity of the environment in which the photovoltaic component is located is still weak. In this case, the first device can return to execute the step of obtaining the open circuit voltage value of the photovoltaic component at the current moment, so that the photovoltaic component continues to operate in the weak light protection mode.

[0177] In some embodiments of the present application, obtaining the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly under the current environment in S303 may include: Figure 7 S4 to S7 in:

[0178] S4. The first device uses the open-circuit voltage value of the photovoltaic module as the search voltage value under the current environment.

[0179] It should be understood that when the reference operating voltage value of the photovoltaic module is greater than the open-circuit voltage value, the input power value of the photovoltaic module is almost 0 kilowatts, and the search voltage value corresponding to the global maximum power value must be smaller than the open-circuit voltage value. Therefore, the first device can use the open-circuit voltage value of the photovoltaic module as the search voltage value in the current environment.

[0180] S5. The first device reduces the search voltage value in sequence according to the second preset voltage value, and obtains the output parameters of the photovoltaic component during the process of reducing the search voltage value in sequence, to obtain an output parameter set, wherein the output parameters include an output power value and an output current value.

[0181] Exemplarily, when obtaining the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic component in the current environment, the search voltage value can be reduced in sequence according to formula (21), the output parameters of the photovoltaic component in the process of sequentially reducing the search voltage value can be obtained, and an output parameter set can be obtained, where the output parameters include output power value and output current value.

[0182] Usearch=U'search-Ustep2 formula (21)

[0183] Among them, Usearch is the search voltage value obtained after the reduction, U'search is the search voltage value before the reduction, and Ustep2 is the second preset voltage value.

[0184] In one implementation, in order to avoid missing the search voltage value corresponding to the maximum power value during the process of reducing the search voltage value, the second preset voltage value may be determined as 0.1 volt.

[0185] Combine the following Figure 8 , taking the open circuit voltage value of the photovoltaic module as 90 volts and the second preset voltage value as 0.1 volt as an example, the process of obtaining the output parameter set is described.

[0186] like Figure 8 As shown, the photovoltaic characteristic curve is curve a 81 In the first search, the search voltage value is 90V, and the output voltage and output current values ​​of the photovoltaic module are as follows: Figure 4 As shown in point 801 in FIG. 1 , the corresponding output power value is 0 kilowatts and the output current value is 0A. During the second search, the search voltage value is 89.9 volts. The output voltage value and output current value of the photovoltaic module are as follows: Figure 8 As shown in point 802 in FIG. 1 , the corresponding output power value is 5 kilowatts and the output current value is 0.2 amperes. In the third search, the search voltage value is 89.8 volts. The output voltage value and output current value of the photovoltaic module are as follows: Figure 8 As shown in point 803 in , the corresponding output power value is 10 kilowatts and the output current value is 0.3 amperes. The subsequent search process is the same as above, and the output parameters obtained in the search process are determined as the output parameter set.

[0187] S6. When the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, the first device obtains the maximum output power value in the output parameter set.

[0188] It should be understood that since the output voltage value corresponding to the maximum output power value of most photovoltaic modules is 0.78 times the open circuit voltage value, in the process of successively decreasing the search voltage value, if the search voltage value is less than the rated search voltage value, it means that the maximum power value is likely to have been searched, and in order to reduce the amount of calculation, there is no need to continue the search.

[0189] Exemplarily, the rated search voltage value may be determined according to the open circuit voltage value of the photovoltaic module.

[0190] For example, the rated search voltage value may be 0.2 times the open circuit voltage value of the photovoltaic module.

[0191] It should be understood that during the search process, if the current value is too large, it may cause damage to the photovoltaic module. Therefore, in the process of searching for voltage values ​​that decrease successively, if the output current value is greater than the rated maximum current value, in order to protect the photovoltaic module, the search will not continue.

[0192] Optionally, when the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, the first device no longer searches, and obtains the maximum output power value in the output set based on the output parameter set obtained during the search process.

[0193] For example, when the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, the output power values ​​in the output parameter set obtained during the search process are 20 kW, 100 kW, 150 kW, 230 kW, 250 kW, 210 kW, 170 kW, 120 kW, 90 kW, and 10 kW, respectively, then the maximum output power value obtained in the output set is 250 kW.

[0194] S7. The first device obtains a search voltage value corresponding to the maximum output power value, and uses the search voltage value corresponding to the maximum output power value as a maximum reference voltage value of the photovoltaic component under the current environment.

[0195] For example, the maximum output power value acquired by the first device is 250 kilowatts, and the corresponding search voltage value when the output power value is 250 kilowatts is 60 volts, then 60 volts is used as the maximum reference voltage value of the photovoltaic component in the current environment.

[0196] In some embodiments of the present application, the method provided by the embodiment of the present application also includes Figure 7 S8 in:

[0197] S8. When the first device sequentially reduces the search voltage value according to the second preset voltage value and obtains the output parameters of the photovoltaic component during the process of sequentially reducing the search voltage value, calculate the second power fluctuation coefficient according to two consecutive output power values ​​of the photovoltaic component.

[0198] It should be understood that the environment in which the photovoltaic module is located may still change dramatically when the first device sequentially reduces the search voltage value and obtains the output parameters of the photovoltaic module during the process of sequentially reducing the search voltage value. Therefore, when the first device obtains the output parameters of the photovoltaic module, the second power fluctuation coefficient is calculated based on two consecutive output power values ​​of the photovoltaic module, so as to determine whether the environment in which the photovoltaic module is located changes dramatically during the process of obtaining the output parameters of the photovoltaic module.

[0199] Exemplarily, in this step, when the second power fluctuation coefficient is greater than the second rated power fluctuation coefficient, the first device returns to execute step S4.

[0200] Exemplarily, when the second fluctuation coefficient is greater than the second rated power fluctuation coefficient, it indicates that in the process of successively reducing the search voltage value and obtaining the output parameters of the photovoltaic component in the process of successively reducing the search voltage value, the environment in which the photovoltaic component is located has undergone a drastic change. Therefore, the first device needs to return to the step of using the open-circuit voltage value of the photovoltaic component as the search voltage value in the current environment, and re-search to obtain the maximum reference voltage value of the photovoltaic component after the environment changes.

[0201] In some other embodiments of the present application, obtaining the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly under the current environment in S303 may include: Fig. 9 S9 to S12:

[0202] S9. The first device uses the open-circuit voltage value of the photovoltaic module as the search voltage value under the current environment, and initializes the search power value.

[0203] It should be understood that when the reference operating voltage value of the photovoltaic module is greater than the open-circuit voltage value, the output power value of the photovoltaic module is almost 0 kilowatts, and the search voltage value corresponding to the global maximum power value must be smaller than the open-circuit voltage value. Therefore, the first device can use the open-circuit voltage value of the photovoltaic module as the search voltage value in the current environment.

[0204] Exemplarily, when initializing the search power value, the search power value may be determined as a preset power value.

[0205] It should be understood that the preset power value is usually small, for example, the search power value may be determined as 0 kilowatts.

[0206] S10. The first device reduces the search voltage value in sequence according to the second preset voltage value, and obtains the output power value and the output current value of the photovoltaic component during the process of reducing the search voltage value in sequence.

[0207] Exemplarily, when the first device reduces the search voltage value in sequence according to the second preset voltage value, and obtains the output power and output current of the photovoltaic component during the process of reducing the search voltage value in sequence, the method for obtaining the output parameters in S5 above can be referred to. For the sake of brevity, it will not be repeated here.

[0208] S11. In the process of sequentially decreasing the search voltage value, the first device updates the search power value according to the output power value of the photovoltaic component so that the search power value is maintained at a maximum value.

[0209] It should be understood that in the process of decreasing the search voltage value, the search voltage value is different and the output power value of the photovoltaic module is also different. Therefore, the first device can update the search power value according to the output power value of the photovoltaic module in the process of decreasing the search voltage value in sequence.

[0210] Specifically, when the first device updates the search power value according to the output power value of the photovoltaic component, if the output power value collected by the photovoltaic component during the process of reducing the search voltage value is greater than the search power value, the search power value is determined to be the output power value; conversely, if the output power value collected by the photovoltaic component during the process of reducing the search voltage value is less than or equal to the search power value, the search power value remains unchanged. Thus, the search power value can be updated according to the output power value of the photovoltaic component so that the search power value is maintained at the maximum value.

[0211] For example, after initializing the search power value, the search power value is 0 kilowatts. In the process of decreasing the search voltage value in sequence, if the search voltage value decreases by 3 volts each time, when the search voltage value is 70 volts, the output power value of the photovoltaic component is 20 kilowatts, and the search power value is updated to 20 kilowatts; continue to reduce the search voltage value to 67 volts, and the output power value of the photovoltaic component is 45 kilowatts, then the search power value is updated to 45 kilowatts; continue to reduce the search voltage value, and in the process of reducing, if the output power value of the photovoltaic component is greater than the search power value, the output power value is updated, otherwise, the output power value is not updated.

[0212] For example, when the search voltage value is reduced to 50 volts, the search power value is 200 kilowatts; continue to reduce the search voltage value, and when the search voltage value is reduced to 47 volts, the output power value of the photovoltaic module is 180 kilowatts. Since the output power value is less than the search power value, the search power value is not updated, so that the search power value remains at the maximum value; continue to reduce the search voltage value to determine whether the output power value of the photovoltaic module is greater than the search power value when the search voltage value is 44 volts, so as to determine whether the search power value needs to be updated.

[0213] Exemplarily, in this step, when the second power fluctuation coefficient is greater than the second rated power value coefficient, the first device returns to execute step S9.

[0214] When the second power fluctuation coefficient is greater than the second rated power value coefficient, it means that the environment in which the photovoltaic component is located has changed drastically and the global maximum power value of the photovoltaic component has changed. Therefore, the first device returns to execute the step of using the open-circuit voltage value of the photovoltaic component as the search voltage value in the current environment and initializing the search power value to re-obtain the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic component in the current environment.

[0215] S12. When the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, the first device obtains the search voltage value corresponding to the search power value, and uses the search voltage value corresponding to the search power value as the maximum reference voltage value of the photovoltaic component under the current environment.

[0216] Exemplarily, during the search process, the search voltage value is reduced in sequence until the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current, and the search voltage value is no longer reduced. At this time, the search power value is the maximum output power value of the photovoltaic module during the process of reducing the search voltage value. Then, the search voltage value corresponding to the search is obtained, and the search voltage value corresponding to the search power value is used as the maximum reference voltage value of the photovoltaic module in the current environment.

[0217] It should be understood that when the light intensity of the environment in which the photovoltaic module is located changes, for example, when part of the photovoltaic module is blocked from light, the part of the photovoltaic module that is blocked from light will become a load and generate heat, causing damage to the photovoltaic module. Therefore, in order to prevent the photovoltaic module from being damaged, a diode is usually connected in parallel to the output end of the photovoltaic module to protect the photovoltaic module. This method causes the photovoltaic characteristic curve of the photovoltaic module to have multiple peaks. Therefore, when obtaining the global maximum power value of the photovoltaic module in the current environment, it is easy to take any peak of the multiple peaks as the global maximum power value.

[0218] The method provided in the embodiment of the present application, by determining the open circuit voltage value as the search voltage value, reducing the search voltage value in sequence, obtaining the output parameter set obtained during the search process, and obtaining the maximum output power value in the output set based on the output parameter set, can effectively avoid using one of the multiple peak values ​​as the global maximum power value, so that the photovoltaic module can search for the correct global maximum power value.

[0219] During the operation of the photovoltaic module, when the environment in which the photovoltaic module is located changes, the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic module in the current environment is re-acquired, and the acquired maximum reference voltage value is sent to the photovoltaic module as the operating reference voltage value, so that the photovoltaic module can quickly track the maximum power value when the environment changes.

[0220] Fig.10 A schematic block diagram of a photovoltaic module maximum power tracking device 1000 provided in an embodiment of the present application includes an acquisition module 1001 and a calculation module 1002 .

[0221] The acquisition module 1001 is used to acquire the first output power value of the photovoltaic component at the current sampling moment and the sampled power value of the photovoltaic component at the previous sampling moment.

[0222] The calculation module 1002 is used to calculate a first power fluctuation coefficient of the photovoltaic component according to the first output power value and the sampled power value.

[0223] The acquisition module 1001 is further configured to acquire a maximum reference voltage value corresponding to a global maximum power value of the photovoltaic assembly under a current environment when the first power fluctuation coefficient is greater than or equal to a rated fluctuation coefficient;

[0224] The communication module 1003 is used to send the maximum reference voltage value as an operating reference voltage value to the photovoltaic component, and the photovoltaic component is used to perform maximum power tracking according to the operating reference voltage value.

[0225] Optionally, when the first power fluctuation coefficient is less than the first rated fluctuation coefficient, the calculation module 1002 is further configured to calculate a stability coefficient of the photovoltaic assembly according to the first output power value and the sampled power value.

[0226] Optionally, when the stability coefficient is greater than or equal to the rated stability coefficient, the acquisition module 1001 is further configured to acquire a second output power value of the photovoltaic component at a preset time interval.

[0227] Optionally, the calculation module 1002 is further configured to calculate an absolute value of a power change of the photovoltaic component according to the first output power value and the second output power value.

[0228] Optionally, the device further includes a processing module, configured to compare the absolute value of the power change with the rated power change value, and determine the voltage change value according to the comparison result.

[0229] Optionally, the processing module is further used to update the operating reference voltage value of the photovoltaic component according to the voltage change value to obtain a first operating reference voltage value.

[0230] Optionally, the communication module 1003 is further configured to send the first operating reference voltage value to the photovoltaic component.

[0231] Optionally, the acquisition module 1001 is further configured to acquire a first output voltage value of the photovoltaic component at a current sampling moment and a sampled voltage value of the photovoltaic component at a previous sampling moment.

[0232] Optionally, the processing module is also used to determine the voltage change value according to the sampled power value, the first output voltage value, the sampled voltage value and the second output power value when the absolute value of the power change is greater than or equal to the rated power change value.

[0233] Optionally, the processing module is further used to determine the voltage change value according to the first output power value, the first output voltage value, the sampled power value and the sampled voltage value when the absolute value of the power change is less than the rated power change value.

[0234] Optionally, the acquisition module 1001 is further used to acquire the current sampling number of the photovoltaic component when the power fluctuation coefficient is less than the rated fluctuation coefficient.

[0235] Optionally, the acquisition module 1001 is also used to obtain the open circuit voltage value of the photovoltaic component at the current moment when the current sampling number is greater than or equal to the rated sampling number and the first output power value is less than the minimum operating power value of the photovoltaic component.

[0236] Optionally, the processing module is further used to output a stop working signal to the photovoltaic component when the open circuit voltage value of the photovoltaic component at a current moment is less than or equal to the rated working voltage value, and the stop working signal is used to instruct the photovoltaic component to stop working.

[0237] Optionally, the processing module is also used to control the photovoltaic component to enter a low-light protection mode when the open-circuit voltage value of the photovoltaic component at a current moment is greater than the rated voltage value, perform sampling in the low-light protection mode, and update the operating reference voltage value of the photovoltaic component according to the power difference and voltage difference of two samples to obtain a second operating reference voltage value.

[0238] Optionally, the communication module 1003 is further configured to send the second operating reference voltage value to the photovoltaic component.

[0239] Optionally, the acquisition module 1001 is further used to obtain the output power value of the photovoltaic component in the weak light protection mode.

[0240] Optionally, the processing module is further used to control the photovoltaic component to exit the weak light protection mode when the output power value of the photovoltaic component in the weak light protection mode is greater than or equal to the rated minimum power value.

[0241] Optionally, the processing module is further used to return to the step of obtaining the open-circuit voltage value of the photovoltaic component at the current moment when the output power value of the photovoltaic component in the weak light protection mode is less than the rated minimum power value.

[0242] Optionally, the processing module is also used to increase the operating reference voltage value of the photovoltaic component by a first preset voltage value when the ratio of the power difference value and the voltage difference value of the two samples is greater than a preset difference value, or to reduce the operating reference voltage value of the photovoltaic component by a first preset voltage value when the ratio of the power difference value and the voltage difference value of the two samples is less than the preset difference value, or to not update the operating reference voltage value of the photovoltaic component when the ratio of the power difference value and the voltage difference value of the two samples is equal to the preset difference value.

[0243] Optionally, the processing module is further configured to use the open circuit voltage value of the photovoltaic component as the search voltage value under the current environment.

[0244] Optionally, the processing module is further used to reduce the search voltage value in sequence according to the second preset voltage value.

[0245] Optionally, the acquisition module 1001 is further used to acquire output parameters of the photovoltaic component during the process of sequentially decreasing the search voltage value, and obtain an output parameter set, wherein the output parameters include an output power value and an output current value.

[0246] Optionally, the acquisition module 1001 is further used to obtain the maximum output power value in the output parameter set when the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value.

[0247] Optionally, the acquisition module 1001 is further used to obtain a search voltage value corresponding to the maximum output power value.

[0248] Optionally, the processing module is further configured to use the search voltage value corresponding to the maximum output power value as the maximum reference voltage value of the photovoltaic component under the current environment.

[0249] Optionally, the calculation module 1002 is also used to calculate the second power fluctuation coefficient based on two consecutive output power values ​​of the photovoltaic component in the process of successively reducing the search voltage value according to the second preset voltage value and obtaining the output parameters of the photovoltaic component in the process of successively reducing the search voltage value.

[0250] Optionally, the processing module is further used to return to the step of using the open-circuit voltage value of the photovoltaic component as the search voltage value under the current environment when the second power fluctuation coefficient is greater than the second rated power value coefficient.

[0251] Optionally, the processing module is further configured to use the open circuit voltage value of the photovoltaic component as the search voltage value under the current environment and initialize the search power value.

[0252] Optionally, the acquisition module 1001 is further configured to sequentially reduce the search voltage value according to a second preset voltage value, and to acquire the output power value and the output current value of the photovoltaic component during the process of sequentially reducing the search voltage value.

[0253] Optionally, the processing module is further used to update the search power value according to the output power value of the photovoltaic component during the process of the search voltage value being reduced successively, so that the search power value is maintained at a maximum value.

[0254] Optionally, the acquisition module 1001 is also used to obtain the search voltage value corresponding to the search power value when the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, and use the search voltage value corresponding to the search power value as the maximum reference voltage value of the photovoltaic component under the current environment.

[0255] Optionally, the calculation module 1002 is also used to calculate the second power fluctuation coefficient based on two consecutive output power values ​​of the photovoltaic component in the process of successively reducing the search voltage value according to the second preset voltage value and obtaining the output power value and output current value of the photovoltaic component in the process of successively reducing the search voltage value.

[0256] Optionally, the processing module is further used to return to the step of using the open-circuit voltage value of the photovoltaic component as the search voltage value under the current environment and initializing the search power value when the second power fluctuation coefficient is greater than the second rated power value coefficient.

[0257] It should be understood that the device 1000 of the embodiment of the present application can be implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), and the PLD can be a complex programmable logical device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. It can also be implemented by software. Figure 3 or Figure 4 The maximum power point tracking method of the photovoltaic module shown in the figure is implemented by software. Figure 3 or Figure 4 In the case of the maximum power point tracking method of the photovoltaic assembly shown, the device 1000 and its various modules may also be software modules.

[0258] Fig.11 This is a schematic diagram of the structure of a device provided in an embodiment of the present application. Fig.11 As shown, the device 1100 includes a processor 1101, a memory 1102, a communication interface 1103 and a bus 1104. The processor 1101, the memory 1102 and the communication interface 1103 communicate via the bus 1104, or other means such as wireless transmission. The memory 1102 is used to store instructions, and the processor 1101 is used to execute the instructions stored in the memory 1102. The memory 1102 stores program code 11021, and the processor 1101 can call the program code 11021 stored in the memory 1102 to execute Figure 3 or Figure 4 The maximum power point tracking method for photovoltaic modules is shown.

[0259] It should be understood that in the embodiment of the present application, the processor 1101 may be a CPU, and the processor 1101 may also be 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. The general-purpose processor may be a microprocessor or any conventional processor, etc.

[0260] The memory 1102 may include a read-only memory and a random access memory, and provide instructions and data to the processor 1101. The memory 1102 may also include a non-volatile random access memory. The memory 1102 may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0261] In addition to the data bus, the bus 1104 may also include a power bus, a control bus, and a status signal bus. Fig.11 Various buses are labeled as bus 1104.

[0262] It should be understood that the device 1100 according to the embodiment of the present application may correspond to the apparatus 1000 in the embodiment of the present application, and may correspond to the embodiment of the present application. Figure 3 or Figure 4 In the first device of the method shown, when the device 1100 corresponds to Figure 3 or Figure 4 In the case of the first device in the method shown, the above and other operations and / or functions of each module in the device 1100 are respectively to implement Figure 3 or Figure 4 The operation steps of the method executed by the first device in the embodiment will not be repeated here for the sake of brevity.

[0263] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0264] An embodiment of the present application provides a computer program product. When the computer program product is run on a first device, the first device can implement the steps in the above-mentioned method embodiments when the computer program product is executed.

[0265] An embodiment of the present application provides a chip, including a processor, which is coupled to a memory and is used to execute a computer program or instruction stored in the memory to implement the steps in the above-mentioned various method embodiments.

[0266] An embodiment of the present application provides a photovoltaic power supply structure, which includes: a photovoltaic component and a maximum power tracking device for the photovoltaic component. The maximum power tracking device for the photovoltaic component can implement the steps in the above-mentioned various method embodiments.

[0267] An embodiment of the present application provides an energy storage device, including a processor, which is coupled to a memory and is used to execute a computer program or instruction stored in the memory to implement the steps in the above-mentioned various method embodiments.

[0268] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean 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 application.

Claims

1. A maximum power tracking method for a photovoltaic module, characterized in that: include: Acquire a first output power value of the photovoltaic component at a current sampling moment and a sampled power value of the photovoltaic component at a previous sampling moment; Calculating a first power fluctuation coefficient of the photovoltaic component according to the first output power value and the sampled power value; When the first power fluctuation coefficient is greater than or equal to the first rated fluctuation coefficient, obtaining a maximum reference voltage value corresponding to a global maximum power value of the photovoltaic assembly under the current environment; sending the maximum reference voltage value as an operating reference voltage value to the photovoltaic component, and the photovoltaic component is used to perform maximum power tracking according to the operating reference voltage value; The maximum power tracking method further includes: When the first power fluctuation coefficient is less than the first rated fluctuation coefficient, calculating the stability coefficient of the photovoltaic assembly according to the first output power value and the sampled power value; When the stability coefficient is greater than or equal to the rated stability coefficient, obtaining a second output power value of the photovoltaic component at a preset time interval; Calculating an absolute value of a power change of the photovoltaic module according to the first output power value and the second output power value; Comparing the power change absolute value with the rated power change value, and determining the voltage change value according to the comparison result; Updating an operating reference voltage value of the photovoltaic component according to the voltage change value to obtain a first operating reference voltage value; The first operating reference voltage value is sent to the photovoltaic component.

2. The maximum power tracking method according to claim 1, characterized in that: The maximum power tracking method further includes: Acquire a first output voltage value of the photovoltaic component at a current sampling moment and a sampled voltage value of the photovoltaic component at a previous sampling moment; Then the comparing the absolute value of the power change with the rated power change value and determining the voltage change value according to the comparison result includes: In a case where the absolute value of the power change is greater than or equal to the rated power change value, determining the voltage change value according to the sampled power value, the first output voltage value, the sampled voltage value and the second output power value; When the absolute value of the power change is smaller than the rated power change value, the voltage change value is determined according to the first output power value, the first output voltage value, the sampled power value, and the sampled voltage value.

3. The maximum power tracking method according to any one of claims 1 to 2, characterized in that: The maximum power tracking method further includes: When the power fluctuation coefficient is less than the rated fluctuation coefficient, obtaining a current sampling number of the photovoltaic component; When the current sampling number is greater than or equal to the rated sampling number and the first output power value is less than the minimum operating power value of the photovoltaic component, obtaining the open circuit voltage value of the photovoltaic component at the current moment; When the open-circuit voltage value of the photovoltaic module at the current moment is less than or equal to the rated working voltage value, outputting a stop-working signal to the photovoltaic module, wherein the stop-working signal is used to instruct the photovoltaic module to stop working; When the open-circuit voltage value of the photovoltaic component at the current moment is greater than the rated operating voltage value, the photovoltaic component is controlled to enter a weak light protection mode, sampling is performed when the photovoltaic component is in the weak light protection mode, and an operating reference voltage value of the photovoltaic component is updated according to a power difference and a voltage difference of two samples to obtain a second operating reference voltage value; The second operating reference voltage value is sent to the photovoltaic component.

4. The maximum power tracking method according to claim 3, characterized in that: After updating the operating reference voltage value of the photovoltaic assembly according to the voltage difference and power difference of two samples, the maximum power tracking method further includes: Obtaining the output power value of the photovoltaic module in a weak light protection mode; When the output power value of the photovoltaic component in the weak light protection mode is greater than or equal to the rated minimum power value, controlling the photovoltaic component to exit the weak light protection mode; When the output power value of the photovoltaic component in the weak light protection mode is less than the rated minimum power value, the step of obtaining the open-circuit voltage value of the photovoltaic component at the current moment is returned to be executed.

5. The maximum power tracking method according to claim 3, characterized in that: The updating of the operating reference voltage value of the photovoltaic assembly according to the power difference and voltage difference of two samples comprises: When the ratio of the power difference and the voltage difference of the two samples is greater than the preset difference, the operating reference voltage value of the photovoltaic module is increased by a first preset voltage value; or, When the ratio of the power difference value and the voltage difference value of the two samples is less than the preset difference value, the operating reference voltage value of the photovoltaic module is reduced by a first preset voltage value; or, When the ratio of the power difference value and the voltage difference value of the two samples is equal to the preset difference value, the operating reference voltage value of the photovoltaic component is not updated.

6. The maximum power tracking method according to any one of claims 1 to 2, characterized in that: The obtaining of the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly under the current environment includes: Using the open circuit voltage value of the photovoltaic module as the search voltage value under the current environment; According to the second preset voltage value, the search voltage value is sequentially reduced, and the output parameters of the photovoltaic component are obtained during the process of sequentially reducing the search voltage value to obtain an output parameter set, wherein the output parameters include an output power value and an output current value; When the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, obtaining a maximum output power value in the output parameter set; A search voltage value corresponding to the maximum output power value is acquired, and the search voltage value corresponding to the maximum output power value is used as a maximum reference voltage value of the photovoltaic component under the current environment.

7. The maximum power tracking method according to claim 6, characterized in that: The maximum power tracking method further includes: In the process of sequentially reducing the search voltage value according to the second preset voltage value and acquiring the output parameter of the photovoltaic component in the process of sequentially reducing the search voltage value, calculating the second power fluctuation coefficient according to two consecutive output power values ​​of the photovoltaic component; When the second power fluctuation coefficient is greater than the second rated power coefficient, the step of returning to the step of using the open-circuit voltage value of the photovoltaic component as the search voltage value under the current environment is executed.

8. The maximum power tracking method according to any one of claims 1 to 2, characterized in that: The obtaining of the maximum reference voltage value corresponding to the global maximum power value of the photovoltaic assembly under the current environment includes: Using the open circuit voltage value of the photovoltaic module as the search voltage value under the current environment, and initializing the search power value; According to the second preset voltage value, the search voltage value is reduced in sequence, and the output power value and the output current value of the photovoltaic component are obtained during the process of the search voltage value being reduced in sequence; In the process of sequentially decreasing the search voltage value, updating the search power value according to the output power value of the photovoltaic module so that the search power value is maintained at a maximum value; When the search voltage value is less than the rated search voltage value or the output current value is greater than the rated maximum current value, obtaining a search voltage value corresponding to the search power value, and using the search voltage value corresponding to the search power value as the maximum reference voltage value of the photovoltaic module under the current environment; Wherein, in the process of sequentially reducing the search voltage value according to the second preset voltage value and obtaining the output power value and the output current value of the photovoltaic component in the process of sequentially reducing the search voltage value, the second power fluctuation coefficient is calculated according to two consecutive output power values ​​of the photovoltaic component; When the second power fluctuation coefficient is greater than the second rated power coefficient, the method returns to the step of using the open-circuit voltage value of the photovoltaic module as the search voltage value under the current environment and initializing the search power value.

9. A maximum power tracking device for a photovoltaic module, characterized in that: The method applied to any one of claims 1 to 8, comprising: An acquisition module, used to acquire a first output power value of the photovoltaic component at a current sampling moment and a sampled power value of the photovoltaic component at a previous sampling moment; A calculation module, configured to calculate a first power fluctuation coefficient of the photovoltaic assembly according to the first output power value and the sampled power value; The acquisition module is further configured to acquire a maximum reference voltage value corresponding to a global maximum power value of the photovoltaic assembly under a current environment when the first power fluctuation coefficient is greater than or equal to a rated fluctuation coefficient; The communication module is used to send the maximum reference voltage value as an operating reference voltage value to the photovoltaic component, and the photovoltaic component is used to perform maximum power tracking according to the operating reference voltage.

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