Fault diagnosis method of photovoltaic inverter and related product

Abstract

The invention relates to a fault diagnosis method of a photovoltaic inverter, a computer program product and equipment. The fault diagnosis method comprises the following steps: applying a test input signal to a photovoltaic inverter to be diagnosed, and collecting an actual measurement test signal of the photovoltaic inverter in response to the test input signal; performing analog simulation on the test input signal by using a photovoltaic inverter model pre-generated by the photovoltaic inverter to obtain an analog test signal; and comparing the actual measurement test signal with the simulation test signal to obtain the operation state of the photovoltaic inverter. According to the invention, whether the photovoltaic inverter is in an abnormal operation state or not can be known conveniently and quickly by comparing the actual measurement test signal with the simulation test signal. Furthermore, when the photovoltaic inverter is in an abnormal operation state, possible fault reasons of the photovoltaic inverter can be quickly positioned by analyzing the difference value between the actual measurement test signal and the simulation test signal, and a control scheme or a design scheme of the photovoltaic inverter can be adjusted.

Description

Technical Field

[0001] The present invention relates to the field of diagnosis of electrical properties, and more particularly to a fault diagnosis method for a photovoltaic inverter. Background Art

[0002] An intelligent factory is a modern production site integrating advanced technologies and innovative management models. Among them, the intelligent factory for inverters aims to produce photovoltaic inverters efficiently and with high quality to meet the growing demand in the clean energy market. In terms of hardware facilities, the intelligent factory is equipped with automated production equipment, such as high-precision chip mounters, advanced welding robots, intelligent material handling systems, intelligent testing systems, etc. The intelligent factory deploys an advanced digital manufacturing management platform, which comprehensively covers production planning, logistics scheduling, real-time production monitoring, product quality inspection, and finished product tracking. Intelligent fault diagnosis is also an important part of the intelligent factory.

[0003] As the core device in a solar photovoltaic power generation system, a photovoltaic inverter is used to convert the direct current generated by solar panels into alternating current so that it can be connected to the power grid or used by loads. Its performance and stability are directly related to the power generation efficiency and operation reliability of the entire photovoltaic power generation system. During the production process of a photovoltaic inverter, fault diagnosis is a key link to ensure its quality and stability. The purpose is to diagnose and analyze the faults existing in the photovoltaic inverter while conducting production tests on the photovoltaic inverter, helping technicians quickly and accurately locate the cause of the faults and efficiently repair and optimize the possible faults.

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

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

[0006] A further object of the present invention is to perform fault diagnosis on a photovoltaic inverter by comparing measured test signals and simulated test signals.

[0007] Another further object of the present invention is to greatly save the energy consumption during the photovoltaic inverter testing process by using the electric energy in the measured test signal generated by the photovoltaic inverter as part of the electric energy of the test input signal.

[0008] Another further object of the present invention is to store the process data during the testing process in a database and generate a detection result report on the display interface according to the process data, so that technicians can intuitively monitor the real-time testing situation of the photovoltaic inverter.

[0009] In particular, the present invention provides a fault diagnosis method for a photovoltaic inverter, including: applying a test input signal to the photovoltaic inverter to be diagnosed, and collecting the measured test signal of the photovoltaic inverter in response to the test input signal; using a photovoltaic inverter model pre-generated by the photovoltaic inverter to perform simulation on the test input signal to obtain a simulated test signal; comparing the measured test signal with the simulated test signal to obtain the operating state 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 application environment of the photovoltaic inverter and the photovoltaic modules used in conjunction with the photovoltaic inverter according to the configuration information; obtaining the 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 the 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, and 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 a plurality of 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 plurality of switching power supplies in series and then connecting them to the photovoltaic inverter; the plurality of switching power supplies jointly apply an input signal to the photovoltaic inverter to be diagnosed; the number of the plurality of switching power supplies is determined by the configuration information.

[0012] Optionally, after the step of obtaining the configuration information of the photovoltaic inverter, it further includes: generating the test parameters of the photovoltaic inverter according to the configuration information; making the photovoltaic inverter enter the test state according to the test parameters, and recording the test process data of the photovoltaic inverter.

[0013] Optionally, after the step of recording the test process data of the photovoltaic inverter, it further includes: storing the process data in a pre-configured database, and generating a detection result report on the display interface through a visualization program for the process data stored in the database.

[0014] Optionally, the step of generating the test parameters of the photovoltaic inverter according to the configuration information further includes: obtaining the test requirements of the photovoltaic inverter and the test requirements of the power devices in the photovoltaic inverter, where the test requirements include: test temperature and test duration; correcting the test duration of the power devices to the equivalent test duration at the test temperature of the photovoltaic inverter; comparing the test duration applied to the photovoltaic inverter and the equivalent test duration; and generating test parameters according to the test requirements applied to the photovoltaic inverter when the test duration applied to the photovoltaic inverter is greater than or equal to the equivalent test duration.

[0015] Optionally, when the test duration applied to the photovoltaic inverter is less than the equivalent test duration, it further includes: integrating the test requirements applied to the photovoltaic inverter and 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 and the simulated test signal to obtain the operating state of the photovoltaic inverter includes: obtaining the parameters of the measured test signal and the simulated test signal, where the parameters include peak parameters, power parameters, and phase parameters; determining whether the difference in the parameters is greater than a preset difference threshold; if so, adjusting the control scheme or design scheme of the photovoltaic inverter. Among them, 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; when the difference value between the measured test signal and the simulated test signal is greater than the preset difference threshold, adjusting the control scheme or design scheme of the photovoltaic inverter.

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

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

[0019] According to still another aspect of the present invention, there is also provided a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the steps of the fault diagnosis method of the photovoltaic inverter according to any one of the above.

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

[0021] The fault diagnosis method of the photovoltaic inverter provided by the present 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 uses the photovoltaic inverter model pre-generated by the photovoltaic inverter to simulate the test input signal to obtain a simulated test signal; finally, obtains the operating state of the photovoltaic inverter by comparing the measured test signal with the simulated test signal. During the fault diagnosis of the photovoltaic inverter, the operating state of the photovoltaic inverter to be diagnosed can be obtained conveniently and efficiently.

[0022] Further, for the fault diagnosis method of the photovoltaic inverter of the present invention, the configuration information of the photovoltaic inverter is obtained; the environmental parameters of the application environment of the photovoltaic inverter and the photovoltaic modules used in conjunction with the photovoltaic inverter are determined according to the configuration information; the simulation model of the photovoltaic modules is obtained; the environmental parameters are input into the simulation model of the photovoltaic modules to generate the electrical parameters of the test input signal; the control signal generation device modulates the test input signal according to the electrical parameters, and the signal generation device is also connected to the output of the photovoltaic inverter, and at least part of the electrical energy of the test input signal is derived from the measured test signal. After testing the photovoltaic inverter, using the electrical energy in the measured test signal as the source of at least part of the electrical energy of the signal generation device can greatly save electrical energy loss and reduce the power consumption cost of the photovoltaic inverter during the test process and the fault diagnosis process.

[0023] Further, for the fault diagnosis method of the photovoltaic inverter of the present invention, the difference in the test requirements between the power devices and the photovoltaic inverter is also considered, and the test duration of the power devices is corrected to the equivalent test duration at the test temperature of the photovoltaic inverter; the test duration applied to the photovoltaic inverter and the equivalent test duration are compared; when 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. When the test duration applied to the photovoltaic inverter is less than the equivalent test duration, the test requirements applied to the photovoltaic inverter and the test requirements of the power devices are integrated to obtain the test parameters of the photovoltaic inverter. The comprehensive test of the photovoltaic inverter is realized, the risk that may be brought by the early failure of the power devices is further reduced, and the reliability of the photovoltaic inverter is improved.

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

[0025] Some specific embodiments of the present invention will be described in detail hereinafter with reference to the drawings in an exemplary but non-limiting manner. The same reference numerals in the drawings denote the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

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

[0027] Figure 2 is a schematic flow diagram of a fault diagnosis method of a photovoltaic inverter according to an embodiment of the present invention;

[0028] Figure 3 is a schematic flow diagram 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 is a schematic flow diagram of generating test parameters of a photovoltaic inverter according to configuration information according to an embodiment of the present invention;

[0030] Figure 5 is a schematic flow diagram of optimizing an operation scheme of a photovoltaic inverter according to an embodiment of the present invention;

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

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

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

[0034] Those skilled in the art should understand that the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. This part of the embodiments is intended to explain the technical principles of the present invention, rather than to limit the protection scope of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts should still fall within the protection scope of the present invention.

[0035] It should be noted that the logic and / or steps represented in the flowcharts or described in other ways herein can be considered as a definite sequence list of executable instructions for implementing logical functions, which can be specifically implemented 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 instructions from the instruction execution system, apparatus or device and execute the instructions), or in combination with these instruction execution systems, apparatus or devices.

[0036] In a fault diagnosis method for a photovoltaic inverter provided by the present invention, a signal generation device 100 and a photovoltaic inverter 300 are included. Figure 1 It is a schematic connection diagram of a test system for the fault diagnosis method of 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 electric 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 the use of electric energy. Among them, the signal generation device 100 is composed of a plurality of switching power supplies 200 connected in series, and the specific number of the 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; the output voltage of each switching power supply 200 is 12V, and the output current is 50A. 24 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 test requirements of the photovoltaic inverter 300. By adjusting the number of the switching power supplies 200, the fault diagnosis and other test requirements of different models of photovoltaic inverters 300 can be met.

[0037] The present invention provides a fault diagnosis method for a photovoltaic inverter. Figure 2 It is a schematic flowchart of the fault diagnosis method of a photovoltaic inverter according to an embodiment of the present invention. As Figure 2 shown, the optimization simulation method of the photovoltaic inverter at least includes the following steps S201 to step 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. Among them, the test input signal can include current signals, voltage signals, light intensity signals, and temperature signals, etc.; and the measured test signal can include AC voltage signals, AC current signals, frequency signals, and phase signals, etc. That is, applying a certain test input signal to the photovoltaic inverter to be diagnosed should be able to output a measured test signal corresponding to the test input signal. By detecting the measured test signal, it can be determined whether there is an abnormality in the operation of the photovoltaic inverter to be diagnosed.

[0039] Step S202: Use the photovoltaic inverter model pre-generated by the photovoltaic inverter to simulate the test input signal to obtain a simulated test signal. Among them, the photovoltaic inverter model should be able to generate a corresponding simulated test signal according to the above test input signal, and the simulated test signal should also include AC voltage signals, AC current signals, frequency signals, and phase signals, etc.

[0040] Step S203: Compare the measured test signal with the simulated test signal to obtain the operating state of the PV inverter. After separately comparing and then synthesizing the AC voltage signal, AC current signal, frequency signal, phase signal, etc. in the measured test signal and the simulated test signal, or first synthesizing the above-mentioned signals and then comparing them, the operating state of the PV inverter can be obtained. That is, the simulated test signal generated by the PV inverter model is the theoretical signal value generated according to the electrical parameters of the PV inverter. By comparing it with the measured test signal, the gap between the theoretical value and the measured test signal can be obtained, thereby analyzing whether there is an abnormality in the operation of the PV inverter. The fault diagnosis method of the present invention can conveniently and efficiently complete the fault diagnosis of the PV inverter, and can greatly improve the fault diagnosis efficiency of the PV inverter during the production test process.

[0041] In some alternative embodiments, the present invention further provides a step of applying a test input signal to the PV inverter to be diagnosed. Figure 3 It is a schematic flow chart of applying a test input signal to the PV inverter to be diagnosed in the fault diagnosis method according to another embodiment of the present invention, as Figure 3 shown. The fault diagnosis method of this PV 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 PV inverter. Among them, the obtained configuration information may include the model information of the PV inverter and various electrical parameters corresponding to this type of PV inverter. The obtained configuration information may also include the specification information of the internal components of the PV inverter. For example: the rated input and output voltage values and current values of power devices, or parameters such as the package type of capacitors, resistors, and power devices, or the operating ambient temperature of the devices.

[0043] Step S302: Determine the environmental parameters of the application environment of the PV inverter and the PV modules used in conjunction with the PV inverter according to the configuration information. According to the configuration information, the environmental parameters during use can be determined, such as important parameters such as the ambient temperature and humidity during operation. It is also possible to determine the PV modules that match the PV inverter. For example, according to the specific input power and input voltage and other parameters of the PV inverter, the type of the corresponding PV module can be determined. It can avoid damaging the PV inverter when the power and voltage and other parameters output by the PV module do not match the input power or voltage of the PV inverter.

[0044] Step S303: Obtain the simulation model of the photovoltaic module. According to the type of the photovoltaic module determined above, the simulation model of the photovoltaic module can be determined. When the configuration information is known, input signals such as the output voltage, current, and current fluctuation value of the photovoltaic module can be generated based on the input illumination data and temperature data, that is, the test input signals of the photovoltaic inverter.

[0045] Step S304: Input the environmental parameters into the simulation model of the photovoltaic module to generate the electrical parameters of the test input signals. According to the determined simulation model of the photovoltaic module above, and then generate the test input signals after synthesizing parameters such as the output voltage, current, and current fluctuation value based on the input environmental parameters such as illumination data and temperature data. The actual working conditions of the photovoltaic inverter can be simulated, improving the accuracy and authenticity of the test.

[0046] Step S305: The control signal generating device modulates the test input signals according to the electrical parameters. The input of the signal generating device can also be connected to the output terminal of the photovoltaic inverter, so that the electrical energy in the measured test signals of the photovoltaic inverter can be used to provide the electrical energy required for the operation of the signal generating device. Among them, the signal generating device can be a switching power supply or other devices that can achieve a rectification effect. For example: after completing the fault diagnosis test of the photovoltaic inverter, alternating current will be generated at the output terminal of the photovoltaic inverter. The generated alternating current can be input into the switching power supply, so that the switching power supply modulates the alternating current into the direct current required in the test input signals of the photovoltaic inverter, enabling the recycling of electrical energy and greatly saving the consumption of electrical energy.

[0047] In some alternative embodiments, the signal generating device is multiple switching power supplies, and the step of applying the test input signals to the photovoltaic inverter to be diagnosed is: connect the output terminals of the multiple switching power supplies in series and then connect them to the photovoltaic inverter; the multiple switching power supplies jointly apply the input signals to the photovoltaic inverter to be diagnosed; the number of the multiple switching power supplies is determined by the 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. The output voltage of each switching power supply is 12V and the output current is 50A. 24 switching power supplies can be connected in series to obtain a signal generating device with an output voltage of 288V and an output current of 50A to meet the test requirements of the photovoltaic inverter. By adjusting the number of switching power supplies, the requirements for fault diagnosis and other tests of different models of photovoltaic inverters can be met.

[0048] In some alternative embodiments, after the step of obtaining the configuration information of the PV inverter, test parameters of the PV inverter are further generated according to the configuration information; the PV inverter is made to enter a test state according to the test parameters, and the test process data of the PV inverter is recorded. After recording the test process data of the PV 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 a display interface through a visualization program. Among them, the process data may include electrical parameters, operating status, and dynamic response data of the PV inverter; the process data is stored in a pre-configured database. By this method, the test data can be prevented from being lost due to equipment power failure, system failure, or human operation errors, and technicians can conduct a systematic analysis of the PV inverters in this batch based on the process data in the database, which helps technicians quickly discover systematic quality problems and quickly improve the production process. Further, the process data stored in the database is used to generate a test result report on a display interface through a visualization program. This enables technicians to clearly and intuitively obtain the production test conditions of multiple PV inverters arranged on the test platform.

[0049] In some alternative embodiments, it is necessary to test the PV inverter. Generally speaking, in the test scheme of the PV inverter, mainly the whole machine of the PV inverter is tested. However, during the process of testing the PV inverter, the influence of important components (such as power devices) in the PV inverter on the test should also be considered. Figure 4 It is a schematic flow chart of generating test parameters of a PV inverter according to configuration information according to an embodiment of the present invention; as Figure 4 shown, in the step of generating test parameters of the PV inverter according to the configuration information, at least the following steps S401 to S405 are included. In this process, the step of generating test parameters of the PV inverter according to the configuration information includes:

[0050] Step S401, obtaining the test requirements of the PV inverter and the test requirements of the power devices in the PV inverter;

[0051] Step S402, correcting the test duration of the power device to the equivalent test duration at the test temperature of the PV inverter;

[0052] Step S403, determining whether the test duration applied to the PV inverter is greater than or equal to the equivalent test duration;

[0053] Step S404, in the case where the test duration applied to the PV inverter is greater than or equal to the equivalent test duration, generating test parameters according to the test requirements applied to the PV inverter;

[0054] Step S405, when the test duration applied to the PV inverter is less than the equivalent test duration, the test requirements applied to the PV inverter and the test requirements of the power device are integrated to obtain the test parameters of the PV inverter.

[0055] Among them, when integrating the overall machine test plan and the power device test plan of the PV inverter, the order of these two aging plans can be arranged according to the test temperatures of the overall machine test plan and the power device test plan of the PV inverter. For example: when the test temperature of the overall machine test plan of the PV inverter is lower than the test temperature of the power device test plan, the overall machine test plan of the PV inverter can be run first, and then the power device test plan can be run. Another example: still taking the test temperature of the overall machine test plan of the PV inverter being lower than the test temperature of the power device test plan as an example, the overall machine test plan of the PV inverter can be run for a period of time first, then the power device test plan can be run, and finally the overall machine test plan of the PV inverter can be run again.

[0056] The inventor realizes that there may be some limitations in only testing the overall machine of the PV inverter, resulting in the inability to deeply detect potential problems of key components (such as power devices). Optimizing the test plan to a plan that combines overall machine testing and power device testing can make the optimized simulation method of this application have a more comprehensive reliability assessment, be able to discover deeper potential problems, and help further improve product quality. Among them, power devices mainly include: IGBT (Insulated Gate Bipolar Transistor), MOSFET (Metal Oxide Semiconductor Field Effect Transistor), etc.

[0057] For example: the test temperature of the power device in the PV inverter is 100 °C, the test duration is 6 h, the overall machine test temperature is 50 °C, and the test duration is 24 h. The test duration of the power device is corrected to the equivalent test duration at a test temperature of 50 °C. If the equivalent test duration is greater than 24 h, a power device test plan is generated according to the test requirements of the power device, and the overall machine test plan and the power device test plan of the PV inverter are integrated to obtain the detection plan of the PV inverter. If the equivalent aging duration is less than or equal to 24 h, the overall machine aging test plan is used as the test parameter of the PV inverter.

[0058] In the process of correcting the test duration of the power device to the equivalent test duration at the test temperature of the entire photovoltaic inverter, the temperature conversion coefficients of the entire machine test and the power device test can be determined first, and then the test durations under the same temperature condition can be obtained by converting through the temperature conversion coefficient. For example, the aging temperature conversion coefficient can be obtained according to the formula {1 + (the test temperature of the power device - the test temperature of the entire machine) / the test temperature of the entire machine}. That is, the temperature conversion coefficient of the power device is {1 + (100°C - 50°C) / 50°C} = 2, and the converted duration is the product of the test duration of the power device and the temperature conversion coefficient calculated above.

[0059] Another conversion step is to pre-configure the test temperature conversion coefficients corresponding to the power device in each temperature range, so as to compare the test durations of the power device and the entire machine under the same temperature condition. A specific example of the configuration of the test temperature conversion coefficient is shown in Table 1.

[0060] Table 1

[0061] 100℃ 65℃ 50℃ 100℃ 1 1.6 2

[0062] It can be seen from the table that the conversion coefficient corresponding to the test temperature of 100°C for the test temperature of 50°C 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 above example are only for illustration, and those skilled in the art can configure the specific test requirements according to the specific specifications and models of the photovoltaic inverter, the operating environment, and the performance of the device. Therefore, the test parameters of the above specific device types and their test requirements do not limit the solution of the present invention.

[0063] In some alternative embodiments, the steps of comparing the measured test signal with the simulated test signal to obtain the operating state of the PV inverter may 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 the core parameters. Among them, the parameters may include the peak parameters, power parameters, and phase parameters of the measured test signal and the simulated test signal, and these parameters can reflect the magnitude of the measured test signal and the simulated test signal to a certain extent. For example: the peak value of the measured test signal is 311V, and the peak value of the simulated test signal is 300V, then the difference is 11V. At this time, if the preset difference threshold is 10V, it can be considered that there is an abnormality in the operation of the PV inverter, and the PV inverter needs to be inspected and optimized. Another example: the peak value of the measured test signal is 311V, the frequency is 100MHz, the peak value of the signal to be tested is 300V, and the frequency is 120MHz. Assume that the weight of the peak value is 0.6 and the weight of the frequency is 0.4. Then the calculation method of the difference value between the two signals is: (peak value of the measured test signal - peak value of the simulated test signal) × 0.6 + (frequency of the measured test signal - frequency of the simulated test signal) × 0.4 = (311 - 300) × 0.6 + (100 - 120) = -11.67. The absolute value can also be taken for the difference value obtained by the above calculation method, and by comparing the difference value with the preset difference threshold, it can be determined whether the PV inverter is in an abnormal operating state.

[0064] In some alternative embodiments, when the difference between the parameters of the measured test signal and the simulated test signal is greater than the preset difference threshold, it is generally considered that there is a defect in the PV inverter, but it is still necessary to determine which specific defect exists so that technicians can quickly optimize the existing defect. Figure 5 is a schematic flowchart of optimizing the operation scheme of a PV inverter according to an embodiment of the present invention; as Figure 5 shown, in the steps of optimizing the operation scheme of the PV inverter, at least the following steps S501 to step S504 are included. In this process, the steps of optimizing the operation scheme of the PV inverter include:

[0065] Step S501, determine when the difference in parameters is greater than the preset difference threshold;

[0066] Step S502, detect whether the internal components of the PV inverter are damaged;

[0067] Step S503, when the internal components of the PV inverter are damaged, adjust the design scheme of the PV inverter;

[0068] Step S504: Adjust the control scheme of the PV inverter when the internal components of the PV inverter are not damaged.

[0069] When the difference between the measured test signal and the simulated test signal is greater than the difference threshold, the inventor realizes that it is possible to determine the type of defect existing in the PV inverter by detecting whether the internal components of the PV inverter are damaged. When the internal components of the PV inverter are damaged, it indicates that there may be problems with the component selection inside the PV inverter. For example, the power of the component does not match the actual required power, the anti-interference ability does not meet the standard, or the components are not compatible, etc. At this time, the design scheme of the PV inverter should be adjusted so that the internal components of the PV inverter can meet the usage conditions of the PV inverter. When the internal components of the PV inverter are not damaged, it indicates that the abnormal operating state of the PV inverter is not caused by hardware reasons. At this time, it is necessary to consider whether there are defects in the control scheme inside the PV inverter. For example, the switching frequency of the power device is too fast; or, the heat dissipation strategy inside the PV inverter is unreasonable, and the logic setting for starting and stopping the cooling fan is inappropriate. At this time, technicians should focus on optimizing the control scheme of the PV inverter. Through this method, the fault can be quickly located, enabling technicians to efficiently eliminate the possible defects in the PV inverter and quickly solve the possible equipment failures.

[0070] The flowcharts provided in this embodiment are not intended to indicate that the operations of the method will be executed in any specific order, or that all operations of the method are included in every case. In addition, the method may include additional operations. Within the scope of the technical concept provided by the method of this embodiment, additional changes can be made to the above method.

[0071] It should be understood that in some embodiments, each part can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a 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 is a schematic diagram of a computer program product 10 according to an embodiment of the present invention, Figure 7 is a schematic diagram of a computer-readable storage medium 20 according to an embodiment of the present invention, Figure 8FIG. 0 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, and when the computer program 11 is executed by a processor 32, it implements the steps of any one of the above photovoltaic inverter production test methods. The computer-readable storage medium 20 stores the above computer program 11, and when the computer program 11 is executed by the processor 32, it implements the steps of the photovoltaic inverter production test method of any one of the above embodiments. The computer device 30 may include a memory 31, a processor 32, and a computer program 11 stored on the memory 31 and running on the processor 32.

[0073] The computer program 11 for performing the operations of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, configuration data of an integrated circuit, 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 be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone 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 through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider via the Internet). In some embodiments, in order to perform various aspects of the present invention, an electronic circuit, including, for example, a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA), may execute computer-readable program instructions by utilizing the state information of the computer-readable program instructions to personalize the electronic circuit.

[0074] For the description of this embodiment, the computer program product 10 is a related product containing the computer program 11. For the description of this embodiment, the computer-readable storage medium 20 is a tangible device capable of retaining and storing the computer program 11, which can be any device that can contain, store, communicate, propagate, or transmit the program 11 for use by an instruction execution system, apparatus, or device or in combination with these instruction execution systems, apparatuses, or devices. More specific examples (non-exhaustive list) of the computer-readable storage medium 20 include the following: 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 compact disc read-only memory (CD-ROM), digital versatile disc (DVD), memory stick, floppy disk, mechanically encoded device, and any suitable combination of the above.

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

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

[0077] The computer device 30 can also include a network adapter / interface and an input / output (I / O) interface. The I / O interface allows data to be input and output with external devices that can be connected to the computer device. The network adapter / interface can provide communication between the computer device and a network, which is usually shown as a communication network.

[0078] At this point, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived from the disclosed content 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 construed as covering all such other variations or modifications.

Claims

1. A fault diagnosis method for a photovoltaic inverter, characterized in that Including: Applying a test input signal to the photovoltaic inverter to be diagnosed, and collecting the measured test signal of the photovoltaic inverter in response to the test input signal; Performing simulation on the test input signal by using a pre-generated photovoltaic inverter model of the photovoltaic inverter to obtain a simulated test signal; Comparing the measured test signal with the simulated test signal to obtain the operating state of the photovoltaic inverter.

2. The fault diagnosis method of the photovoltaic inverter according to claim 1, characterized in that 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 application environment of the photovoltaic inverter and the photovoltaic modules used in conjunction with the photovoltaic inverter according to the configuration information; Obtaining the 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; A 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, and at least part of the electrical energy of the test input signal is derived from the measured test signal.

3. The fault diagnosis method of the photovoltaic inverter according to claim 2, characterized in that, The signal generating device includes a plurality of switching power supplies, and the step of applying a test input signal to the photovoltaic inverter to be diagnosed includes: Connecting the output ends of the plurality of switching power supplies in series and then connecting them to the photovoltaic inverter; The plurality of switching power supplies jointly apply the input signal to the photovoltaic inverter to be diagnosed; The number of the plurality of switching power supplies is determined by the configuration information.

4. The fault diagnosis method of a photovoltaic inverter according to claim 2, wherein After the step of obtaining the configuration information of the photovoltaic inverter, it further includes: Generating the test parameters of the photovoltaic inverter according to the configuration information; According to the test parameters, making the photovoltaic inverter enter the test state and recording the test process data of the photovoltaic inverter.

5. The fault diagnosis method of a photovoltaic inverter according to claim 4, wherein After the step of recording the test process data of the photovoltaic inverter, it further includes: Storing the process data into a pre-configured database, and generating a detection result report on a display interface through a visualization program for the process data stored in the database.

6. The fault diagnosis method of a photovoltaic inverter according to claim 4, wherein The step of generating the test parameters of the photovoltaic inverter according to the configuration information further includes: Obtaining the test requirements of the photovoltaic inverter and the test requirements of the power devices in the photovoltaic inverter, and the test requirements include: test temperature and test duration; Correcting the test duration of the power device to the equivalent test duration at the test temperature of the photovoltaic inverter; Comparing the test duration applied to the photovoltaic inverter and the equivalent test duration; When the test duration applied to the photovoltaic inverter is greater than or equal to the equivalent test duration, generating the test parameters according to the test requirements applied to the photovoltaic inverter.

7. The fault diagnosis method of a photovoltaic inverter according to claim 6, wherein When the test duration applied to the PV inverter is less than the equivalent test duration, it further includes: Integrating the test requirements applied to the PV inverter with the test requirements of the power device to obtain the test parameters of the PV inverter.

8. The fault diagnosis method of the photovoltaic inverter according to claim 1, characterized in that It includes: The step of comparing the measured test signal with the simulated test signal to obtain the operating state of the PV inverter includes: Obtaining the parameters of the measured test signal and the simulated test signal, where the parameters include peak parameters, power parameters, and phase parameters; Judging whether the difference between the parameters is greater than a preset difference threshold; If so, adjusting the control scheme or design scheme of the PV inverter.

9. The fault diagnosis method of a photovoltaic inverter according to claim 8, characterized in that It includes: When it is judged that the difference between the parameters is greater than the preset difference threshold, detecting whether the internal components of the PV inverter are damaged; When the internal components are not damaged, adjusting the control scheme of the PV inverter; When the internal components are damaged, adjusting the design scheme of the PV inverter.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the fault diagnosis method of the PV inverter according to any one of claims 1 to 9.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that When the computer program is executed by a processor, it implements the steps of the fault diagnosis method of the PV inverter according to any one of claims 1 to 9.

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

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