Converter control method, electronic equipment and computer readable medium

Abstract

The invention provides a converter control method, electronic equipment and a computer readable medium, and the method comprises the steps: determining an input gain control value according to a difference value between an input voltage set value and an input voltage sampling value of a converter; determining an output gain control value according to a difference value between an output voltage target value and an output voltage sampling value of the converter; selecting a target gain control value; switching the converter into a working mode corresponding to the target gain control value, wherein the working mode is one of a power tracking mode and an output voltage limiting mode; in the power tracking mode, the converter is used for adjusting an input voltage actual value of the converter into an input voltage set value according to an input gain control value; in the output voltage limiting mode, the converter is used for adjusting the actual value of the output voltage of the converter to the target value of the output voltage according to the output gain control value. According to the method, the working modes can be automatically selected and switched, and the hardware overhead and cost can be reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic power generation technology, and in particular to a control method of a converter, an electronic device, and a computer-readable medium. Background Art

[0002] Photovoltaic converters can be used to convert the output power of photovoltaic panels and track their maximum power output. However, photovoltaic converters do not always need to operate in maximum power output tracking mode. In actual application scenarios, photovoltaic converters need to switch between maximum power output tracking mode and output voltage limiting mode according to actual conditions. Summary of the Invention

[0003] Embodiments of the present application provide a converter control method, an electronic device, and a computer-readable medium.

[0004] In a first aspect, an embodiment of the present application provides a control method for a converter, the method comprising: determining an input gain control value based on a difference between an input voltage setting value and an input voltage sampling value of the converter; determining an output gain control value based on a difference between an output voltage target value and an output voltage sampling value of the converter; selecting a target gain control value from the input gain control value and the output gain control value; when the operating mode corresponding to the selected target gain control value is different from the current operating mode, switching the converter to an operating mode corresponding to the target gain control value, wherein the operating mode is one of a power tracking mode and an output voltage limiting mode; in the power tracking mode, the converter is used to adjust the actual input voltage value of the converter to the input voltage setting value according to the input gain control value; in the output voltage limiting mode, the converter is used to adjust the actual output voltage value of the converter to the output voltage target value according to the output gain control value.

[0005] In a second aspect, an embodiment of the present application provides a photovoltaic power generation system, comprising: at least one photovoltaic component and at least one converter, the output end of each photovoltaic component being connected to the input of a converter; a converter, configured to execute any one of the above-mentioned converter control methods based on a received input voltage set value and a received output voltage target value.

[0006] In a third aspect, an embodiment of the present application provides an electronic device comprising: at least one processor; and a memory storing at least one program, wherein when the at least one program is executed by at least one processor, any one of the above-mentioned converter control methods is implemented.

[0007] In a fourth aspect, an embodiment of the present application provides a computer-readable medium having a computer program stored thereon, and when the computer program is executed by a processor, any of the above-mentioned converter control methods is implemented.

[0008] The converter control method, electronic device, and computer-readable medium provided in embodiments of the present application, after determining an input gain control value based on the difference between the converter's input voltage set value and the input voltage sampling value, and determining an output gain control value based on the difference between the converter's output voltage target value and the output voltage sampling value, can select a gain control value from the input gain control value and the output gain control value as a target gain control value. If the operating mode corresponding to the selected target gain control value is different from the current operating mode, the converter is switched to the operating mode corresponding to the target gain control value. In this converter control method, after calculating the input gain control value and the output gain control value, the corresponding operating mode can be automatically selected and switched based on the selection of the target gain control value and the subsequent comparison with the current operating mode, without the need for additional control devices or communication devices, which helps reduce hardware overhead and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic diagram of a photovoltaic power generation system in an embodiment of the present application.

[0010] Figure 2 Schematic diagram of photovoltaic output characteristic curve of an exemplary embodiment of the present application.

[0011] Figure 3 This is a flow chart of a method for controlling a converter provided in an embodiment of the present application.

[0012] Figure 4 A block diagram of a converter switching control system provided for an exemplary embodiment of the present application.

[0013] Figure 5 Schematic diagram of the operating point change process when switching from output voltage limiting mode to power tracking mode provided in an embodiment of the present application.

[0014] Figure 6 Schematic diagram of the voltage change process when the converter provided in an embodiment of the present application switches from output voltage limiting mode to power tracking mode.

[0015] Figure 7 Schematic diagram of the operating point change process when switching from power tracking mode to output voltage limiting mode provided in an embodiment of the present application.

[0016] Figure 8 Schematic diagram of the voltage change process when the converter provided in an embodiment of the present application switches from power tracking mode to output voltage limiting mode.

[0017] Figure 9 This is a block diagram of the control device of the converter provided in an embodiment of the present application.

[0018] Figure 10This is a block diagram of a photovoltaic power generation system provided according to an embodiment of the present application.

[0019] Figure 11 A block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0020] To enable those skilled in the art to better understand the technical solution of the present application, the photovoltaic converter mode control method, electronic device, and computer-readable medium provided in the present application are described in detail below with reference to the accompanying drawings.

[0021] Example embodiments will be described more fully hereinafter with reference to the accompanying drawings, but the example embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete and will fully convey the scope of this application to those skilled in the art.

[0022] In the absence of conflict, the various embodiments of the present application and the various features therein may be combined with each other.

[0023] As used herein, the term "and / or" includes any and all combinations of at least one of the associated listed items.

[0024] The terms used herein are used only to describe specific embodiments and are not intended to limit this application. As used herein, the singular forms "a," "an," and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It will also be understood that when the terms "comprising" and / or "made of" are used in this specification, the presence of the features, wholes, steps, operations, elements, and / or components is specified, but the presence or addition of at least one other feature, whole, step, operation, element, component, and / or group thereof is not excluded.

[0025] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this application, and will not be interpreted as having an idealized or overly formal meaning unless expressly defined as such herein.

[0026] Figure 1 A schematic diagram of a photovoltaic power generation system in an embodiment of the present application is shown. In this scenario, the photovoltaic power generation system includes: N photovoltaic panels 101 , a photovoltaic converter 102 corresponding to each photovoltaic panel 101 , a busbar 103 , and a subsequent device 104 .

[0027] Each photovoltaic panel 101 is connected in series with a photovoltaic converter 102 to form a combination. A plurality of such combinations are connected in series and parallel and then connected to a bus 103 . The bus 103 is connected to a subsequent device 104 to provide output power for the subsequent device 104 .

[0028] In an embodiment of the present application, each photovoltaic converter 1023 can convert the voltage output by the connected photovoltaic panel 101 into a voltage that meets the requirements of the bus 103. The bus 103 can be, for example, a high-voltage DC bus, and the downstream device 104 can be, for example, at least one of a load, an inverter, and other electronic devices.

[0029] The following combination Figure 2 , introduces the working characteristics and working principles of photovoltaic panels.

[0030] Figure 2 Schematic diagram of photovoltaic output characteristic curve of exemplary embodiment of the present application is shown. Figure 2 As shown, the output characteristic curve of the photovoltaic panel includes a current-voltage characteristic curve (IV curve) and a power-voltage characteristic curve (PV curve).

[0031] exist Figure 2 In FIG, the X-axis is the panel output voltage V, that is, the output voltage V of the photovoltaic panel, and the Y-axis includes the panel output current I and the panel output power P, that is, the output current I of the photovoltaic panel and the panel output power P of the photovoltaic panel.

[0032] pass Figure 2 It can be seen from the IV curve and PV curve in the figure that the input curve of the photovoltaic panel is nonlinear. When the output voltage of the photovoltaic panel is the maximum, the maximum output voltage of the photovoltaic panel is called the open circuit voltage ( Figure 2 The open circuit voltage Voc in the PV panel is 0, at which point the output current and output power of the PV panel are both zero. As the output voltage of the PV panel decreases, the output current and output power of the PV panel increase.

[0033] exist Figure 2 When the output current of the photovoltaic panel increases to a certain level, the photovoltaic panel works at a certain working point (such as Figure 2 The output power of the photovoltaic panel reaches its maximum at this working point, which is the maximum power point Pmax of the photovoltaic panel.

[0034] In the embodiment of the present application, the process of the photovoltaic converter making the photovoltaic panel operate at the maximum power point through conversion of the internal circuit is called Maximum Power Point Tracking (MPPT).

[0035] Continue to refer Figure 2 As the output voltage of the photovoltaic panel continues to decrease, the output current of the photovoltaic panel slowly increases, while the output power of the photovoltaic panel begins to decrease continuously. When the output voltage of the photovoltaic panel decreases to zero, the output current of the photovoltaic panel is the maximum. The maximum output current of the photovoltaic panel is called the short-circuit current, such as Figure 2 The short-circuit current Isc is shown in , and the output power of the photovoltaic panel is zero at this time.

[0036] In actual applications, PV converters can track the maximum power output of PV panels, but they do not always operate in this mode. For example, when a PV converter is operating in this mode, if the output power of downstream equipment decreases or stops (i.e., if the load on the downstream equipment decreases), the output voltage of the PV converter in this mode will increase, posing an overvoltage risk. At this point, the PV converter needs to switch to output voltage limiting mode to control the output voltage and avoid overvoltage.

[0037] When the photovoltaic converter works in the output voltage limiting mode, if the load of the downstream equipment increases, the power provided by the photovoltaic converter will increase. Under the action of the output voltage limiting loop, the photovoltaic converter will quickly increase the output current of the photovoltaic panel and quickly reduce the output voltage of the photovoltaic panel. Figure 2 According to the characteristics of photovoltaic panels, if the output current of the photovoltaic panel continues to increase, the output voltage of the photovoltaic panel may drop to zero, thereby causing the output power of the photovoltaic panel to drop to zero, affecting the photovoltaic utilization rate of the photovoltaic panel. The photovoltaic converter needs to be switched from the output voltage limiting mode to the maximum power tracking mode.

[0038] In the related art, the working mode (power control state) of the photovoltaic converter is usually switched in two ways. The first switching method is based on the amplitude of the detected bus voltage, and the second switching method is based on the load change of the detected downstream device. In the first switching method, it is necessary to first determine whether the bus voltage has reached the set high-voltage point threshold or the set low-voltage point threshold. When the set threshold is reached, the switching is performed. The switching speed is slow, and the interference caused by the output voltage of the photovoltaic converter is easy to cause false switching. The fault tolerance is low, which will reduce the stability of the working mode switching. In the second switching method, it is necessary to establish communication between the downstream device and the photovoltaic converter, which will increase the communication cost. In the scenario where the load of the downstream device suddenly changes, it is difficult to achieve a fast response to the mode switching.

[0039] In a first aspect, an embodiment of the present application provides a method for controlling a converter.

[0040] Figure 3 Flowchart of the control method of the converter provided in the embodiment of the present application. Figure 3 , the method may include the following steps.

[0041] S310 , determining an input gain control value according to a difference between an input voltage setting value and an input voltage sampling value of the converter.

[0042] For example, the input terminal of the converter can be connected to the output terminal of a photovoltaic panel. A photovoltaic panel, also known as a solar photovoltaic panel, is a device that directly converts solar energy into electrical energy using the photovoltaic effect of semiconductor materials.

[0043] Exemplarily, the input voltage setting value may be the input voltage of the converter calculated in combination with the MPPT algorithm; the input voltage sampling value may be the actual input voltage of the converter collected by the sampling circuit; and the input gain controller is the difference between the two.

[0044] In this step, the input voltage of the converter can be adjusted according to the input gain control value. When the adjusted input voltage of the converter is equal to the input voltage set value, the maximum power tracking of the photovoltaic panel can be achieved, so that the photovoltaic panel can achieve maximum power generation efficiency.

[0045] S320 , determining an output gain control value according to a difference between the output voltage target value and the output voltage sampling value of the converter.

[0046] In this step, the output voltage target value can be a voltage value set according to the output voltage limit requirement of the converter, the output voltage sampling value can be the actual output voltage of the converter collected by the sampling circuit, and the output gain control value is the difference between the two.

[0047] S330: Select a target gain control value from the input gain control value and the output gain control value.

[0048] In this step, one of the input gain control value and the output gain control value is selected as the target gain control value.

[0049] S340, when the operating mode corresponding to the selected target gain control value is different from the current operating mode, the converter is switched to the operating mode corresponding to the target gain control value, wherein the operating mode is one of the power tracking mode and the output voltage limiting mode; in the power tracking mode, the converter is used to adjust the actual value of the input voltage of the converter to the input voltage set value according to the input gain control value; in the output voltage limiting mode, the converter is used to adjust the actual value of the output voltage of the converter to the output voltage target value according to the output gain control value.

[0050] Exemplarily, the operating mode corresponding to the input gain control value is the power tracking mode, and the operating mode corresponding to the output gain control value is the output voltage limiting mode. When the selected target gain control value is the input gain control value and the current operating mode is the output voltage limiting mode, the converter is switched to the power tracking mode; when the selected target gain control value is the output gain control value and the current operating mode is the power tracking mode, the converter is switched to the output voltage limiting mode.

[0051] According to the converter control method of an embodiment of the present application, after determining an input gain control value based on the difference between the converter's input voltage set value and the input voltage sampling value, and determining an output gain control value based on the difference between the converter's output voltage target value and the output voltage sampling value, a gain control value can be selected from the input gain control value and the output gain control value as a target gain control value, thereby switching the converter to the operating mode corresponding to the target gain control value when the operating mode corresponding to the selected target gain control value is different from the current operating mode. In this converter control method, after calculating the input gain control value and the output gain control value, the corresponding operating mode can be automatically switched based on the selection of the target gain control value and the subsequent comparison result with the current operating mode, thereby achieving automatic and rapid switching of the transformer between a power tracking mode and an output voltage limiting mode, without the need for additional control devices or communication devices, which helps reduce hardware overhead and costs.

[0052] In some embodiments, the input of the converter is connected to the output of a photovoltaic module. As an example, the photovoltaic module can be a photovoltaic panel, a solar panel, or other device that can convert solar energy into electrical energy.

[0053] In this embodiment, after the converter is switched to the operating mode corresponding to the target gain control value in step S340, the converter control method further includes the following steps.

[0054] S11, when the working mode after switching is the output voltage limiting mode, determine the output gain control value according to the preset output voltage target value and the output voltage sampling value of the converter, and control the actual output voltage to be equal to the output voltage target value according to the output gain control value.

[0055] In this step, in the output voltage limiting mode, the output gain control value is obtained according to the difference between the output voltage target value of the converter and the output voltage sampling value of the converter. According to the gain control value, the actual output voltage is controlled at the output voltage target value, thereby achieving output voltage limiting of the converter. In the output voltage limiting mode, the output voltage of the converter is ensured to be limited in time to avoid overvoltage problems.

[0056] S12, when the current working mode after switching is the power tracking mode, obtain the input voltage set value through the maximum power point tracking method, determine the input gain control value according to the input voltage set value and the input voltage sampling value of the converter, and control the actual input voltage value to be equal to the input voltage set value according to the input gain control value, so that the converter performs maximum power point tracking on the photovoltaic module; wherein the input voltage set value is equal to the input voltage corresponding to the maximum output power of the photovoltaic module.

[0057] In this step, in the power tracking mode, the input voltage set value can be obtained by the maximum power point tracking method. Then, after the input gain control value is calculated, the actual input voltage value is controlled to be equal to the input voltage set value according to the input gain control value, thereby realizing the control function of the photovoltaic module to the maximum power point tracking of the photovoltaic module.

[0058] In this embodiment, after the converter is switched to the operating mode corresponding to the target gain control value, corresponding control (output voltage limiting control or maximum power tracking) is performed according to the operating mode corresponding to the target gain control value to achieve rapid switching control of the converter operating mode.

[0059] In some embodiments, the input of the converter is connected to the output of the photovoltaic module, and the output of the converter is connected to the subsequent device through a bus; the above-mentioned step S330 may specifically include: S21, based on the detected load changes of the subsequent device, continuously calculating the input gain control value and the output gain control value, and selecting the target control gain according to the calculated input gain control value and output gain value to determine the working mode corresponding to the target control gain.

[0060] In this embodiment, the photovoltaic components, converter, busbar and downstream equipment are connected in sequence. According to the detected load changes of the downstream equipment, the input gain control value and the output gain control value of the converter can be continuously calculated, and the target control gain can be selected according to the calculation results, so as to determine the working mode corresponding to the target control gain, so as to facilitate the subsequent switching control according to the working mode corresponding to the target control gain.

[0061] Figure 4 A block diagram illustrating a converter switching control system according to an exemplary embodiment of the present application is shown.

[0062] exist Figure 4 The system includes: an output voltage limiting loop control unit 401, an input voltage loop control unit 402, a loop selection unit 403 and a drive control unit 404.

[0063] pass Figure 4It can be seen that the input data of the output voltage limiting loop control unit 401 include: output voltage target value and output voltage sampling value, and the input data of the input voltage loop control unit 402 include: input voltage setting value and input voltage sampling value.

[0064] Exemplarily, the output voltage target value, also known as the output voltage limit point, can be obtained from the input of an external input device or can be read in advance from a storage device or storage address, and the embodiments of the present application do not make specific limitations; exemplarily, the output voltage sampling value and the input voltage sampling value can be the voltage value sampled by the corresponding conditioning circuit or fed back by the voltage sampling circuit; exemplarily, the input voltage setting value can be the input voltage of the converter calculated according to the MPPT algorithm.

[0065] refer to Figure 4 The output voltage limiting loop control unit 401 is used to receive the output voltage target value and the output voltage sampling value, and calculate the output gain control value (the first topology gain control value for drive control) based on the output voltage target value (the set target value) and the output voltage sampling value (the actual value of the sampling feedback).

[0066] The input voltage loop control unit 402 is used to receive the input voltage set value (the input voltage set value used for maximum power tracking) and the input voltage sampling value (the actual value of the input voltage for sampling feedback), and calculate the input gain control value (the second topology gain control value used for drive control).

[0067] The loop selection unit 403 is configured to receive the output gain control value from the output voltage limiting loop control unit 401 and the input gain control value from the input voltage loop control unit 402 and select a value from the output gain control value and the input gain control value as a target gain control value.

[0068] The driving control unit 404 is configured to receive the target gain control value from the loop selection unit 403 and switch the converter to the operating mode corresponding to the target gain control value when the operating mode corresponding to the target gain control value is different from the current operating mode.

[0069] For example, when the target gain control value is an output gain control value, this value acts on the driver control unit 404 to control the actual output voltage to the target output voltage. When the target gain control value is an input gain control value, this value acts on the driver control unit 404 to perform power conversion in the power topology of the converter, thereby controlling the converter's input voltage to the input voltage set value. When the input voltage set value is an input voltage provided by an MPPT algorithm, the converter can achieve maximum power point tracking of the connected photovoltaic panels.

[0070] In the embodiment of the present disclosure, the output voltage limiting loop control unit 401 is used to implement the control function of input voltage limitation; the input voltage loop control unit 402 is used to implement the maximum power tracking control function in combination with the MPPT algorithm; the loop selection unit 403 is used to select the output gain control value and the input gain control value; the drive control unit 404 is used to perform corresponding drive control according to the selection result of the loop selection unit 403.

[0071] In actual application scenarios, when the load of the downstream equipment connected to the output end of the converter through the bus changes, in order to ensure that the downstream equipment is not affected by high voltage shocks and avoid power loss, the converter control system needs to continuously calculate the input gain control value and the output gain control value, and select the target control gain based on the calculated input gain control value and output gain value to determine the operating mode corresponding to the target control gain, so as to ensure that a reliable voltage range and power output are provided to the output back-end equipment.

[0072] Exemplarily, the control principle of the output voltage limiting loop control unit 401 is: if the output voltage sampling value is "less than" the output voltage target value, the control direction is to increase the drive, that is, to "increase" the output gain control value; if the output voltage sampling value is "greater than" the output voltage target value, the control direction is to decrease the drive, that is, to "decrease" the output gain control value.

[0073] In addition, the control principle of the input voltage loop control unit 402 is: if the input voltage sampling value is "less than" the input voltage setting value, the control direction is to reduce the drive, that is, to "reduce" the input gain control value; if the input voltage sampling value is "greater than" the input voltage setting value, the control direction is to increase the drive, that is, to "increase" the input gain control value.

[0074] In some embodiments, the actual value of the input voltage and the actual value of the output voltage of the converter can be obtained through voltage sampling. Therefore, the input voltage sampling value of the converter can represent its output voltage sampling value, and the output voltage sampling value of the converter can represent its output voltage sampling value.

[0075] In some embodiments, the output voltage limiting loop operates in a "reverse" mode: when the actual output voltage is less than the target output voltage, the output gain control value needs to be increased; when the actual output voltage is greater than the target output voltage, the output gain control value needs to be decreased. The input voltage loop operates in a "forward" mode: when the actual input voltage is less than the set input voltage, the input gain control value needs to be decreased; when the actual input voltage is greater than the set input voltage, the input gain control value needs to be increased.

[0076] In some embodiments, the above step S330 may specifically include: obtaining a smaller value between the input gain control value and the output gain control value as the target gain control value.

[0077] In this embodiment, for the input gain control value and the output gain control value, according to the smaller principle, the smaller value of the input gain control value and the output gain control value is selected as the target gain control value.

[0078] Next, continue to combine Figure 4 , a brief introduction is given to the control process of the converter based on the minimization principle.

[0079] In some scenarios, when the converter operates in maximum power tracking mode, the converter's drive control unit 404 is controlled by the input voltage loop control unit 402 to achieve maximum power tracking. When the load of the downstream device decreases or is suddenly unloaded, the output voltage of the converter will rise, and the control amount (output gain control value) output by the output voltage limiting loop control unit 401 will decrease. At this time, the input power of the converter can be considered to be relatively fixed, and thus the output power of the converter is also almost fixed (only experiencing some efficiency loss), so the control amount (input gain control value) of the input voltage loop control unit 402 will only fluctuate within a small range. When the load is suddenly unloaded or reduced, the output voltage will rise. Once it exceeds the voltage limit point, there is a risk of overshoot, so the output voltage limiting loop will reduce the output gain control value to quickly pull the voltage down. In this way, the input gain control value fluctuates within a small range, and the output gain control value keeps decreasing. Finally, when the output gain control value is less than the input gain control value, according to the smaller principle, the loop selection unit 403 selects the output gain control value as the target gain control value, and the output voltage limiting loop control unit 401 takes over the driving control right of the driving control unit 404, and the converter enters the output voltage limiting mode, thereby quickly limiting the output voltage overshoot of the converter.

[0080] In other scenarios, when the converter operates in the output voltage limiting mode, the converter's drive control unit 404 is controlled by the output voltage limiting loop control unit 401 to achieve the output voltage operating at the voltage limiting point. When the load of the downstream device increases suddenly or continuously, the converter's output voltage will be pulled down. In order to maintain the output voltage at the voltage limiting point, the output voltage limiting loop control unit 401 needs to continuously "increase" the control amount (output gain control value) to increase the transformer's output voltage. The increase in load will also cause the output power required to be provided by the photovoltaic panel to increase. According to the above embodiment combined with Figure 2 The photovoltaic panel characteristics described in the previous section will increase the output current, thereby increasing the output power of the photovoltaic panel, until the output power of the photovoltaic panel reaches the upper limit of the maximum power point. At this time, since the output current of the photovoltaic panel continues to increase, combined with the Figure 2As can be seen from the described characteristics of the photovoltaic panel, the power of the photovoltaic panel actually begins to decrease. In other words, as the photovoltaic panel increases its current, the output power it can provide has reached its upper limit. Further increasing the current will not provide any more energy, but will only cause the photovoltaic panel's output power and output voltage (corresponding to the converter's input power and input voltage) to continue to decrease (the converter's input voltage is less than the output voltage Vmpp corresponding to the photovoltaic panel's maximum power point). At this point, the input voltage loop control unit 402 will "reduce" the input gain control value. Thus, the output gain control value increases while the input gain control value decreases. Ultimately, when the input gain control value is less than the output gain control value, according to the aforementioned principle of taking the smaller value, the loop selection unit 403 selects the input gain control value, and the input voltage loop control unit 402 takes over drive control of the drive control unit 404, achieving maximum power tracking control of the photovoltaic panel by the converter, while also preventing the converter's output voltage from exceeding the voltage limit.

[0081] The control method of the converter in the embodiment of the present application is suitable for fast switching scenarios that require maximum power tracking and output voltage limiting control. The output voltage limiting loop and the input voltage loop are automatically switched through the loop selection logic, thereby responding to the load changes of the downstream equipment in a timely manner. Even if the load changes rapidly, the downstream equipment can be guaranteed not to be impacted by high voltage, and the power will not drop to zero, which will affect the photovoltaic utilization rate. The entire control process does not require additional hardware overhead, nor does it require the addition of other control or communication devices, and the control cost is low.

[0082] In some embodiments, when the current working mode is the output voltage limiting mode, the above step S21 may specifically include: S31, when it is detected that the subsequent device meets the first change condition, increasing the output gain control value and decreasing the input gain control value to obtain an updated output gain control value and an updated input gain control value;

[0083] The first change condition includes: the load of the downstream device increases, causing the output power required to be provided by the photovoltaic module to be greater than the maximum output power of the photovoltaic module; or the load of the downstream device increases, causing the output power of the converter to increase, but the increased output power is less than the power required by the downstream device;

[0084] S32 : When the updated input gain control value is smaller than the updated output gain control value, select the updated input gain control value as the target gain control value.

[0085] In this embodiment, if the current operating mode of the converter is the output voltage limiting mode, when the load of the downstream device increases, the output voltage limiting loop is continuously adjusted to increase the output gain control value, and the input voltage limiting loop is continuously adjusted to reduce the input gain control value until the input gain control value is less than the output gain control value, and the converter is switched to the power tracking mode to achieve fast and automatic mode switching.

[0086] For ease of understanding, the following Figure 5 and attached Figure 6 The following describes the process of switching a converter from output voltage limiting mode to power tracking mode in an embodiment of the present application. For ease of description, in the following embodiments, the output voltage sampling value may be referred to as the actual output voltage, the output voltage limiting loop control unit may be referred to as the output voltage limiting loop, the input voltage sampling value may be referred to as the actual input voltage, the input voltage loop control unit may be referred to as the input voltage loop, and the output voltage target value may be referred to as the voltage limiting point.

[0087] In the embodiment of the present application, the control principle of the converter is to perform maximum power point tracking as much as possible, provided that the converter output voltage does not exceed the output voltage target value. In other words, control can be performed according to MPPT, but the prerequisite is that the converter output voltage does not exceed the set voltage limit.

[0088] From the content of the above embodiment, it can be seen that when the load of the downstream equipment decreases, if the converter forcibly performs maximum power tracking on the photovoltaic converter, the output voltage of the photovoltaic converter will increase, and there is a risk of overvoltage. Therefore, the photovoltaic converter should operate in output voltage limiting mode at this time.

[0089] Figure 5 A schematic diagram showing the operating point change process when switching from the output voltage limiting mode to the power tracking mode in an embodiment of the present application is shown. Figure 5 and Figure 2 The same reference numerals have the same meanings. Figure 2 different, Figure 5 Also included are working points 1 to 4.

[0090] In this embodiment, the current working mode of the converter is the output voltage limiting mode. Figure 5 Assume that the output voltage of the photovoltaic panel corresponding to the current load state of the downstream equipment is the output voltage of the photovoltaic panel corresponding to operating point 1. At this time, if the converter is forced to perform maximum power tracking (which can be understood as forcibly carrying a higher power) on the photovoltaic panel, the corresponding output voltage of the converter will be very large. However, for the downstream equipment, the converter output voltage has an upper limit requirement, that is, the actual output voltage of the converter is equal to the set voltage limit point, and the converter operates in output voltage limiting mode.

[0091] Assuming the converter's input voltage setpoint is near Vmpp (the difference between the input voltage setpoint and Vmpp is less than a predetermined voltage threshold), according to the loop regulation principle (i.e., the input voltage loop's control principle), since the converter's actual input voltage is higher than the input voltage setpoint Vmpp, its control direction is to increase the drive, that is, to "increase" the input gain control value. In other words, the input voltage loop will begin to increase its output control variable (input gain control value), thereby increasing the current and keeping the converter's input current at Impp (operating point 4). As the input voltage loop increases its control variable, the converter's input power gradually increases, correspondingly increasing the converter's output power and output voltage. Since the output voltage limiting loop needs to maintain the voltage limit point (operating point 1), the output voltage limiting loop will begin to decrease its output control variable (output gain control value). According to the loop selection unit's operating principle of taking the smallest value, the output voltage limiting loop's output control variable is selected (the actual selected control output), allowing the converter to stably operate at operating point 1.

[0092] refer to Figure 5 If the load of the downstream device increases suddenly or continuously, the output voltage of the converter will be pulled down. To maintain the current output voltage, the output voltage limiting loop needs to continuously "increase" the output gain control value to pull up the output voltage of the converter, thereby maintaining the output voltage of the converter stable at the voltage limit point. At this time, for the photovoltaic panel, the increase in load will result in an increase in the output power required by the panel. According to the characteristics of the photovoltaic panel, the photovoltaic panel will increase the output current, thereby increasing the panel output power. Figure 5 The operating point 1 of the photovoltaic panel moves to the operating point 2. During this process, because the converter input voltage is constantly approaching the target value Vmpp of the input voltage loop, the converter input voltage is decreasing. The input voltage loop will begin to reduce the control amount of its own output to maintain the converter input voltage at the voltage Vmpp, until the actual input voltage of the converter constantly approaches and reaches the input voltage set value Vmpp, and the output power of the photovoltaic panel reaches the maximum power point (operating point 4).

[0093] As the load continues to increase, the output current of the photovoltaic panel continues to increase, but the power of the photovoltaic panel begins to decrease (entering operating point 3). At this time, the input voltage of the converter corresponding to operating point 3 is less than the input voltage setting value Vmpp. Accordingly, the output voltage of the photovoltaic panel is less than the output voltage Vmpp corresponding to the maximum power point of the photovoltaic panel.

[0094] It can be seen from this that as the photovoltaic panel increases its current, the output power that the panel can provide will reach its upper limit. After reaching the upper limit, further increasing the current will not provide more energy, and will only cause the output power and output voltage of the photovoltaic panel (corresponding to the input power and input voltage of the converter) to continue to decrease. For example, the input voltage of the converter corresponding to operating point 3 is lower than the input voltage setting value Vmpp of the converter. According to the control principle of the input voltage loop, the input voltage loop will reduce its own output control value (input gain control value) more quickly to maintain the input voltage of the converter at Vmpp.

[0095] It can be seen from the description of the above embodiment that after entering working point 3, the output power of the photovoltaic panel decreases and the output voltage drops, the input voltage loop starts to work and the control direction is to reduce the control output, while the output voltage limiting loop always increases the control output. Finally, the control amount output by the input voltage loop (input gain control value) will be smaller than the control amount output by the output voltage limiting loop, that is, the input gain control value will eventually be smaller than the output gain control value. According to the design of the loop selection unit, the input voltage loop will eventually take over the drive control of the drive control unit. After that, the input voltage loop will continue to reduce the input gain control value and reduce the input current of the converter until it runs at the input voltage set value, that is, near working point 4. After that, the input target value is continuously adjusted to Vmpp through the MPPT algorithm, so that the input voltage of the converter runs at the panel output voltage corresponding to working point 4, so that the photovoltaic panel operates at the maximum power point.

[0096] Figure 6 A schematic diagram showing the voltage change process when the converter switches from output voltage limiting mode to power tracking mode in an embodiment of the present application is shown. Figure 6 The X-axis is time (t), and the Y-axis is the converter output voltage and the converter input voltage.

[0097] like Figure 6 As shown, in the output voltage limiting mode, Figure 6 As shown in "Input voltage starts to fall below Vmpp", when the actual value of the converter's input voltage begins to fall below the input voltage set value Vmpp, both the converter's input voltage and output voltage are decreasing. However, since the input voltage loop is reducing the output control amount, the output voltage limiting loop is increasing the control amount. Figure 6 In the “Switching from Output Voltage Limiting Mode to Maximum Power Tracking Mode”, when the control quantity output by the input voltage loop (input gain control value) is less than the control quantity output by the output voltage limiting loop (output gain control value), the converter will switch from output voltage limiting mode to power tracking mode by designing the loop selection unit to take the smaller of the input gain control value and the output control quantity. Figure 6 As shown in the “steady-state point” in the figure, after switching to the power tracking mode, the input voltage set value can be adjusted according to the MPPT algorithm to make the converter operate stably in the power tracking mode.

[0098] In some embodiments, when the current operating mode is the power tracking mode, the above step S21 may specifically include: S41, when it is detected that the subsequent device meets the second change condition, reducing the output gain control value and increasing the input gain control value to obtain an updated output gain control value and an updated input gain control value; wherein the second change condition includes: the load of the subsequent device is reduced or the load is turned off;

[0099] S42 : When the updated input gain control value is greater than the updated output gain value, select the updated output gain control value as the target gain control value.

[0100] In this embodiment, if the current operating mode of the converter is the power tracking mode, when the load of the downstream device decreases, the output voltage limiting loop is continuously adjusted to reduce the output gain control value, and the input voltage limiting loop is continuously adjusted to increase the input gain control value until the output gain control value is less than the input gain control value, and the converter is switched to the output voltage limiting mode, thereby realizing fast and automatic mode switching.

[0101] For ease of understanding, the following Figure 7 and attached Figure 8 , describing the processing process of the converter switching from power tracking mode to output voltage limiting mode in an embodiment of the present application.

[0102] Figure 7 A schematic diagram showing the operating point change process when the power tracking mode switches to the output voltage limiting mode in an embodiment of the present application is shown.

[0103] In this embodiment, the current working mode of the converter is the power tracking mode. Figure 7 If the load of the downstream device is unloaded, the control quantity output by the input voltage loop of the converter will fluctuate within a small range to maintain the current input voltage of the converter, and the input power will be constant. As the load of the downstream device decreases, the output voltage of the converter will rise rapidly. During the output voltage rise of the converter, the output voltage limiting loop will start to work, reducing the loop output, that is, reducing the output gain control value. When the output voltage exceeds the set voltage limit point, the output control quantity will be reduced more quickly. According to the design of the smallest loop selection unit, the final output voltage limiting loop will serve as the final loop output control, reducing the input current and increasing the input voltage, corresponding to Figure 7 The PV panel's output voltage moves from operating point 1 to operating point 3, ultimately limiting the converter's output voltage to the set voltage limit (operating point 3). At operating point 3, the output voltage-limiting loop reduces the output control variable (output gain control value), while the input voltage loop continues to increase the output control variable (input gain control value) to maintain the converter's input voltage at Vmpp. Due to the loop selector's principle of minimizing, the final loop control output remains in output voltage limiting mode.

[0104] Figure 8 A schematic diagram showing the voltage change process when the converter switches from power tracking mode to output voltage limiting mode in an embodiment of the present application is shown. Figure 8 The X-axis is time, and the Y-axis is the transformer output voltage and the transformer input voltage.

[0105] exist Figure 8 In the “rear load reduction point”, it means the time point when the load of the rear equipment starts to decrease. Figure 8 As shown, in power tracking mode, Figure 8 As shown in the “post-stage load reduction point” in , when the load of the post-stage equipment decreases, the converter can maintain the input voltage under the action of the input voltage loop; Figure 8 As shown in the “output voltage is greater than the voltage limit point” in the figure, the output voltage of the converter begins to rise and can rise to exceed the output voltage target value. Since the control amount output by the input voltage loop fluctuates within a small range, the control amount output by the output voltage limit loop decreases. When the control amount output by the output voltage loop (output gain control value) is less than the control amount output by the input voltage limit loop (input gain control value), the converter will switch from power tracking mode to output voltage limit mode according to the smaller design of the two gain control values ​​by the loop selection unit. Figure 8 As shown in the “steady-state point” in FIG, after switching to the output voltage limiting mode, the converter can stably operate in the output voltage limiting mode.

[0106] An embodiment of the present application provides a control method for a converter. After determining an input gain control value based on the difference between the converter's input voltage set value and an input voltage sampling value, and determining an output gain control value based on the difference between the converter's output voltage target value and an output voltage sampling value, a gain control value can be selected from the input gain control value and the output gain control value as a target gain control value. Thus, when the operating mode corresponding to the selected target gain control value is different from the current operating mode, the converter is switched to the operating mode corresponding to the target gain control value. In this converter control method, after calculating the input gain control value and the output gain control value, the corresponding operating mode can be automatically switched based on the selection of the target gain control value and the subsequent comparison result with the current operating mode, thereby achieving automatic and rapid switching of the transformer between a power tracking mode and an output voltage limiting mode. This method does not require additional control devices or communication devices, thereby reducing hardware overhead and costs.

[0107] According to the control method of the converter, the target gain control value can be determined based on the selected gain control value, and the converter can be switched to the operating mode corresponding to the target gain control value, thereby simply realizing the conversion between modes through simple loop selection. The conversion speed is fast, the stability is high, and there is no need to increase the communication cost. Rapid conversion can be achieved for scenarios with sudden load changes.

[0108] It is understood that the various method embodiments mentioned in this application can be combined with each other to form combined embodiments without violating the principle logic. Due to space limitations, this application will not go into details. Those skilled in the art will understand that in the above-mentioned methods of specific implementation, the specific execution order of each step should be determined by its function and possible internal logic.

[0109] The following combination Figure 9 , introduces the control device of the converter according to an embodiment of the present application.

[0110] Figure 9 This is a block diagram of the control device for the converter provided in the embodiment of the present application. Figure 9 , an embodiment of the present application provides a control device for a converter, and the control device 900 for the converter may include the following modules.

[0111] An input voltage loop control unit 910 is configured to determine an input gain control value based on a difference between an input voltage setting value and an input voltage sampling value of the converter;

[0112] The output voltage limiting loop control unit 920 is used to determine the output gain control value according to the difference between the output voltage target value and the output voltage sampling value of the converter;

[0113] a loop selection unit 930, configured to select a target gain control value from the input gain control value and the output gain control value;

[0114] The drive control unit 940 is used to switch the converter to the operating mode corresponding to the target gain control value when the operating mode corresponding to the selected target gain control value is different from the current operating mode, wherein the operating mode is one of a power tracking mode and an output voltage limiting mode; in the power tracking mode, the converter is used to adjust the actual value of the input voltage of the converter to the input voltage set value according to the input gain control value; in the output voltage limiting mode, the converter is used to adjust the actual value of the output voltage of the converter to the output voltage target value according to the output gain control value.

[0115] It should be noted that the input voltage loop control unit 910 is equivalent to Figure 4 The input voltage loop control unit 402 and the output voltage limiting loop control unit 920 are equivalent to Figure 4The output voltage limiting loop control unit 401 and the loop selection unit 930 are equivalent to Figure 4 The loop selection unit 403 in the drive control unit 940 is equivalent to Figure 4 In the drive control unit 404, in the embodiment of the present application, the same or equivalent modules are used to implement the same functions.

[0116] In some embodiments, the input of the converter is connected to the output of the photovoltaic module; the output voltage limiting loop control unit 920 is further configured to, after switching the converter to an operating mode corresponding to a target gain control value, determine an output gain control value based on a preset output voltage target value and an output voltage sample value of the converter when the switched operating mode is an output voltage limiting mode; the drive control unit 940 is further configured to control the actual output voltage to be equal to the output voltage target value based on the output gain control value;

[0117] The input voltage loop control unit 910 is further configured to obtain an input voltage set value through a maximum power point tracking method when the current operating mode after switching is a power tracking mode, and determine an input gain control value based on the input voltage set value and an input voltage sampling value of the converter; the drive control unit 940 is further configured to control the actual input voltage value to be equal to the input voltage set value based on the input gain control value, so that the converter performs maximum power point tracking on the photovoltaic module; wherein the input voltage set value is equal to the input voltage corresponding to the maximum output power of the photovoltaic module.

[0118] In some embodiments, the input of the converter is connected to the output of the photovoltaic module, and the output of the converter is connected to the subsequent device through a bus; the loop selection unit 930, when used to select the target gain control value from the input gain control value and the output gain control value, is specifically used to: based on the detected load changes of the subsequent device, continuously calculate the input gain control value and the output gain control value, and select the target control gain based on the calculated input gain control value and output gain value to determine the working mode corresponding to the target control gain.

[0119] In some embodiments, when the current operating mode is the output voltage limiting mode, the loop selection unit 930, when used to continuously calculate the input gain control value and the output gain control value based on the detected load change of the downstream device, and select the target control gain according to the calculated input gain control value and output gain value, is specifically used to: when it is detected that the downstream device meets the first change condition, increase the output gain control value and decrease the input gain control value to obtain an updated output gain control value and an updated input gain control value; wherein the first change condition includes: the load of the downstream device increases, and the output power required to be provided by the photovoltaic component is greater than the maximum output power of the photovoltaic component; or, the load of the downstream device increases, and the output power of the converter increases and the increased output power is less than the power required by the downstream device; when the updated input gain control value is less than the updated output gain control value, select the updated input gain control value as the target gain control value.

[0120] In some embodiments, when the current operating mode is the power tracking mode, the loop selection unit 930, when used to continuously calculate the input gain control value and the output gain control value based on the detected load change of the downstream device, and select the target control gain according to the calculated input gain control value and output gain value, is specifically used to: when it is detected that the downstream device meets the second change condition, reduce the output gain control value and increase the input gain control value to obtain an updated output gain control value and an updated input gain control value; wherein the second change condition includes: the load of the downstream device is reduced or the load is turned off; when the updated input gain control value is greater than the updated output gain value, select the updated output gain control value as the target gain control value.

[0121] In some embodiments, the loop selection unit 930 is configured to select a target gain control value from the input gain control value and the output gain control value, specifically to obtain the smaller value between the input gain control value and the output gain control value as the target gain control value.

[0122] According to a control device for a converter according to an embodiment of the present application, after determining an input gain control value based on the difference between the converter's input voltage set value and the input voltage sampling value, and determining an output gain control value based on the difference between the converter's output voltage target value and the output voltage sampling value, a gain control value can be selected from the input gain control value and the output gain control value as a target gain control value. Thus, when the operating mode corresponding to the selected target gain control value is different from the current operating mode, the converter is switched to the operating mode corresponding to the target gain control value. In this converter control device, after calculating the input gain control value and the output gain control value, the corresponding operating mode can be automatically switched based on the selection of the target gain control value and the subsequent comparison result with the current operating mode, thereby achieving automatic and rapid switching between the power tracking mode and the output voltage limiting mode of the transformer. This eliminates the need for additional control devices or communication devices, thereby reducing hardware overhead and costs.

[0123] The converter control device of the present invention is applicable to scenarios where a photovoltaic converter needs to quickly switch between maximum power point tracking (MPPT) mode and output voltage limiting mode, or other scenarios requiring rapid transitions between these two modes, such as when the output is not powered by a battery. The loop selector module enables transitions between MPPT and output voltage limiting modes without requiring additional hardware overhead or additional detection information or control instructions.

[0124] Next, continue to combine Figure 9 , describing the control process of the converter of the exemplary embodiment of the present application.

[0125] For example, when the converter's current operating mode is power tracking mode and the load on the downstream device decreases or is turned off, the downstream device needs to reduce or turn off its power output. At this point, the bus voltage (i.e., the converter's output voltage) rises rapidly. During this process, the output voltage limiting loop control unit 920 begins to reduce the loop output (reduces the output gain control value), and the input voltage loop control unit 910 begins to increase the loop output (increases the input gain control value). When the control value output by the output voltage limiting loop control unit 920 is lower than the control value output by the input voltage loop control unit 910, the control state automatically and quickly switches from power tracking mode to output voltage limiting mode.

[0126] The specific process is as follows:

[0127] First, when the power required by the downstream equipment of the photovoltaic converter is greater than the maximum power that the panel can provide, the input voltage setting value Vmpp of the converter can be calculated according to the MPPT algorithm. This voltage value is the converter input voltage that can make the photovoltaic panel reach the maximum power point. The input voltage loop control unit 910 calculates the input gain control value based on the input voltage setting value and the input voltage sampling value, and increases the output power to the maximum power point. During this process, the output voltage limiting loop control unit 920 is also running, but because the output power is always less than the power required by the downstream stage, the actual value of the converter output voltage cannot rise to the output voltage target value (voltage limiting point), so the direction of output voltage regulation is to continuously increase the output gain control value. According to the loop switching design with a small value, the converter can stably operate in MPPT mode.

[0128] Then, when the load on the downstream device decreases or becomes unavailable, meaning the downstream device power is reduced or shut down, the converter output voltage will rise rapidly until it exceeds the output limit (output voltage target value). During this process, the output voltage limiting loop control unit 920 continuously adjusts and reduces the output control amount (output gain control value), while the input voltage loop control unit 910 maintains the current control. According to the minimum control logic, the loop selection unit 930 ultimately selects the output gain control value as the target gain control value, and the converter enters the output voltage limiting mode, quickly and automatically completing the mode switch.

[0129] For example, when the converter's current operating mode is output voltage limiting mode and the load on downstream equipment increases, the downstream equipment needs to increase its power output. At this point, the bus voltage (i.e., the converter's output voltage) rapidly decreases. During this decrease, the output voltage limiting loop control unit 920 begins to increase the output control (output gain control value), increasing the converter's input current and input power. Due to the characteristics of the photovoltaic panel, the converter's input voltage begins to decrease. When the converter's input voltage falls below the input voltage setting value Vmpp, the input voltage loop control unit 910 begins to decrease the loop output (input gain control value) in an attempt to reduce the input current and control the input voltage to the input voltage setting value Vmpp. During this process, as the output gain control value increases while the input gain control value decreases, when the input gain control value is less than the output gain control value, the loop selection unit 930 ultimately selects the input gain control value as the target gain control value according to the smaller control logic. The converter enters power tracking mode, quickly and automatically completing mode switching.

[0130] The specific process is as follows:

[0131] First, when the power required by the photovoltaic converter's downstream equipment is less than the maximum power the panel can provide, the input voltage loop control unit 910 controls the converter's input voltage according to the input voltage set value Vmpp, increasing the converter's input current. If the actual input voltage value of the converter does not reach Vmpp, the converter's output voltage will exceed the output voltage target value (voltage limit point). At this point, the output voltage loop detects the output voltage rising process and begins to reduce the output control variable (output gain control value). Because the converter's output voltage is greater than the output voltage target value, the output voltage loop continues to reduce the output gain control value. When the output gain control value ultimately falls below the output control variable (input gain control value) of the input voltage loop control unit 910, the loop selection unit 930 selects the output gain control value as the target gain control value, and the converter enters a stable output voltage limiting mode.

[0132] Then, as the load on the downstream equipment increases, the power required by the downstream equipment increases, and the converter output voltage drops rapidly, eventually falling below the target output voltage value. During this process, the output voltage limiting loop control unit 920 continuously adjusts and increases the output control variable (output gain control value) and increases the input current to enable the panel to provide greater output power. Due to the characteristics of the photovoltaic panel, the photovoltaic panel output voltage and the corresponding converter input voltage will continue to decrease. When the converter input voltage is lower than the input voltage setting value Vmpp, the input voltage loop control unit 910 continuously decreases the output control variable (input gain control value), reducing the converter input current to increase the converter input voltage. When the input gain control value is lower than the output gain control value, the loop selection unit 930 selects the input gain control value as the target gain control value, and the converter enters the input voltage loop control unit 910 control mode, namely the MPPT control mode, automatically completing the mode switch.

[0133] In the embodiment of the present application, voltage detection and working mode switching are automatically completed according to the load change of the downstream equipment of the converter. And the loop control has a pre-action feature, that is, it is found that the voltage detection value has a trend of approaching the target value (see the above combination Figure 5 The change process from operating point 3 to operating point 4 described in the figure can be adjusted according to the corresponding gain control value. When the target value is exceeded or lower than the target value, the working mode of the converter can be quickly switched to avoid overshoot or lag caused by the detection value deviating too much from the target value.

[0134] In a second aspect, an embodiment of the present application provides a photovoltaic power generation system. Figure 10 A block diagram of a photovoltaic power generation system provided in an embodiment of the present application is shown. Figure 10 and Figure 1 The same or equivalent modules use the same reference numerals. Figure 10The photovoltaic power generation system includes: at least one photovoltaic module 1010 and at least one converter 1020, the output end of each photovoltaic module 1010 is connected to the input end of a converter 1020; the converter 1020 is used to execute the control method of the converter of the above embodiment according to the received input voltage set value and the received output voltage target value.

[0135] In some embodiments, the photovoltaic power generation system also includes a power transmission line and downstream equipment; each photovoltaic module is connected to the busbar of the power transmission line through a converter, and the busbar is connected to the downstream equipment; the connection method of the output ends of different converters includes at least one of series and parallel connection.

[0136] It should be understood that the present invention is not limited to the specific configurations and processes described in the above embodiments and illustrated in the figures. For the sake of convenience and brevity, detailed descriptions of known methods are omitted here. The specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0137] In a third aspect, the present application also provides an electronic device. Figure 11 The electronic device includes: at least one processor 1101; at least one memory 1102, and one or more I / O interfaces 1103; wherein the memory 1102 stores one or more computer programs that can be executed by the at least one processor 1101, and the one or more computer programs are executed by the at least one processor 1101 to enable the at least one processor 1101 to perform the above method.

[0138] Among them, the processor is a device with data processing capabilities, including but not limited to the central processing unit (CPU); the memory is a device with data storage capabilities, including but not limited to random access memory (RAM, more specifically such as SDRAM, DDR, etc.), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), and flash memory (FLASH); the I / O interface (read-write interface) is connected between the processor and the memory, which can realize information exchange between the memory and the processor, including but not limited to the data bus (Bus), etc.

[0139] The present application also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor / processing core, implements the aforementioned converter control method. The computer-readable storage medium may be a volatile or non-volatile computer-readable storage medium.

[0140] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As is well known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0141] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and should be interpreted only in a general illustrative sense and not for purposes of limitation. In some instances, it will be apparent to those skilled in the art that, unless otherwise expressly indicated, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the present application as set forth in the appended claims.

Claims

1. A method for controlling a converter, wherein: The method comprises: determining an input gain control value according to a difference between an input voltage setting value and an input voltage sampling value of the converter; determining an output gain control value according to a difference between an output voltage target value and an output voltage sampling value of the converter; selecting a target gain control value from the input gain control value and the output gain control value; When the operating mode corresponding to the selected target gain control value is different from the current operating mode, the converter is switched to the operating mode corresponding to the target gain control value, wherein the operating mode is one of a power tracking mode and an output voltage limiting mode; in the power tracking mode, the converter is used to adjust the actual input voltage value of the converter to the input voltage set value according to the input gain control value; in the output voltage limiting mode, the converter is used to adjust the actual output voltage value of the converter to the output voltage target value according to the output gain control value.

2. The method according to claim 1, wherein The input of the converter is connected to the output of the photovoltaic module; After switching the converter to an operating mode corresponding to the target gain control value, the method further includes: When the switched operating mode is the output voltage limiting mode, determining the output gain control value according to a preset output voltage target value and an output voltage sampling value of the converter, and controlling the actual output voltage to be equal to the output voltage target value according to the output gain control value; When the current operating mode after switching is the power tracking mode, the input voltage set value is obtained through the maximum power point tracking method, the input gain control value is determined according to the input voltage set value and the input voltage sampling value of the converter, and the input voltage actual value is controlled to be equal to the input voltage set value according to the input gain control value, so that the converter performs maximum power point tracking on the photovoltaic component; wherein the input voltage set value is equal to the input voltage corresponding to the maximum output power of the photovoltaic component.

3. The method according to claim 1, wherein The input of the converter is connected to the output of the photovoltaic module, and the output of the converter is connected to the subsequent equipment through a busbar; the selecting of the target gain control value from the input gain control value and the output gain control value includes: Based on the detected load change of the downstream device, the input gain control value and the output gain control value are continuously calculated, and a target control gain is selected according to the calculated input gain control value and output gain value to determine the working mode corresponding to the target control gain.

4. The method according to claim 3, wherein: When the current operating mode is the output voltage limiting mode, the continuously calculating the input gain control value and the output gain control value based on the detected load change of the downstream device, and selecting the target control gain according to the calculated input gain control value and output gain value, includes: When it is detected that the subsequent device meets the first change condition, the output gain control value is increased and the input gain control value is decreased to obtain an updated output gain control value and an updated input gain control value; The first change condition includes: the load of the downstream device increases, and the output power required by the photovoltaic module is greater than the maximum output power of the photovoltaic module; or the load of the downstream device increases, and the output power of the converter increases, and the increased output power is less than the power required by the downstream device; In a case where the updated input gain control value is smaller than the updated output gain control value, the updated input gain control value is selected as the target gain control value.

5. The method according to claim 3, wherein: When the current operating mode is the power tracking mode, the continuously calculating the input gain control value and the output gain control value based on the detected load change of the downstream device, and selecting the target control gain according to the calculated input gain control value and output gain value, includes: When it is detected that the downstream device satisfies a second change condition, the output gain control value is reduced and the input gain control value is increased to obtain an updated output gain control value and an updated input gain control value; wherein the second change condition includes: the load of the downstream device is reduced or the load is turned off; In a case where the updated input gain control value is greater than the updated output gain value, the updated output gain control value is selected as the target gain control value.

6. The method according to claim 1, wherein The selecting a target gain control value from the input gain control value and the output gain control value comprises: A smaller value between the input gain control value and the output gain control value is obtained as the target gain control value.

7. A photovoltaic power generation system, wherein: The system comprises: at least one photovoltaic module and at least one converter, wherein the output end of each photovoltaic module is connected to the input end of a converter; The converter is configured to execute the converter control method according to any one of claims 1 to 6 based on a received input voltage setting value and a received output voltage target value.

8. The system according to claim 7, further comprising a power transmission line and a subsequent device; Each photovoltaic module is connected to the busbar of the power transmission line through a converter, and the busbar is connected to the subsequent equipment; the connection mode of the output ends of different converters includes at least one of series connection and parallel connection.

9. An electronic device comprising: at least one processor; A memory having at least one program stored thereon, wherein when the at least one program is executed by the at least one processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer-readable medium having a computer program stored thereon, wherein the computer program implements the method according to any one of claims 1 to 6 when executed by a processor.

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