Photovoltaic optimizer

Abstract

The photovoltaic optimizer is suitable for a photovoltaic system, the photovoltaic optimizer is electrically connected with a photovoltaic module and an inverter, the photovoltaic optimizer comprises a switching module, a control module and a conversion module, the switching module is used for switching working modes of the photovoltaic optimizer, the working modes comprise a disconnection mode and an MPPT mode, and the switching module is used for switching the working modes of the photovoltaic optimizer. The working modes further comprise a straight-through mode and / or a bypass mode; the control module controls the switching module to switch among different working modes according to the working condition of the photovoltaic optimizer; and the conversion module is connected with the control module, and the conversion module is used for adjusting the output current and the output voltage of the photovoltaic optimizer, so that the photovoltaic optimizer outputs stable current and voltage to the inverter. Through the arrangement, when the photovoltaic system fails, the photovoltaic optimizer has better response capability, so that the power output of the photovoltaic system is ensured.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic equipment, and in particular to a photovoltaic optimizer. Background Art

[0002] Solar photovoltaic arrays are usually laid out in relatively open areas, such as rooftops, plains, and mountainsides. Because the laying area is large and easily affected by weather, plant shading, and the angle of the sun, even in the same area, the power generation efficiency of several photovoltaic arrays is different. Due to the barrel effect in photovoltaic power generation, if a photovoltaic panel in a photovoltaic array is damaged or is blocked by plants, resulting in a decrease in power generation efficiency, the overall power generation efficiency of the photovoltaic array will decrease.

[0003] In order to improve the power generation efficiency of photovoltaic module arrays, the conventional practice is to add photovoltaic optimizers to photovoltaic modules. Photovoltaic power optimizers are electronic devices that can be adjusted between photovoltaic panels and inverters to adjust the output power of photovoltaic panels so that they can reach maximum power output. The output power of photovoltaic panels is affected by many factors, such as temperature, light intensity, shadows, etc. Photovoltaic power optimizers monitor and adjust these factors to maximize the output power of photovoltaic panels, thereby improving the efficiency of photovoltaic power generation systems.

[0004] Photovoltaic power optimizers are used to improve the power generation efficiency of components that protect photovoltaic systems, while ensuring the normal operation of photovoltaic systems and preventing and preventing equipment operation accidents. For example, when the surface temperature of photovoltaic panels is too high, the photovoltaic power optimizer can reduce the output power of the photovoltaic power optimizer, or disconnect the output of photovoltaic panels to prevent the panels from being damaged due to excessive temperature; when there is too much dust on the surface of photovoltaic panels, the photovoltaic power optimizer can shut down the photovoltaic panels to prevent the dust from affecting the performance of the photovoltaic panels, and bypass the photovoltaic battery group without affecting the operation of other photovoltaic battery groups in series.

[0005] Existing photovoltaic optimizers are not capable of preventing faults from happening and responding to faults after they occur, which can easily lead to the expansion of faults and fail to ensure the safety of personnel and the stable operation of equipment. Generally speaking, photovoltaic optimizers can control the disconnection of the faulty photovoltaic battery group from other photovoltaic battery groups in the event of a fault, but this can easily lead to a decrease in the overall production capacity of the photovoltaic system, affecting the overall stable operation of the photovoltaic system. Summary of the invention

[0006] In order to solve the deficiencies of the prior art, an object of the present invention is to provide a photovoltaic optimizer which has a high fault handling capability and can ensure the overall stable operation of the photovoltaic system.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] The present application provides a photovoltaic optimizer, which is suitable for a photovoltaic system. The input end of the photovoltaic optimizer is electrically connected to a photovoltaic component, and the output end of the photovoltaic optimizer is electrically connected to an inverter. The photovoltaic optimizer includes a switching module, a control module and a conversion module. The switching module is used to switch the working mode of the photovoltaic optimizer, wherein the working mode includes not only a disconnect mode and an MPPT mode, but also a pass-through mode and / or a bypass mode; the control module controls the switching module to switch between different working modes according to the working condition of the photovoltaic optimizer, wherein the working condition of the photovoltaic optimizer is determined according to the input current, input voltage, output current and output voltage of the photovoltaic optimizer; the conversion module is connected to the control module, and in the MPPT mode, the conversion module is used to adjust the output current and output voltage of the photovoltaic optimizer so that the photovoltaic optimizer outputs stable current and voltage to the inverter.

[0009] Further, the control module includes a first detection unit, which is used to detect the input voltage and the output voltage. If the input voltage is greater than a preset first voltage threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode;

[0010] If the input voltage is less than the first voltage threshold, the control module controls the switching module to switch the photovoltaic optimizer to the direct mode;

[0011] If the output voltage is greater than a preset second voltage threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, and the first voltage threshold and the second voltage threshold are different.

[0012] Furthermore, the control module further includes a second detection unit, which is used to detect the input current and output current of the photovoltaic optimizer. If the input current is greater than a preset first current threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode;

[0013] If the output current is greater than a preset second current threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode, and the first current threshold and the second current threshold are different.

[0014] Further, the control module determines the operating power of the photovoltaic optimizer according to the output voltage and the output current. When the operating power of the photovoltaic optimizer is greater than the rated power of the photovoltaic optimizer and the time for maintaining the operating power is less than a preset time threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode;

[0015] When the operating power of the photovoltaic optimizer is greater than the rated power of the photovoltaic optimizer and the time for maintaining the operating power is greater than or equal to a preset time threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode.

[0016] Furthermore, the control module determines the conversion efficiency of the conversion module based on the input voltage and the output voltage. When the conversion efficiency of the conversion module is less than a preset conversion efficiency threshold, or the loss of the output voltage is greater than or equal to the loss threshold, the control module controls the switching module to switch the photovoltaic optimizer to the pass-through mode.

[0017] Furthermore, the photovoltaic optimizer further comprises a first acquisition module for collecting ambient temperature, the working condition of the photovoltaic optimizer is also determined according to the ambient temperature, and the control module controls the switching module to switch between different working modes according to the ambient temperature;

[0018] If the ambient temperature is greater than or equal to a preset first ambient temperature threshold and less than or equal to a preset second ambient temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, wherein the first ambient temperature threshold is less than the second ambient temperature threshold;

[0019] If the ambient temperature is greater than the second ambient temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the disconnect mode.

[0020] Furthermore, the photovoltaic optimizer further comprises a second acquisition module for acquiring the temperature of the conversion module, the working condition of the photovoltaic optimizer is also determined according to the temperature of the conversion module, and the control module controls the switching module to switch between different working modes according to the temperature of the conversion module;

[0021] If the conversion module temperature is greater than or equal to a preset first conversion module temperature threshold and less than or equal to a preset second conversion module temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, wherein the first conversion module temperature threshold is less than the second conversion module temperature threshold;

[0022] If the conversion module temperature is greater than the second conversion module temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode.

[0023] Further, the photovoltaic optimizer also includes a third acquisition module for collecting the optimizer temperature, the working condition of the photovoltaic optimizer is also determined according to the optimizer temperature, and the control module controls the switching module to switch between different working modes according to the optimizer temperature;

[0024] If the optimizer temperature is greater than or equal to a preset first optimizer temperature threshold and less than or equal to a preset second optimizer temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, wherein the first optimizer temperature threshold is less than the second optimizer temperature threshold;

[0025] If the optimizer temperature is greater than the second optimizer temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the disconnect mode.

[0026] Furthermore, the control module sets the disconnect mode, bypass mode, pass-through mode and MPPT mode in order from high to low priority. When the control module determines at least two different working modes according to the working condition of the photovoltaic optimizer, the control module controls the switching module to switch the photovoltaic optimizer to a working mode with a higher priority.

[0027] Further, when the PV optimizer is in the pass-through mode, the conversion module is short-circuited and the PV assembly is electrically connected to the inverter;

[0028] When the PV optimizer is in bypass mode, the PV optimizer is disconnected from the inverter to stop the electrical energy generated by the PV panels from being output externally.

[0029] The photovoltaic optimizer can switch to a corresponding working mode according to the working conditions of the photovoltaic system, including a disconnect mode, an MPPT mode, a pass-through mode and a bypass mode, so that the photovoltaic optimizer can output a stable current or voltage, improve the photovoltaic optimizer's ability to respond to faults, make the operation of the photovoltaic system more stable, and at the same time improve the power generation efficiency of the photovoltaic system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a connection block diagram of a photovoltaic system in an embodiment of the present application;

[0031] Figure 2 This is a schematic diagram of the structure of the photovoltaic optimizer in the embodiment of the present application.

[0032] Figure 3 This is a connection diagram of a photovoltaic optimizer in an embodiment of the present application;

[0033] Figure 4 This is a connection diagram of the switching module in the embodiment of the present application;

[0034] Figure 5 This is a connection block diagram of a photovoltaic optimizer in an embodiment of the present application;

[0035] Figure 6 This is a flow chart of switching the working mode of the photovoltaic optimizer in the embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the specific implementation modes of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the implementation modes of the present invention.

[0037] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0039] This application provides Figure 1 A photovoltaic optimizer 11 is shown, suitable for Figure 2 The photovoltaic system shown in the figure includes at least a photovoltaic module 12 and an inverter 13. The photovoltaic module 12 is used to convert solar energy into electrical energy and send it to a battery for storage or to drive a load to work. Since the electrical energy generated by the solar panel is direct current, and the electrical energy required for household or industrial use is alternating current. The inverter 13 converts direct current into alternating current so that the electrical energy generated by the solar panel can be used for household or industrial use. In addition, the inverter 13 can also monitor the output of electrical energy, including parameters such as the output power, voltage, and current of the electrical energy. By monitoring and managing electrical energy, abnormal electrical energy output can be discovered in a timely manner to ensure the normal operation of the photovoltaic system.

[0040] Specifically, the input end of the photovoltaic optimizer 11 is electrically connected to the photovoltaic assembly 12 , and the output end of the photovoltaic optimizer 11 is electrically connected to the inverter 13 .

[0041] like Figure 3 As shown, as an implementation, the photovoltaic optimizer 11 includes a switching module 111, a control module 112 and a conversion module 113. The switching module 111 is used to switch the working mode of the photovoltaic optimizer 11, wherein the working mode includes a through mode and / or a bypass mode in addition to the common disconnection mode and MPPT (Maximum Power Point Tracking) mode.

[0042] The control module 112 controls the switching module 111 to switch between different working modes according to the working condition of the photovoltaic optimizer 11. It should be noted that the working condition of the photovoltaic optimizer 11 is determined according to the input voltage, output voltage, input current and output current of the photovoltaic optimizer 11.

[0043] The conversion module 113 is electrically connected to the control module 112 . In the MPPT mode, the conversion module 113 is used to adjust the output current and output voltage of the photovoltaic optimizer 11 so that the photovoltaic optimizer 11 outputs stable current and voltage to the inverter 13 .

[0044] Specifically, the switching module 111 is integrated with the control module 112 , and the control module 112 controls the switching module 111 to switch the working mode of the photovoltaic optimizer 11 to at least include a digital control mode and an analog control mode.

[0045] Exemplarily, the digital control method refers to controlling the switching module 111 by converting the control signal into a digital signal, and a microcontroller or a digital signal processor is usually used as the control module 112. The specific operation method is to input the data to be controlled into the control module 112, and the control module 112 automatically calculates and outputs the control signal, thereby controlling the switching module 111 to switch the working mode of the photovoltaic optimizer 11.

[0046] Exemplarily, the analog control method refers to controlling the switching module 111 by directly using an analog signal as a control signal, and usually an amplifier or a comparator is used as the control module 112. The specific operation method is to input the analog signal to be controlled into the control module 112, and then output the control signal after amplification, filtering and other operations are performed inside the control module 112, so as to control the switching module 111 to switch the working mode of the photovoltaic optimizer 11.

[0047] It should be noted that different types of control modules 112 have different control accuracy and response speed. At the same time, when performing switch control, different control modules 112 and control methods need to be selected according to actual conditions.

[0048] As an implementation method, when the working modes include disconnect mode, MPPT mode and pass-through mode, the photovoltaic optimizer 11 can directly electrically connect the photovoltaic component 12 to the inverter 13 when the input voltage is undervoltage, thereby reducing the energy loss between the photovoltaic component 12 and the inverter 13.

[0049] Optionally, when the working modes include disconnection mode, MPPT mode and bypass mode, the photovoltaic optimizer 11 can stop the power generated by the photovoltaic module 12 from being output when the input voltage is overvoltage or the input current is overcurrent, while ensuring the normal operation of the photovoltaic system. Through the above settings, when the overvoltage or overcurrent situation stops, the photovoltaic optimizer 11 can respond to the control of the photovoltaic optimizer 11 in time and continue to output power to the outside, so that the photovoltaic system has a better response capability to occasional faults.

[0050] Optionally, when the working modes include disconnect mode, MPPT mode, bypass mode and pass-through mode, the photovoltaic optimizer 11 has better fault response capability and more contingency measures, which can reduce the voltage loss between the photovoltaic component 12 and the inverter 13, and can also promptly control the photovoltaic component 12 to stop outputting the electric energy generated by the photovoltaic component 12 when a fault occurs in the photovoltaic system.

[0051] This application provides Figure 4 The connection diagram of the switching module 111 shown in the figure, the switching module 111 includes a first position S1, a second position S2, a third position S3 and a fourth position S4, wherein when the switching module 111 is in the first position S1, the photovoltaic optimizer 11 is in a disconnection mode; when the switching module 111 is in the second position S2, the photovoltaic optimizer 11 is in a bypass mode; when the switching module 111 is in the third position S3, the photovoltaic optimizer 11 is in a pass-through mode; when the switching module 111 is in the fourth position S4, the photovoltaic optimizer 11 is in an MPPT mode.

[0052] It should be noted that the switching module 111 also includes a bypass switch S5. When the switching module 111 is in the second position S2, the bypass switch S5 is closed so that the photovoltaic assembly 12 still maintains normal operation but does not output electrical energy to the outside. The bypass switch S5 can be a relay. When the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode, the control module 112 simultaneously outputs a control signal to control the bypass switch S5 to be closed.

[0053] like Figure 5 As shown, as an implementation, the control module 112 includes a first detection unit 1121, and the first detection unit 1121 is used to detect the input voltage and output voltage of the photovoltaic optimizer 11. The first detection unit 1121 can be one or more combinations of a resistor divider, a comparator, an onboard analog-to-digital converter, and a reset IC.

[0054] Specifically, if the input voltage is greater than a preset first voltage threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode. The first voltage threshold is generally the rated input voltage of the photovoltaic optimizer 11, so as to avoid the photovoltaic optimizer 11 and related components being damaged due to excessive input voltage of the photovoltaic optimizer 11. When the input voltage is greater than the first voltage threshold, the photovoltaic optimizer 11 is in the bypass mode so that the photovoltaic assembly 12 remains in normal operation but does not output electrical energy to the outside.

[0055] It should be noted that in a photovoltaic system, several photovoltaic modules 12 are connected in series to form a photovoltaic string. In the related art, if one or more photovoltaic modules 12 in the photovoltaic modules 12 fail and the input voltage of the photovoltaic optimizer 11 connected to the photovoltaic modules 12 is greater than a first voltage threshold, the connection between the photovoltaic modules 12 and the photovoltaic optimizer 11 is generally disconnected to ensure the normal operation of the entire photovoltaic system. However, since the failed photovoltaic module 12 is connected in series with the adjacent normally operating photovoltaic module 12, if the failed photovoltaic module 12 is disconnected, the entire photovoltaic string stops operating, thereby reducing the power generation efficiency of the entire photovoltaic system.

[0056] In this embodiment, when the input voltage is greater than a preset first voltage threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode, and the photovoltaic string where the failed photovoltaic component 12 is located can still operate normally.

[0057] Specifically, when the photovoltaic optimizer 11 is in the bypass mode, the photovoltaic optimizer 11 is disconnected from the inverter 13 so that the electric energy generated by the photovoltaic assembly 12 connected to the photovoltaic optimizer 11 stops being output externally.

[0058] Problems that may cause the input voltage to be greater than the first voltage threshold include: insufficient DC load, excessive light intensity, or a failure of the photovoltaic component 12 .

[0059] Optionally, if the input voltage is less than the first voltage threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the direct mode. Problems that may cause the input voltage to be less than the first voltage threshold are: insufficient light intensity and the photovoltaic component 12 being blocked. This improves the power generation efficiency of the photovoltaic component 12.

[0060] Optionally, if the output voltage is greater than a preset second voltage threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the MPPT mode, wherein the first voltage threshold and the second voltage threshold are different, thereby ensuring that the photovoltaic component 12 has a stable energy output, thereby improving the stability of the photovoltaic system operation.

[0061] like Figure 5 As shown, as an implementation method, the control module 112 also includes a second detection unit 1122, which is used to detect the input current and output current of the photovoltaic optimizer 11. If the input current is greater than a preset first current threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode.

[0062] Specifically, the second detection unit 1122 can be a current comparator, whose basic working principle is to input two currents into the circuit, compare them through a comparator inside the circuit, and output a signal (high level or low level) related to the input current size, which is used to control other devices or provide a signal to the control module 112 for processing.

[0063] For example, if the light intensity is too high and the current output by the photovoltaic module 12 is too high, the current load of the photovoltaic optimizer 11 will increase, which may easily cause the photovoltaic optimizer 11 to heat up or short-circuit. At this time, the photovoltaic optimizer 11 switches to the bypass mode to disconnect the connection between the photovoltaic module 12 and the photovoltaic optimizer 11, but the photovoltaic module 12 remains in operation until the current output by the photovoltaic module 12 returns to normal. This avoids affecting the operating status of other photovoltaic modules 12 in the same string, thereby ensuring the stable operation of the photovoltaic system.

[0064] Optionally, if the output current is greater than a preset second current threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode, thereby ensuring the stable operation of the photovoltaic system, which will not be elaborated here.

[0065] like Figure 5 As shown, as an implementation method, the control module 112 determines the operating power of the photovoltaic optimizer 11 according to the output voltage and the output current. When the operating power of the photovoltaic optimizer 11 is greater than the rated power of the photovoltaic optimizer 11 and the time for the photovoltaic optimizer 11 to maintain the operating power is less than a preset time threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the MPPT mode.

[0066] Exemplarily, the preset time threshold is 30s. Even if the operating power of the photovoltaic optimizer 11 is greater than the rated power of the photovoltaic optimizer 11, if the operating power is maintained for less than 30s, the photovoltaic optimizer 11 switches to the MPPT mode, thereby avoiding occasional failures of the photovoltaic component 12 that cause the photovoltaic component 12 to be disconnected, so as to make the operation of the photovoltaic system more stable and improve the power generation efficiency of the photovoltaic component 12.

[0067] Furthermore, when the operating power of the PV optimizer 11 is greater than the rated power of the PV optimizer 11 and the time for maintaining the operating power is greater than or equal to a preset time threshold, the control module 112 controls the switching module 111 to switch the PV optimizer 11 to the bypass mode.

[0068] Exemplarily, if the PV optimizer 11 maintains operating power for 30 seconds or longer, the PV optimizer 11 switches to bypass mode to avoid damage to related equipment (PV modules 12, PV optimizer 11, etc.) due to prolonged failure time.

[0069] like Figure 5 As shown, as an implementation method, the control module 112 can also determine the conversion efficiency of the conversion module 113 based on the input voltage and the output voltage. When the conversion efficiency of the conversion module 113 is less than a preset conversion efficiency threshold, or the loss of the output voltage is greater than or equal to the loss threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the pass-through mode.

[0070] Exemplarily, the input voltage is converted into a stable output voltage after being optimized by the conversion module 113. If the voltage loss is greater than 20W at this time, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the direct-pass mode, thereby improving the power generation efficiency of the photovoltaic component 12.

[0071] Exemplarily, if the conversion efficiency of the conversion module 113 is less than 0.7, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the direct mode, thereby improving the power generation efficiency of the photovoltaic module 12. The conversion efficiency of the conversion module 113 satisfies the following relationship:

[0072]

[0073] Compared with the related art, if the input voltage of the photovoltaic optimizer 11 is too small, the conversion efficiency of the conversion module 113 is too low, or the voltage loss of the conversion module 113 is too large, the output power is generally increased by controlling the photovoltaic optimizer 11 to improve the power generation efficiency of the photovoltaic component 12. However, increasing the output power requires working in conjunction with the conversion module 113. Even if the power generation efficiency can be increased to a certain extent, the conversion module 113 has a certain voltage loss, which makes it impossible to maximize the output power.

[0074] In this embodiment, the through mode is that the conversion module 113 is short-circuited to electrically connect the photovoltaic component 12 to the inverter 13, and the power output by the photovoltaic component 12 is directly transmitted to the inverter 13, thereby reducing the power loss in the intermediate process of power transmission.

[0075] like Figure 5 As shown, as an implementation, the photovoltaic optimizer 11 further includes a first acquisition module 114, which is used to obtain the ambient temperature of the area where the photovoltaic system is arranged. The working condition of the photovoltaic optimizer 11 is also determined according to the ambient temperature, and the control module 112 controls the switching module 111 to switch between different working modes according to the ambient temperature.

[0076] Specifically, the first acquisition module 114 is a temperature sensing device. The first acquisition module 114 is connected to the control module 112 . The first acquisition module 114 acquires the ambient temperature and packages the ambient temperature into a sampling signal and sends it to the control module 112 .

[0077] The first acquisition module 114 can be disposed outside the photovoltaic optimizer 11 , and any photovoltaic optimizer 11 is configured with a corresponding first acquisition module 114 .

[0078] Optionally, since the photovoltaic strings composed of several photovoltaic components 12 are in the same position and the ambient temperatures of the photovoltaic optimizers 11 under the same photovoltaic string are basically the same, the first acquisition module 114 can also be connected in parallel with several photovoltaic optimizers 11, so that the first acquisition module 114 sends the sampling signals to different photovoltaic optimizers 11 under the same photovoltaic string, respectively, thereby reducing the installation cost of the photovoltaic system.

[0079] Exemplarily, if the ambient temperature is greater than or equal to a preset first ambient temperature threshold and less than or equal to a preset second ambient temperature threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the MPPT mode, wherein the first ambient temperature threshold is less than the second ambient temperature threshold. Through the above settings, within the range in which the photovoltaic optimizer 11 can operate normally, the power generation efficiency of the photovoltaic system is maximized, and the stability of the photovoltaic system can be taken into account.

[0080] Exemplarily, if the ambient temperature is greater than the second ambient temperature threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the disconnection mode.

[0081] like Figure 5 As shown, as an optional implementation, the photovoltaic optimizer 11 also includes a second acquisition module 115, and the connection relationship of the second acquisition module 115 is consistent with the connection relationship of the first acquisition module 114, which will not be repeated here. The difference is that the second acquisition module 115 is used to collect the temperature of the conversion module 113 (the temperature of the conversion module 113), the working condition of the photovoltaic optimizer 11 is also determined according to the temperature of the conversion module 113, and the control module 112 controls the switching module 111 to switch between different working modes according to the temperature of the conversion module 113.

[0082] Exemplarily, if the temperature of the conversion module 113 is greater than or equal to a preset first conversion module 113 temperature threshold and less than or equal to a preset second conversion module 113 temperature threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the MPPT mode, wherein the first conversion module 113 temperature threshold is less than the second conversion module 113 temperature threshold;

[0083] Exemplarily, if the temperature of the conversion module 113 is greater than the second conversion module 113 temperature threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode.

[0084] Through the above configuration, within the normal operating range of the photovoltaic optimizer 11, the power generation efficiency of the photovoltaic system is maximized, while taking into account the stability of the photovoltaic system.

[0085] like Figure 5 As shown, as an optional implementation, the photovoltaic optimizer 11 also includes a third acquisition module 116, and the connection relationship of the third acquisition module 116 is consistent with the connection relationship of the first acquisition module 114, which will not be repeated here. The difference is that the third acquisition module 116 is used to collect the optimizer temperature (the temperature of the photovoltaic optimizer 11), the working condition of the photovoltaic optimizer 11 is also determined according to the optimizer temperature, and the control module 112 controls the switching module 111 to switch between different working modes according to the temperature of the conversion module 113.

[0086] Exemplarily, if the optimizer temperature is greater than or equal to a preset first optimizer temperature threshold and less than or equal to a preset second optimizer temperature threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the MPPT mode, wherein the first optimizer temperature threshold is less than the second optimizer temperature threshold;

[0087] Exemplarily, if the optimizer temperature is greater than the second optimizer temperature threshold, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the disconnection mode.

[0088] Through the above configuration, within the normal operating range of the photovoltaic optimizer 11, the power generation efficiency of the photovoltaic system is maximized, while taking into account the stability of the photovoltaic system.

[0089] In summary, in the embodiment of the present application, a first detection unit 1121, a second detection unit 1122, a first acquisition module 114, a second acquisition module 115 and a third acquisition module 116 are provided to enable the photovoltaic optimizer 11 to monitor various faults in the photovoltaic system in real time, and the means for handling the faults are more diverse, so as to make the power generation efficiency of the photovoltaic system higher and the working state more stable.

[0090] The switching process of the working mode of the photovoltaic optimizer 11 is as follows: Figure 6 shown.

[0091] As an implementation method, the control module 112 sets the disconnect mode, bypass mode, pass-through mode and MPPT mode in order from high to low priority. When the control module 112 determines at least two different working modes according to the working conditions of the photovoltaic optimizer 11, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to a working mode with a higher priority.

[0092] Specifically, the disconnect mode is the first priority, the bypass mode is the second priority, the direct mode is the third priority, and the MPPT mode is the fourth priority, wherein the first priority is greater than the second priority, the second priority is greater than the third priority, and the third priority is greater than the fourth priority. If the photovoltaic optimizer 11 simultaneously has the following conditions: the input voltage is greater than the preset first voltage threshold, and the output voltage is greater than the preset second voltage threshold. According to the respective priorities of different working modes, at this time, the control module 112 controls the switching module 111 to switch the photovoltaic optimizer 11 to the bypass mode.

[0093] It should be noted that other possible situations where different faults occur simultaneously are not described in detail here. In the case of multiple faults occurring simultaneously, implementations that can implement switching of different working modes of the photovoltaic optimizer 11 according to preset priorities are all within the scope of protection claimed in this application.

[0094] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A photovoltaic optimizer, suitable for a photovoltaic system, wherein the input end of the photovoltaic optimizer is electrically connected to a photovoltaic module, and the output end of the photovoltaic optimizer is electrically connected to an inverter, characterized in that: The photovoltaic optimizer comprises: A switching module, used for switching the working mode of the photovoltaic optimizer, wherein the working mode includes not only the disconnect mode and the MPPT mode, but also the through mode and / or the bypass mode; A control module, wherein the control module controls the switching module to switch between the different working modes according to the working condition of the photovoltaic optimizer, wherein the working condition of the photovoltaic optimizer is determined according to the input current, input voltage, output current and output voltage of the photovoltaic optimizer; A conversion module is connected to the control module. In the MPPT mode, the conversion module is used to adjust the output current and the output voltage of the photovoltaic optimizer so that the photovoltaic optimizer outputs stable current and voltage to the inverter.

2. The photovoltaic optimizer according to claim 1, characterized in that: The control module includes a first detection unit, which is used to detect the input voltage and the output voltage. If the input voltage is greater than a preset first voltage threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode; If the input voltage is less than the first voltage threshold, the control module controls the switching module to switch the photovoltaic optimizer to the direct mode; If the output voltage is greater than a preset second voltage threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, and the first voltage threshold and the second voltage threshold are different.

3. The photovoltaic optimizer according to claim 2, characterized in that: The control module further includes a second detection unit, which is used to detect the input current and output current of the photovoltaic optimizer. If the input current is greater than a preset first current threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode; If the output current is greater than a preset second current threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode, and the first current threshold and the second current threshold are different.

4. The photovoltaic optimizer according to claim 1, characterized in that: The control module determines the operating power of the photovoltaic optimizer according to the output voltage and the output current. When the operating power of the photovoltaic optimizer is greater than the rated power of the photovoltaic optimizer and the time for maintaining the operating power is less than a preset time threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode; When the operating power of the photovoltaic optimizer is greater than the rated power of the photovoltaic optimizer and the time for maintaining the operating power is greater than or equal to the preset time threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode.

5. The photovoltaic optimizer according to claim 1, characterized in that: The control module determines the conversion efficiency of the conversion module according to the input voltage and the output voltage. When the conversion efficiency of the conversion module is less than a preset conversion efficiency threshold, or the loss of the output voltage is greater than or equal to a loss threshold, the control module controls the switching module to switch the photovoltaic optimizer to the pass-through mode.

6. The photovoltaic optimizer according to claim 1, characterized in that: The photovoltaic optimizer further comprises a first acquisition module for acquiring ambient temperature, the working condition of the photovoltaic optimizer is also determined according to the ambient temperature, and the control module controls the switching module to switch between different working modes according to the ambient temperature; If the ambient temperature is greater than or equal to a preset first ambient temperature threshold and less than or equal to a preset second ambient temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, wherein the first ambient temperature threshold is less than the second ambient temperature threshold; If the ambient temperature is greater than the second ambient temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the disconnection mode.

7. The photovoltaic optimizer according to claim 6, characterized in that: The photovoltaic optimizer further comprises a second acquisition module for acquiring the temperature of the conversion module. The working condition of the photovoltaic optimizer is also determined according to the temperature of the conversion module. The control module controls the switching module to switch between different working modes according to the temperature of the conversion module. If the temperature of the conversion module is greater than or equal to a preset first conversion module temperature threshold and less than or equal to a preset second conversion module temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, wherein the first conversion module temperature threshold is less than the second conversion module temperature threshold; If the conversion module temperature is greater than the second conversion module temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the bypass mode.

8. The photovoltaic optimizer according to claim 7, characterized in that: The photovoltaic optimizer further includes a third acquisition module for acquiring the optimizer temperature, the working condition of the photovoltaic optimizer is also determined according to the optimizer temperature, and the control module controls the switching module to switch between different working modes according to the optimizer temperature; If the optimizer temperature is greater than or equal to a preset first optimizer temperature threshold and less than or equal to a preset second optimizer temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the MPPT mode, wherein the first optimizer temperature threshold is less than the second optimizer temperature threshold; If the optimizer temperature is greater than the second optimizer temperature threshold, the control module controls the switching module to switch the photovoltaic optimizer to the disconnection mode.

9. The photovoltaic optimizer according to any one of claims 1 to 8, characterized in that: The control module sets the disconnect mode, the bypass mode, the pass-through mode and the MPPT mode in order from high to low priority. When the control module determines at least two different working modes according to the working condition of the photovoltaic optimizer, the control module controls the switching module to switch the photovoltaic optimizer to the working mode with higher priority.

10. The photovoltaic optimizer according to claim 1, characterized in that: When the photovoltaic optimizer is in the direct-through mode, the conversion module is short-circuited, and the photovoltaic assembly is electrically connected to the inverter; When the photovoltaic optimizer is in the bypass mode, the photovoltaic optimizer is disconnected from the inverter to stop outputting the electric energy generated by the photovoltaic assembly.

Images