Photovoltaic maximum power tracking method and device based on incremental conductance method

Abstract

The invention relates to the technical field of photovoltaic cells, and discloses a photovoltaic maximum power tracking method and device based on an incremental conductance method.The method comprises the steps that a power voltage output characteristic curve of a target photovoltaic cell panel is obtained, random sampling is conducted on the power voltage output characteristic curve of the target photovoltaic cell panel, and the power voltage output characteristic curve of the target photovoltaic cell panel is obtained; obtaining a plurality of adjacent voltage sampling points; comparing the power values corresponding to the plurality of adjacent voltage sampling points, and if a comparison result of the power values corresponding to the plurality of adjacent voltage sampling points meets a power value discrimination condition, obtaining a straight slope between the plurality of adjacent voltage sampling points; and adjusting the switching period of the target photovoltaic inverter based on the straight slope between the plurality of adjacent voltage sampling points to obtain the photovoltaic maximum power point. The photovoltaic maximum power point can be quickly captured by the photovoltaic cell panel, the energy loss is avoided, and the energy utilization rate is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a photovoltaic maximum power point tracking method and device based on a conductance increment method. Background Art

[0002] The power output of solar photovoltaic panels is closely related to the intensity of sunlight radiation and the surrounding weather environment. In order to achieve higher power generation efficiency and make the panels output as much power as possible, it is necessary to ensure that the solar photovoltaic panels always operate at the maximum power point.

[0003] Related photovoltaic maximum power point tracking methods are difficult to quickly capture the maximum power point, resulting in energy loss and reducing the energy utilization rate of photovoltaic panels. Summary of the Invention

[0004] In view of this, the present invention provides a photovoltaic maximum power point tracking method and device based on the conductance increment method to solve the problem that photovoltaic panels are difficult to quickly capture the maximum power point, resulting in energy loss.

[0005] In a first aspect, the present invention provides a photovoltaic maximum power point tracking method based on a conductance increment method, the method comprising:

[0006] Obtaining a power-voltage output characteristic curve of a target photovoltaic panel, and randomly sampling the power-voltage output characteristic curve of the target photovoltaic panel to obtain a plurality of adjacent voltage sampling points;

[0007] Comparing the power values ​​corresponding to the plurality of adjacent voltage sampling points, and if the comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets the power value judgment condition, obtaining the slope of the straight line between the plurality of adjacent voltage sampling points;

[0008] The target switching period is adjusted based on the slope of the straight line between multiple adjacent voltage sampling points to obtain the photovoltaic maximum power point.

[0009] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment randomly samples the power-voltage output characteristic curve of the target photovoltaic panel to obtain multiple adjacent voltage sampling points. The power values ​​corresponding to the multiple adjacent voltage sampling points are compared to determine the operating status of the target photovoltaic panel. The photovoltaic panel is gradually operated at the maximum power point through different instructions, so that the target photovoltaic panel can quickly capture the photovoltaic maximum power point, avoid energy loss, and improve energy utilization.

[0010] In an optional embodiment, power values ​​corresponding to multiple adjacent voltage sampling points are compared. If the comparison result of the power values ​​corresponding to the multiple adjacent voltage sampling points meets the power value judgment condition, the slope of the straight line between the multiple adjacent voltage sampling points is obtained, including:

[0011] If a comparison result of power values ​​corresponding to multiple adjacent voltage sampling points meets a power value determination condition, then obtaining a slope of a straight line between the multiple adjacent voltage sampling points; wherein the power value determination condition is that the power value of the first voltage sampling point is less than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point; the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are adjacent voltage sampling points;

[0012] Alternatively, if the power values ​​corresponding to multiple adjacent voltage sampling points do not meet the power value judgment condition, the multiple adjacent voltage sampling points are adjusted multiple times in a cycle using a preset adjustment step until the power values ​​corresponding to the multiple adjacent voltage sampling points meet the power value judgment condition, and the slopes of the straight lines corresponding to the multiple adjacent voltage sampling points after adjustment are obtained.

[0013] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment determines whether the power value comparison results corresponding to multiple adjacent voltage sampling points meet the power value judgment conditions, and adjusts the multiple adjacent voltage sampling points based on the judgment results. This allows the multiple adjacent voltage sampling points to quickly approach the photovoltaic maximum power point, laying the foundation for rapid capture of the photovoltaic maximum power point.

[0014] In an optional embodiment, if the power values ​​corresponding to the plurality of adjacent voltage sampling points do not meet the power value determination condition, the plurality of adjacent voltage sampling points are adjusted cyclically multiple times using a preset adjustment step size until the power values ​​corresponding to the plurality of adjacent voltage sampling points meet the power value determination condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained, including:

[0015] If the power value of the first voltage sampling point is smaller than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is smaller than the power value of the third voltage sampling point, the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are shifted rightward along the horizontal axis using a preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet the power value judgment condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

[0016] In an optional embodiment, if the power values ​​corresponding to the plurality of adjacent voltage sampling points do not meet the power value determination condition, the plurality of adjacent voltage sampling points are adjusted cyclically multiple times using a preset adjustment step size until the power values ​​corresponding to the plurality of adjacent voltage sampling points meet the power value determination condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained, further comprising:

[0017] If the power value of the first voltage sampling point is greater than or equal to the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point, the plurality of adjacent voltage sampling points are shifted leftward along the horizontal axis using a preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet the power value judgment condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

[0018] In an optional embodiment, adjusting the target switching period based on the slope of a straight line between a plurality of adjacent voltage sampling points to obtain the photovoltaic maximum power point includes:

[0019] determining a total slope based on slopes of straight lines corresponding to a plurality of adjacent voltage sampling points;

[0020] If the total slope is zero, the current switching cycle of the target photovoltaic inverter is obtained, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the current switching cycle;

[0021] Alternatively, if the total slope is positive, the sum of the current switching cycle and the preset switching cycle is used as the next switching cycle, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle;

[0022] Alternatively, if the total slope is negative, the difference between the current switching cycle and the preset switching cycle is used as the next switching cycle, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle.

[0023] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment uses the slopes of the lines corresponding to multiple adjacent voltage sampling points to determine the total slope. The switching period of the target photovoltaic inverter is adjusted based on the total slope. The characteristic that the slopes of the lines corresponding to sampling points near the maximum power point are relatively small is utilized to achieve rapid capture of the photovoltaic maximum power point, thereby improving the accuracy of the photovoltaic maximum power point.

[0024] In an optional embodiment, the method further includes:

[0025] If the power value at the first voltage sampling point is greater than or equal to the power value at the second voltage sampling point, and the power value at the second voltage sampling point is less than or equal to the power value at the third voltage sampling point, the preset switching period is adjusted, and the current switching period is adjusted using the adjusted preset switching period to obtain the photovoltaic maximum power point.

[0026] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment uses the adjusted preset switching cycle to adjust the current switching cycle, thereby avoiding operational confusion of the target photovoltaic panel due to rapid changes in light intensity, improving the operational stability of the photovoltaic panel, and improving the accuracy of the photovoltaic maximum power point. It can not only ensure that the target photovoltaic panel operates at the maximum power point, but also enable the photovoltaic panel to operate again at the new maximum power point when the light intensity changes.

[0027] In a second aspect, the present invention provides a photovoltaic maximum power point tracking device based on a conductance increment method, the device comprising:

[0028] A sampling module is used to obtain the power-voltage output characteristic curve of the target photovoltaic panel, and randomly sample the power-voltage output characteristic curve of the target photovoltaic panel to obtain multiple adjacent voltage sampling points;

[0029] A comparison module is used to compare the power values ​​corresponding to multiple adjacent voltage sampling points, and if the comparison result of the power values ​​corresponding to the multiple adjacent voltage sampling points meets the power value judgment condition, obtain the slope of the straight line between the multiple adjacent voltage sampling points;

[0030] The adjustment module is used to adjust the switching period based on the slope of a straight line between multiple adjacent voltage sampling points to obtain the photovoltaic maximum power point.

[0031] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to thereby execute the photovoltaic maximum power tracking method based on the conductance increment method of the above-mentioned first aspect or any corresponding embodiment thereof.

[0032] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the photovoltaic maximum power point tracking method based on the conductance increment method of the above-mentioned first aspect or any corresponding embodiment thereof.

[0033] In a fifth aspect, the present invention provides a computer program product comprising computer instructions for causing a computer to execute the photovoltaic maximum power point tracking method based on the conductance increment method according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 1 is a flow chart of a photovoltaic maximum power point tracking method based on a conductance increment method according to an embodiment of the present invention;

[0036] Figure 2 is a flow chart of another photovoltaic maximum power point tracking method based on the conductance increment method according to an embodiment of the present invention;

[0037] Figure 3 is P according to an embodiment of the present invention A <P B And P B >P C Schematic diagram of power value comparison results;

[0038] Figure 4 is P according to an embodiment of the present invention A <P B And P B <P C Schematic diagram of power value comparison results;

[0039] Figure 5 is P according to an embodiment of the present invention A ≥P B And P B >P C Schematic diagram of power value comparison results;

[0040] Figure 6 1 is a flow chart of another photovoltaic maximum power point tracking method based on the conductance increment method according to an embodiment of the present invention;

[0041] Figure 7 is a flowchart of a photovoltaic maximum power point tracking method based on a conductance increment method according to an embodiment of the present invention;

[0042] Figure 8 is a graph showing power-voltage output characteristics of a photovoltaic panel under different light intensities according to an embodiment of the present invention;

[0043] Figure 9 1 is a structural block diagram of a photovoltaic maximum power point tracking device based on a conductance increment method according to an embodiment of the present invention;

[0044] Figure 10 Schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0046] Currently, photovoltaic MPPT (Maximum Power Point Tracking) algorithms can be divided into three categories. The first category is the MPPT algorithm, including the perturb and observe algorithm (P&O), the incremental conductance method (INC), and the constant voltage tracking (CVT). These algorithms are simple in structure and easy to implement, but when the solar cell temperature and solar irradiance change rapidly, the maximum power point convergence speed of these methods is too slow, and they may even cause the system to oscillate around the maximum power point, resulting in insufficient system stability.

[0047] Among them, the perturbation observation method will cause the operating point of the photovoltaic cell to oscillate near the maximum power point, resulting in a certain power loss and the setting of the tracking step size cannot take into account both tracking accuracy and response speed; the incremental conductance method must perform multiple differential operations, which requires the calculation controller to have a high operation speed.

[0048] The second category is a new MPPT algorithm based on the bionic metaheuristic algorithm. Although the bionic metaheuristic algorithm has significantly improved the tracking accuracy, it pays a lot of computational cost, resulting in a significant reduction in tracking speed.

[0049] The third category is the MPPT algorithm based on neural networks, which uses a simple feedforward neural network structure and can improve the tracking speed in the short term. However, when it comes to temperature and solar irradiance that change over time, there are problems with insufficient accuracy and large errors.

[0050] To solve the above technical problems, an embodiment of the present invention provides a photovoltaic maximum power point tracking method based on the conductance increment method, and a photovoltaic inverter maximum power point tracking optimization control method based on the conductance increment method. This method samples three different PU (Power-Voltage) values ​​of a photovoltaic panel and compares the power values ​​to determine the working state of the photovoltaic panel. Through different pre-set instructions, the photovoltaic panel is gradually operated at the maximum power point, quickly capturing the maximum power point while minimizing energy loss.

[0051] The embodiment of the present invention provides a photovoltaic maximum power point tracking method based on the conductance increment method. It should be noted that the method of photovoltaic maximum power point tracking based on the conductance increment method provided by the embodiment of the present invention can be executed by a device for photovoltaic maximum power point tracking based on the conductance increment method. The device for photovoltaic maximum power point tracking based on the conductance increment method can be implemented as part or all of an electronic device through software, hardware, or a combination of software and hardware. The electronic device can be a server or a terminal. The server in the embodiment of the present application can be a single server or a server cluster composed of multiple servers. The terminal in the embodiment of the present application can be a smart phone, a personal computer, a tablet computer, a wearable device, an intelligent robot, or other intelligent hardware devices. In the following method embodiments, the execution subject is an electronic device as an example for explanation.

[0052] According to an embodiment of the present invention, an embodiment of a photovoltaic maximum power point tracking method based on a conductance increment method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0053] In this embodiment, a photovoltaic maximum power point tracking method based on the conductance increment method is provided, which can be used for the above-mentioned electronic equipment. Figure 1 FIG. 1 is a flow chart of a photovoltaic maximum power point tracking method based on a conductance increment method according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0054] Step S101 : obtaining a power-voltage output characteristic curve of a target photovoltaic panel, and randomly sampling the power-voltage output characteristic curve of the target photovoltaic panel to obtain a plurality of adjacent voltage sampling points.

[0055] Specifically, the output voltage and current values ​​of the target photovoltaic panel are sampled, the power value corresponding to the voltage value is calculated based on the voltage and current values, and then a power-voltage output characteristic curve is constructed according to the output voltage and power values ​​of the target photovoltaic panel.

[0056] Step S102 : comparing power values ​​corresponding to a plurality of adjacent voltage sampling points. If the comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets a power value determination condition, obtaining a slope of a straight line between the plurality of adjacent voltage sampling points.

[0057] Step S103 : adjusting the switching period of the target photovoltaic inverter based on the slope of the straight line between the plurality of adjacent voltage sampling points to obtain the photovoltaic maximum power point.

[0058] Specifically, since the slope of the power-to-voltage curve is larger in areas farther away from the photovoltaic maximum power point, and smaller near the photovoltaic maximum power point, the slope of the straight line between multiple adjacent voltage sampling points is obtained, and the working direction of the system in the next switching cycle is determined through a preset program, thereby gradually making the target photovoltaic panel operate at the maximum power point.

[0059] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment randomly samples the power-voltage output characteristic curve of the target photovoltaic panel to obtain multiple adjacent voltage sampling points. The power values ​​corresponding to the multiple adjacent voltage sampling points are compared to determine the operating status of the target photovoltaic panel. The photovoltaic panel is gradually operated at the maximum power point through different instructions, so that the target photovoltaic panel can quickly capture the photovoltaic maximum power point, avoid energy loss, and improve energy utilization.

[0060] In this embodiment, a photovoltaic maximum power point tracking method based on the conductance increment method is provided, which can be used for the above-mentioned electronic equipment. Figure 2 FIG. 1 is a flow chart of a photovoltaic maximum power point tracking method based on a conductance increment method according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0061] Step S201: Obtain the power-voltage output characteristic curve of the target photovoltaic panel, and randomly sample the power-voltage output characteristic curve of the target photovoltaic panel to obtain multiple adjacent voltage sampling points. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0062] Step S202 : comparing power values ​​corresponding to a plurality of adjacent voltage sampling points. If the comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets a power value determination condition, obtaining a slope of a straight line between the plurality of adjacent voltage sampling points.

[0063] Specifically, the above step S202 includes:

[0064] Step S2021: If the power value comparison result corresponding to the plurality of adjacent voltage sampling points meets the power value determination condition, then the slope of the straight line between the plurality of adjacent voltage sampling points is obtained; wherein the power value determination condition is that the power value of the first voltage sampling point is less than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point; and the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are adjacent voltage sampling points.

[0065] Specifically, three adjacent voltage sampling points A, B and C are selected, and the voltage values ​​corresponding to the three adjacent voltage sampling points A, B and C are U A 、U B and U C , will U A 、U B and U C The corresponding power value P A 、P B and P C For comparison, such as Figure 3 As shown, if P A <P B And P B >P C , then the three adjacent voltage sampling points are all near the maximum power point, and then the slopes of straight lines BA and CB are calculated.

[0066] Or, if P A <P B And P B >P C , then get the switching period D n The operating point voltage U(k) and output power P(k) corresponding to the target photovoltaic panel are taken as point B(U(k), P(k)), and the switching period D is measured. n The target photovoltaic panel operating point voltage U(k-1) and output power P(k-1) obtained when the switching period is -△D are used as point A(U(k-1), P(k-1)). The target photovoltaic panel operating point voltage U(k+1) and output power P(k+1) obtained when the switching period is measured when the switching period is Dn+△D are used as point C(U(k+1), P(k+1)). The slopes of straight lines BA and CB are then calculated; where △D is the preset switching period.

[0067] Alternatively, in step S2022, if the power values ​​corresponding to the plurality of adjacent voltage sampling points do not meet the power value determination condition, the plurality of adjacent voltage sampling points are adjusted cyclically multiple times using a preset adjustment step size until the power values ​​corresponding to the plurality of adjacent voltage sampling points meet the power value determination condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

[0068] In some optional implementations, the above step S2022 includes:

[0069] In step a1, if the power value of the first voltage sampling point is smaller than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is smaller than the power value of the third voltage sampling point, the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are shifted rightward along the horizontal axis using a preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet the power value judgment condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

[0070] Specifically, if Figure 4 As shown, if P A <P B And P B <P C , then the three adjacent voltage sampling points are all on the left side of the maximum power point, and U B is the voltage value corresponding to the current photovoltaic maximum power point, select △U as the adjustment step, and then execute the command: U B =U C , U A =U B -△U,U C =U B +△U.

[0071] Furthermore, if P A <P B And P B <P C , it means that the voltage values ​​corresponding to the three adjacent voltage sampling points are all less than the optimal voltage value corresponding to the photovoltaic maximum power point, because U C >U B , so execute the programming statement U first B =U C , set the voltage value corresponding to the current photovoltaic maximum power point to U B , then execute the programming statement U A =U B -△U and U C =U B +△U, so that the target photovoltaic panel before the next sampling, the current photovoltaic maximum power point corresponding voltage value U B Move right and execute the above programming statements repeatedly until the power value comparison result is P A <P B And P B >P C .

[0072] In step a2, if the power value of the first voltage sampling point is greater than or equal to the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point, the plurality of adjacent voltage sampling points are shifted leftward along the horizontal axis using a preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet the power value judgment condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

[0073] Specifically, if Figure 5 As shown, if P A ≥P B And P B >P C , then the three adjacent voltage sampling points are all on the right side of the maximum power point, and U B is the voltage value corresponding to the current photovoltaic maximum power point, select △U as the adjustment step, and then execute the programming statement: U B =U A , U A =U B -△U,U C =U B +△U.

[0074] Furthermore, if P A ≥P B And P B >P C , indicating that the voltage values ​​corresponding to the three adjacent voltage sampling points are all greater than the voltage values ​​corresponding to the photovoltaic maximum power point, because U C <U B , so execute the programming statement U first B =U A , set the voltage value corresponding to the current photovoltaic maximum power point to U B , then execute the programming statement U A =U B -△U and U C =U B +△U, so that the target photovoltaic panel before the next sampling, the current photovoltaic maximum power point corresponding voltage value U B Move to the left and execute the above programming statements repeatedly until the power value comparison result is P A <P B And P B >P C .

[0075] Furthermore, the power value comparison result is P A <P B And P B <P C or P A ≥P B And P B>P C When , the adjacent voltage sampling points are far away from the photovoltaic maximum power point, so in order to ensure the tracking speed, the value of the adjustment step △U can be increased.

[0076] Step S203: Adjust the switching period of the target photovoltaic inverter based on the slope of the straight line between the multiple adjacent voltage sampling points to obtain the photovoltaic maximum power point. Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0077] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment determines whether the power value comparison results corresponding to multiple adjacent voltage sampling points meet the power value judgment conditions, and adjusts the multiple adjacent voltage sampling points based on the judgment results. This allows the multiple adjacent voltage sampling points to quickly approach the photovoltaic maximum power point, laying the foundation for rapid capture of the photovoltaic maximum power point.

[0078] In this embodiment, a photovoltaic maximum power point tracking method based on the conductance increment method is provided, which can be used for the above-mentioned electronic equipment. Figure 6 FIG. 1 is a flow chart of a photovoltaic maximum power point tracking method based on a conductance increment method according to an embodiment of the present invention. Figure 6 As shown, the process includes the following steps:

[0079] Step S601: Obtain the power-voltage output characteristic curve of the target photovoltaic panel, and randomly sample the power-voltage output characteristic curve of the target photovoltaic panel to obtain multiple adjacent voltage sampling points. Figure 2 Step S201 of the illustrated embodiment will not be described in detail here.

[0080] Step S602: compare the power values ​​corresponding to the multiple adjacent voltage sampling points. If the power value comparison results of the multiple adjacent voltage sampling points meet the power value judgment condition, obtain the slope of the straight line between the multiple adjacent voltage sampling points. Figure 2 Step S202 of the illustrated embodiment will not be described in detail here.

[0081] Step S603 : adjusting the switching period of the target photovoltaic inverter based on the slope of the straight line between the plurality of adjacent voltage sampling points to obtain the photovoltaic maximum power point.

[0082] Specifically, the above step S603 includes:

[0083] Step S6031 : determining a total slope based on the slopes of the straight lines corresponding to a plurality of adjacent voltage sampling points.

[0084] Specifically, to calculate the positive or negative sign of the slope of the straight line between multiple adjacent voltage sampling points, that is, to calculate the slope of straight line BA and straight line CB, an operation variable Tag is required for comparison sign. If the slope of the straight line is greater than 0, then Tag = 1; if the slope of the straight line is less than 0, then Tag = -1; if the slope of the straight line = 0, then Tag = 0.

[0085] Furthermore, the operational variable Tag corresponding to the slopes of the straight line BA and the straight line CB is added to obtain the total slope W. The values ​​of the total slope W include: -2, -1, 0, 1 and 2.

[0086] Step S6032: If the total slope is zero, the current switching cycle of the target photovoltaic inverter is obtained, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the current switching cycle.

[0087] Specifically, if Figure 7 As shown, when the total slope W=0, the output power of the target photovoltaic panel is the maximum power value, and the photovoltaic cell output power and operating voltage corresponding to the current switching cycle Dn are taken as the photovoltaic maximum power point.

[0088] Step S6033, or, if the total slope is positive, the sum of the current switching cycle and the preset switching cycle is used as the next switching cycle, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle.

[0089] Specifically, if Figure 7 As shown in the figure, when the total slope W takes a value of 1 or 2, the output power of the target photovoltaic panel shows an increasing trend. The next switching cycle is set to Dn+△D, so that the target photovoltaic panel can quickly operate at the photovoltaic maximum power point. That is, △D is added to the current switching cycle of points A, B and C, and point B after the increase of △D is used as the photovoltaic maximum power point.

[0090] Step S6034, or if the total slope is negative, the difference between the current switching cycle and the preset switching cycle is used as the next switching cycle, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle.

[0091] Specifically, if Figure 7 As shown in the figure, when the total slope W takes the value of -2 or -1, the output power of the target photovoltaic panel shows a decreasing trend; then the next switching cycle is set to Dn-△D, so that the target photovoltaic panel can quickly operate at the photovoltaic maximum power point, that is, △D is subtracted from the current switching cycles of points A, B and C, and point B after subtracting △D is used as the photovoltaic maximum power point.

[0092] Furthermore, if the power value at the first voltage sampling point is greater than or equal to the power value at the second voltage sampling point, and the power value at the second voltage sampling point is less than or equal to the power value at the third voltage sampling point, the preset switching period is adjusted, and the current switching period is adjusted using the adjusted preset switching period to obtain the photovoltaic maximum power point.

[0093] Among them, Figure 8 As shown in the figure, during the actual operation of the target photovoltaic panel, its output power is related to the environment. When the irradiation intensity changes throughout the day, the power-voltage output characteristic curve of the photovoltaic panel also changes continuously. That is, the power-voltage output characteristic curve is time-varying. However, in actual application, the photovoltaic maximum power point tracking method based on the conductance increment method must be able to ensure that the photovoltaic panel can quickly operate at the new maximum power point when the irradiation intensity changes.

[0094] Furthermore, photovoltaic panels have multiple characteristic curves under different irradiation intensities. The photovoltaic maximum power tracking method based on the conductance increment method continuously samples three different adjacent voltage sampling points; only when the power value comparison result meets P A <P B And P B <P C or P A ≥P B And P B >P C When the programming statement is executed, the power value comparison result is P A <P B And P B >P C Otherwise, it will resample and then search for the MPP (Maximum Power Point) according to the instructions set in this case. Therefore, the photovoltaic maximum power point will not be affected under different irradiation intensities and the irradiation intensity does not change suddenly.

[0095] Furthermore, when the power value comparison result is P A <P B And P B >P C In the case of sudden appearance of clouds outside, P A ≥P B And P B ≤P CThis situation represents the situation where the solar radiation intensity changes rapidly in a short time. In this case, the corresponding operation instructions are set to keep the current switching period Dn unchanged. Only the preset switching period △D needs to be slightly adjusted. The unchanged current switching period Dn ensures that when the radiation intensity changes rapidly in a short time, the target photovoltaic panel can maintain stable operation and will not cause confusion by blindly adjusting the switching period. After a period of time, when the solar radiation intensity returns to another stable state, the preset switching period △D is slightly adjusted, and finally the photovoltaic panel is allowed to work again at the new photovoltaic maximum power point.

[0096] The photovoltaic maximum power point tracking method based on the conductance increment method provided in this embodiment uses the slopes of the lines corresponding to multiple adjacent voltage sampling points to determine the total slope. The switching period of the target photovoltaic inverter is adjusted based on the total slope. The characteristic that the slopes of the lines corresponding to sampling points near the maximum power point are relatively small is utilized to achieve rapid capture of the photovoltaic maximum power point, thereby improving the accuracy of the photovoltaic maximum power point.

[0097] This embodiment also provides a photovoltaic maximum power point tracking device based on the conductance increment method. This device is used to implement the above-mentioned embodiments and preferred embodiments, and the details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0098] This embodiment provides a photovoltaic maximum power point tracking device based on the conductance increment method. Figure 9 Shown, including:

[0099] The sampling module 901 is used to obtain the power-voltage output characteristic curve of the target photovoltaic panel, and randomly sample the power-voltage output characteristic curve of the target photovoltaic panel to obtain a plurality of adjacent voltage sampling points.

[0100] The comparison module 902 is configured to compare power values ​​corresponding to a plurality of adjacent voltage sampling points, and obtain a slope of a straight line between the plurality of adjacent voltage sampling points if the power value comparison result corresponding to the plurality of adjacent voltage sampling points meets a power value determination condition.

[0101] The adjustment module 903 is configured to adjust the switching period of the target photovoltaic inverter based on the slope of the straight line between the plurality of adjacent voltage sampling points to obtain the photovoltaic maximum power point.

[0102] In some optional implementations, the comparison module 902 includes:

[0103] a first acquiring unit, configured to acquire a slope of a straight line between the plurality of adjacent voltage sampling points if a comparison result of power values ​​corresponding to the plurality of adjacent voltage sampling points satisfies a power value determination condition; wherein the power value determination condition is that the power value of the first voltage sampling point is less than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point; and the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are adjacent voltage sampling points.

[0104] The first adjustment unit is configured to, if the power values ​​corresponding to the plurality of adjacent voltage sampling points do not meet the power value determination condition, cyclically adjust the plurality of adjacent voltage sampling points using a preset adjustment step size for multiple times until the power values ​​corresponding to the plurality of adjacent voltage sampling points meet the power value determination condition, and obtain the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment.

[0105] In some optional implementations, the first adjustment unit includes:

[0106] The first translation subunit is configured to, if the power value of the first voltage sampling point is smaller than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is smaller than the power value of the third voltage sampling point, use a preset adjustment step size to translate the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point to the right along the horizontal axis until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet a power value judgment condition, and obtain adjusted straight line slopes corresponding to the plurality of adjacent voltage sampling points.

[0107] The second translation subunit is configured to, if the power value of the first voltage sampling point is greater than or equal to the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point, translate the plurality of adjacent voltage sampling points to the left along the horizontal axis using a preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet a power value judgment condition, and obtain slopes of straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment.

[0108] In some optional implementations, the adjustment module 903 includes:

[0109] The determining unit is configured to determine a total slope based on slopes of straight lines corresponding to a plurality of adjacent voltage sampling points.

[0110] The second acquisition unit is configured to acquire the current switching cycle of the target photovoltaic inverter if the total slope is zero, and determine the photovoltaic maximum power point based on the photovoltaic cell output power and operating voltage corresponding to the current switching cycle.

[0111] The first judgment unit is used to, if the total slope is positive, take the sum of the current switching cycle and the preset switching cycle as the next switching cycle, and determine the photovoltaic maximum power point based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle.

[0112] The second judgment unit is used to take the difference between the current switching cycle and the preset switching cycle as the next switching cycle if the total slope is a negative value, and determine the photovoltaic maximum power point based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle.

[0113] In some optional embodiments, the method further includes:

[0114] a judgment module, configured to adjust the preset switching period if the power value at the first voltage sampling point is greater than or equal to the power value at the second voltage sampling point, and the power value at the second voltage sampling point is less than or equal to the power value at the third voltage sampling point, and to adjust the current switching period using the adjusted preset switching period to obtain the photovoltaic maximum power point.

[0115] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0116] The photovoltaic maximum power point tracking device based on the conductance increment method in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0117] The embodiment of the present invention also provides a computer device having the above Figure 9 The photovoltaic maximum power tracking device based on the conductance increment method is shown.

[0118] See also Figure 10 , Figure 10 is a structural diagram of a computer device provided by an optional embodiment of the present invention, such as Figure 10As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of a GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 10 A processor 10 is taken as an example.

[0119] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0120] The memory 20 stores instructions that can be executed by at least one processor 10, so as to enable at least one processor 10 to execute the method shown in the above embodiment.

[0121] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0122] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0123] The computer device further includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Figure 10 The bus connection is taken as an example.

[0124] The input device 30 can receive input digital or character information and generate key signal input related to user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a trackpad, a touch pad, an indicator stick, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 can include a display device, an auxiliary lighting device (e.g., an LED), and a tactile feedback device (e.g., a vibration motor). The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display, and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0125] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0126] A portion of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the form in which the computer program instruction exists in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc. Accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium that can be accessed by the computer.

[0127] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A photovoltaic maximum power point tracking method based on the conductance increment method, characterized in that: The method comprises: Obtaining a power-voltage output characteristic curve of a target photovoltaic panel, and randomly sampling the power-voltage output characteristic curve of the target photovoltaic panel to obtain a plurality of adjacent voltage sampling points; Comparing the power values ​​corresponding to the plurality of adjacent voltage sampling points, and if a comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets a power value determination condition, obtaining a slope of a straight line between the plurality of adjacent voltage sampling points; The switching period of the target photovoltaic inverter is adjusted based on the slope of the straight line between the multiple adjacent voltage sampling points to obtain a photovoltaic maximum power point.

2. The method according to claim 1, characterized in that The comparing power values ​​corresponding to the plurality of adjacent voltage sampling points, and obtaining a slope of a straight line between the plurality of adjacent voltage sampling points if a comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets a power value determination condition, includes: If a comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets the power value determination condition, obtaining a slope of a straight line between the plurality of adjacent voltage sampling points; wherein the power value determination condition is that the power value of the first voltage sampling point is less than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point; and the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are the adjacent voltage sampling points; Alternatively, if the power values ​​corresponding to the multiple adjacent voltage sampling points do not meet the power value judgment condition, the multiple adjacent voltage sampling points are adjusted cyclically multiple times using a preset adjustment step size until the power values ​​corresponding to the multiple adjacent voltage sampling points meet the power value judgment condition, and the slopes of the straight lines corresponding to the multiple adjacent voltage sampling points after adjustment are obtained.

3. The method according to claim 2, characterized in that If the power values ​​corresponding to the plurality of adjacent voltage sampling points do not meet the power value determination condition, the plurality of adjacent voltage sampling points are adjusted cyclically multiple times using a preset adjustment step until the power values ​​corresponding to the plurality of adjacent voltage sampling points meet the power value determination condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained, including: If the power value of the first voltage sampling point is smaller than the power value of the second voltage sampling point, and the power value of the second voltage sampling point is smaller than the power value of the third voltage sampling point, the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point are shifted rightward along the horizontal axis using the preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet the power value judgment condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

4. The method according to claim 2, characterized in that If the power values ​​corresponding to the plurality of adjacent voltage sampling points do not meet the power value determination condition, the plurality of adjacent voltage sampling points are adjusted cyclically multiple times using a preset adjustment step until the power values ​​corresponding to the plurality of adjacent voltage sampling points meet the power value determination condition, and the slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained, further comprising: If the power value of the first voltage sampling point is greater than or equal to the power value of the second voltage sampling point, and the power value of the second voltage sampling point is greater than the power value of the third voltage sampling point, the plurality of adjacent voltage sampling points are shifted leftward along the horizontal axis using the preset adjustment step size until the power values ​​corresponding to the first voltage sampling point, the second voltage sampling point, and the third voltage sampling point meet the power value judgment condition, and slopes of the straight lines corresponding to the plurality of adjacent voltage sampling points after adjustment are obtained.

5. The method according to claim 2, characterized in that The adjusting the switching period of the target photovoltaic inverter based on the slope of the straight line between the plurality of adjacent voltage sampling points to obtain the photovoltaic maximum power point includes: determining a total slope based on slopes of straight lines corresponding to the plurality of adjacent voltage sampling points; If the total slope is zero, obtaining the current switching cycle of the target photovoltaic inverter, and determining the photovoltaic maximum power point based on the photovoltaic cell output power and operating voltage corresponding to the current switching cycle; Alternatively, if the total slope is a positive value, the sum of the current switching cycle and the preset switching cycle is used as the next switching cycle, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle; Alternatively, if the total slope is a negative value, the difference between the current switching cycle and the preset switching cycle is used as the next switching cycle, and the photovoltaic maximum power point is determined based on the photovoltaic cell output power and operating voltage corresponding to the next switching cycle.

6. The method according to claim 5, characterized in that Also includes: If the power value at the first voltage sampling point is greater than or equal to the power value at the second voltage sampling point, and the power value at the second voltage sampling point is less than or equal to the power value at the third voltage sampling point, the preset switching period is adjusted, and the current switching period of the target is adjusted using the adjusted preset switching period to obtain the photovoltaic maximum power point.

7. A photovoltaic maximum power point tracking device based on the conductance increment method, characterized in that: The device comprises: a sampling module, configured to obtain a power-voltage output characteristic curve of a target photovoltaic panel, and randomly sample the power-voltage output characteristic curve of the target photovoltaic panel to obtain a plurality of adjacent voltage sampling points; a comparison module, configured to compare power values ​​corresponding to the plurality of adjacent voltage sampling points, and obtain a slope of a straight line between the plurality of adjacent voltage sampling points if a comparison result of the power values ​​corresponding to the plurality of adjacent voltage sampling points meets a power value determination condition; An adjustment module is configured to adjust the target switching period based on the slope of a straight line between the plurality of adjacent voltage sampling points to obtain a photovoltaic maximum power point.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the photovoltaic maximum power point tracking based on the conductance increment method according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the photovoltaic maximum power point tracking based on the conductance increment method according to any one of claims 1 to 6.

10. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the photovoltaic maximum power point tracking based on the conductance increment method according to any one of claims 1 to 6.

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