Global maximum power point tracking method and system for segmented scanning

Abstract

The invention provides a global maximum power point tracking method and system for segmented scanning. The method comprises the following steps: step A1, dividing a working interval of a solar panel into a plurality of sub-intervals; a2, periodically collecting voltage data and current data of each subinterval; a3, searching a local maximum power point of the subinterval according to the voltage data and the current data of the subinterval; and A4, determining the global maximum power point of the solar panel according to the local maximum power point of each subinterval. The energy conversion efficiency of a photovoltaic system under a complex illumination condition is improved, stable operation of the system is ensured, and energy output is maximized.

Description

Technical Field

[0001] The present invention relates to the technical field of solar panels, and in particular to a segmented scanning global maximum power point tracking method and system. Background Art

[0002] In photovoltaic power generation systems, MPPT is one of the key components used to ensure that solar panels always operate at the maximum power point under different environmental conditions. In existing technologies, traditional maximum power point tracking (MPPT) technology usually uses global MPPT algorithms to optimize the performance of photovoltaic systems. These algorithms find the maximum power point by searching the power-voltage curve of the entire solar panel, thereby optimizing the solar panel.

[0003] In practical applications, this method works well when there is no shadow. However, due to environmental factors such as shadow, the output characteristics of the solar panel will change, resulting in the inability of the traditional MPPT algorithm to accurately track the true maximum power point, thus affecting the overall performance and energy output of the system. When the photovoltaic system is partially shaded, its PU characteristic curve will change, resulting in multiple peaks. This causes the traditional global MPPT algorithm to fall into a local peak, making it impossible for the photovoltaic system to operate at the true maximum power point, thus affecting the overall efficiency of the system. Secondly, these algorithms require a lot of computing resources and time to search the entire power-voltage curve, resulting in a slow response speed of the system. In addition, the performance of existing MPPT algorithms may be limited when faced with complex and changeable shadow conditions, resulting in serious power loss. Summary of the invention

[0004] Based on the above method, the present invention provides a segmented scanning global maximum power point tracking method and system, aiming to solve the technical problem in the prior art that the MPPT algorithm may fall into a local peak due to environmental changes.

[0005] A segmented scanning global maximum power point tracking method, comprising:

[0006] Step A1, dividing the working range of the solar panel into multiple sub-ranges;

[0007] Step A2, periodically collecting voltage data and current data of each sub-interval;

[0008] Step A3, finding the local maximum power point of the sub-interval according to the voltage data and current data of the sub-interval;

[0009] Step A4: determining the global maximum power point of the solar panel according to the local maximum power points of each sub-interval.

[0010] Furthermore, in step A2, each sub-interval uses a maximum power point tracking algorithm to find a local maximum power point.

[0011] Furthermore, after step A4, step A5 is also included: dynamically adjusting the scanning frequency based on the global maximum power point;

[0012] In step A2, the voltage data and current data of each sub-interval are periodically collected according to the latest adjusted scanning frequency.

[0013] Furthermore, the maximum power point tracking algorithm is at least one of a perturbation observation method, an incremental conductance method, a temperature compensation method and a short-circuit current method.

[0014] A segmented scanning global maximum power point tracking system, used to execute the aforementioned segmented scanning global maximum power point tracking method, comprising:

[0015] Solar panels, the working range of the solar panel is divided into multiple sub-ranges;

[0016] A power point tracking module is connected to the solar panel and is used to: periodically collect voltage data and current data of each sub-interval, find the local maximum power point of the sub-interval according to the voltage data and current data of the sub-interval, and determine the global maximum power point of the solar panel according to the local maximum power point of each sub-interval;

[0017] The DC-DC converter is connected to the solar panel, the power point tracking module and the load respectively, and is used to adjust the output voltage and current of the solar panel according to the global maximum power point to power the load.

[0018] Furthermore, the power point tracking module includes:

[0019] A plurality of signal acquisition units corresponding to the sub-intervals one by one, used for periodically acquiring voltage data and current data of the corresponding sub-intervals;

[0020] The power point tracking unit is connected to a corresponding signal acquisition unit and is used to: find the local maximum power point of the corresponding sub-interval by using a maximum power point tracking algorithm according to the voltage data and current data of the corresponding sub-interval.

[0021] The power point determination unit is connected to each power point tracking unit and is used to determine the global maximum power point of the solar panel according to the local maximum power point of each sub-interval.

[0022] Furthermore, the power point tracking module also includes:

[0023] A parameter adjustment unit, connected to the power point determination unit, is used to: dynamically adjust the scanning frequency based on the global maximum power point;

[0024] The signal acquisition module is connected to the parameter adjustment unit and is used to periodically acquire the voltage data and current data of the corresponding sub-interval according to the latest adjusted scanning frequency.

[0025] Furthermore, the maximum power point tracking algorithm is at least one of a perturbation observation method, an incremental conductance method, a temperature compensation method and a short-circuit current method.

[0026] The beneficial technical effect of the present invention is that the use of segmented scanning technology can provide optimization of maximum power point tracking (MPPT), improve the energy conversion efficiency of the photovoltaic system under complex lighting conditions, ensure stable operation of the system and maximize energy output. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of the steps of a segmented scanning global maximum power point tracking method of the present invention;

[0028] Figure 2 A schematic diagram of a module of a segmented scanning global maximum power point tracking system of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0031] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0032] See also Figure 1 The present invention provides a segmented scanning global maximum power point tracking method, comprising:

[0033] Step A1, dividing the working range of the solar panel into multiple sub-ranges;

[0034] Step A2, periodically collecting voltage data and current data of each sub-interval;

[0035] Step A3, finding the local maximum power point of the sub-interval according to the voltage data and current data of the sub-interval;

[0036] Step A4: determining the global maximum power point of the solar panel according to the local maximum power points of each sub-interval.

[0037] Complex lighting conditions such as shadows can cause different parts of the solar panel to produce different current and voltage characteristics. The segmented scanning technology can identify multi-peak PV curves under different lighting conditions and distinguish between local and global maximum power points, thereby preventing the traditional unsegmented MPPT algorithm from incorrectly converging to the local optimum and missing the global maximum power point. In addition, segmented scanning can divide the entire operating range into multiple small segments and perform a detailed scan of each small segment, effectively reducing the error of the system reaching a steady state, which helps to improve the tracking accuracy of the MPPT algorithm. Moreover, segmented scanning technology ensures maximum energy collection and conversion efficiency under different lighting conditions through precise energy collection optimization.

[0038] In addition, segmented scanning technology can reduce power loss caused by complex lighting conditions such as shadows, ensuring that the photovoltaic modules work at their maximum power point as much as possible. By effectively managing the photovoltaic modules under shadows, segmented scanning technology improves the overall output power of the system, especially under cloudy or partial shadow conditions.

[0039] In addition, segmented scanning technology can cope with complex lighting patterns including single shadows and multi-point local shadows, enhancing the adaptability and flexibility of the system. It can also respond more quickly to sudden changes in the environment, such as the rapid movement of clouds, and quickly respond to environmental changes.

[0040] The maximum power point tracking (MPPT) is optimized using segmented scanning technology to improve the energy conversion efficiency of the photovoltaic system under complex lighting conditions, ensure stable system operation and maximize energy output.

[0041] Specifically, the working area of ​​the solar panel is an array formed by a number of photovoltaic modules, and each sub-area may include a certain number of photovoltaic modules.

[0042] Furthermore, in step A2, each sub-interval uses a maximum power point tracking algorithm to find a local maximum power point.

[0043] Furthermore, after step A4, step A5 is also included: dynamically adjusting the scanning frequency based on the global maximum power point;

[0044] In step A2, the voltage data and current data of each sub-interval are periodically collected according to the latest adjusted scanning frequency.

[0045] Segmented scanning technology can adaptively adjust its scanning strategy to adapt to changing lighting conditions. If the global maximum power point already meets the output requirements, for example, the solar panel can provide a current of 50A, and the load only needs 10A, that is, the solar panel can output sufficient power and does not need to be scanned frequently, the scanning frequency can be reduced, that is, the scanning interval can be extended. On the contrary, if the maximum power point is reduced, there may be more shadows, so the scanning frequency is increased to cope with complex and changing lighting conditions. For example, if there is sufficient sunlight and high power, there is no need for frequent scanning. When the sunlight is blocked, the maximum power point of the solar panel is relatively small. Increasing the scanning frequency helps to find the maximum power point of the solar panel as soon as possible when the blockage disappears, so that the solar panel can work at the maximum power point as much as possible.

[0046] Each sub-interval is optimized independently, thus achieving optimization of the entire solar panel.

[0047] Furthermore, the maximum power point tracking algorithm is at least one of a perturbation observation method, an incremental conductance method, a temperature compensation method and a short-circuit current method.

[0048] See also Figure 2 The present invention also provides a segmented scanning global maximum power point tracking system, which is used to execute the aforementioned segmented scanning global maximum power point tracking method, comprising:

[0049] A solar panel (1), wherein the working range of the solar panel is divided into a plurality of sub-ranges;

[0050] A power point tracking module (2) is connected to the solar panel and is used to: periodically collect voltage data and current data of each sub-interval, find the local maximum power point of the sub-interval according to the voltage data and current data of the sub-interval, and determine the global maximum power point of the solar panel according to the local maximum power points of each sub-interval;

[0051] The DC-DC converter (3) is respectively connected to the solar panel (1), the power point tracking module (2) and the load (4), and is used to adjust the output voltage and current of the solar panel according to the global maximum power point to supply power to the load.

[0052] Complex lighting conditions such as shadows will cause different parts of the solar panel to produce different current and voltage characteristics. The segmented scanning technology can identify multi-peak PV curves under different lighting conditions, and the open scanning can distinguish between local and global maximum power points, thereby preventing the traditional unsegmented MPPT algorithm from erroneously converging to the local optimum and missing the global maximum power point. In addition, segmented scanning can divide the entire operating range into multiple small segments and perform a detailed scan of each small segment, effectively reducing the error of the system reaching a steady state, which helps to improve the tracking accuracy of the MPPT algorithm. Moreover, the segmented scanning technology ensures the maximum energy collection and conversion efficiency under different lighting conditions through precise energy collection optimization.

[0053] In addition, segmented scanning technology can reduce power loss caused by complex lighting conditions such as shadows, ensuring that the photovoltaic modules work at their maximum power point as much as possible. By effectively managing the photovoltaic modules under shadows, segmented scanning technology improves the overall output power of the system, especially under cloudy or partial shadow conditions.

[0054] In addition, segmented scanning technology can cope with complex lighting patterns including single shadows and multi-point local shadows, enhancing the adaptability and flexibility of the system. It can also respond more quickly to sudden changes in the environment, such as the rapid movement of clouds, and quickly respond to environmental changes.

[0055] The segmented scanning technology is used to optimize the maximum power point tracking (MPPT), improve the energy conversion efficiency of the photovoltaic system under complex lighting conditions, ensure stable operation of the system and maximize energy output.

[0056] Specifically, the working area of ​​the solar panel is an array formed by a number of photovoltaic modules, and each sub-area may include a certain number of photovoltaic modules.

[0057] Furthermore, the power point tracking module (2) comprises:

[0058] A plurality of signal acquisition units (21) corresponding one to each of the sub-intervals, used for periodically acquiring voltage data and current data of the corresponding sub-intervals;

[0059] The power point tracking unit (22) is connected to a corresponding signal acquisition unit (21) and is used to: find the local maximum power point of the corresponding sub-interval using a maximum power point tracking algorithm based on the voltage data and current data of the corresponding sub-interval.

[0060] A power point determination unit (23) is connected to each power point tracking unit (22) and is used to determine the global maximum power point of the solar panel according to the local maximum power point of each sub-interval.

[0061] The signal acquisition module includes a current detection unit and a voltage detection unit. The current detection unit detects current data, and the voltage detection unit detects voltage data. The power point tracking module controls the working state of the power converter (DC-DC converter) by analyzing the current data and voltage data.

[0062] Furthermore, the power point tracking module (2) further includes:

[0063] A parameter adjustment unit (24), connected to the power point determination unit (23), is used to: dynamically adjust the scanning frequency based on the global maximum power point;

[0064] The signal acquisition unit (21) is connected to the parameter adjustment unit (24) and is used to periodically acquire voltage data and current data of the corresponding sub-interval according to the latest adjusted scanning frequency.

[0065] Segmented scanning technology can adaptively adjust its scanning strategy to adapt to changing lighting conditions. If the global maximum power point already meets the output demand, for example, the solar panel can provide 50A of current, and the load only needs 10A, that is, the solar panel can output sufficient power, and frequent scanning is not required, the scanning frequency can be reduced, that is, the scanning interval can be extended. On the contrary, if the maximum power point is reduced, there may be more shadows, so the scanning frequency is increased. To cope with complex and changing lighting conditions. For example, if there is sufficient sunlight and high power, there is no need for frequent scanning. When the sunlight is blocked, the maximum power point of the solar panel is relatively small. Increasing the scanning frequency helps to find the maximum power point of the solar panel as soon as possible when the blockage disappears, so that the solar panel can work at the maximum power point as much as possible.

[0066] Each sub-interval is optimized independently, thus achieving optimization of the entire solar panel.

[0067] Furthermore, the maximum power point tracking algorithm is at least one of a perturbation observation method, an incremental conductance method, a temperature compensation method and a short-circuit current method.

[0068] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A segmented scanning global maximum power point tracking method, characterized in that: include: Step A1, dividing the working range of the solar panel into multiple sub-ranges; Step A2, periodically collecting voltage data and current data of each of the sub-intervals; Step A3, finding the local maximum power point of the sub-interval according to the voltage data and current data of the sub-interval; Step A4: determining the global maximum power point of the solar panel according to the local maximum power points of the sub-intervals.

2. The global maximum power point tracking method of segmented scanning according to claim 1, characterized in that: In the step A2, each of the sub-intervals uses a maximum power point tracking algorithm to find the local maximum power point.

3. The global maximum power point tracking method of segmented scanning according to claim 1, characterized in that: The step A4 also includes a step A5: dynamically adjusting the scanning frequency based on the global maximum power point; In the step A2, the voltage data and the current data of each sub-interval are periodically collected according to the latest adjusted scanning frequency.

4. A segmented scanning global maximum power point tracking method as claimed in claim 2, characterized in that: The maximum power point tracking algorithm is at least one of a perturbation and observation method, an incremental conductance method, a temperature compensation method and a short-circuit current method.

5. A segmented scanning global maximum power point tracking system, characterized in that: A global maximum power point tracking method for performing a segmented scan as claimed in any one of claims 1 to 4, comprising: A solar panel, wherein the working range of the solar panel is divided into a plurality of sub-ranges; A power point tracking module, connected to the solar panel, is used to: periodically collect voltage data and current data of each of the sub-intervals, find the local maximum power point of the sub-interval according to the voltage data and current data of the sub-interval, and determine the global maximum power point of the solar panel according to the local maximum power point of each of the sub-intervals; A DC-DC converter is connected to the solar panel, the power point tracking module and the load respectively, and is used to adjust the output voltage and current of the solar panel according to the global maximum power point to power the load.

6. The global maximum power point tracking system with segmented scanning as claimed in claim 5, characterized in that: The power point tracking module includes: A plurality of signal acquisition units corresponding to the sub-intervals one by one, and used for periodically acquiring voltage data and current data of the corresponding sub-intervals; A power point tracking unit is connected to a corresponding one of the signal acquisition units and is used to: find the local maximum power point of the corresponding sub-interval using a maximum power point tracking algorithm based on the voltage data and current data of the corresponding sub-interval. A power point determination unit is connected to each of the power point tracking units and is used to determine the global maximum power point of the solar panel according to the local maximum power point of each of the sub-intervals.

7. The global maximum power point tracking system with segmented scanning as claimed in claim 6, characterized in that: The power point tracking module also includes: A parameter adjustment unit, connected to the power point determination unit, and configured to: dynamically adjust the scanning frequency based on the global maximum power point; The signal acquisition unit is connected to the parameter adjustment unit, and is used to periodically acquire the voltage data and current data of the corresponding sub-interval according to the latest adjusted scanning frequency.

8. The global maximum power point tracking system with segmented scanning as claimed in claim 6, characterized in that: The maximum power point tracking algorithm is at least one of a perturbation and observation method, an incremental conductance method, a temperature compensation method and a short-circuit current method.

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