Automatic optimization method and system for maximum power of photovoltaic inverter

Abstract

The invention belongs to the technical field of photovoltaic power generation, and provides an automatic optimization method and system for the maximum power of a photovoltaic inverter, and the method comprises the steps: obtaining key parameters and current bus voltage of the photovoltaic inverter, the key parameters at least comprising an automatic optimization voltage range and an automatic optimization disturbance time step length; judging whether the obtained current bus voltage is within an automatic optimization voltage range, if not, adjusting the duty ratio of an IGBT (Insulated Gate Bipolar Translator) of a DC / DC (Direct Current / Direct Current) boosting unit of the photovoltaic inverter, and calculating the generated power of the adjusted photovoltaic inverter; and performing optimization of variable-step voltage disturbance based on the adjusted generated power of the photovoltaic inverter to obtain the maximum power of the photovoltaic inverter, and completing automatic optimization of the maximum power of the photovoltaic inverter.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic power generation technology, specifically relating to a method and system for automatically optimizing the maximum power of a photovoltaic inverter. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Under different external conditions, such as panel temperature, solar irradiance, and load, photovoltaic cells have different and unique maximum power points. Therefore, if a photovoltaic power generation system cannot adjust the operating state of the photovoltaic cells in a timely manner according to changes in the external environment to convert light energy into electrical energy at maximum power, the power generation of the photovoltaic power station will be reduced, resulting in economic losses.

[0004] Currently, maximum power point tracking (MPPT) for photovoltaic (PV) cells is primarily implemented in PV inverters. Common MPPT methods include voltage perturbation, incremental conductance, and AI-based MPPT control. Voltage perturbation and incremental conductance methods are relatively simple, but suffer from misjudgment and oscillation issues. While measures such as varying step size, introducing hysteresis comparison, and using center differential have improved these issues, they cannot completely eliminate them, and the operational condition judgments for these measures are quite complex. AI-based MPPT control, while capable of obtaining the maximum power point more accurately, requires significant computing power and a long training period. Furthermore, if an anomaly occurs (such as PV panel shading), the training must be restarted. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an automatic maximum power optimization method and system for photovoltaic inverters. Based on a variable step size mechanism using the power-voltage rate of change, the photovoltaic inverter automatically reduces the step size as it approaches the maximum power point. By eliminating steady-state oscillations near the maximum power point through a steady-state maintenance mode, the maximum power tracking accuracy and power generation efficiency of the photovoltaic inverter are significantly improved.

[0006] According to some embodiments, the first aspect of the present invention provides an automatic maximum power optimization method for a photovoltaic inverter, employing the following technical solution: An automatic maximum power optimization method for a photovoltaic inverter includes: Obtain the key parameters of the photovoltaic inverter and the current bus voltage. The key parameters include at least the automatic optimization voltage range and the automatic optimization disturbance time step. Determine whether the current bus voltage obtained is within the automatic optimization voltage range. If not, adjust the duty cycle of the IGBT in the DC / DC boost unit of the photovoltaic inverter and calculate the power generation of the photovoltaic inverter after adjustment. The maximum power of the photovoltaic inverter is obtained by optimizing the step-size voltage disturbance based on the adjusted power output of the photovoltaic inverter, thus completing the automatic optimization of the maximum power of the photovoltaic inverter.

[0007] As a further technical limitation, the process of optimizing the variable step-size voltage disturbance is as follows: Apply an initial voltage disturbance, measure the power output of the photovoltaic inverter after the disturbance, and calculate the ratio of the change in photovoltaic inverter power output to the change in voltage, which gives the power-voltage change rate. Based on the current power-voltage change rate and the historical power-voltage change rate, the next voltage perturbation step size is calculated using a variable step size algorithm; Apply the obtained next voltage perturbation step size, update the DC bus voltage, and calculate the new photovoltaic power generation and power-voltage rate of change; Iteratively calculate the next voltage perturbation step size and power-voltage change rate until the preset convergence condition is met, thus completing the variable step size voltage perturbation optimization.

[0008] Furthermore, the preset convergence condition is that the absolute value of the power change of a series of consecutive voltage disturbances is less than a set threshold.

[0009] Furthermore, when the optimization process converges to near the maximum power point, it enters a steady-state maintenance mode, reduces or suspends voltage disturbances, and continuously monitors power changes. If it is determined that the maximum power point has drifted, it returns to restart the optimization process. During the optimization process, the voltage disturbance step size and voltage value are monitored in real time. If the step size is detected to be continuously diverging or the voltage is continuously exceeding the optimization range, it is determined that the automatic optimization is abnormal, and the automatic optimization is intervened and a fault alarm is issued.

[0010] Furthermore, the judgment condition for the continuous divergence of the step size is as follows: when the absolute value of the voltage disturbance step size calculated for several consecutive times continues to increase and exceeds the safety threshold, or the DC bus voltage continues to exceed the automatic optimization voltage range, it is determined that the automatic optimization may have divergent oscillations or faults such as local obstruction or component damage. The MPPT controller will forcibly reset the disturbance step size to the automatic optimization base voltage step size or pull the voltage back to the starting point of the optimization range, triggering a fault alarm signal.

[0011] As a further technical limitation, it is based on a photovoltaic inverter maximum power automatic optimization device, which includes at least a photovoltaic matrix, a photovoltaic matrix DC bus, a DC / DC boost unit, an inverter unit DC bus, a DC / AC inverter unit, an AC filter unit, a power grid, and an MPPT control unit.

[0012] According to some embodiments, the second aspect of the present invention provides an automatic maximum power optimization system for a photovoltaic inverter, which adopts the following technical solution: An automatic maximum power optimization system for a photovoltaic inverter includes: The acquisition module is configured to acquire key parameters of the photovoltaic inverter and the current bus voltage, wherein the key parameters include at least the automatic optimization voltage range and the automatic optimization disturbance time step. The judgment module is configured to determine whether the current bus voltage is within the automatic optimization voltage range. If not, it adjusts the duty cycle of the IGBT in the DC / DC boost unit of the photovoltaic inverter and calculates the power generation of the photovoltaic inverter after adjustment. The optimization module is configured to perform variable step-size voltage perturbation optimization based on the adjusted power generation of the photovoltaic inverter to obtain the maximum power of the photovoltaic inverter, thus completing the automatic optimization of the maximum power of the photovoltaic inverter.

[0013] According to some embodiments, a third aspect of the present invention provides a computer-readable storage medium, employing the following technical solution: A computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps in the automatic maximum power optimization method for a photovoltaic inverter as described in the first aspect of the present invention.

[0014] According to some embodiments, the fourth aspect of the present invention provides an electronic device, which adopts the following technical solution: An electronic device includes a memory, a processor, and a program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps in the automatic maximum power optimization method for a photovoltaic inverter as described in the first aspect of the present invention.

[0015] According to some embodiments, the fifth aspect of the present invention provides a computer program product, which adopts the following technical solution: A computer program product includes software code, wherein the program in the software code performs the steps of the automatic maximum power optimization method for a photovoltaic inverter as described in the first aspect of the present invention.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention introduces an intelligent variable step-size mechanism based on the power-voltage rate of change, particularly incorporating PID control principles. This enables the system to rapidly approach the maximum power point with large steps when far from it, and to automatically reduce the step size for fine-tuning when approaching the maximum power point. Ultimately, the steady-state maintenance mode almost eliminates steady-state oscillations near the maximum power point, significantly improving tracking accuracy and power generation efficiency. The proportional and differential terms in this invention make the algorithm highly sensitive to changes in the external environment, enabling it to quickly respond to sudden changes in irradiance and temperature, and promptly adjust the tracking direction and step size, shortening the time to track the new maximum power point. The integral term helps overcome the effects of system nonlinearity, improving adaptability under different operating conditions. Mechanisms such as step-size divergence protection and voltage range limiting ensure stable operation of the system under abnormal conditions, avoiding the runaway phenomena that may occur with traditional methods.

[0017] This invention is based on an improvement in voltage perturbation, requires little computation, does not require pre-training, does not demand high computing power from the microprocessor, and is inexpensive. It is very easy to implement and promote on existing photovoltaic inverter hardware platforms. Through multiple judgment logics (convergence judgment, steady-state judgment, divergence judgment), a complete control and protection closed loop is formed, which greatly improves the reliability and safety of system operation. Attached Figure Description

[0018] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0019] Figure 1 This is a flowchart of the automatic maximum power optimization method for photovoltaic inverters in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the power-voltage characteristic curve of the photovoltaic cell in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the automatic maximum power tracking device for photovoltaic inverters in Embodiment 1 of the present invention; Figure 4 This is a structural block diagram of the automatic maximum power optimization system for a photovoltaic inverter in Embodiment 2 of the present invention; In the diagram, 1 is the photovoltaic matrix unit; 2 is the photovoltaic matrix DC bus; 3 is the DC / DC voltage regulation unit; 301 is the DC / DC voltage regulation unit IGBT; 4 is the DC / AC inverter unit DC bus; 5 is the DC / AC inverter unit; 6 is the AC filter unit; 7 is the AC power grid; 8 is the MPPT control unit; 801 is the voltmeter; 802 is the ammeter; and 803 is the MPPT controller. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, 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 invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] In this invention, terms such as "upper," "lower," "left," "right," "front," "back," "vertical," "horizontal," "side," and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only to facilitate the description of the structural relationships of the various components or elements of this invention and do not specifically refer to any component or element in this invention. They should not be construed as limiting the invention.

[0024] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.

[0025] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0026] Example 1 Embodiment 1 of this invention introduces an automatic maximum power optimization method for photovoltaic inverters.

[0027] like Figure 1 The method for automatically optimizing the maximum power of a photovoltaic inverter, as shown, includes: Obtain the key parameters of the photovoltaic inverter and the current bus voltage. The key parameters include at least the automatic optimization voltage range and the automatic optimization disturbance time step. Determine whether the current bus voltage obtained is within the automatic optimization voltage range. If not, adjust the duty cycle of the IGBT in the DC / DC boost unit of the photovoltaic inverter and calculate the power generation of the photovoltaic inverter after adjustment. The maximum power of the photovoltaic inverter is obtained by optimizing the step-size voltage disturbance based on the adjusted power output of the photovoltaic inverter, thus completing the automatic optimization of the maximum power of the photovoltaic inverter.

[0028] As one or more implementation methods, this embodiment presets key parameters of the photovoltaic inverter, including at least: Optimization of voltage range ( , ), that is, through analysis such as Figure 2 The family of PU characteristic curves for the photovoltaic array shown (obtainable experimentally or from a datasheet) defines a range that covers the maximum power point voltage under all expected operating conditions (e.g., irradiance from 100 W / m² to 1000 W / m², temperature from -10°C to 70°C). This range is designed to narrow the optimization search space, improve efficiency, and prevent voltage runaway.

[0029] base step size This refers to the smallest unit of voltage disturbance. To ensure adjustment accuracy, It should be set small enough to cover the entire optimization voltage range. If divided into much more than 100 portions (e.g., 500-1000 portions), then , where N is a natural number greater than 100.

[0030] Disturbance time step In other words, the time interval between two voltage disturbances needs to be greater than the response time of the DC / DC circuit and the sampling system to avoid misjudgments caused by the system not stabilizing before the next sampling. This interval is typically set to a few milliseconds to several hundred milliseconds, depending on the system's dynamic response characteristics.

[0031] PID coefficients ( , , The weights of the proportional, integral, and differential terms in variable step-size calculations are determined by these factors and need to be tuned according to the specific characteristics of the photovoltaic system to achieve the optimal balance between speed, accuracy, and stability. The main impact is on the agility of tracking. Affects the ability to eliminate steady-state error and overshoot. It is used to suppress oscillations.

[0032] The judgment thresholds include a convergence threshold used to determine whether the power has stabilized near its maximum value. (Usually set to a very small percentage of the rated power), the number of times the convergence condition needs to be met consecutively to improve the reliability of the judgment. Used to determine whether arrival has been made steady-state threshold The number of times the steady-state condition must be met consecutively before entering the steady-state maintenance mode is called the steady-state maintenance count. And the number of divergence protection cycles in which the step size continuously increases before triggering the divergence protection. .

[0033] As one or more implementation methods, the automatic maximum power optimization in this embodiment is a closed-loop iterative process, specifically: The controller continuously monitors the DC bus voltage U. If U falls below a preset value... Outside the range (e.g., during system startup or after a severe disturbance), a control signal is immediately output to adjust the IGBT duty cycle, forcibly pulling the voltage back to a safe starting point within the range (e.g., or ), calculate the power P at this time.

[0034] This embodiment applies an initial voltage disturbance (typically...). or ), making the voltage become Waiting for a perturbation time step. After the system stabilizes, the voltage and current are sampled again to calculate the new power. Then calculate the power change. and power-voltage change rate ,this Value (i.e.) () is a key indicator for determining the position of the operating point relative to the maximum power point.

[0035] In this embodiment, the next voltage perturbation step size It is no longer a fixed value, but is dynamically calculated using a formula that incorporates PID principles. The proportion term in this embodiment , This determines the direction of the disturbance (moving closer to the point of maximum power). The magnitude reflects the distance between the current operating point and the maximum power point; the greater the distance, the higher the power level. The larger the value, the larger the step size, enabling rapid approximation; the closer the distance, the smaller the step size automatically, enabling fine adjustment; the integral term in this embodiment... accumulating history When the system oscillates continuously around the maximum power point, the integral term can effectively identify this steady-state error trend and generate a reverse corrective force, helping the system quickly escape local oscillations and accelerate convergence; simultaneously, when smoothly approaching the maximum power point, the integral term can also smoothly change the step size; the differential term in this embodiment This reflects The changing trend, if As the operating point rapidly approaches its maximum power point, the derivative term will decrease its step size in advance to prevent overshoot; if When the trend reverses, the differential term responds promptly and corrects its tracking direction. It acts as a "brake" or "booster" for the effect of the integral term.

[0036] In this embodiment, after each disturbance, the continuous... Absolute value of power change within each disturbance period Are they all less than If so, the system is considered to have successfully converged to the maximum power point and enters the next stage of steady-state maintenance mode; otherwise, it returns to recalculate the photovoltaic power generation and continues iterative optimization.

[0037] After convergence, to eliminate the continuous oscillations near the maximum power point in the traditional perturbation observation method, this embodiment introduces a steady-state maintenance mode, adjusting the voltage perturbation step size. Set to zero or a very small value (much smaller than) This allows the operating voltage to remain essentially unchanged, greatly reducing unnecessary power loss.

[0038] During the steady-state maintenance period, this embodiment continuously monitors the power-voltage rate of change. (Or directly monitor changes in power P). If changes in illumination occur due to cloud movement or other reasons, affecting the calculated... (or power change) exceeds a preset threshold If the maximum power point has shifted, the controller immediately exits the steady-state maintenance mode, resets relevant parameters (such as clearing the integral term), and restarts the core optimization process to find a new maximum power point.

[0039] When the external environment undergoes drastic changes (such as sudden dense cloud cover), the shape of the PU curve may change dramatically, potentially affecting the calculation. The abnormal increase is addressed by incorporating step size divergence protection in this embodiment, which continuously monitors the step size. Voltage perturbation step size per cycle If it is found to continue increasing and exceed a certain safety limit, the system is determined to be at risk of divergence; the next perturbation step size is forcibly reset to a safe level. Alternatively, the operating voltage can be pulled back to the starting point of the optimization range, and then the optimization can be restarted, thereby effectively avoiding system runaway and divergent oscillations.

[0040] If, after multiple adjustments, the DC bus voltage U still cannot stabilize... If the system power output is significantly lower than expected, and considering factors such as step size divergence, the MPPT controller can infer that the photovoltaic array may have experienced severe mismatch, partial shading, or damage. In this case, in addition to the aforementioned protective interventions, the controller will also send a fault alarm signal to the upper-level monitoring unit of the system, prompting maintenance and inspection.

[0041] This embodiment uses, as follows: Figure 3 The automatic maximum power optimization device for photovoltaic inverters, as shown, specifically includes: Photovoltaic matrix 1 is used to convert solar energy into direct current electrical energy; The photovoltaic matrix DC bus 2 is connected to the photovoltaic matrix 1 and is used to collect and transmit DC power. DC / DC boost unit 3, whose input terminal is connected to the DC bus 2 of the photovoltaic matrix, is used to boost DC voltage. This unit includes an IGBT switch 301 that can be controlled to switch on and off. The inverter unit DC bus 4 is connected to the output terminal of the DC / DC boost unit 3; DC / AC inverter unit 5, whose input terminal is connected to the DC bus 4 of the inverter unit, is used to convert DC power into AC power. AC filter unit 6 is connected to the output terminal of the DC / AC inverter unit 5 and is used to filter out harmonics in AC power. The power grid is connected to the output terminal of the AC filter unit 6. The MPPT control unit 8 includes: a voltage detection module 801, disposed on the DC bus 2 of the photovoltaic matrix, for detecting the DC bus voltage value; a current detection module 802, disposed on the DC bus 2 of the photovoltaic matrix, for detecting the DC bus current value; and an MPPT controller 803, whose signal input terminal is connected to the voltage detection module 801 and the current detection module 802, and whose control output terminal is connected to the control electrode of the IGBT switch 301 of the DC / DC boost unit 3; the MPPT controller 301 executes the automatic maximum power optimization method of the photovoltaic inverter in this embodiment.

[0042] Example 1: Sunny weather with relatively stable irradiance This embodiment monitors the DC bus voltage measured by the photovoltaic array voltage meter V. =500V, (530V, 780V), at this time the MPPT controller outputs a control signal to adjust the IGBT duty cycle, so that the DC bus voltage... And calculate the power generation of the photovoltaic matrix. =150kW; MPPT controller output voltage disturbance =0.5V, adjust the DC bus voltage And calculate the photovoltaic matrix power at this time. , obtain ; Calculate the ratio of disturbance power to disturbance voltage change The MPPT controller outputs a second voltage disturbance, in Substitute ,Right now ,have to Monitoring at this time , The MPPT controller outputs the third voltage disturbance, which will Substitute ,have to Monitoring at this time , MPPT controller output number Each voltage disturbance will Substitute and monitor ,get MPPT controller output number Voltage disturbance ,get This indicates that the maximum power point has been found, and the MPPT controller outputs the first... voltage disturbance ; Under certain conditions, such as This indicates the current maximum power point, and the voltage disturbance value after that is 0. Under certain conditions, such as This indicates that the current maximum power point has shifted. , MPPT controller according to Output the first A voltage disturbance is used to find a new maximum power point.

[0043] Example 2: Cloudy weather with relatively unstable irradiance According to Example 1, the photovoltaic power generation inverter system obtains its maximum power point and maintains operation at this point; cloud cover or cloud movement will cause changes in irradiance, at which point the previous voltage disturbance will occur. Under certain conditions, such as This indicates that the current maximum power point has shifted. , MPPT controller according to formula Output the first The system uses voltage perturbations to find a new maximum power point; however, due to drastic changes in irradiance, there is a limitation on the calculation step size for voltage perturbations. In this situation, to ensure adjustment accuracy and avoid divergent oscillations, Then recalculate the first equation according to equation -1. Voltage disturbances; drastic irradiation changes may lead to over-regulation, meaning the real-time voltage exceeds the optimization range. At this point, intervention is needed to adjust the regulation process and adjust the DC bus voltage to... We need to find the best solution again.

[0044] This embodiment introduces an intelligent variable step-size mechanism based on the power-voltage rate of change, particularly incorporating PID control principles. This allows the system to rapidly approach the maximum power point with large steps when far from it, and automatically reduce the step size for fine-tuning when close to the maximum power point. Ultimately, the steady-state maintenance mode almost eliminates steady-state oscillations near the maximum power point, significantly improving tracking accuracy and power generation efficiency. The proportional and derivative terms in this embodiment make the algorithm highly sensitive to changes in the external environment, enabling it to quickly respond to sudden changes in irradiance and temperature, and adjust the tracking direction and step size in a timely manner, shortening the time to track the new maximum power point. The integral term helps overcome the effects of system nonlinearity, improving adaptability under different operating conditions. Mechanisms such as step-size divergence protection and voltage range limiting ensure stable operation of the system under abnormal conditions, avoiding the runaway phenomena that may occur with traditional methods.

[0045] This embodiment is based on an improvement in voltage perturbation, which requires less computation, does not require pre-training, does not demand high computing power from the microprocessor, and is inexpensive. It is very easy to implement and promote on existing photovoltaic inverter hardware platforms. Through multiple judgment logics (convergence judgment, steady-state judgment, divergence judgment), a complete control and protection closed loop is formed, which greatly improves the reliability and safety of system operation.

[0046] Example 2 Embodiment 2 of the present invention introduces an automatic maximum power optimization system for photovoltaic inverters.

[0047] like Figure 4 The automatic maximum power optimization system for a photovoltaic inverter shown includes: The acquisition module is configured to acquire key parameters of the photovoltaic inverter and the current bus voltage, wherein the key parameters include at least the automatic optimization voltage range and the automatic optimization disturbance time step. The judgment module is configured to determine whether the current bus voltage is within the automatic optimization voltage range. If not, it adjusts the duty cycle of the IGBT in the DC / DC boost unit of the photovoltaic inverter and calculates the power generation of the photovoltaic inverter after adjustment. The optimization module is configured to perform variable step-size voltage perturbation optimization based on the adjusted power generation of the photovoltaic inverter to obtain the maximum power of the photovoltaic inverter, thus completing the automatic optimization of the maximum power of the photovoltaic inverter.

[0048] The detailed steps are the same as the automatic maximum power optimization method for photovoltaic inverters provided in Example 1, and will not be repeated here.

[0049] Example 3 Embodiment 3 of the present invention provides a computer-readable storage medium.

[0050] A computer-readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps in the automatic maximum power optimization method for a photovoltaic inverter as described in Embodiment 1 of the present invention.

[0051] The detailed steps are the same as the automatic maximum power optimization method for photovoltaic inverters provided in Example 1, and will not be repeated here.

[0052] Example 4 Embodiment 4 of the present invention provides an electronic device.

[0053] An electronic device includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, it implements the steps in the automatic maximum power optimization method for a photovoltaic inverter as described in Embodiment 1 of the present invention.

[0054] The detailed steps are the same as the automatic maximum power optimization method for photovoltaic inverters provided in Example 1, and will not be repeated here.

[0055] Example 5 Embodiment 5 of the present invention provides a computer program product.

[0056] A computer program product includes software code, wherein the program in the software code performs the steps of the automatic maximum power optimization method for photovoltaic inverters as described in Embodiment 1 of the present invention.

[0057] The detailed steps are the same as the automatic maximum power optimization method for photovoltaic inverters provided in Example 1, and will not be repeated here.

[0058] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0059] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0060] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0061] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0062] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0063] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0064] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A method for automatically optimizing the maximum power of a photovoltaic inverter, characterized in that, include: Obtain the key parameters of the photovoltaic inverter and the current bus voltage. The key parameters include at least the automatic optimization voltage range and the automatic optimization disturbance time step. Determine whether the current bus voltage obtained is within the automatic optimization voltage range. If not, adjust the duty cycle of the IGBT in the DC / DC boost unit of the photovoltaic inverter and calculate the power generation of the photovoltaic inverter after adjustment. The maximum power of the photovoltaic inverter is obtained by optimizing the step-size voltage disturbance based on the adjusted power output of the photovoltaic inverter, thus completing the automatic optimization of the maximum power of the photovoltaic inverter.

2. The automatic maximum power optimization method for a photovoltaic inverter as described in claim 1, characterized in that, The process of optimizing the variable step size voltage disturbance is as follows: Apply an initial voltage disturbance, measure the power output of the photovoltaic inverter after the disturbance, and calculate the ratio of the change in photovoltaic inverter power output to the change in voltage, which gives the power-voltage change rate. Based on the current power-voltage change rate and the historical power-voltage change rate, the next voltage perturbation step size is calculated using a variable step size algorithm; Apply the obtained next voltage perturbation step size, update the DC bus voltage, and calculate the new photovoltaic power generation and power-voltage rate of change; Iteratively calculate the next voltage perturbation step size and power-voltage change rate until the preset convergence condition is met, thus completing the variable step size voltage perturbation optimization.

3. The automatic maximum power optimization method for a photovoltaic inverter as described in claim 2, characterized in that, The preset convergence condition is that the absolute value of the power change of a series of consecutive voltage disturbances is less than a set threshold.

4. The automatic maximum power optimization method for a photovoltaic inverter as described in claim 2, characterized in that, When the optimization process converges to near the maximum power point, it enters steady-state maintenance mode, reduces or suspends voltage disturbances, and continuously monitors power changes. If it is determined that the maximum power point has drifted, it returns to restart the optimization process. During the optimization process, the voltage disturbance step size and voltage value are monitored in real time. If the step size is detected to be continuously diverging or the voltage is continuously exceeding the optimization range, it is determined that the automatic optimization is abnormal, and the automatic optimization is intervened and a fault alarm is issued.

5. The automatic maximum power optimization method for a photovoltaic inverter as described in claim 4, characterized in that, The condition for determining the continuous divergence of the step size is as follows: when the absolute value of the voltage disturbance step size calculated for several consecutive times continues to increase and exceeds the safety threshold, or the DC bus voltage continues to exceed the automatic optimization voltage range, it is determined that the automatic optimization may have divergent oscillations or faults such as local obstruction or component damage. The MPPT controller will forcibly reset the disturbance step size to the automatic optimization base voltage step size or pull the voltage back to the starting point of the optimization range, triggering a fault alarm signal.

6. The automatic maximum power optimization method for a photovoltaic inverter as described in claim 1, characterized in that, This is achieved using an automatic maximum power optimization device for photovoltaic inverters. The automatic maximum power optimization device for photovoltaic inverters includes at least a photovoltaic matrix, a photovoltaic matrix DC bus, a DC / DC boost unit, an inverter unit DC bus, a DC / AC inverter unit, an AC filter unit, a power grid, and an MPPT control unit.

7. A maximum power automatic optimization system for a photovoltaic inverter, characterized in that, include: The acquisition module is configured to acquire key parameters of the photovoltaic inverter and the current bus voltage, wherein the key parameters include at least the automatic optimization voltage range and the automatic optimization disturbance time step. The judgment module is configured to determine whether the current bus voltage is within the automatic optimization voltage range. If not, it adjusts the duty cycle of the IGBT in the DC / DC boost unit of the photovoltaic inverter and calculates the power generation of the photovoltaic inverter after adjustment. The optimization module is configured to perform variable step-size voltage perturbation optimization based on the adjusted power generation of the photovoltaic inverter to obtain the maximum power of the photovoltaic inverter, thus completing the automatic optimization of the maximum power of the photovoltaic inverter.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the automatic maximum power optimization method for photovoltaic inverters as described in any one of claims 1-6.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the program, it implements the steps of the automatic maximum power optimization method for photovoltaic inverters as described in any one of claims 1-6.

10. A computer program product, comprising software code, characterized in that, The program in the software code executes the steps of the automatic maximum power optimization method for photovoltaic inverters as described in any one of claims 1-6.

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