Method for maximum power tracking, electronic device and computer readable storage medium

Abstract

The application provides a maximum power tracking method, an electronic device and a computer readable storage medium. The method comprises the following steps: obtaining a current maximum power point power and a current maximum power point voltage of a photovoltaic module; determining a voltage adjustment step according to a multi-peak tracking number, wherein the voltage adjustment step is positively correlated with the multi-peak tracking number; determining an input voltage given value according to the voltage adjustment step and the current maximum power point voltage; determining a local maximum power point power and a local maximum power point voltage of the photovoltaic module according to the input voltage given value and a preset maximum power tracking algorithm; when the current maximum power point power is less than the local maximum power point power, updating the current maximum power point power to the local maximum power point power, and updating the current maximum power point voltage to the local maximum power point voltage. The maximum power tracking method provided by the application can quickly determine a global maximum power point in the case that the photovoltaic module appears a multi-peak curve.

Description

Technical Field

[0001] This application relates to the field of clean energy technology, and in particular to a maximum power point tracking method, electronic device, and computer-readable storage medium. Background Technology

[0002] With the development of solar photovoltaic technology, photovoltaic systems are widely used in scenarios such as home energy storage. The power output of photovoltaic modules varies with factors such as sunlight conditions; therefore, by tracking the peak power of photovoltaic modules, their maximum power output can be achieved.

[0003] However, due to differences in the installation location of photovoltaic modules in each household, the sunshine conditions in the installation area, and factors such as shading, aging of photovoltaic modules, and unclean photovoltaic panels, the power-voltage curve of photovoltaic modules often has multiple peaks. As a result, the traditional maximum power point tracking method fails, causing a significant drop in photovoltaic output power, resulting in serious power loss, reduced power generation efficiency, increased power generation costs, and increased difficulty in fault detection. Summary of the Invention

[0004] In view of this, this application provides a maximum power point tracking method, an electronic device, and a computer-readable storage medium that can quickly determine the global maximum power point even when a photovoltaic module exhibits a multi-peak curve.

[0005] The first aspect of this application provides a maximum power point tracking (MPPT) method, comprising: obtaining the current maximum power point power and the current maximum power point voltage of a photovoltaic (PV) module; determining a voltage adjustment step size based on the number of multi-peak tracking attempts, wherein the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts; determining an input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage; determining the local maximum power point power and the local maximum power point voltage of the PV module based on the input voltage setpoint and a preset MPPT algorithm; and updating the current maximum power point power to the local maximum power point power and updating the current maximum power point voltage to the local maximum power point voltage when the current maximum power point power is less than the local maximum power point power.

[0006] In one embodiment, the method further includes: increasing the number of multi-peak tracking times by a preset value when the current maximum power point power is greater than or equal to the local maximum power point power; and updating the input voltage setpoint based on the current maximum power point voltage.

[0007] In one embodiment, determining the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage includes: after each voltage adjustment step size update, when the tracking direction is leftward, decreasing the current maximum power point voltage by the voltage adjustment step size to obtain the input voltage setpoint; when the tracking direction is rightward, increasing the current maximum power point voltage by the voltage adjustment step size to obtain the input voltage setpoint; wherein, the input voltage setpoint is adjusted at least twice for each update of the voltage adjustment step size, and the tracking direction is different during the two adjacent adjustments of the input voltage setpoint.

[0008] In one embodiment, determining the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage further includes: when the input voltage setpoint is greater than a first voltage threshold and less than a second voltage threshold, performing a step of determining the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the input voltage setpoint and a preset maximum power point tracking algorithm, wherein the second voltage threshold is greater than the first voltage threshold.

[0009] In one embodiment, determining the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage further includes: when the input voltage setpoint is less than or equal to a first voltage threshold, or when the input voltage setpoint is greater than or equal to a second voltage threshold, resetting the multi-peak tracking count to an initial value, and updating the input voltage setpoint based on the current maximum power point voltage.

[0010] In one embodiment, determining the voltage adjustment step size based on the number of multi-peak tracking attempts includes: obtaining a reference step size; determining a step size coefficient based on the number of multi-peak tracking attempts and a preset mapping relationship; wherein the preset mapping relationship records the correspondence between the step size coefficient and the number of multi-peak tracking attempts; the step size coefficient is positively correlated with the number of multi-peak tracking attempts; and determining the voltage adjustment step size based on the reference step size and the step size coefficient.

[0011] In one embodiment, determining the local maximum power point power and local maximum power point voltage of a photovoltaic module based on a given input voltage value and a preset maximum power point tracking algorithm includes: obtaining a perturbation step size; and determining the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the perturbation observation method, according to the perturbation step size and the given input voltage value.

[0012] In one embodiment, before determining the voltage adjustment step size based on the number of multi-peak tracking iterations, the method further includes: when the output power of the photovoltaic module is less than a preset power value and the current maximum power point power and the current maximum power point voltage remain unchanged for a first preset time, performing the step of determining the voltage adjustment step size based on the number of multi-peak tracking iterations.

[0013] A second aspect of this application provides an electronic device including a memory and a processor. The memory is used to store a computer program. The processor is used to execute the method described in any of the preceding claims when the computer program is invoked.

[0014] A third aspect of this application provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the steps of the maximum power tracking method as described in any of the preceding claims.

[0015] In the maximum power point tracking (MPPT) method provided in this application, the current maximum power point (MPPT) of the photovoltaic module is first obtained, i.e., the MPPT power and the MPPT voltage. Then, the voltage adjustment step size is determined based on the number of multi-peak tracking attempts. The input voltage setpoint is determined based on the voltage adjustment step size and the MPPT voltage. On this basis, the local maximum power point is determined based on the input voltage setpoint and the preset MPPT algorithm, i.e., the local maximum power point power and the corresponding local maximum power point voltage are obtained. If the local maximum power point power is greater than the maximum power point power, the current MPPT is updated based on the local maximum power point. Since the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts, different voltage adjustment step sizes can be configured based on the number of multi-peak tracking attempts. In this way, for photovoltaic modules with multi-peak PV curves, the tracking range of MPPT can be changed by adjusting the voltage adjustment step size. While taking into account the tracking efficiency, MPPT can be performed on as many peak-to-peak intervals of the multi-peak PV curve as possible to obtain different local maximum power points, and the true maximum power point is determined based on the tracking results. In summary, the maximum power point tracking method provided in this application can reduce the scanning time of photovoltaic modules when the photovoltaic module exhibits a multi-peak curve, determine the maximum output power of the photovoltaic module more quickly, and improve the power generation efficiency of the photovoltaic module. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation on the scope of protection of this application. In the various drawings, similar components are numbered similarly.

[0017] Figure 1 This is a schematic diagram of a single-peak PV curve of a photovoltaic module in one embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the multi-peak PV curve of a photovoltaic module in one embodiment of this application.

[0019] Figure 3 This is a schematic diagram illustrating the application environment of an MPPT circuit according to an embodiment of this application.

[0020] Figure 4 This is a schematic flowchart of a maximum power point tracking method provided in an embodiment of this application.

[0021] Figure 5 This is a flowchart illustrating the maximum power point tracking method provided in an embodiment of this application after step S404.

[0022] Figure 6 This is a flowchart illustrating a sub-step of step S403 in one embodiment of this application.

[0023] Figure 7 This is a flowchart illustrating a sub-step of step S402 in one embodiment of this application.

[0024] Figure 8 This is a flowchart illustrating a sub-step of step S404 in one embodiment of this application.

[0025] Figure 9 This is a schematic block diagram of an electronic device provided in an embodiment of this application.

[0026] Figure 10 This is a schematic block diagram of a control device provided in an embodiment of this application.

[0027] Figure 11 This is a schematic block diagram of a computer-readable storage medium provided in an embodiment of this application. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0029] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may also have an intervening component. The terms "top," "bottom," "upper," "lower," "left," "right," "front," "back," and similar expressions used in this article are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] Some embodiments will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0032] With the development of solar photovoltaic technology, photovoltaic systems are widely used in scenarios such as home energy storage. The power output of photovoltaic modules varies with factors such as sunlight conditions; therefore, by tracking the peak power of photovoltaic modules, their maximum power output can be achieved.

[0033] However, due to differences in the installation location of photovoltaic modules in each household, the sunshine conditions in the installation area, and factors such as shading, aging of photovoltaic modules, and unclean photovoltaic panels, the power-voltage curve of photovoltaic modules often has multiple peaks. As a result, the traditional maximum power point tracking method fails, causing a significant drop in photovoltaic output power, resulting in serious power loss, reduced power generation efficiency, increased power generation costs, and increased difficulty in fault detection.

[0034] For example, please see Figure 1 Under constant solar irradiance and operating temperature, the PV curve of a photovoltaic module exhibits a single peak. However, when sunlight is unstable or the photovoltaic module is partially shaded, please refer to [the relevant documentation / reference needed]. Figure 2 As a result, the PV curve of a photovoltaic module will exhibit a multi-peak phenomenon. This will cause the traditional maximum power point tracking algorithm to experience drastic fluctuations during the tracking of the maximum power point. It is also prone to stopping the tracking when it reaches a local optimum but fails to find the global optimum, thus getting stuck in a local optimum and failing to accurately determine the true maximum power point, resulting in low efficiency in determining the maximum power point.

[0035] Based on this, this application provides a maximum power point tracking method that can effectively determine the global maximum power point even when photovoltaic modules exhibit multi-peak curves.

[0036] Understandably, the maximum power point tracking method provided in this application can be applied to MPPT circuits or electronic devices equipped with MPPT circuits. For example, please refer to... Figure 3 , Figure 3 This is a block diagram of an MPPT circuit 10 that applies the maximum power point tracking method provided in this application in one embodiment.

[0037] like Figure 3As shown, the photovoltaic module 20 and the load 30 are connected via an MPPT circuit 10. The MPPT circuit 10 includes a DC / DC conversion unit 110, a processor 120, and a pulse width modulation (PWM) controller 130. The processor 120 continuously detects changes in the current or voltage of the photovoltaic module 20 and outputs a control signal to the PWM controller 130 based on these changes. The PWM controller 130 then adjusts the duty cycle of the PWM signal of the DC / DC conversion unit 110, thereby regulating the input voltage of the DC / DC conversion unit 110 (i.e., the output voltage of the photovoltaic module 20). Since the photovoltaic module 20 and the DC / DC conversion unit 110 can be considered linear circuits for a short period of time, as long as the equivalent resistance of the DC / DC conversion unit 110 is always equal to the internal resistance of the photovoltaic module 20 while adjusting the input voltage of the DC / DC conversion unit 110, the maximum output of the photovoltaic module 20 can be achieved, thus realizing the MPPT function of the photovoltaic module 20. The DC / DC conversion unit 110 may be composed of a BUCK circuit, a BOOST circuit, or a BUCK-BOOST circuit, and this application does not limit this.

[0038] The photovoltaic module 20 includes a plurality of photovoltaic panels. The photovoltaic panels convert light energy into electrical energy to output direct current (DC) to the MPPT circuit 10. Understandably, this application does not limit the connection method of the photovoltaic panels in the photovoltaic module 20. For example, in some embodiments, the photovoltaic panels in the photovoltaic module 20 can be connected in series, in parallel, or first in series and then in parallel. The load 30 can be various types of DC power loads. In some embodiments, an AC / DC conversion unit is also included, connected between the DC / DC conversion unit and the AC load, thereby converting the DC power output from the DC / DC conversion unit into AC power to supply AC power to the AC load.

[0039] In some embodiments, the PWM controller 130 may also be integrated within the processor 120.

[0040] Please see Figure 4 , Figure 4 This is a schematic flowchart illustrating a maximum power point tracking (MPPT) method according to an embodiment of this application. It is understood that this MPPT method can be executed by the processor 120 in the MPPT circuit 10. The MPPT method includes the following steps:

[0041] Step S401: Obtain the current maximum power point power and the current maximum power point voltage of the photovoltaic module.

[0042] The current maximum power point power refers to the PV power corresponding to the maximum power point determined by the MPPT circuit 10 from startup to the current time point. The current maximum power point voltage is the PV voltage corresponding to the maximum power point determined by the MPPT circuit 10 from startup to the current time point (i.e., the input voltage of the MPPT circuit 10).

[0043] Step S402: Determine the voltage adjustment step size based on the number of multi-peak tracking attempts, wherein the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts.

[0044] The multi-peak tracking number refers to the number of peak-to-peak maximum power tracking operations performed before the current maximum power point (MPPT) power is updated. Each peak-to-peak MPPT operation adjusts the voltage scan range for maximum power tracking. During each multi-peak tracking operation of the MPPT circuit 10, a local maximum power point within that voltage scan range can be obtained for different voltage scan ranges. Furthermore, when a local maximum power point is tracked, the PV power decreases when the MPPT circuit 10 is perturbed to the left or right.

[0045] The voltage adjustment step size is used to characterize the step size of the voltage change of the input voltage of the DC / DC conversion unit 110 relative to the current maximum power point voltage.

[0046] For example, similar Figure 2 In the multi-peak PV curve shown, within the voltage range from point X1 to peak point X2, when the MPPT circuit 10 reaches steady state according to the preset maximum power point tracking algorithm, peak point X2 is a local maximum power point; within the voltage range from peak point X2 to point X3, when the MPPT circuit 10 reaches steady state according to the preset maximum power point tracking algorithm, peak point X2 is a local maximum power point; within the voltage range between point X3 and peak point X4, when the MPPT circuit 10 reaches steady state according to the preset maximum power point tracking algorithm, peak point X4 is a local maximum power point. Maximum power point; within the voltage range between peak point X4 and point X5, when the MPPT circuit 10 reaches steady state according to the preset maximum power point tracking algorithm, peak point X4 is a local maximum power point; within the voltage range between point X5 and peak point X6, when the MPPT circuit 10 reaches steady state according to the preset maximum power point tracking algorithm, peak point X6 is a local maximum power point; within the voltage range between peak point X6 and point X7, when the MPPT circuit 10 reaches steady state according to the preset maximum power point tracking algorithm, peak point X6 is a local maximum power point. Clearly, when... Figure 2When performing maximum power point tracking (MPPT) on the multi-peak PV curve shown, the voltage range between points X1 and peak point X2 should jump to the voltage range between points X3 and X5 to potentially track the true maximum power point. However, in the actual operation of the photovoltaic module 20, the length of the voltage range between every two peaks of the multi-peak PV curve cannot be determined. Therefore, in step S402, the voltage adjustment step size is configured to be positively correlated with the number of multi-peak tracking attempts. This allows different voltage adjustment step sizes to be determined based on the number of multi-peak tracking attempts, thereby adjusting the input voltage of the DC / DC conversion unit 110 from the current maximum power point voltage to different peak-to-peak ranges of the multi-peak PV curve as much as possible. This increases the probability of tracking the true maximum power point and also reduces the number of MPPT attempts, improving MPPT efficiency.

[0047] Step S403: Determine the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage.

[0048] In some embodiments, when the MPPT circuit 10 is tracking to the left, the difference between the maximum power point voltage and the voltage adjustment step size can be used as the input voltage setpoint; when the MPPT circuit 10 is tracking to the right, the sum of the current maximum power point voltage and the voltage adjustment step size can be used as the input voltage setpoint. In other embodiments, after obtaining the input voltage reference value based on the voltage adjustment step size and the current maximum power point voltage, the input voltage setpoint can be obtained based on the input voltage reference value and a preset adjustment coefficient. This application does not limit the specific calculation method for determining the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage in step S403.

[0049] Step S404: Determine the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the input voltage setpoint and the preset maximum power point tracking algorithm.

[0050] This application does not limit the preset maximum power point tracking (MPPT) algorithm. For example, the preset MPPT algorithm can be an MPPT algorithm based on any of the following principles: perturbation and observation, incremental conductance, and current scanning.

[0051] In step S404, the processor 120 adjusts the input voltage of the DC / DC converter 110 according to the input voltage setpoint and the preset maximum power point tracking algorithm, and detects the input voltage and input current of the DC / DC converter 110 to calculate the input power of the DC / DC converter 110, thereby realizing maximum power point tracking of the photovoltaic module 20 until a local maximum power point is reached. The power corresponding to the local maximum power point is called the local maximum power point power, and the voltage corresponding to the local maximum power point is called the local maximum power point voltage.

[0052] Step S405: When the current maximum power point power is less than the local maximum power point power, update the current maximum power point power to the local maximum power point power, and update the current maximum power point voltage to the local maximum power point voltage.

[0053] By executing step S405, the power of each local maximum power point can be compared with the power of the current maximum power point to ensure that the final power of the current maximum power point is the maximum value among all the local maximum power points obtained so as to improve the accuracy of tracking the power of the maximum power point.

[0054] Understandably, the maximum power point tracking (MPPT) method provided in this application first obtains the current maximum power point (MPPT) of the photovoltaic module 20, i.e., the MPPT power and voltage. Then, it determines the voltage adjustment step size based on the number of multi-peak tracking attempts. Based on the voltage adjustment step size and the MPPT voltage, it determines the input voltage setpoint. On this basis, it determines the local maximum power point (MPPT) based on the input voltage setpoint and a preset MPPT algorithm, i.e., it obtains the local MPPT power and its corresponding local MPPT voltage. If the local MPPT power is greater than the current maximum power point power, it updates the local MPPT to the current maximum power point. Since the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts, different voltage adjustment step sizes can be configured based on the number of multi-peak tracking attempts. Thus, for photovoltaic modules with multi-peak PV curves, the MPPT tracking range can be changed by adjusting the voltage adjustment step size. While maintaining tracking efficiency, it performs MPPT on as many peak-to-peak intervals of the multi-peak PV curve as possible to obtain different local MPPTs, and determines the true maximum power point based on the tracking results. In summary, the maximum power point tracking method provided in this application can reduce the scanning time of the photovoltaic module 20 when the photovoltaic module 20 exhibits a multi-peak curve, determine the maximum output power of the photovoltaic module 20 more quickly, and improve the power generation efficiency of the photovoltaic module 20.

[0055] In some embodiments, after performing step S405, the maximum power tracking method further includes: resetting the number of multi-peak tracking attempts to an initial value.

[0056] In this way, during the cyclic execution of steps S401 to S405, the number of multi-peak tracking attempts is reset to the initial value after each update of the current maximum power point. This ensures that when multi-peak tracking is performed again, the voltage adjustment step size can be gradually increased based on the number of multi-peak tracking attempts to adjust the input voltage setpoint. This allows the MPPT circuit 10 to perform maximum power tracking in different peak-to-peak ranges of the multi-peak PV curve of the photovoltaic module 20, thus avoiding the occurrence of maximum power tracking getting trapped in local optima.

[0057] Please see Figure 5In some embodiments, the maximum power point tracking method further includes:

[0058] Step S501: When the current maximum power point power is greater than or equal to the local maximum power point power, increase the number of multi-peak tracking times by a preset value.

[0059] In some embodiments, the preset value can be a constant, such as 1.

[0060] Thus, by executing step S501, when no new maximum power point is tracked, the number of multi-peak tracking times is accumulated, which allows the MPPT circuit 10 to obtain different voltage adjustment step sizes when performing multi-peak tracking next time, thereby performing local maximum power tracking again based on different input voltage setpoints.

[0061] Step S502: Update the input voltage setpoint based on the current maximum power point voltage.

[0062] In some embodiments, step S502 may be to update the input voltage setpoint based on the current maximum power point voltage and a preset voltage, thereby continuing maximum power point tracking based on the updated input voltage setpoint. For example, when the MPPT circuit 10 is tracking to the left, the difference between the current maximum power point voltage and the preset voltage can be used as the input voltage setpoint; when the MPPT circuit 10 is tracking to the right, the sum of the current maximum power point voltage and the preset voltage can be used as the input voltage setpoint.

[0063] It is understandable that when the local maximum power point is less than the current maximum power point, it means that the current maximum power point is already the largest among all the local MPP points (Max Power Points) that have been tracked so far, which is also the global MPP point. At this time, it is only necessary to keep running at the current maximum power point.

[0064] In some embodiments, after performing step S502, the maximum power point tracking method further includes:

[0065] The photovoltaic module's current maximum power point power and current maximum power point voltage are updated based on the input voltage setpoint and the preset maximum power point tracking algorithm.

[0066] When photovoltaic modules are working stably, their PV curves usually change over time and with the environment. Therefore, after determining the actual global MPP point, when running stably at the global MPP point, the input voltage setpoint can be updated according to the current maximum power point voltage, and the preset maximum power point tracking algorithm can be continuously executed to track the latest global MPP point in real time.

[0067] In this way, by performing the above steps, the maximum power point tracking of the photovoltaic module 20 can be continuously maintained to update the maximum power point power and maximum power point voltage, in response to the changing actual working conditions of the photovoltaic module 20.

[0068] In some embodiments, step S403 includes:

[0069] After each voltage adjustment step size update, when the tracking direction is leftward, the input voltage setpoint is obtained by decreasing the current maximum power point voltage with the voltage adjustment step size; when the tracking direction is rightward, the input voltage setpoint is obtained by increasing the current maximum power point voltage with the voltage adjustment step size.

[0070] Each time the voltage adjustment step size is updated, the input voltage setpoint is adjusted at least twice, and the tracking direction is different when the input voltage setpoint is adjusted in two adjacent adjustments.

[0071] Understandably, since the illumination conditions of the photovoltaic module 20 are easily changed, such as by changes in illumination conditions caused by clouds or leaves, the local maximum power point of the photovoltaic module 20 may shift. Therefore, in this embodiment, by performing the above steps, the input voltage setpoint is updated based on different tracking directions each time the voltage adjustment step size is updated, thereby enabling maximum power tracking based on at least two input voltage setpoints. In this way, even if the local maximum power point shifts, the probability of tracking the local maximum power point is increased.

[0072] Specifically, in some embodiments, a tracking direction flag may be configured. When the tracking direction flag is set, it indicates that the tracking direction of the MPPT circuit 10 is a first direction; when the tracking direction flag is reset, it indicates that the tracking direction of the MPPT circuit 10 is a second direction. The first direction can be either leftward or rightward tracking, and the second direction can be either leftward or rightward tracking.

[0073] For example, the tracking direction flag can be a memory of the MPPT circuit 10 ( Figure 3 The data (not shown) is a bit containing at least one digit. When the corresponding binary number is "0", the tracking direction flag is set; when the corresponding binary number is "1", the tracking direction flag is reset. In other embodiments, the tracking direction flag may be reset when the corresponding binary number is "0" and set when the corresponding binary number is "1". This application does not limit this to any particular embodiment.

[0074] For example, please refer to Figure 6After the voltage adjustment step size is updated, step S403 may include the following sub-steps:

[0075] Step S601: Obtain the status of the tracking direction flag.

[0076] Specifically, each time the tracking direction reaches a local maximum power point to the left, the tracking direction flag switches from the set state to the reset state. Each time the tracking direction reaches a local maximum power point to the right, the tracking direction flag switches from the reset state to the set state.

[0077] Step S602: When the tracking direction flag is set, the current maximum power point voltage is reduced by a voltage adjustment step to obtain the input voltage setpoint.

[0078] Step S603: When the tracking direction flag is in the reset state, increase the current maximum power point voltage by voltage adjustment step size to obtain the input voltage setpoint.

[0079] In summary, by executing steps S601 to S603, it can be achieved that the input voltage setpoint is adjusted at least twice for each update of the voltage adjustment step size, and the tracking direction is different when adjusting the input voltage setpoint in two adjacent adjustments.

[0080] It is understandable that when MPPT tracking stops at a local MPP point (the current MPP point) due to multiple peaks in the PV curve, the actual global MPP point may be located to the right or left of that local MPP point. Furthermore, due to the volatility of the PV curve, for example, when occlusion changes, the global MPP point may move from the left to the right of the current MPP point. Therefore, when performing multi-peak tracking, the same voltage adjustment step size but different tracking directions can be used between adjacent tracking attempts to track the actual global MPP point as closely as possible.

[0081] In some embodiments, step S403 further includes:

[0082] When the input voltage setpoint is greater than the first voltage threshold and less than the second voltage threshold, the step of determining the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the input voltage setpoint and the preset maximum power point tracking algorithm is executed, wherein the second voltage threshold is greater than the first voltage threshold.

[0083] Furthermore, the first voltage threshold is greater than or equal to the lower limit of the voltage scan range of the MPPT circuit 10, and the second voltage threshold is less than or equal to the upper limit of the voltage scan range of the MPPT circuit 10. This ensures that the maximum power point tracking method provided in this application operates within the voltage scan range of the MPPT circuit 10, thus ensuring that the maximum power point tracking method provided in this application can function normally.

[0084] In some embodiments, step S403 further includes:

[0085] When the input voltage setpoint is less than or equal to the first voltage threshold, or greater than or equal to the second voltage threshold, the multi-peak tracking count is reset to the initial value, and the input voltage setpoint is updated according to the current maximum power point voltage.

[0086] It is understandable that if the input voltage setpoint, adjusted according to the voltage adjustment step size, exceeds the voltage scan range of the MPPT circuit 10, it indicates that the tracking boundary of the MPPT circuit 10 has been reached, and there is no need to track left or right further. Therefore, it returns to the current maximum power point. At this time, since the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts, resetting the number of multi-peak tracking attempts to its initial value ensures that the voltage adjustment step size determined by the number of multi-peak tracking attempts reset to the initial value is minimized. Thus, when entering multi-peak tracking again, multi-peak tracking can restart with the minimum voltage adjustment step size.

[0087] Please see Figure 7 In some embodiments, step S402 includes:

[0088] Step S701: Obtain the reference step size.

[0089] The reference step size is used as a reference value to characterize the voltage adjustment step size. Specifically, the reference step size can be a preset value.

[0090] Understandably, the reference step size can be larger than the adjustment step size during each tracking iteration in the preset maximum power point tracking algorithm. Taking the perturbation-observation method as an example of the preset maximum power point tracking algorithm, assuming the perturbation step size is 2V, the reference step size should be set to be larger than the perturbation step size, for example, 10V.

[0091] Step S702: Determine the step size coefficient based on the number of multi-peak tracking attempts and the preset mapping relationship; wherein, the preset mapping relationship records the correspondence between the step size coefficient and the number of multi-peak tracking attempts.

[0092] Among them, the step size coefficient is positively correlated with the number of multi-peak tracking attempts.

[0093] The step size factor is used to characterize the effect of the number of multi-peak tracking attempts on the voltage adjustment step size.

[0094] In some embodiments, assuming that the two multi-peak tracking operations are performed alternately, one to the left and one to the right, with the same voltage adjustment step size, the preset mapping relationship can be:

[0095]

[0096] in, Where k represents the number of multi-peak tracking attempts, This indicates rounding up. The initial value of k is 1. Since the same voltage adjustment step size is used in both reverse multi-peak tracking operations, the number of voltage adjustment step size adjustments is half the number of multi-peak tracking operations rounded up. f(n) represents the step size coefficient. The above function is actually a function expression of the Fibonacci sequence, and this preset mapping relationship also satisfies the requirement that the step size coefficient and the number of multi-peak tracking operations are positively correlated. Understandably, the initial value of the Fibonacci sequence is small, but as n increases, the rate of change of f(n) becomes faster and faster. Therefore, the values ​​in the Fibonacci sequence can be used as the step size coefficient, and the rate of change of the voltage adjustment step size can be controlled based on the step size coefficient.

[0097] This application does not limit the specific functional expression of the preset mapping relationship. In other embodiments, the specific functional expression of the preset mapping relationship can also be an exponential function, a logarithmic function, or a composite function, as long as the preset mapping relationship also satisfies the requirement that the step size coefficient is positively correlated with the number of multi-peak tracking.

[0098] Step S703: Determine the voltage adjustment step size based on the reference step size and step size coefficient.

[0099] Among them, the voltage adjustment step size is positively correlated with the step size coefficient. Furthermore, since the step size coefficient is positively correlated with the number of multi-peak tracking attempts, this ensures that the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts.

[0100] In some embodiments, the product of the reference step size and the step size coefficient can be used as the voltage adjustment step size.

[0101] Understandably, this application does not restrict the specific calculation method for determining the voltage adjustment step size in step S703, as long as the voltage adjustment step size and the step size coefficient are positively correlated.

[0102] In summary, by executing steps S701 to S703, the voltage adjustment step size can be determined based on the number of multi-peak tracking attempts.

[0103] Please see Figure 8 In some embodiments, step S404 includes:

[0104] Step S801: Obtain the perturbation step size.

[0105] The perturbation step size represents the adjustment step size of the input voltage setpoint when performing local maximum power tracking.

[0106] The perturbation step size can be a preset value. For example, the perturbation step size can be greater than or equal to 2V, and less than or equal to 8V. This application does not limit the specific value of the perturbation step size.

[0107] Step S802: Based on the perturbation observation method, determine the local maximum power point power and local maximum power point voltage of the photovoltaic module according to the perturbation step size and the input voltage setpoint.

[0108] For example, the target input voltage of the DC / DC converter unit 110 can be determined first based on the perturbation step size and the input voltage setpoint. For instance, the target input voltage can be the difference between the input voltage setpoint and the perturbation step size (i.e., perturbation to the left), or the target input voltage can be the sum of the input voltage setpoint and the perturbation step size (i.e., perturbation to the right). Then, the processor 120 drives the PWM controller 130 to control the switching logic and duty cycle of the DC / DC converter unit 110 with the target input voltage as the target, so that the input voltage of the DC / DC converter unit 110 is close to the target input voltage, thereby achieving left-tracking or right-tracking.

[0109] For example, the difference between the input voltage setpoint and the perturbation step size can be used as the target input voltage to perturb to the left. Specifically, within a second preset time period, the processor 120 samples multiple sets of current input voltages and multiple sets of current input currents of the DC / DC conversion unit 110, determines the average value of the current input voltage based on the multiple sets of current input voltages, and determines the average value of the current input current based on the multiple sets of current input currents, and then determines the current input power of the DC / DC conversion unit 110 based on the average value of the current input voltage and the average value of the current input current, which is the current output power of the photovoltaic module 20. The current input power is compared with the input power of the DC / DC conversion unit 110 at the previous sampling time. If the current input power is greater than the input power at the previous sampling time, and the previous perturbation direction was to the left, the current input voltage is perturbed to the left based on the perturbation step size. If the current input power is greater than the input power at the previous sampling time, and the previous perturbation direction was to the right, the current input voltage is perturbed to the right based on the perturbation step size. If the current input power is less than the input power at the previous sampling time, and the previous perturbation direction was to the left, the input voltage setpoint is perturbed to the right based on the perturbation step size. If the current input power is less than the input power at the previous sampling time, and the previous perturbation direction was to the right, the input voltage setpoint is perturbed to the left based on the perturbation step size. This perturbation process is repeated until the current input power obtained by perturbing to the left or right is less than the input power at the previous sampling time. Then, the input power corresponding to the previous sampling time is taken as the local maximum power point power obtained by this left perturbation. Furthermore, when the current maximum power point power is less than the local maximum power point power, the current maximum power point power is updated to the local maximum power point power, and the current maximum power point voltage is updated to the local maximum power point voltage.

[0110] Next, the sum of the input voltage setpoint and the perturbation step size can be used as the target input voltage to perturb to the right. The process of perturbing to the right is roughly the same as the process described above, and will not be repeated here.

[0111] In some embodiments, prior to performing step S402, the maximum power point tracking method further includes:

[0112] When the output power of the photovoltaic module is less than the preset power value and the current maximum power point power and the current maximum power point voltage remain unchanged for a first preset time, the step of determining the voltage adjustment step size based on the number of multi-peak tracking times is executed.

[0113] The preset power value is less than the rated output power of the photovoltaic module 20. Therefore, if the output power of the photovoltaic module 20 is less than the preset power value and the maximum power point and voltage remain unchanged for a first preset time, it indicates that the maximum power point tracked at this time is likely not the true maximum power point of the photovoltaic module 20. If the output power of the photovoltaic module 20 is greater than the preset power value, it indicates that the current output power of the photovoltaic module 20 is within an acceptable range and can meet the power requirements of the load 30. If the current maximum power point power and voltage remain unchanged for less than the first preset time, it indicates that the MPPT circuit 10 has tracked a new current maximum power point power and voltage.

[0114] In this way, in this embodiment, when the output power of the photovoltaic module is less than the preset power value and the maximum power point and the maximum power point voltage remain unchanged for a first preset time, step S402 is executed to determine the voltage adjustment step size, which can reduce the number of multi-peak tracking times of the MPPT circuit 10.

[0115] Please refer to it again. Figure 2 The following content is based on Figure 2 Taking the multi-peak PV curve shown as an example, the specific process of the maximum power point tracking method provided in this application is explained.

[0116] For example, when peak point X4 is the current maximum power point, the input voltage setpoint can be obtained based on the updated voltage adjustment step size and the current maximum power point voltage (i.e., the voltage of peak point X4), i.e., according to steps S601 to S603. Assume multi-peak tracking first tracks to the left and then to the right. Specifically, when the input voltage setpoint is obtained as the voltage corresponding to point X41 according to steps S601 and S602, local maximum power tracking is performed based on the perturbation observation method, using the perturbation step size and the voltage corresponding to point X41 as the target input voltage, resulting in the local maximum power point being peak point X4. At this time, the current maximum power point power is equal to the local maximum power point power, and there is no need to update the current maximum power point power and voltage; that is, the current maximum power point remains peak point X4. Then, according to steps S601 and S603, when the input voltage setpoint is the voltage corresponding to point X42 (the voltage difference between points X41 and X4 is equal to the voltage difference between points X42 and X4, meaning that the same voltage adjustment step size is used in two adjacent tracking steps), based on the perturbation observation method, local maximum power tracking is performed according to the perturbation step size and using the voltage corresponding to point X41 as the target input voltage, and the local maximum power point is obtained as the peak point X4. At this time, the current maximum power point is still the peak point X4.

[0117] For example, when peak point X6 is the current maximum power point, the input voltage setpoint can be obtained based on the updated voltage adjustment step size and the current maximum power point voltage (i.e., the voltage of peak point X6), i.e., according to steps S601 to S603. Specifically, when the input voltage setpoint is first obtained as the voltage corresponding to point X61 according to steps S601 and S602, local maximum power tracking is performed based on the perturbation observation method, using the perturbation step size and the voltage corresponding to point X61 as the target input voltage, resulting in the local maximum power point being peak point X6. At this time, the current maximum power point power is equal to the local maximum power point power, and there is no need to update the current maximum power point power and the current maximum power point voltage; that is, the current maximum power point remains peak point X6. Then, according to steps S601 and S603, when the input voltage setpoint is the voltage corresponding to point X62 (the voltage difference between points X61 and X6 is equal to the voltage difference between points X62 and X6, meaning that the same voltage adjustment step size is used in two adjacent tracking steps), based on the perturbation observation method, local maximum power tracking is performed according to the perturbation step size and using the voltage corresponding to point X61 as the target input voltage, and the local maximum power point is obtained as the peak point X4. At this time, the power of the current maximum power point is less than the power of the local maximum power point, that is, the power corresponding to the peak point X6 is less than the power corresponding to the peak point X4. Thus, the power of the current maximum power point is updated to the power of the local maximum power point, and the voltage of the current maximum power point is updated to the voltage of the local maximum power point, which is to say, the current maximum power point is updated to the peak point X4.

[0118] Please see Figure 9 This application also provides an electronic device 100. The electronic device 100 includes a memory 140 and a processor 120. The memory 140 is used to store computer programs. The processor 120 is used to execute the methods described in any of the above embodiments when the computer program is invoked.

[0119] Understandably, electronic device 100 can be any electronic device equipped with MPPT circuit 10, such as mobile energy storage device, home energy storage device, portable air conditioner, portable refrigerator, inverter, etc. This application does not limit the specific functions of electronic device 100.

[0120] One embodiment of this application also provides a control device applied to an MPPT circuit 10 or an electronic device integrating an MPPT circuit 10. Figure 10 A schematic block diagram of the control device 200 provided in an embodiment of this application is shown. Figure 10 As shown, the control device 200 includes:

[0121] The acquisition module 210 is used to acquire the current maximum power point power and the current maximum power point voltage of the photovoltaic module.

[0122] The first determining module 220 is used to determine the voltage adjustment step size based on the number of multi-peak tracking attempts, wherein the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts.

[0123] The second determining module 230 is used to determine the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage.

[0124] The third determining module 240 is used to determine the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the input voltage setpoint and the preset maximum power point tracking algorithm.

[0125] The update module 250 is used to update the current maximum power point power to the local maximum power point power and update the current maximum power point voltage to the local maximum power point voltage when the current maximum power point power is less than the local maximum power point power.

[0126] The specific details of the control device 200 provided in this application embodiment to implement the maximum power point tracking method have been described in detail in the corresponding maximum power point tracking method embodiment, and will not be repeated here.

[0127] Please see Figure 11This application also provides a computer-readable medium 300 storing a computer program 310, which, when executed by a processor, implements the maximum power point tracking method as described above. The computer-readable medium may be a portable compact disc read-only memory (CD-ROM) and include program code, and can run on a terminal device, such as a personal computer. However, the program product of this invention is not limited thereto. In this document, the readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0128] The above-described program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0129] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0130] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0131] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0132] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0133] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A maximum power point tracking method, characterized in that, include: Obtain the current maximum power point power and current maximum power point voltage of the photovoltaic module; The voltage adjustment step size is determined based on the number of multi-peak tracking attempts, wherein the voltage adjustment step size is positively correlated with the number of multi-peak tracking attempts; the number of multi-peak tracking attempts refers to the number of times maximum power tracking is performed before the current maximum power point power is updated. The input voltage setpoint is determined based on the voltage adjustment step size and the current maximum power point voltage. Each time the voltage adjustment step size is updated, when the tracking direction is leftward, the current maximum power point voltage is decreased by the voltage adjustment step size to obtain the input voltage setpoint; when the tracking direction is rightward, the current maximum power point voltage is increased by the voltage adjustment step size to obtain the input voltage setpoint. Each time the voltage adjustment step size is updated, the input voltage setpoint is adjusted at least twice, with different tracking directions during adjacent adjustments. The local maximum power point power and local maximum power point voltage of the photovoltaic module are determined based on the input voltage setpoint and the preset maximum power point tracking algorithm. When the local maximum power point power is tracked, the power decreases when the disturbance is to the left or to the right. When the current maximum power point power is less than the local maximum power point power, update the current maximum power point power to the local maximum power point power, update the current maximum power point voltage to the local maximum power point voltage, and reset the number of multi-peak tracking attempts to the initial value. When the current maximum power point power is greater than or equal to the local maximum power point power, the number of multi-peak tracking times is increased by a preset value.

2. The method according to claim 1, characterized in that, When the current maximum power point power is greater than or equal to the local maximum power point power, the method further includes: The input voltage setpoint is updated based on the current maximum power point voltage.

3. The method according to claim 1, characterized in that, The step of determining the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage further includes: When the input voltage setpoint is greater than the first voltage threshold and less than the second voltage threshold, the step of determining the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the input voltage setpoint and the preset maximum power point tracking algorithm is executed, wherein the second voltage threshold is greater than the first voltage threshold.

4. The method according to claim 3, characterized in that, The step of determining the input voltage setpoint based on the voltage adjustment step size and the current maximum power point voltage further includes: When the input voltage setpoint is less than or equal to the first voltage threshold, or when the input voltage setpoint is greater than or equal to the second voltage threshold, the number of multi-peak tracking attempts is reset to the initial value, and the input voltage setpoint is updated according to the current maximum power point voltage.

5. The method according to claim 1, characterized in that, The step size for determining the voltage adjustment based on the number of multi-peak tracking iterations includes: Obtain the reference step size; The step size coefficient is determined based on the number of multi-peak tracking attempts and a preset mapping relationship; wherein the preset mapping relationship records the correspondence between the step size coefficient and the number of multi-peak tracking attempts; the step size coefficient and the number of multi-peak tracking attempts are positively correlated. The voltage adjustment step size is determined based on the reference step size and the step size coefficient.

6. The method according to claim 1, characterized in that, The step of determining the local maximum power point power and local maximum power point voltage of the photovoltaic module based on the input voltage setpoint and a preset maximum power point tracking algorithm includes: Obtain the perturbation step size; Based on the perturbation observation method, the local maximum power point power and local maximum power point voltage of the photovoltaic module are determined according to the perturbation step size and the input voltage setpoint.

7. The method according to any one of claims 1-6, characterized in that, Before performing the step size determination based on the number of multi-peak tracking iterations, the method further includes: When the output power of the photovoltaic module is less than the preset power value and the current maximum power point power and the current maximum power point voltage remain unchanged for a first preset time, the step of determining the voltage adjustment step size based on the number of multi-peak tracking is executed.

8. An electronic device, characterized in that, It includes a memory and a processor, the memory being used to store a computer program; the processor being used to execute the maximum power tracking method as described in any one of claims 1-7 when the computer program is invoked.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the maximum power tracking method as described in any one of claims 1-7.

Images