Fault diagnosis methods and related products for photovoltaic inverters

Abstract

This invention relates to a fault diagnosis method, computer program product, and equipment for photovoltaic (PV) inverters. The fault diagnosis method includes: applying a test input signal to the PV inverter to be diagnosed and acquiring a measured test signal from the PV inverter in response to the test input signal; simulating the test input signal using a pre-generated PV inverter model to obtain a simulated test signal; and comparing the measured test signal with the simulated test signal to determine the operating status of the PV inverter. This application allows for convenient and quick identification of whether the PV inverter is in an abnormal operating state by comparing the measured test signal with the simulated test signal. Furthermore, when the PV inverter is in an abnormal operating state, the potential causes of the fault can be quickly located by analyzing the difference between the measured test signal and the simulated test signal, allowing for adjustments to the PV inverter's control scheme or design scheme.

Description

Technical Field

[0001] This invention relates to the field of electrical performance diagnosis, and in particular to a fault diagnosis method for photovoltaic inverters. Background Technology

[0002] A smart factory is a modern production facility that integrates advanced technologies and innovative management models. The inverter smart factory, in particular, aims to produce photovoltaic inverters efficiently and with high quality to meet the growing demand in the clean energy market. In terms of hardware, the smart factory is equipped with automated production equipment, such as high-precision surface mount technology (SMT) machines, advanced welding robots, intelligent material handling systems, and intelligent testing systems. The smart factory also deploys an advanced digital manufacturing management platform that comprehensively covers production planning, logistics scheduling, real-time production monitoring, product quality inspection, and finished product tracking. Intelligent fault diagnosis is also a crucial component of the smart factory.

[0003] As the core device in a solar photovoltaic (PV) power generation system, the photovoltaic (PV) inverter converts the direct current (DC) generated by solar panels into alternating current (AC) for grid connection or power supply to loads. Its performance and stability directly affect the power generation efficiency and operational reliability of the entire PV power generation system. During the production process of PV inverters, fault diagnosis is a crucial step in ensuring their quality and stability. The aim is to diagnose and analyze faults present in the PV inverter during production testing, helping technicians quickly and accurately pinpoint the cause of the fault and efficiently repair and optimize any potential problems.

[0004] However, current fault diagnosis methods for photovoltaic inverters have some shortcomings. On the one hand, traditional fault diagnosis methods can only test the appearance and some basic electrical parameters of the photovoltaic inverter. Such methods are inconvenient to operate and have low efficiency, which cannot meet the fault diagnosis efficiency requirements for large-scale production. On the other hand, some fault diagnosis methods in this field only test the entire photovoltaic inverter, which may lead to limitations in the test results and thus relatively low accuracy. Summary of the Invention

[0005] One object of the present invention is to overcome at least one deficiency in the prior art and to provide a fault diagnosis method for photovoltaic inverters, a computer program product, a computer-readable storage medium, and a computer device.

[0006] A further objective of this invention is to diagnose faults in photovoltaic inverters by comparing measured test signals with simulated test signals.

[0007] Another further objective of this invention is to greatly reduce energy consumption during the testing process of photovoltaic inverters by using the electrical energy in the measured test signal generated by the photovoltaic inverter as part of the electrical energy source of the test input signal.

[0008] Another further objective of this invention is to store the process data during the testing process in a database and generate a test result report on the display interface based on the process data, so that technicians can intuitively monitor the real-time testing status of the photovoltaic inverter.

[0009] Specifically, the present invention provides a fault diagnosis method for a photovoltaic inverter, comprising: applying a test input signal to the photovoltaic inverter to be diagnosed, and acquiring a measured test signal of the photovoltaic inverter in response to the test input signal; simulating the test input signal using a pre-generated photovoltaic inverter model to obtain a simulated test signal; and comparing the measured test signal with the simulated test signal to determine the operating status of the photovoltaic inverter.

[0010] Optionally, the step of applying a test input signal to the photovoltaic inverter to be diagnosed includes: obtaining the configuration information of the photovoltaic inverter; determining the environmental parameters of the photovoltaic inverter's application environment and the photovoltaic modules used in conjunction with the photovoltaic inverter based on the configuration information; obtaining a simulation model of the photovoltaic modules; inputting the environmental parameters into the simulation model of the photovoltaic modules to generate the electrical parameters of the test input signal; controlling a signal generation device to modulate the test input signal according to the electrical parameters, and the signal generation device is also connected to the output of the photovoltaic inverter, wherein at least part of the electrical energy of the test input signal comes from the measured test signal.

[0011] Optionally, the signal generation device includes multiple switching power supplies, and the step of applying a test input signal to the photovoltaic inverter to be diagnosed includes: connecting the output terminals of the multiple switching power supplies in series with the photovoltaic inverter; the multiple switching power supplies jointly apply an input signal to the photovoltaic inverter to be diagnosed; the number of multiple switching power supplies is determined by configuration information.

[0012] Optionally, after obtaining the configuration information of the photovoltaic inverter, the method further includes: generating test parameters for the photovoltaic inverter based on the configuration information; putting the photovoltaic inverter into a test state based on the test parameters; and recording the test process data of the photovoltaic inverter.

[0013] Optionally, after recording the test process data of the photovoltaic inverter, the process data may further include: storing the process data in a pre-configured database, and generating a test result report on the display interface using a visualization program.

[0014] Optionally, the step of generating test parameters for the photovoltaic inverter based on the configuration information further includes: obtaining the test requirements for the photovoltaic inverter and the test requirements for the power devices in the photovoltaic inverter, the test requirements including: test temperature and test duration; correcting the test duration of the power devices to an equivalent test duration at the test temperature of the photovoltaic inverter; comparing the test duration applied to the photovoltaic inverter with the equivalent test duration; and generating test parameters based on the test requirements applied to the photovoltaic inverter if the test duration applied to the photovoltaic inverter is greater than or equal to the equivalent test duration.

[0015] Optionally, if the test duration applied to the photovoltaic inverter is less than the equivalent test duration, the method further includes: combining the test requirements applied to the photovoltaic inverter with the test requirements of the power devices to obtain the test parameters of the photovoltaic inverter.

[0016] Optionally, the step of comparing the measured test signal with the simulated test signal to determine the operating status of the photovoltaic inverter includes: obtaining parameters of the measured test signal and the simulated test signal, including peak parameters, power parameters, and phase parameters; determining whether the difference between the parameters is greater than a preset difference threshold; and if so, adjusting the control scheme or design scheme of the photovoltaic inverter. Specifically, when calculating the difference between the measured test signal and the simulated test signal, the difference value can be calculated by quantifying the core parameters; if the difference value between the measured test signal and the simulated test signal is greater than the preset difference threshold, the control scheme or design scheme of the photovoltaic inverter is adjusted.

[0017] Optionally, the steps when the difference between the measured test signal and the simulated test signal is greater than a preset difference threshold include: detecting whether the internal components of the photovoltaic inverter are damaged; if the internal components are not damaged, adjusting the control scheme of the photovoltaic inverter; if the internal components are damaged, adjusting the design scheme of the photovoltaic inverter.

[0018] According to another aspect of the present invention, a computer program product is also provided, which, when executed by a processor, implements the steps of the fault diagnosis method for a photovoltaic inverter according to any one of the preceding claims.

[0019] According to another aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the fault diagnosis method for a photovoltaic inverter according to any of the preceding claims.

[0020] According to another aspect of the present invention, a computer device is also provided, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the fault diagnosis method for a photovoltaic inverter according to any of the above claims.

[0021] The fault diagnosis method for photovoltaic inverters provided by this invention first applies a test input signal to the photovoltaic inverter to be diagnosed and collects the measured test signal of the photovoltaic inverter in response to the test input signal; then, it uses a pre-generated photovoltaic inverter model to simulate the test input signal to obtain a simulated test signal; finally, it compares the measured test signal with the simulated test signal to determine the operating status of the photovoltaic inverter. This method allows for convenient and efficient determination of the operating status of the photovoltaic inverter during fault diagnosis.

[0022] Furthermore, the fault diagnosis method for photovoltaic inverters of the present invention involves: acquiring configuration information of the photovoltaic inverter; determining the environmental parameters of the application environment of the photovoltaic inverter and the photovoltaic modules used in conjunction with the photovoltaic inverter based on the configuration information; acquiring a simulation model of the photovoltaic modules; inputting the environmental parameters into the simulation model of the photovoltaic modules to generate electrical parameters for the test input signal; controlling a signal generation device to modulate the test input signal according to the electrical parameters, and the signal generation device is also connected to the output of the photovoltaic inverter, wherein at least a portion of the electrical energy of the test input signal originates from the measured test signal. After testing the photovoltaic inverter, using the electrical energy in the measured test signal as at least a portion of the electrical energy source for the signal generation device can greatly save energy loss and reduce the electricity cost of the photovoltaic inverter during testing and fault diagnosis.

[0023] Furthermore, the fault diagnosis method for photovoltaic inverters of the present invention also considers the differences in testing requirements between power devices and photovoltaic inverters, correcting the testing duration of power devices to an equivalent testing duration at the testing temperature of the photovoltaic inverter; comparing the testing duration applied to the photovoltaic inverter with the equivalent testing duration; when the testing duration applied to the photovoltaic inverter is greater than or equal to the equivalent testing duration, generating test parameters based on the testing requirements applied to the photovoltaic inverter. When the testing duration applied to the photovoltaic inverter is less than the equivalent testing duration, combining the testing requirements applied to the photovoltaic inverter with the testing requirements of the power devices to obtain the test parameters of the photovoltaic inverter. This achieves comprehensive testing of the photovoltaic inverter, further reducing the risks that may arise from early failure of power devices and improving the reliability of the photovoltaic inverter.

[0024] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. Attached Figure Description

[0025] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0026] Figure 1 This is a connection diagram of a test system for applying a fault diagnosis method for a photovoltaic inverter according to an embodiment of the present invention.

[0027] Figure 2 This is a flowchart illustrating a fault diagnosis method for a photovoltaic inverter according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the process of applying a test input signal to a photovoltaic inverter to be diagnosed in a fault diagnosis method according to another embodiment of the present invention;

[0029] Figure 4 This is a flowchart illustrating the process of generating test parameters for a photovoltaic inverter based on configuration information according to an embodiment of the present invention.

[0030] Figure 5 This is a flowchart illustrating the optimization of the operation scheme of a photovoltaic inverter according to an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of a computer program product according to an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of a computer-readable storage medium according to an embodiment of the present invention; and

[0033] Figure 8 This is a schematic diagram of a computer device according to an embodiment of the present invention. Detailed Implementation

[0034] Those skilled in the art should understand that the embodiments described below are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. These partial embodiments are intended to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those skilled in the art without creative effort should still fall within the scope of protection of the present invention.

[0035] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein can be considered as a ordered list of executable instructions for implementing logical functions, which can be embodied in any computer-readable medium for use by an instruction execution system, apparatus or device (such as a computer-based system, a processor-based system or other system that can fetch and execute instructions from an instruction execution system, apparatus or device) or in conjunction with such instruction execution system, apparatus or device.

[0036] The present invention provides a fault diagnosis method for a photovoltaic inverter, which includes a signal generation device 100 and a photovoltaic inverter 300. Figure 1 This is a schematic diagram of the connection of a test system applying a fault diagnosis method for a photovoltaic inverter according to an embodiment of the present invention. The signal generation device 100 applies a test input signal to the photovoltaic inverter 300 to be diagnosed. The electrical energy in the measured test signal obtained after fault diagnosis and testing of the photovoltaic inverter 300 can be reused as the test input signal of the signal generation device 100, greatly saving energy. The signal generation device 100 consists of multiple switching power supplies 200 connected in series, and the specific number of switching power supplies 200 is determined by configuration information. For example, the rated input voltage of the photovoltaic inverter 300 is 288V, and the rated input current is 50A; each switching power supply 200 has an output voltage of 12V and an output current of 50A. Twenty-four switching power supplies 200 can be connected in series to obtain a signal generation device 100 with an output voltage of 288V and an output current of 50A, to meet the testing needs of the photovoltaic inverter 300. By adjusting the number of switching power supplies 200, the fault diagnosis and other testing needs of different models of photovoltaic inverters 300 can be met.

[0037] This invention provides a fault diagnosis method for photovoltaic inverters. Figure 2 This is a flowchart illustrating a fault diagnosis method for a photovoltaic inverter according to an embodiment of the present invention, as shown below. Figure 2 As shown, the optimization simulation method for the photovoltaic inverter includes at least the following steps S201 to S203.

[0038] Step S201: Apply a test input signal to the photovoltaic inverter to be diagnosed and collect the measured test signal of the photovoltaic inverter in response to the test input signal. The test input signal may include current signal, voltage signal, light intensity signal, and temperature signal, etc.; while the measured test signal may include AC voltage signal, AC current signal, frequency signal, and phase signal, etc. That is, applying a certain test input signal to the photovoltaic inverter to be diagnosed should result in the output of a measured test signal corresponding to the test input signal. Detecting the measured test signal allows determination of whether the photovoltaic inverter to be diagnosed has any abnormalities during operation.

[0039] Step S202: Simulate the test input signal using a pre-generated photovoltaic inverter model to obtain a simulated test signal. The photovoltaic inverter model should be able to generate a corresponding simulated test signal based on the aforementioned test input signal. The simulated test signal should include AC voltage, AC current, frequency, and phase signals, etc.

[0040] Step S203 involves comparing the measured test signal with the simulated test signal to determine the operating status of the photovoltaic inverter. The measured test signal can be compared individually with the AC voltage signal, AC current signal, frequency signal, and phase signal in the simulated test signal, followed by a comprehensive comparison. Alternatively, the above signals can be combined first and then compared to obtain the operating status of the photovoltaic inverter. In other words, the simulated test signal generated by the photovoltaic inverter model is a theoretical signal value generated based on the electrical parameters of the photovoltaic inverter. By comparing it with the measured test signal, the difference between the theoretical value and the measured test signal can be obtained, thereby analyzing whether there are any abnormalities in the operation of the photovoltaic inverter. The fault diagnosis method of this invention can conveniently and efficiently complete the fault diagnosis of photovoltaic inverters, greatly improving the fault diagnosis efficiency of photovoltaic inverters during production testing.

[0041] In some alternative embodiments, the present invention also provides a step of applying a test input signal to a photovoltaic inverter to be diagnosed. Figure 3 This is a flowchart illustrating the application of a test input signal to a photovoltaic inverter to be diagnosed in a fault diagnosis method according to another embodiment of the present invention, as shown below. Figure 3 As shown, the fault diagnosis method for this photovoltaic inverter includes at least the following steps S301 to S305. In this process, the fault diagnosis scheme includes:

[0042] Step S301: Obtain the configuration information of the photovoltaic inverter. The obtained configuration information may include the model information of the photovoltaic inverter and various electrical parameters corresponding to that model. The obtained configuration information may also include the specifications of the internal components of the photovoltaic inverter. For example, the rated input and output voltage and current values ​​of the power devices, or parameters such as capacitors, resistors, the package type of the power devices, or the operating temperature of the devices.

[0043] Step S302: Determine the environmental parameters of the photovoltaic inverter's application environment and the photovoltaic modules used in conjunction with the inverter based on the configuration information. The configuration information determines the environmental parameters during operation, such as important parameters like ambient temperature and humidity. It also identifies the photovoltaic modules that match the inverter. For example, the type of photovoltaic module can be determined based on the inverter's specific input power and input voltage. This avoids damage to the photovoltaic inverter caused by a mismatch between the photovoltaic module's output power and voltage and the inverter's input power or voltage.

[0044] Step S303: Obtain the simulation model of the photovoltaic module. Based on the photovoltaic module type determined above, the simulation model of the photovoltaic module can be determined. With known configuration information, input signals such as the output voltage, current, and current fluctuation values ​​of the photovoltaic module can be generated based on the input sunlight data and temperature data; these are also the test input signals for the photovoltaic inverter.

[0045] Step S304 involves inputting environmental parameters into the simulation model of the photovoltaic module to generate the electrical parameters of the test input signal. Based on the determined simulation model of the photovoltaic module, and then based on the input environmental parameters such as illumination data and temperature data, a test input signal is generated that integrates parameters such as output voltage, current, and current fluctuation values. This can simulate the real operating conditions of the photovoltaic inverter, improving the accuracy and realism of the test.

[0046] Step S305: The control signal generating device modulates the test input signal according to the electrical parameters. Alternatively, the input of the signal generating device can be connected to the output of the photovoltaic inverter, allowing the electrical energy in the measured test signal of the photovoltaic inverter to provide the signal generating device with the power required for its operation. The signal generating device can be a switching power supply or other device capable of rectification. For example, after completing the fault diagnosis test of the photovoltaic inverter, the output of the photovoltaic inverter will generate AC power. This AC power can be input into the switching power supply, which modulates the AC power into the DC power required for the test input signal of the photovoltaic inverter, enabling the recycling of electrical energy and significantly saving energy consumption.

[0047] In some optional embodiments, the signal generation device comprises multiple switching power supplies, and the step of applying a test input signal to the photovoltaic inverter to be diagnosed is as follows: the output terminals of multiple switching power supplies are connected in series and then connected to the photovoltaic inverter; the multiple switching power supplies jointly apply an input signal to the photovoltaic inverter to be diagnosed; the number of multiple switching power supplies is determined by configuration information. For example, the configuration information of the photovoltaic inverter specifies that the rated input voltage of the photovoltaic inverter is 288V and the rated input current is 50A. Each switching power supply has an output voltage of 12V and an output current of 50A. Twenty-four switching power supplies can be connected in series to obtain a signal generation device with an output voltage of 288V and an output current of 50A to meet the testing needs of the photovoltaic inverter. By adjusting the number of switching power supplies, the fault diagnosis and other testing needs of different models of photovoltaic inverters can be met.

[0048] In some optional embodiments, after obtaining the configuration information of the photovoltaic inverter, test parameters for the photovoltaic inverter are further generated based on the configuration information; the photovoltaic inverter is then put into test mode according to the test parameters, and the test process data of the photovoltaic inverter is recorded. After recording the test process data of the photovoltaic inverter, the process data is further stored in a pre-configured database, and the process data stored in the database is used to generate a test result report on the display interface through a visualization program. The process data may include the electrical parameters, operating status, and dynamic response data of the photovoltaic inverter; storing the process data in the pre-configured database ensures that test data is not lost due to equipment power outages, system failures, or human error, and technicians can perform systematic analysis of this batch of photovoltaic inverters based on the process data in the database, helping technicians to quickly identify systemic quality problems and rapidly improve the production process. Furthermore, generating a test result report on the display interface through a visualization program based on the process data stored in the database allows technicians to clearly and intuitively obtain the production test status of multiple photovoltaic inverters deployed on the testing platform.

[0049] In some alternative embodiments, the photovoltaic inverter needs to be tested. Generally, the testing scheme for photovoltaic inverters mainly involves testing the entire inverter unit. However, during the testing process, the impact of important components (such as power devices) on the test should also be considered. Figure 4 This is a flowchart illustrating the process of generating test parameters for a photovoltaic inverter based on configuration information according to an embodiment of the present invention; as shown below. Figure 4 As shown, the step of generating test parameters for a photovoltaic inverter based on configuration information includes at least the following steps S401 to S405. In this process, the step of generating test parameters for a photovoltaic inverter based on configuration information includes:

[0050] Step S401: Obtain the test requirements for the photovoltaic inverter and the test requirements for the power devices in the photovoltaic inverter;

[0051] Step S402: Correct the test duration of the power device to the equivalent test duration at the test temperature of the photovoltaic inverter;

[0052] Step S403: Determine whether the test duration applied to the photovoltaic inverter is greater than or equal to the equivalent test duration;

[0053] Step S404: If the test duration applied to the photovoltaic inverter is greater than or equal to the equivalent test duration, generate test parameters according to the test requirements applied to the photovoltaic inverter.

[0054] Step S405: If the test duration applied to the photovoltaic inverter is less than the equivalent test duration, the test requirements applied to the photovoltaic inverter are combined with the test requirements of the power devices to obtain the test parameters of the photovoltaic inverter.

[0055] When integrating the overall photovoltaic inverter test scheme and the power device test scheme, the order of these two aging schemes can be arranged according to their test temperatures. For example, if the test temperature of the overall photovoltaic inverter test scheme is lower than that of the power device test scheme, the overall photovoltaic inverter test scheme can be run first, followed by the power device test scheme. As another example, again using the lower test temperature of the overall photovoltaic inverter test scheme as an example, the overall photovoltaic inverter test scheme can be run for a period of time first, followed by the power device test scheme, and finally the overall photovoltaic inverter test scheme.

[0056] The inventors recognized that testing only the entire photovoltaic inverter might have limitations, preventing in-depth detection of potential problems in key components (such as power devices). They optimized the testing scheme to combine overall system testing and power device testing, enabling the optimized simulation method to provide a more comprehensive reliability assessment, uncover deeper-level potential problems, and further improve product quality. The power devices mainly include IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0057] For example, the power devices in a photovoltaic inverter are tested at 100℃ for 6 hours, while the entire unit is tested at 50℃ for 24 hours. The power device test duration is adjusted to the equivalent test duration at 50℃. If the equivalent test duration is greater than 24 hours, a power device test plan is generated based on the power device test requirements. The photovoltaic inverter's overall test plan and the power device test plan are then combined to obtain the photovoltaic inverter's testing plan. If the equivalent aging time is less than or equal to 24 hours, the overall aging test plan is used as the photovoltaic inverter's test parameter.

[0058] The process of correcting the test duration of power devices to the equivalent test duration under the test temperature of the entire photovoltaic inverter can be achieved by first determining the temperature conversion coefficient between the entire system test and the power device test, and then converting it into a test duration under the same temperature conditions for comparison. For example, the aging temperature conversion coefficient can be obtained according to the formula {1 + (power device test temperature - entire system test temperature) / entire system test temperature}, that is, the temperature conversion coefficient of the power device is {1 + (100℃ - 50℃) / 50℃} = 2. The converted duration is the product of the power device test duration and the temperature conversion coefficient calculated above.

[0059] Another conversion step involves pre-configuring the test temperature conversion coefficients for the power devices in various temperature ranges, so that the test durations of the power devices and the entire device can be compared under the same temperature conditions. Examples of specific test temperature conversion coefficient configurations are shown in Table 1.

[0060] Table 1

[0061] 100℃ 65℃ 50℃ 100℃ 1 1.6 2

[0062] As shown in the table, the conversion coefficient between a test temperature of 100℃ and a test temperature of 50℃ is 2. The converted duration is the product of the test duration and the temperature conversion coefficient calculated above. It should be noted that the specific values ​​in the examples above are merely illustrative. Those skilled in the art can configure specific test requirements based on the specific specifications of the photovoltaic inverter, the operating environment, and the performance of the devices. Therefore, the specific device types and their test parameters described above are not limitations on the present invention.

[0063] In some optional embodiments, the step of comparing the measured test signal with the simulated test signal to determine the operating status of the photovoltaic inverter can be as follows: First, obtain the parameters of the measured test signal and the simulated test signal, and then determine whether the difference between the measured test signal and the simulated test signal is greater than a preset difference threshold. When calculating the difference between the measured test signal and the simulated test signal, the difference value can be calculated by quantifying core parameters. These parameters may include the peak value, power parameter, and phase parameter of the measured test signal and the simulated test signal. These parameters can reflect the magnitude of the measured test signal and the simulated test signal to a certain extent. For example, if the peak value of the measured test signal is 311V and the peak value of the simulated test signal is 300V, the difference is 11V. If the preset difference threshold is 10V, then the operation of the photovoltaic inverter can be considered abnormal, and the photovoltaic inverter needs to be checked and optimized. Another example: if the peak value of the measured test signal is 311V and the frequency is 100MHz, and the peak value of the test signal is 300V and the frequency is 120MHz, assuming the weight of the peak value is 0.6 and the weight of the frequency is 0.4. The difference between the two signals is calculated as follows: (peak value of the measured test signal - peak value of the analog test signal) × 0.6 + (frequency of the measured test signal - frequency of the analog test signal) × 0.4 = (311 - 300) × 0.6 + (100 - 120) = -11.67. Alternatively, the absolute value of the difference obtained from the above calculation can be taken, and compared with a preset difference threshold to determine whether the photovoltaic inverter is in an abnormal operating state.

[0064] In some optional embodiments, if the difference between the parameters of the measured test signal and the simulated test signal is greater than a preset difference threshold, the photovoltaic inverter is generally considered to have a defect. However, it is still necessary to determine the specific type of defect so that technicians can quickly optimize the existing defect. Figure 5 This is a flowchart illustrating the optimization of the operation scheme of a photovoltaic inverter according to an embodiment of the present invention; as follows: Figure 5 As shown, the steps for optimizing the operation scheme of the photovoltaic inverter include at least the following steps S501 to S504. In this process, the steps for optimizing the operation scheme of the photovoltaic inverter include:

[0065] Step S501: Determine if the difference in parameters is greater than a preset difference threshold;

[0066] Step S502: Check whether the internal components of the photovoltaic inverter are damaged;

[0067] Step S503: If the internal components of the photovoltaic inverter are damaged, adjust the design scheme of the photovoltaic inverter.

[0068] Step S504: If the internal components of the photovoltaic inverter are not damaged, adjust the control scheme of the photovoltaic inverter.

[0069] When the difference between the measured test signal and the simulated test signal exceeds a threshold, the inventors realized that the type of defect in a photovoltaic inverter can be determined by detecting whether the internal components are damaged. If internal components are damaged, it indicates a problem with the selection of these components, such as a mismatch between the device power and the actual required power, inadequate anti-interference capabilities, or incompatibility between components. In this case, the inverter design should be adjusted to ensure the internal components meet the operating conditions. If the internal components are not damaged, the abnormal operation is not due to hardware issues. In this case, the internal control scheme should be examined for defects. For example, the switching frequency of power devices might be too high; or the internal heat dissipation strategy might be unreasonable, or the logic settings for starting and stopping the cooling fan might be inappropriate. Technicians should focus on optimizing the inverter's control scheme. This method allows for rapid fault location, enabling technicians to efficiently eliminate potential defects in the photovoltaic inverter and quickly resolve potential equipment malfunctions.

[0070] The flowchart provided in this embodiment is not intended to indicate that the operations of the method will be performed in any particular order, or that all operations of the method are included in every case. Furthermore, the method may include additional operations. Within the scope of the technical concept provided by the method in this embodiment, additional variations can be made to the above method.

[0071] It should be understood that in some embodiments, the components may be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods may be implemented using software or firmware stored in memory and executed by a suitable instruction execution system.

[0072] This embodiment also provides a computer program product 10, a computer-readable storage medium 20, and a computer device 30. Figure 6 This is a schematic diagram of a computer program product 10 according to an embodiment of the present invention. Figure 7 This is a schematic diagram of a computer-readable storage medium 20 according to an embodiment of the present invention. Figure 8This is a schematic diagram of a computer device 30 according to an embodiment of the present invention. The computer program product 10 includes a computer program 11, which, when executed by the processor 32, implements the steps of the production testing method for any of the above-described photovoltaic inverters. A computer-readable storage medium 20 stores the computer program 11 thereon, which, when executed by the processor 32, implements the steps of the production testing method for any of the above-described photovoltaic inverters. The computer device 30 may include a memory 31, a processor 32, and the computer program 11 stored in the memory 31 and running on the processor 32.

[0073] The computer program 11 used to perform the operations of this invention may be assembly instructions, Instruction Set Architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, integrated circuit configuration data, or source code or object code written in any combination of one or more programming languages ​​and procedural programming languages. The computer program 11 may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer may be connected to the user's computer via any type of network, including a Local Area Network (LAN) or Wide Area Network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, to perform aspects of this invention, electronic circuits, including, for example, programmable logic circuits, Field-Programmable Gate Arrays (FPGAs), or Programmable Logic Arrays (PLAs), may execute computer-readable program instructions using status information from computer-readable program instructions to personalize the electronic circuits.

[0074] For the purposes of this embodiment, computer program product 10 is a related product containing computer program 11. For the purposes of this embodiment, computer-readable storage medium 20 is a tangible device capable of holding and storing computer program 11, and can be any device capable of containing, storing, communicating, propagating, or transmitting program 11 for use by or in conjunction with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable storage medium 20 include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable optical disc read-only memory (CD-ROM), digital versatile disc (DVD), memory stick, floppy disk, mechanical encoding device, and any suitable combination thereof.

[0075] Computer device 30 can be, for example, a server, desktop computer, laptop computer, tablet computer, or smartphone. In some examples, computer device 30 can be a cloud computing node. Computer device 30 can be described in the general context of computer system executable instructions (such as program modules) executed by a computer system. Typically, program modules can include routines, programs, object programs, components, logic, data structures, etc., that perform specific tasks or implement specific abstract data types. Computer device 30 can be implemented in a distributed cloud computing environment where tasks are performed by remote processing devices linked through a communication network. In a distributed cloud computing environment, program modules can reside on local or remote computing system storage media, including storage devices.

[0076] Computer device 30 may include a processor 32 adapted to execute stored instructions and a memory 31 that provides temporary storage space for the operation of instructions during operation. The processor 32 may be a single-core processor, a multi-core processor, a computing cluster, or any other configuration. The memory 31 may include random access memory (RAM), read-only memory, flash memory, or any other suitable storage system.

[0077] Computer device 30 may also include a network adapter / interface and an input / output (I / O) interface. The I / O interface allows external devices that can be connected to the computer device to input and output data. The network adapter / interface provides communication between the computer device and a network, typically represented as a communication network.

[0078] At this point, those skilled in the art will recognize that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A fault diagnosis method for a photovoltaic inverter, characterized in that... include: A test input signal is applied to the photovoltaic inverter to be diagnosed, and the measured test signal of the photovoltaic inverter in response to the test input signal is collected. The test input signal is simulated using a pre-generated photovoltaic inverter model to obtain a simulated test signal; The operating status of the photovoltaic inverter is determined by comparing the measured test signal with the simulated test signal; wherein... The steps for applying a test input signal to the photovoltaic inverter to be diagnosed include: Obtain the configuration information of the photovoltaic inverter; Following the step of obtaining the configuration information of the photovoltaic inverter, the method further includes: The test parameters for the photovoltaic inverter are generated based on the configuration information. The photovoltaic inverter is put into test mode according to the test parameters, and the test process data of the photovoltaic inverter is recorded. The step of generating the test parameters of the photovoltaic inverter based on the configuration information further includes: Obtain the test requirements for the photovoltaic inverter and the test requirements for the power devices in the photovoltaic inverter. The test requirements include: test temperature and test duration. The test duration of the power device is corrected to the equivalent test duration at the test temperature of the photovoltaic inverter; Compare the test duration applied to the photovoltaic inverter with the equivalent test duration; If the test duration applied to the photovoltaic inverter is greater than or equal to the equivalent test duration, the test parameters are generated according to the test requirements applied to the photovoltaic inverter. If the test duration applied to the photovoltaic inverter is less than the equivalent test duration, the method further includes: The test requirements applied to the photovoltaic inverter are combined with the test requirements of the power device to obtain the test parameters of the photovoltaic inverter.

2. The fault diagnosis method for a photovoltaic inverter according to claim 1, characterized in that... The steps of applying a test input signal to the photovoltaic inverter to be diagnosed also include: The environmental parameters of the photovoltaic inverter application environment and the photovoltaic modules used in conjunction with the photovoltaic inverter are determined based on the configuration information. Obtain the simulation model of the photovoltaic module; The environmental parameters are input into the simulation model of the photovoltaic module to generate the electrical parameters of the test input signal; The control signal generating device modulates the test input signal according to the electrical parameters, and the signal generating device is also connected to the output of the photovoltaic inverter. At least part of the electrical energy of the test input signal comes from the measured test signal.

3. The fault diagnosis method for a photovoltaic inverter according to claim 2, characterized in that, The signal generation device includes multiple switching power supplies, and the step of applying a test input signal to the photovoltaic inverter to be diagnosed includes: The output terminals of multiple switching power supplies are connected in series and then connected to the photovoltaic inverter. Multiple switching power supplies jointly apply the input signal to the photovoltaic inverter to be diagnosed; The number of the multiple switching power supplies is determined by the configuration information.

4. The fault diagnosis method for a photovoltaic inverter according to claim 1, characterized in that, Following the step of recording the test process data of the photovoltaic inverter, the following is also included: The process data is stored in a pre-configured database, and the process data stored in the database is used to generate a test result report on the display interface through a visualization program.

5. The fault diagnosis method for a photovoltaic inverter according to claim 1, characterized in that... include: The step of comparing the measured test signal with the simulated test signal to determine the operating status of the photovoltaic inverter includes: Obtain the parameters of the measured test signal and the simulated test signal, including peak value parameters, power parameters, and phase parameters; Determine whether the difference in the parameters is greater than a preset difference threshold; If so, adjust the control scheme or design scheme of the photovoltaic inverter.

6. The fault diagnosis method for a photovoltaic inverter according to claim 5, characterized in that... include: If the difference in the parameters is greater than the preset difference threshold, the internal components of the photovoltaic inverter are checked for damage. If the internal components are not damaged, adjust the control scheme of the photovoltaic inverter. In the event of damage to the internal components, the design of the photovoltaic inverter shall be adjusted.

7. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the fault diagnosis method for the photovoltaic inverter as described in any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that... When the computer program is executed by the processor, it implements the steps of the fault diagnosis method for the photovoltaic inverter as described in any one of claims 1 to 6.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the fault diagnosis method for the photovoltaic inverter according to any one of claims 1 to 6.

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