Photovoltaic inverter control method, computer storage medium and photovoltaic inverter

Abstract

The invention discloses a photovoltaic inverter control method, a computer storage medium and a photovoltaic inverter, the photovoltaic inverter comprises an inverter circuit and a fan, the photovoltaic inverter control method comprises the following steps: under the condition that the inverter circuit is started and the fan does not rotate, acquiring temperature information of the inverter circuit; and controlling the operation state of the inverter circuit according to the temperature information. According to the method, on the premise that the equipment cost is not increased, the generating capacity of the photovoltaic inverter is ensured, and the inverter is prevented from being damaged due to over-temperature.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic technology, and in particular, to a control method for a photovoltaic inverter, a computer storage medium, and a photovoltaic inverter. Background Art

[0002] A photovoltaic inverter is a core device of a photovoltaic power generation system, which is responsible for converting the DC electric energy generated by photovoltaic modules into AC electric energy and then transmitting it to the power grid. Photovoltaic inverters deployed in high-latitude or high-altitude areas often encounter low-temperature environments, and in extreme cases, it can reach -20°C or even lower. Since the photovoltaic inverter cannot generate electricity at night, it will enter a shutdown state at night. At the same time, the fan used for heat dissipation in the photovoltaic inverter may freeze at night. When the sun rises in the morning and the photovoltaic inverter is about to enter the power generation state again, the fan cannot rotate due to freezing and may be judged as a fan failure. If the fan cannot work, the continuous operation of the photovoltaic inverter may be damaged due to the inability to dissipate heat. At this time, to avoid damage to the photovoltaic inverter, the photovoltaic inverter enters a shutdown state or a power-limited operation state, resulting in a loss of power generation.

[0003] In related technologies, the photovoltaic inverter can be additionally equipped with other devices for thawing the fan, such as configuring an air conditioner to keep the device warm to avoid freezing or adding a dehumidification resistor, and generating heat through the resistor to avoid device freezing. However, this will increase the device cost. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of the present invention is to provide a control method for a photovoltaic inverter, which can ensure the power generation of the photovoltaic inverter and avoid over-temperature damage to the inverter circuit without increasing the device cost.

[0005] A second object of the present invention is to provide a computer storage medium.

[0006] A third object of the present invention is to provide a photovoltaic inverter.

[0007] To solve the above problems, an embodiment of the first aspect of the present invention provides a control method for a photovoltaic inverter, where the photovoltaic inverter includes an inverter circuit and a fan, and the control method includes: when the photovoltaic inverter starts and the fan does not rotate, obtaining temperature information of the inverter circuit; and controlling the operating state of the inverter circuit according to the temperature information.

[0008] According to the control method of a photovoltaic inverter according to an embodiment of the present invention, when the photovoltaic inverter is in a startup state and the fan is not rotating, temperature information of the inverter circuit is acquired, and the operating state of the inverter circuit is controlled based on the temperature information of the inverter circuit. The heat generated during the operation of the inverter circuit is used to prevent the fan from freezing and causing a reduction in the power generation of the inverter circuit, without additionally increasing the equipment cost, and also ensuring that the inverter circuit will not be damaged due to overheating.

[0009] In some embodiments, the operating state includes a non-power-limited state and a power-limited state. Controlling the operating state of the inverter circuit according to the temperature information includes: determining that the temperature information is less than or equal to a first temperature threshold, and then controlling the inverter circuit to alternately operate in the non-power-limited state and the power-limited state until the fan rotates.

[0010] In some embodiments, controlling the inverter circuit to alternately operate in the non-power-limited state and the power-limited state includes: Step a, controlling the inverter circuit to operate in the non-power-limited state; Step b, when it is determined that the temperature information is greater than a second temperature threshold, controlling the inverter circuit to switch from the non-power-limited state to the power-limited state, where the second temperature threshold is greater than the first temperature threshold; Step c, when it is determined that the inverter circuit meets the non-power-limited condition, controlling the inverter circuit to switch from the power-limited state to the non-power-limited state. The steps a, b, and c are executed cyclically.

[0011] In some embodiments, in the non-power-limited state, the upper limit value of the actual output power of the inverter circuit is greater than half of the maximum allowable output power of the inverter circuit and less than or equal to the maximum allowable output power of the inverter circuit.

[0012] In some embodiments, in the power-limited state, the actual output power of the inverter circuit is less than the maximum allowable output power of the inverter circuit.

[0013] In some embodiments, the actual output power of the inverter circuit is half of the maximum allowable output power.

[0014] In some embodiments, when it is determined that the temperature information is greater than a third temperature threshold, the actual output power of the inverter circuit is greater than or equal to zero and less than half of the maximum allowable output power.

[0015] In some embodiments, the non-power-limited condition includes any one of the following: the temperature information is less than a fourth temperature threshold, the fourth temperature threshold is greater than the first temperature threshold and less than or equal to the second temperature threshold; the power-limited duration of the inverter circuit is greater than a preset duration and the temperature reduction amplitude of the inverter circuit is greater than a preset amplitude during the power-limited duration.

[0016] In some embodiments, controlling the output state of the inverter circuit according to the temperature information includes: determining that the temperature information is greater than a first temperature threshold, and controlling the operating state of the inverter circuit to be a shutdown state or a power limit state.

[0017] According to the photovoltaic inverter of the embodiment of the present invention, by the processor executing the control method of the photovoltaic inverter in the above embodiment, it is possible to ensure the power generation of the photovoltaic inverter and avoid over-temperature damage of the inverter circuit without increasing the equipment cost.

[0018] The second aspect embodiment of the present invention proposes a computer storage medium, on which a computer program is stored, characterized in that when the computer program is executed by a processor, it implements the control method of the photovoltaic inverter in the above embodiment.

[0019] The third aspect embodiment of the present invention proposes a photovoltaic inverter, characterized in that it includes: an inverter circuit and a fan; a controller, respectively connected to the inverter circuit and the fan, and configured to execute the control method of the photovoltaic inverter in the above embodiment.

[0020] According to the photovoltaic inverter of the embodiment of the present invention, the heat generated by the operation of the inverter circuit is used to defrost the fan, without the need to additionally increase the equipment cost, ensuring the power generation of the photovoltaic inverter and avoiding over-temperature damage of the inverter circuit.

[0021] The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein: Figure 1 is a flowchart of a control method of a photovoltaic inverter according to an embodiment of the present invention; Figure 2 (a)-(c) are schematic diagrams of a control method of a photovoltaic inverter according to an embodiment of the present invention; Figure 3 (a)-(c) are schematic diagrams of a control method of a photovoltaic inverter according to another embodiment of the present invention; Figure 4 (a)-(c) are schematic diagrams of a control method of a photovoltaic inverter according to another embodiment of the present invention; Figure 5 (a)-(c) are schematic diagrams of a control method of a photovoltaic inverter according to another embodiment of the present invention; Figure 6(a)-(c) are schematic diagrams of a control method for a photovoltaic inverter according to another embodiment of the present invention; Figure 7 is a flowchart of a control method for a photovoltaic inverter according to another embodiment of the present invention; Figure 8 is a structural block diagram of a photovoltaic inverter according to another embodiment of the present invention; Figure 9 is a schematic diagram of a photovoltaic inverter according to an embodiment of the present invention; Figure 10 is a structural block diagram of a photovoltaic inverter according to an embodiment of the present invention.

[0023] Reference numerals: Photovoltaic inverter 1000; Processor 10; Memory 20; Inverter circuit 30; Fan 40; Controller 50; Photovoltaic module 60. Detailed implementation manners

[0024] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present invention will be described in detail below.

[0025] Generally, the control system of a photovoltaic inverter only judges whether the fan is damaged according to whether the fan rotates according to the instruction, and does not configure a corresponding sensor to judge the feature of fan freezing. Therefore, when the fan stops rotating, it is impossible to distinguish whether the fan cannot rotate temporarily due to fan freezing or cannot rotate permanently due to fan failure. Therefore, false alarms may be caused; and there is temporarily a lack of economical and effective fan thawing means, and usually additional equipment needs to be configured. For example, a centralized inverter can be arranged in a container and an air conditioner can be configured to keep the equipment warm to avoid freezing, or a dehumidification resistor can be added to the inverter to generate heat through the resistor to avoid equipment freezing. Whichever method requires an increase in cost.

[0026] To solve the above problems, an embodiment of the first aspect of the present invention proposes a control method for a photovoltaic inverter, which can ensure the power generation of the photovoltaic inverter and avoid overheating damage of the inverter circuit without increasing the equipment cost.

[0027] Next, refer to Figure 1 Describe the control method of the photovoltaic inverter according to the embodiment of the present invention. The control method of the photovoltaic inverter includes step S1-step S2, and the specific steps are as follows.

[0028] Step S1, when the photovoltaic inverter is started and the fan is not rotating, obtain the temperature information of the inverter circuit.

[0029] Specifically, after the PV inverter starts up, if the fan does not rotate, it may be due to fan freezing or a malfunction. In the prior art, since the PV inverter cannot determine the feature of fan freezing, it is difficult to distinguish between fan freezing and a malfunction. After determining that the PV inverter has started up and the fan does not rotate, the present application obtains the temperature information of the inverter circuit, and then judges whether the fan may be frozen, so as to be able to thaw the fan in the case of fan freezing, improve the power generation of the PV inverter, and at the same time monitor the temperature information of the inverter circuit to avoid over-temperature damage of the inverter circuit. Among them, the temperature information of the inverter circuit may include the temperature of the power semiconductor module or the temperature of the radiator.

[0030] Step S2, control the operating state of the inverter circuit according to the temperature information.

[0031] Specifically, if the inverter circuit is in a low-temperature scenario where the fan can be frozen, since the semiconductor module is the main internal heat source of the inverter circuit and the heat generated by the inverter circuit mainly comes from the losses generated by the working state of the semiconductor, the temperature of the semiconductor module inside the inverter circuit is also very low at this time. Therefore, according to the temperature information, it is judged whether the fan may be frozen, so as to control the inverter circuit to generate heat and transfer the heat to the fan for fan thawing. Without additional thawing equipment, the fan can be thawed to ensure the power generation of the PV inverter. However, if it is detected according to the temperature information that the temperature of the semiconductor module of the inverter circuit is too high and over-temperature damage may occur, the operating state of the inverter circuit is controlled to reduce heat generation and avoid over-temperature damage.

[0032] According to the control method of the PV inverter according to the embodiment of the present invention, when the PV inverter is in the startup state and the fan does not rotate, the temperature information of the inverter circuit is obtained, the operating state of the inverter circuit is controlled based on the temperature information of the inverter circuit, and the heat generated during the operation of the inverter circuit is used to avoid the reduction of the power generation of the inverter circuit caused by fan freezing, without additionally increasing the equipment cost, and it is also ensured that the inverter circuit will not suffer from over-temperature damage.

[0033] In some embodiments, the operating state includes a non-power-limited state and a power-limited state. Controlling the operating state of the inverter circuit according to the temperature information includes determining that the temperature information is less than or equal to the first temperature threshold, and then controlling the inverter circuit to alternately operate in the non-power-limited state and the power-limited state until the fan rotates.

[0034] Specifically, if it is determined that the temperature information is less than or equal to the first temperature threshold, the temperature of the environment where the inverter circuit is located is very low at this time, and the fan may be frozen. Since the inverter circuit can withstand high-power operation without being damaged when the fan is frozen or damaged, the inverter circuit is controlled to alternately operate in a non-power-limited state and a power-limited state. By transferring the heat generated during the operation of the inverter circuit to the fan for defrosting, the defrosting of the fan can be achieved without additional equipment costs. Although the higher the output power of the inverter circuit, the more heat is generated and the fan can complete defrosting faster, since the fan cannot rotate, the heat generated during the operation of the inverter circuit cannot be dissipated. If the inverter circuit always operates in a non-power-limited state, the inverter circuit will be damaged due to overheating. Therefore, the inverter circuit is controlled to operate in a non-power-limited state and a power-limited state to defrost the fan while ensuring that the inverter circuit will not be damaged due to overheating until the fan rotates, thereby realizing an increase in the power generation of the photovoltaic inverter. Among them, the first temperature threshold can be set according to the actual situation, such as -19°C, -20°C, -22°C, etc., and no specific limitation is made here. It should be noted that the non-power-limited state can be a full-power operation state, and less heat is generated in the power-limited operation state, and overheating damage will not occur.

[0035] In some embodiments, controlling the inverter circuit to alternately operate in a non-power-limited state and a power-limited state includes: Step a, controlling the inverter circuit to operate in a non-power-limited state; Step b, when it is determined that the temperature information is greater than the second temperature threshold, controlling the inverter circuit to switch from the non-power-limited state to the power-limited state, where the second temperature threshold is greater than the first temperature threshold; Step c, when it is determined that the inverter circuit meets the non-power-limited condition, controlling the inverter circuit to switch from the power-limited state to the non-power-limited state. Steps a, b, and c are executed in a loop.

[0036] Specifically, since the inverter circuit can withstand high-power operation without being damaged when the fan is frozen or damaged, the inverter circuit is controlled to operate in a non-power-limited state to increase the heat generated by the inverter circuit and accelerate the defrosting of the fan. However, when it is determined that the temperature information is greater than the second temperature threshold, the fan may have a real fault and cannot rotate, and there is a risk of overheating damage to the inverter circuit. Therefore, the output power of the inverter circuit should be limited to reduce the heat generated by the inverter circuit, thereby avoiding overheating damage to the inverter circuit. Therefore, the inverter circuit is controlled to switch from the power-limited state to the non-power-limited state. When it is determined that the temperature information is less than the second temperature threshold, there is no risk of overheating damage to the inverter circuit, and the output power of the inverter circuit can be increased to accelerate the defrosting of the fan. The second temperature threshold can be set according to the actual situation, such as 49°C, 50°C, 51°C, etc., and no specific limitation is made here.

[0037] In some embodiments, in the non-limited power state, the upper limit of the actual output power of the inverter circuit is greater than half of the maximum allowable output power of the inverter circuit and less than or equal to the maximum allowable output power of the inverter circuit, which can be expressed as: 0.5 × the maximum allowable output power of the inverter < the upper limit of the actual output power of the inverter ≤ the maximum allowable output power.

[0038] Specifically, when the inverter circuit operates in the non-limited power state, the actual output power of the inverter circuit can reach the upper limit of the actual output power. The actual power of the inverter circuit increases as the solar illumination intensity increases. In this application, in the non-limited power state, the upper limit of the actual output power of the inverter circuit is greater than half of the maximum allowable output power of the inverter circuit and less than or equal to the maximum allowable output power. The upper limit of the actual output power = a × the maximum allowable output power, where a is greater than 0.5 and less than or equal to 1. For example, a can be 0.6, 0.9, or 1, etc., and no specific limitation is made here.

[0039] Exemplarily, as Figure 2 shown in (a)-(c), Figure 2 (a) is a schematic diagram of the temperature information of the inverter circuit, Figure 2 (b) is a schematic diagram of the upper limit of the actual output power of the inverter circuit, Figure 2 (c) is a schematic diagram of the actual output power of the inverter circuit. At time t1, the photovoltaic inverter starts, and it is determined that the temperature information is less than the first temperature threshold Tth1. The inverter circuit operates in the non-limited power state, and the upper limit of the actual output power = 1 × the maximum allowable output power. The upper limit of the actual output power of the inverter circuit is set to the maximum allowable output power Pmax. The actual power of the inverter circuit can increase as the solar illumination intensity increases until it reaches and remains at the maximum allowable output power Pmax. The maximum allowable output power Pmax is maintained until a fan rotation signal is detected.

[0040] The actual output power of the inverter circuit is affected by light. In the case of insufficient light, the actual output power of the inverter circuit will not be able to reach the upper limit of the actual output power. Therefore, in the non-limited power state, the upper limit of the actual output power of the inverter circuit can also be set to be less than the maximum allowable output power and greater than half of the maximum allowable output power. For example Figure 3 (a)-(c) show that although the upper limit of the actual output power of the inverter circuit is set to Pmax at times t1 and t3, due to the influence of light, the light intensity is insufficient at this time, and the actual power of the inverter circuit cannot reach Pmax and can only operate at a magnitude slightly higher than 0.5 × Pmax.

[0041] Among them, the first temperature threshold is Tth1, the second temperature threshold is Tth2, and the maximum allowable output power is Pmax.

[0042] In some embodiments, in the power limit state, the actual output power of the inverter circuit is less than the maximum allowable output power of the inverter circuit, which can be expressed as: the actual output power of the inverter < the maximum allowable output power of the inverter.

[0043] Specifically, when it is determined that the temperature information is greater than the second temperature threshold, the inverter circuit meets the non-power limit condition. To avoid overheating and damage to the device, the inverter circuit will switch from the power limit state to the non-power limit state. At this time, the actual output power of the inverter circuit will be less than the maximum allowable output power of the inverter circuit. Since the output power of the inverter circuit decreases, the heat generated by the loss also decreases, and the temperature of the inverter circuit will gradually drop. Among them, the actual output power of the inverter circuit can be set according to the actual situation. For example, the actual output power = b × the maximum allowable output power, where b is greater than 0 and less than 1. For example, b can be 0.1, 0.5, 0.6, or 0.9, etc. There is no specific limitation here.

[0044] In some embodiments, the actual output power of the inverter circuit is half of the maximum allowable output power, which can be expressed as: the actual output power of the inverter = the maximum allowable output power × 0.5.

[0045] Specifically, as Figure 2 As shown in (a)-(c), at time t2, it is determined that the temperature information is greater than the second temperature threshold Tth2. To avoid overheating and damage to the device, the inverter circuit meets the non-power limit condition. At this time, the temperature information shows a downward trend. Therefore, the upper limit value of the actual output power of the inverter circuit is set to Pmax × 0.5, and the actual output power is also limited to Pmax × 0.5.

[0046] In some embodiments, when it is determined that the temperature information is greater than the third temperature threshold, the actual output power of the inverter circuit is greater than or equal to zero and less than half of the maximum allowable output power, which can be expressed as: 0 ≤ the actual output power of the inverter < the maximum allowable output power × 0.5.

[0047] Specifically, as Figure 4 As shown in (a)-(c), after time t2, the inverter circuit enters the power limit mode. Due to problems with the heat dissipation system and other reasons, the temperature information will continue to rise slowly. Therefore, a third temperature threshold is set above the second temperature threshold. When the temperature information is greater than the third temperature threshold, the power of the inverter circuit is further limited, and the upper limit value of the actual output power of the inverter circuit is set to a smaller value, that is, less than the maximum allowable output power × 0.5. In the most extreme case, the photovoltaic inverter can be directly shut down to ensure that the actual output power of the inverter circuit is 0. Among them, the third temperature threshold is Tth3.

[0048] In some embodiments, the temperature information is less than a fourth temperature threshold, where the fourth temperature threshold is greater than the first temperature threshold and less than or equal to the second temperature threshold, which can be expressed as: the first temperature threshold < the fourth temperature threshold ≤ the second temperature threshold; the power limit duration of the inverter circuit is greater than a preset duration, and under the power limit duration, the temperature drop of the inverter circuit is greater than a preset amplitude.

[0049] Specifically, after the inverter circuit enters the power limit state, it is continuously determined whether the temperature information is less than the fourth temperature threshold. If the temperature information is less than the fourth temperature threshold, it is considered that there is temporarily no risk of overheating damage to the inverter circuit. As shown in Figure 2 Figures (a)-(c), at time t3, the temperature information is less than the fourth temperature threshold, and the inverter circuit is still allowed to operate at full power. Since the natural heat dissipation capabilities of different devices and environments are different, in some scenarios, even when the inverter circuit enters the power limit operation mode, the temperature drop rate of the inverter circuit may be very slow, and it takes a very long time to reach the fourth temperature threshold, which will prolong the time for the fan to defrost. Therefore, a power drop gradient judgment condition is added, that is, when the power limit operation duration exceeds the preset duration and the temperature drop amplitude is greater than the preset amplitude. As shown in Figure 5 Figures (a)-(c), it is also considered that there is no risk of overheating of the device at this time, and the device is allowed to operate at full power to accelerate the fan defrosting speed.

[0050] Among them, the fourth temperature threshold is Tth4, the preset duration is Δts, the preset amplitude is ΔT, and the preset duration and preset amplitude can be set according to actual situations, and no specific limitations are made here.

[0051] It should be noted that due to the possible lag between temperature change and power change, as shown in Figure 6 Figures (a)-(c), it is also possible to consider setting the fourth temperature threshold equal to the second temperature threshold, which can shorten the power limit operation time, improve the average power and loss, and accelerate the fan defrosting process.

[0052] In some embodiments, the output state of the inverter circuit is controlled according to the temperature information, including determining that the temperature information is greater than the first temperature threshold, and controlling the operation state of the inverter circuit to be a shutdown state or a power limit state.

[0053] Specifically, if it is determined that the temperature information is greater than the first temperature threshold, since the fan cannot be frozen at this temperature and the fan is not rotating according to the instruction at this time, it is determined that the fan is damaged, and a fan fault alarm is reported.

[0054] Next, with reference to Figure 7 shown, the control method of the photovoltaic inverter according to the embodiments of the present invention is described, and the specific steps are as follows.

[0055] Step S3, start.

[0056] Step S4, determine whether the temperature information is greater than the first temperature threshold. If so, execute Step S8; if not, execute Step S5.

[0057] Step S5, the inverter circuit operates in a non-limited power state.

[0058] Step S6, determine whether the fan resumes rotation. If so, execute Step S7; if not, execute Step S8.

[0059] Step S7, determine whether the temperature information is greater than the second temperature threshold. If so, execute Step S9; if not, execute Step S8.

[0060] Step S8, the fan is not frozen.

[0061] Step S9, the inverter circuit operates in a limited power state.

[0062] Step S10, determine whether the fan resumes rotation. If so, execute Step S6; if not, execute Step S11.

[0063] Step S11, determine whether the temperature information is greater than the fourth temperature threshold, or the operation duration is greater than the preset duration and the temperature drop amplitude is greater than the preset amplitude. If so, execute Step S5; if not, execute Step S9.

[0064] Step S12 ends.

[0065] An embodiment of the second aspect of the present invention provides a computer storage medium, on which a computer program is stored. The computer program, when executed by a processor, implements the control method of the photovoltaic inverter in the above embodiment.

[0066] An embodiment of the third aspect of the present invention provides a photovoltaic inverter 100, as Figure 8 shown. The photovoltaic inverter 100 includes an inverter circuit 30, a fan 40, and a controller 50.

[0067] Among them, the controller 50 is respectively connected to the inverter circuit 30 and the fan 40, and is used to execute the control method of the photovoltaic inverter in the above embodiment.

[0068] According to the photovoltaic inverter 100 of the embodiment of the present invention, by executing the control method of the photovoltaic inverter by the controller, the heat generated by the operation of the inverter circuit 30 is used for fan defrosting, without the need to additionally increase equipment costs, ensuring the power generation of the photovoltaic inverter 100, and avoiding over-temperature damage to the inverter circuit 30.

[0069] Exemplarily, the architecture of the photovoltaic inverter 100 is as Figure 9 shown. The inverter circuit 30 is the core device of the photovoltaic inverter 100, and is responsible for converting the DC electric energy generated by the photovoltaic module 60 into AC electric energy and then transmitting it to the power grid.

[0070] In some embodiments, such as Figure 10 shown, the photovoltaic inverter 100 includes at least one processor 10; and a memory 20 communicatively connected to the at least one processor 10.

[0071] Wherein, a computer program executable by the at least one processor 10 is stored in the memory 20, and when the at least one processor 10 executes the computer program, the control method of the photovoltaic inverter in the above embodiments is implemented.

[0072] Specifically, by executing the control method of the photovoltaic inverter 100 in the above embodiments through the processor 10, the photovoltaic inverter 100 can ensure the power generation amount of the photovoltaic inverter 100 and avoid overheating damage of the inverter circuit without increasing the equipment cost.

[0073] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention.

[0074] In the description of this specification, any process or method description in the flowchart or described in other ways herein can be understood to represent a module, segment, or part of code including one or more executable instructions for implementing a customized logic function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in a reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0075] The logic and / or steps represented in the flowchart or otherwise described herein can, for example, be considered as a definitional sequence list of executable instructions for implementing logical functions, which can be embodied specifically in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in conjunction with such instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which a program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or otherwise processing as appropriate, and then storing it in a computer memory.

[0076] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0077] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0078] In addition, each functional unit in the various embodiments of the present invention may be integrated into a processing module, may exist physically alone for each unit, or two or more units may be integrated into one module. The above integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0079] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0080] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0081] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A control method for a photovoltaic inverter, characterized in that, The photovoltaic inverter includes an inversion circuit and a fan, and the control method includes: When the inversion circuit starts and the fan does not rotate, obtain the temperature information of the inversion circuit; Control the operating state of the inversion circuit according to the temperature information.

2. The control method of the photovoltaic inverter according to claim 1, wherein, The operating state includes a non-power-limited state and a power-limited state. Controlling the operating state of the inversion circuit according to the temperature information includes: Determine that the temperature information is less than or equal to a first temperature threshold, and then control the inversion circuit to alternately operate in the non-power-limited state and the power-limited state until the fan rotates.

3. The control method of the photovoltaic inverter according to claim 2, wherein, Controlling the inversion circuit to alternately operate in the non-power-limited state and the power-limited state includes: Step a, control the inversion circuit to operate in the non-power-limited state; Step b, when it is determined that the temperature information is greater than a second temperature threshold, control the inversion circuit to switch from the non-power-limited state to the power-limited state, where the second temperature threshold is greater than the first temperature threshold; Step c, when it is determined that the inversion circuit meets the non-power-limited condition, control the inversion circuit to switch from the power-limited state to the non-power-limited state; Loop and execute step a, step b, and step c.

4. The control method of the photovoltaic inverter according to claim 3, wherein, In the non-power-limited state, the upper limit value of the actual output power of the inversion circuit is greater than half of the maximum allowable output power of the inversion circuit and less than or equal to the maximum allowable output power of the inversion circuit.

5. The control method of the photovoltaic inverter according to claim 3, wherein, In the power-limited state, the actual output power of the inversion circuit is less than the maximum allowable output power of the inversion circuit.

6. The control method of the photovoltaic inverter according to claim 5, wherein, The actual output power of the inversion circuit is half of the maximum allowable output power.

7. The control method of the photovoltaic inverter according to claim 5, characterized in that, When it is determined that the temperature information is greater than a third temperature threshold, the actual output power of the inversion circuit is greater than or equal to zero and less than half of the maximum allowable output power.

8. The control method of the photovoltaic inverter according to claim 3, wherein, The non-power-limited condition includes any one of the following: The temperature information is less than a fourth temperature threshold, where the fourth temperature threshold is greater than the first temperature threshold and less than or equal to the second temperature threshold; The power-limited duration of the inversion circuit is greater than a preset duration and the temperature reduction amplitude of the inversion circuit is greater than a preset amplitude during the power-limited duration.

9. The control method of the photovoltaic inverter according to claim 1, wherein, Controlling the output state of the inversion circuit according to the temperature information includes: Determine that the temperature information is greater than the first temperature threshold, and control the operating state of the inversion circuit to be a shutdown state or a power-limited state.

10. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the control method of the photovoltaic inverter according to any one of claims 1-9.

11. A photovoltaic inverter, characterized in that, Including: An inversion circuit and a fan; A controller, respectively connected to the inversion circuit and the fan, and configured to execute the control method of the photovoltaic inverter according to any one of claims 1-9.

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