Photovoltaic system with point-mounted component-level optimizer and installation method thereof

Abstract

The present application provides a photovoltaic system with a point-mounted component-level optimizer and an installation method thereof. The method includes: determining a target component from the photovoltaic system according to a preset installation ratio of the component MPPT controller; installing the component MPPT controller on the target component. For the entire photovoltaic system, according to the installation ratio, the component MPPT controller is only installed on some components, which greatly reduces the installation cost and invalid energy loss of the component MPPT controller of the photovoltaic system while increasing the power generation increment, and effectively improves the economic benefits. It effectively reduces the number of hardware installations, reduces the investment of time and cost, and reducing the number of hardware installations can bring fewer failure points and less standby power consumption.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic systems, and in particular to a photovoltaic system with a point-mounted component-level optimizer and an installation method thereof. Background Art

[0002] The construction of photovoltaic power stations is easily restricted by environmental conditions, which makes it easy for battery modules to be shadowed when working. Photovoltaic power stations use centralized inversion. The MPPT (Maximum Power Point Tracking) adjustment of the inverter cannot ensure that each battery module is in ideal conditions and cannot output maximum power, resulting in partial power loss. This problem is solved by installing a component MPPT controller. At present, the installation method of the component MPPT controller is to install all the photovoltaic components of the photovoltaic system. Although the loss of electricity can be excavated, the installation cost is high. At the same time, with the increase of hardware, the number of fault points is prone to increase. In addition, for photovoltaic systems with abnormal components, the control self-loss after all the component MPPT controllers are installed offsets the increase in electricity obtained by reducing the abnormal loss of the photovoltaic system. Summary of the invention

[0003] In view of the above problems, the present application provides a photovoltaic system with a point-mounted component MPPT controller and an installation method thereof. The technical solution of the present application is as follows:

[0004] According to a first aspect of an embodiment of the present application, there is provided a method for installing a point-mounted assembly MPPT controller, comprising:

[0005] Determine the target components from the photovoltaic system according to the preset installation ratio of component MPPT controllers;

[0006] An assembly MPPT controller is installed on the target assembly.

[0007] In some embodiments of the present application, the installation ratio of the MPPT controller of the component is preset, including:

[0008] The installation ratio of the component MPPT controllers is determined based on the power generation increase after the component MPPT controllers are installed and the cost of installing the component MPPT controllers.

[0009] In some embodiments of the present application, the step of installing an MPPT controller on the target component includes:

[0010] One component MPPT controller is installed for each target component, or one component MPPT controller is installed for multiple target components, or, for the target components whose power exceeds a preset range, multiple component MPPT controllers are installed.

[0011] In some embodiments of the present application, Figure 3 As shown, the step of determining a target component from a photovoltaic system includes:

[0012] The components in the photovoltaic system are inspected and abnormal components are locked, wherein the target components include abnormal components that meet the fault type requirements among the abnormal components.

[0013] In some embodiments of the present application, determining the target component from the photovoltaic system further includes:

[0014] Obtaining quantity information of the abnormal components;

[0015] If the quantity information is less than the installation ratio, it is predicted that a set of predicted components will be blocked with seasonal changes or environmental changes; the target component includes the abnormal component and the set of predicted components.

[0016] In some embodiments of the present application, inspecting components in the photovoltaic system and locking abnormal components includes:

[0017] The components in the photovoltaic system are inspected by a drone inspection system to identify abnormal components; wherein the abnormal components include components that produce hot spots and components with damaged appearance.

[0018] In some embodiments of the present application, inspecting components in the photovoltaic system and locking abnormal components includes:

[0019] For the photovoltaic system, component IV detection, string IV detection and EL detection are performed to lock abnormal components, and the abnormal components include components with power attenuation.

[0020] In some embodiments of the present application, the inspection of components in the photovoltaic system and locking of abnormal components further includes:

[0021] For the photovoltaic system, determine whether there is power loss in the photovoltaic system through power generation analysis and PR value analysis;

[0022] If there is power loss, it is determined that there are abnormal components in the photovoltaic system.

[0023] In some embodiments of the present application, the method further includes:

[0024] Obtaining a first power of a string to which the abnormal component belongs after the component MPPT controller is installed, and comparing the first power with a second power of a normal period when the components of the string to which the abnormal component belongs are not abnormal;

[0025] If the comparison result meets the preset condition, the component MPPT controller on the abnormal component is always in the installed state;

[0026] If the comparison result does not meet the preset conditions, the fault point of the abnormal component is further analyzed and corresponding processing is performed until the fault point of the abnormal component is resolved, and then the component MPPT controller connected to the abnormal component is removed.

[0027] According to a second aspect of an embodiment of the present application, a photovoltaic system with a point-mounted component-level optimizer is provided, the photovoltaic system comprising a plurality of components, and the plurality of components are installed with the method described in the first aspect to implement component MPPT controller installation.

[0028] The installation method and photovoltaic system of the point-mounted component MPPT controller provided in the embodiment of the present application, for the entire photovoltaic system, according to the installation ratio, only installs the component MPPT controller on some components, while increasing the power generation increment, greatly reducing the component MPPT controller installation cost and invalid energy loss of the photovoltaic system, and effectively improving economic benefits. It effectively reduces the number of hardware installations, reduces the investment of time and cost, and reducing the number of hardware installations can bring fewer failure points and less standby power consumption.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0031] Figure 1 It is a flow chart of a method for installing a point-mounted component MPPT controller according to an embodiment.

[0032] Figure 2 is an architecture diagram of a photovoltaic system according to an embodiment.

[0033] Figure 3 It is a schematic flow chart of a method for determining a target component according to an embodiment. DETAILED DESCRIPTION

[0034] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0035] It should be noted that the terms "first", "second", etc. in this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the application described here can be implemented in an order other than those illustrated or described here. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0036] Explanation of terms in this application:

[0037] The full name of MPPT (Maximum Power Point Tracking) controller is "Maximum Power Point Tracking" solar controller.

[0038] PR (Performance Ratio) value: It is an internationally accepted photovoltaic system quality evaluation indicator, which refers to the ratio of actual power generation to expected power generation and is dimensionless.

[0039] The construction of photovoltaic power stations is easily restricted by environmental conditions, which makes it easy for battery modules to be shaded when working. For example: the spacing between photovoltaic arrays is not large enough, and the front row of photovoltaic modules (referred to as modules) will shade the rear row of photovoltaic modules during sunrise and sunset; there are mountains or buildings near the power station to form shadows; in cloudy weather, part of the photovoltaic array is blocked by dark clouds.

[0040] The centralized inverter method is used in photovoltaic power stations. The MPPT adjustment of the inverter cannot ensure that each battery module is in ideal conditions, and the maximum power cannot be output, resulting in partial power loss.

[0041] The module MPPT controller (power optimizer or module optimizer) has internal buck-boost circuits and sensors to sample the output voltage and current of the solar panel in real time. It controls the buck-boost circuit through advanced MPPT algorithms to keep the solar panel working at maximum power, output matching string voltage and current, and maximize power generation.

[0042] The higher the output voltage, the smaller the output current; the larger the output current, the lower the output voltage. Only when the voltage and current are ideally matched can the battery module output the maximum power. When the irradiance decreases, the maximum power current becomes lower and the maximum power point shifts to low voltage.

[0043] What the component MPPT controller achieves is that when the component current is not large enough and the string is short-circuited, the component MPPT controller performs a step-down conversion to output a larger current; when the component current is too high and the power cannot be output, a step-up conversion is performed, the voltage at the output end of the component MPPT controller remains high, the current matches the string current, and the voltage at the component input end drops to the MPPT position, thereby outputting maximum power.

[0044] At present, the installation method of the component MPPT controller is to install the component MPPT controller on all the photovoltaic components of the photovoltaic system, and this installation method is defined as full installation. The disadvantages of the full installation method are: the component MPPT controller is expensive, and the cost of full installation investment is high; for power loss, the benefits of increased power generation from the full installation of the component MPPT controller may not necessarily be high; the component MPPT controller is meaningful for components that need to be "optimized" (such as shadow shading, or severe component attenuation, etc.), and has a higher significance after installation, but for components that do not have shadow shading or severe attenuation, not only does it not have an optimization effect, but it increases additional standby power consumption, and also increases the complexity of the entire photovoltaic system, thereby increasing the potential for failure.

[0045] Therefore, in response to this problem, the present application proposes a more scientific installation strategy for the component MPPT controller, that is, installing the component MPPT controller on some components, that is, fixed-point installation, to achieve point installation.

[0046] Figure 1 FIG. 1 is a flow chart of a method for installing a point-mounted MPPT controller according to an embodiment of the present application. Figure 1 As shown, the method may include the following steps.

[0047] S101, determining a target component from a photovoltaic system according to a preset installation ratio of component MPPT controllers;

[0048] When setting the installation ratio, many factors need to be considered, such as the power generation increment after installing the component MPPT controller, the cost of installing the component MPPT controller, the output power, and the loss of the photovoltaic system, etc. The considerations are not limited to these. Different installation ratios will result in different power generation increments after installing the component MPPT controller in the photovoltaic system, and different costs for installing the component MPPT controller.

[0049] In this embodiment, optionally, the installation ratio of the component MPPT controllers is determined based on the power generation increment after the component MPPT controllers are installed and the cost of installing the component MPPT controllers.

[0050] There may be many screening conditions for determining the target components in the photovoltaic system where the component MPPT controller is to be installed, such as abnormal components, components prone to shading, evenly distributed components, etc.

[0051] S102, installing a component MPPT controller on the target component.

[0052] Each target component is equipped with one component MPPT controller, or multiple target components are equipped with one component MPPT controller, or, for the target component whose power exceeds the preset range, multiple component MPPT controllers are installed. For example, for a target component with relatively large power, two component MPPT controllers are installed.

[0053] The installation method of the point-mounted component MPPT controller of the embodiment of the present application is to install the component MPPT controller only on some components of the entire photovoltaic system according to the installation ratio, thereby greatly reducing the installation cost and invalid energy loss of the component MPPT controller of the photovoltaic system while increasing the power generation increment, and effectively improving economic benefits. It effectively reduces the number of hardware installations, reduces the investment of time and cost, and reducing the number of hardware installations can bring fewer failure points and less standby power consumption.

[0054] In some embodiments, the method for determining a target component from a photovoltaic system includes:

[0055] The components in the photovoltaic system are inspected and abnormal components are locked, wherein the target components include abnormal components that meet the fault type requirements among the abnormal components.

[0056] The output power of abnormal components is impaired, and it is necessary to install a component MPPT controller for optimization.

[0057] It can be understood that if a large number of abnormal components are detected, that is, if they exceed the installation ratio, all abnormal components need to be installed.

[0058] In general, the number of abnormal components is far less than the installation ratio, for example, the number of abnormal components is only 1%. At this time, the installation can be carried out according to the preset installation ratio, and the installation points cover all abnormal components. The selection of installation points for components that are not yet abnormal can be considered from multiple angles. For example, when determining the target component, you can consider installing components that are prone to obstruction, or randomly select, or predict which components are more prone to abnormalities. For example, for the selection of installation points for components that are not yet abnormal, predict which photovoltaic components are most likely to be obstructed, defective, etc. Some photovoltaic components are not obstructed in summer, but may be obstructed in winter. Some locations are prone to grass and trees, etc., which can be judged and predicted on site. It is also possible to judge which components are prone to aging, damage, etc. based on historical data.

[0059] Among them, for the predicted component set, the component MPPT controller can be installed dynamically, for example, the component MPPT controller is regularly installed and removed according to time changes to achieve dynamic changes.

[0060] In some embodiments, optionally, the method for determining a target component from a photovoltaic system further includes:

[0061] Obtaining quantity information of the abnormal components;

[0062] If the quantity information is less than the installation ratio, it is predicted that a set of predicted components will be blocked with seasonal changes or environmental changes; the target component includes the abnormal component and the set of predicted components.

[0063] After installing the MPPT controller on components that are not currently abnormal, it will also play an optimization role if defects occur later.

[0064] It should be noted that there are many ways to inspect components in a photovoltaic system and locate abnormal components. Different inspection methods may result in different abnormal components being inspected, and abnormal components are fault points.

[0065] In one implementation, inspecting components in the photovoltaic system and locking abnormal components includes:

[0066] The components in the photovoltaic system are inspected by a drone inspection system to identify abnormal components; wherein the abnormal components include components that produce hot spots and components with damaged appearance.

[0067] In yet another implementation, for the photovoltaic system, component IV detection, string IV detection, and EL detection are performed to lock abnormal components, where the abnormal components include components experiencing power attenuation.

[0068] It should be noted that there are many types of abnormal components (ie, fault types), and different processing strategies can be adopted for different abnormal types.

[0069] Because there are many factors that may cause the abnormal components to fail, it is impossible to find the cause of the failure at once, and invisible failures are difficult to detect and handle. Therefore, a remote diagnosis method can be used. The causes of the failure may include A) array power failure, B) low array input power, C) low inverter efficiency, D) inverter damage, E) circuit breaker failure, and F) data collector damage.

[0070] For different fault types, the target component includes the abnormal components that meet the fault type requirements among the abnormal components, that is, the component MPPT controller is not installed for all abnormal components of all fault types. For example, if the abnormal component is a component with damaged appearance, the abnormal component is directly short-circuited and the fault is handled immediately. If there is obvious damage to the appearance, which endangers the safe operation of the string or even the station area, the abnormal component can be directly short-circuited. If the abnormal component has no abnormal appearance, the component MPPT controller is directly installed to quickly and temporarily repair the string. For example, if there are bird droppings or sticky leaves on the component, such obstructions will cause hot spots, but will not endanger the safety of the string, and on-site processing will be more troublesome. Generally, the operation and maintenance of photovoltaic power stations will not handle it, and will not even make records, waiting for the component to be cleaned or the rain to clean up the abnormal points. Photovoltaic power stations are generally located in areas with little rain, the frequency of rain is not high, and the frequency of component cleaning is even lower. In this way, the cycle of abnormal state will be relatively long, continuously reducing the power of the string, and affecting the power generation for a long time. For such components that have no external damage but have external abnormalities, you can directly install the component MPPT controller to quickly improve the power drop caused by hot spots and other problems and increase the power generation of the string. After the component is cleaned, if the drone inspection finds that the component has returned to normal, the component MPPT controller can be removed.

[0071] For example, if the attenuation of the component is greater than expected, the MPPT controller solution of the point-mounted component can improve the power of the string and maintain a high string power generation. If the abnormal component continues to decay rapidly and reaches a level that requires replacement. The replacement cycle of components is generally long, especially in the middle and late stages of the operation of photovoltaic power stations, when spare components of the same version have been used up, the iteration speed of component products on the market is fast, and the matching degree of the iterative components that can be purchased normally is relatively low, then the procurement and replacement cycle will become longer. During this period, the MPPT controller of the point-mounted component can continue to maintain the string at a higher power level.

[0072] Based on the above embodiment, the inspection of components in the photovoltaic system and locking of abnormal components further includes:

[0073] For the photovoltaic system, it is determined whether there is power loss in the photovoltaic system through power generation analysis and PR value analysis; if there is power loss, it is determined that there are abnormal components in the photovoltaic system.

[0074] The embodiment of the present application conducts a preliminary assessment of the photovoltaic system, analyzes the power loss of the photovoltaic system, influencing factors, etc., and determines whether there are abnormal components in the photovoltaic system, that is, whether it is necessary to install a component MPPT controller for the abnormal components.

[0075] Based on the above embodiment, optionally, the installation method of the point-mounted component MPPT controller may further include:

[0076] Obtaining a first power of a string to which the abnormal component belongs after the component MPPT controller is installed, and comparing the first power with a second power of a normal period when the components of the string to which the abnormal component belongs are not abnormal;

[0077] If the comparison result meets the preset condition, the component MPPT controller on the abnormal component is always in the installed state;

[0078] If the comparison result does not meet the preset conditions, the fault point of the abnormal component is further analyzed and corresponding processing is performed until the fault point of the abnormal component is resolved, and then the component MPPT controller connected to the abnormal component is removed.

[0079] For example, analyze the power comparison between the string after MPPT installation and the string during normal period. If it reaches more than 98% of the normal period, MPPT is installed and maintenance is completed. If it does not reach 98% of the normal period, MPPT is used as a means to temporarily increase the string power. Further analyze the fault point of the abnormal component. If there is no safety hazard, MPPT can be used as a temporary solution. After the fault point is completely resolved, the MPPT can be removed. Generally, the cycle of replacing components is relatively long. During this period before replacement, MPPT can be used as an effective temporary solution to effectively improve the abnormal string power by more than 3.2%.

[0080] The installation method of the point-mounted component MPPT controller of the embodiment of the present application is to install the component MPPT controller only on some components of the entire photovoltaic system according to the installation ratio, which greatly reduces the installation cost and invalid energy loss of the component MPPT controller of the photovoltaic system while increasing the power generation increment, and effectively improves the economic benefits. It effectively reduces the number of hardware installations, reduces the investment of time and cost, and reduces the number of hardware installations. It can bring fewer failure points and less standby power consumption. It can further accurately judge the abnormal components of the photovoltaic power station and achieve the best optimization effect. For photovoltaic components that are not installed with component MPPT controllers, after the component fails, the component MPPT controllers installed on other photovoltaic components will also play an optimization role, reducing the losses caused by the mismatch of the photovoltaic system.

[0081] Figure 2 is an architectural diagram of a photovoltaic system with a point-mounted component-level optimizer according to an embodiment of the present application. Figure 2 As shown, the photovoltaic system includes multiple components, and the multiple components use the above-mentioned point-mounted component MPPT controller installation method to achieve the installation of the component MPPT controller.

[0082] The photovoltaic system with a point-mounted component-level optimizer proposed in the embodiment of the present application, for the entire photovoltaic system, only some components are installed with component MPPT controllers according to the installation ratio, which greatly reduces the installation cost and invalid energy loss of the component MPPT controller of the photovoltaic system while increasing the power generation increment, and effectively improves economic benefits. It effectively reduces the number of hardware installations, reduces the investment in time and cost, and reduces the number of hardware installations. It can bring fewer failure points and less standby power consumption. It can further accurately judge the abnormal components of the photovoltaic power station and achieve the best optimization effect. For photovoltaic components that are not installed with component MPPT controllers, after the component fails, the component MPPT controllers installed on other photovoltaic components will also play an optimization role, reducing the losses caused by the mismatch of the photovoltaic system.

[0083] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only.

[0084] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for installing a point-mounted component MPPT controller, characterized in that: include: Determining the installation ratio of the component MPPT controller based on the power generation increment after installing the component MPPT controller and the cost of installing the component MPPT controller; Determining target components from the photovoltaic system according to a preset installation ratio of component MPPT controllers; including: obtaining quantity information of abnormal components; if the quantity information is less than the installation ratio, predicting a set of predicted components that will be blocked with seasonal changes or environmental changes; the target components include the abnormal components and the set of predicted components; Installing a component MPPT controller on the target component; Obtaining a first power of a string to which the abnormal component belongs after the component MPPT controller is installed, and comparing the first power with a second power of a normal period when the components of the string to which the abnormal component belongs are not abnormal; If the comparison result meets the preset condition, the component MPPT controller on the abnormal component is always in the installed state; If the comparison result does not meet the preset conditions, the fault point of the abnormal component is further analyzed and corresponding processing is performed until the fault point of the abnormal component is resolved, and then the component MPPT controller connected to the abnormal component is removed.

2. The method according to claim 1, characterized in that The step of installing an MPPT controller on the target component includes: One component MPPT controller is installed for each target component, or one component MPPT controller is installed for multiple target components, or, for the target components whose power exceeds a preset range, multiple component MPPT controllers are installed.

3. The method according to claim 1, characterized in that The step of determining a target component from a photovoltaic system comprises: The components in the photovoltaic system are inspected and abnormal components are locked, wherein the target components include abnormal components that meet the fault type requirements among the abnormal components.

4. The method according to claim 3, characterized in that The inspection of components in the photovoltaic system and locking of abnormal components include: The components in the photovoltaic system are inspected by a drone inspection system to identify abnormal components; wherein the abnormal components include components that produce hot spots and components with damaged appearance.

5. The method according to claim 4, characterized in that The inspection of components in the photovoltaic system and locking of abnormal components include: For the photovoltaic system, component IV detection, string IV detection and EL detection are performed to lock abnormal components, and the abnormal components include components with power attenuation.

6. The method according to claim 3, characterized in that The inspection of the components in the photovoltaic system and the locking of the abnormal components also include: For the photovoltaic system, determine whether there is power loss in the photovoltaic system through power generation analysis and PR value analysis; If there is power loss, it is determined that there are abnormal components in the photovoltaic system.

7. A photovoltaic system with a point-mounted component-level optimizer, characterized in that: The photovoltaic system includes a plurality of components, and the plurality of components are installed with a component MPPT controller using the method described in any one of claims 1 to 6.

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