Testing device

Abstract

The utility model discloses a testing device, and relates to the technical field of inverters, the testing device comprises a power supply module, an acquisition module, a communication module and a control module, the power supply module is used for being connected with a to-be-tested inverter and outputting a testing power supply to the to-be-tested inverter, so that the to-be-tested inverter makes a corresponding response action according to the received testing power supply; the acquisition module is connected with the inverter to be detected, and is used for detecting an electric signal output by the inverter to be detected and the time when the inverter to be detected makes a corresponding response action, and outputting an acquisition signal; the communication module is respectively connected with the power supply module, the acquisition module and a to-be-tested inverter connected to the test device; the control module is in communication connection with the power supply module, the acquisition module and the inverter to be tested through the communication module; the control module is used for controlling the power supply module to work so as to output a test power supply to the to-be-tested inverter; and receiving the acquisition signal output by the acquisition module and outputting a corresponding test result according to the acquisition signal. The problem that a test result cannot be automatically obtained is solved.

Description

Technical Field

[0001] This application relates to the field of inverter technology, and in particular to a testing device. Background Technology

[0002] Before inverter products leave the factory, a series of tests are required to ensure their safety performance meets standards. Among these tests, fault protection time, such as over / under voltage protection time and over / under frequency protection time, is one of the important indicators for measuring inverter safety performance. However, most existing inverter abnormal operating condition tests rely on manual operation of testing equipment and cannot obtain test results automatically. Utility Model Content

[0003] The main objective of this application is to propose a testing device that addresses the problem of not being able to automatically obtain test results.

[0004] To achieve the above objectives, this application proposes a testing apparatus comprising:

[0005] A power module is used to connect to the inverter under test. The power module is used to output test power to the inverter under test so that the inverter under test can make a corresponding response action according to the received test power.

[0006] The acquisition module is connected to the inverter under test. The acquisition module is used to detect the electrical signal output by the inverter under test, the time when the inverter under test makes a corresponding response action, and output the corresponding acquisition signal.

[0007] The communication module is electrically connected to the power module and the acquisition module respectively, and the communication module is electrically connected to the inverter under test connected to the test device;

[0008] The control module is communicatively connected to the power supply module, the acquisition module, and the inverter under test via the communication module. The control module is used to control the power supply module to output test power to the inverter under test, and to receive and output corresponding test results based on the acquisition signals output by the acquisition module.

[0009] In one embodiment, the inverter under test includes an AC side and a DC side, and the power module includes an AC source and a DC source. The AC source is connected to the AC side of the inverter under test, and the DC source is connected to the DC side of the inverter under test.

[0010] In one embodiment, the control module is connected to the AC source, and the control module is used to control the AC source to output test power of different magnitudes to simulate overvoltage, undervoltage, overfrequency, and underfrequency operating conditions.

[0011] In one embodiment, the acquisition module includes an AC acquisition module and an oscilloscope. The AC acquisition module is electrically connected to the AC source and the inverter under test, respectively. The oscilloscope is electrically connected to the AC source, the AC acquisition module, and the communication module, respectively. The oscilloscope is used to detect the test power output by the AC source and also to output the acquisition signal.

[0012] In one embodiment, the control module is electrically connected to the oscilloscope via the communication module, and is used to control the oscilloscope to display the electrical signal output by the inverter under test and the time when the inverter under test makes a corresponding response action.

[0013] In one embodiment, the testing device further includes a switch module, and the power supply module is connected to an external power supply through the switch module;

[0014] The control module is electrically connected to the switch module and is used to control the connection between the power supply module and the external power supply.

[0015] In one embodiment, the switching module includes an AC contactor and a circuit breaker connected to each other. The AC contactor is electrically connected to the power supply module, and the circuit breaker is used to connect to an external power supply.

[0016] In one embodiment, the testing device further includes a display screen, which is electrically connected to the control module. The control module is used to receive a product target signal input by a user and to control the display screen to output the electrical signal and the time of the inverter under test to make a corresponding response action based on the acquired signal, the product target signal, at least one of the following:

[0017] In one embodiment, the testing device is equipped with a wiring strip, and the control module, the acquisition module, and the display screen are respectively connected to an external power supply through the wiring strip;

[0018] An emergency stop button is provided between the power strip and the external power supply.

[0019] In one embodiment, the communication module includes a switch.

[0020] The control module communicates with the power supply module, the acquisition module, and the inverter under test (DUT) via the communication module. The control module controls the power supply module's operating state, ensuring it outputs a stable and compliant test power supply to the DUT. This test power supply simulates various abnormal operating conditions such as overvoltage, undervoltage, overfrequency, and underfrequency, thus testing the DUT's response capability to these conditions. The acquisition module detects the electrical signals output by the DUT and their response times, outputting these signals and the DUT's response times as acquisition signals to the control module. The control module receives and outputs the corresponding test results based on the acquisition signals. These results visually demonstrate the DUT's abnormal operating condition protection capabilities, effectively achieving automatic control of the overfrequency / undervoltage and overfrequency / undervoltage abnormal operating condition testing process. This significantly reduces testing time and improves efficiency. Furthermore, automatic control reduces errors from manual operation, improving the accuracy and reliability of test results and providing strong support for evaluating the performance of the DUT. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a module of an embodiment of the testing apparatus provided in this application;

[0023] Figure 2 One of the electrical control schematic diagrams of an embodiment of the test apparatus provided in this application;

[0024] Figure 3 A second electrical control schematic diagram of an embodiment of the test apparatus provided in this application;

[0025] Figure 4 The third electrical control schematic diagram of an embodiment of the test device provided in this application.

[0026] Explanation of icon numbers:

[0027] 110. Power supply module; 111. AC power source; 112. DC power source;

[0028] 120. Acquisition module; 121. AC acquisition module; 122. Oscilloscope;

[0029] 130. Communication module; 131. Switch;

[0030] 140. Control module; 141. Industrial computer;

[0031] 150. Switch module;

[0032] 160. Display screen;

[0033] 170. Power strip;

[0034] 200, Inverter under test; 201, AC side; 202, DC side.

[0035] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0037] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0038] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0039] An inverter mainly consists of an input module, a main inverter module, an output module, auxiliary modules, a control module, and a protection module. These components work together to convert DC to AC and ensure the stable operation of the inverter. The inverter's protection mechanisms are primarily implemented through hardware and software protection. Hardware protection relies heavily on the inverter's module design and physical structure; for example, overload protection, over-temperature protection, and short-circuit protection are typically implemented through hardware modules. Software protection, on the other hand, is achieved through program control; for example, voltage protection and islanding protection can be monitored and controlled using software algorithms. In practical applications, hardware and software protection work together to form a complete protection system for the inverter. Specifically, when parameters on the inverter's input side (such as DC voltage) or output side (such as AC voltage, current, and frequency) exceed preset thresholds, the inverter will identify these anomalies and automatically trigger protection mechanisms. These mechanisms include adjusting power and disconnecting from the power supply to prevent equipment damage.

[0040] The duration of fault protection times, such as over / under voltage protection time and over / under frequency protection time, directly affects the safety performance of the inverter. If the protection time is too long, the equipment may operate for extended periods under abnormal voltage or frequency conditions, increasing the risk of equipment damage and the likelihood of safety accidents. Therefore, a series of tests are required before inverter products leave the factory to ensure their safety performance meets standards. Among these tests, the duration of fault protection times, such as over / under voltage protection time and over / under frequency protection time, is one of the important indicators for measuring the safety performance of an inverter.

[0041] Let's take over / under voltage protection and over / under frequency protection as examples:

[0042] When the inverter detects that the voltage on the AC side 201 or the DC side 202 exceeds the preset safety range, it will trigger the over / under voltage protection mechanism. The protection time, which is the time required for the inverter to take protective measures (such as reducing output power, disconnecting from the grid in case of overvoltage, cutting off power in case of undervoltage, completely stopping operation when the undervoltage is too low to maintain normal operation, and issuing an alarm) from detecting an abnormal voltage, is one of the important indicators of its safety performance. A shorter over / under voltage protection time means that the inverter can respond more quickly to voltage anomalies, thereby more effectively protecting equipment and the grid from damage.

[0043] When an inverter detects frequency fluctuations and triggers over / under frequency protection mechanisms when the frequency exceeds the allowable range, the protection time—the time required for the inverter to take protective measures (such as reducing output power in case of overfrequency, increasing output power in case of underfrequency, or disconnecting from the grid if necessary)—is a crucial indicator of its safety performance. The protection time directly impacts the inverter's ability to promptly protect equipment and the grid in the event of frequency anomalies. Shorter over / under frequency protection times help reduce the impact of frequency anomalies on equipment and the grid, improving the stability and security of the power system.

[0044] The fault protection time is determined by the time from the output test power of power module 110 to the corresponding response action of the inverter. Existing inverter abnormal operating condition tests have the following drawbacks when measuring the actual over / under voltage protection time, over / under frequency protection time, or other fault protection times: reliance on manual operation of the test equipment, unstable selection criteria for characteristic points representing test results such as fault protection time, and excessively long test times. Based on the drawbacks of existing tests, and referring to... Figures 1 to 4 This application proposes a testing device with higher automation, higher reliability, and higher testing efficiency to obtain test results more accurately.

[0045] The testing device proposed in this application includes a power module 110, a data acquisition module 120, a communication module 130, and a control module 140. The power module 110 is used to connect to the inverter under test 200 and to output test power to the inverter under test 200, so that the inverter under test 200 can perform corresponding response actions based on the received test power.

[0046] The acquisition module 120 is connected to the inverter under test 200. The acquisition module 120 is used to detect the electrical signal output by the inverter under test 200, the time when the inverter under test 200 makes the corresponding response action, and output the corresponding acquisition signal. The communication module 130 is electrically connected to the power supply module 110 and the acquisition module 120 respectively, and the communication module 130 is electrically connected to the inverter under test 200 connected to the test device.

[0047] The control module 140 is communicatively connected to the power supply module 110, the acquisition module 120, and the inverter under test 200 via the communication module 130. The control module 140 controls the power supply module 110 to output test power to the inverter under test 200; and receives and outputs corresponding test results based on the acquisition signals from the acquisition module 120. This allows for automatic acquisition of test results, including electrical signals (including electrical performance parameters and waveforms) and the time taken for the inverter under test 200 to respond (abnormal operating condition response time), while simultaneously performing automatic testing.

[0048] Understandably, in this application, the power module 110, as a key component of the test apparatus, is responsible for providing electrical energy. It includes a transformer, rectifier, filter, and voltage regulator, and is capable of outputting a stable and controllable test power supply to the inverter under test 200 according to the control signals from the control module 140. This simulates various operating conditions that the inverter may encounter in actual applications, such as different load conditions and input voltage fluctuations. This test power supply is output to the inverter under test 200 to trigger its possible abnormal protection mechanisms. In this way, the inverter's response capability to abnormal operating conditions such as over / under voltage and over / under frequency can be tested, thereby evaluating its performance. For example, when testing the undervoltage protection function, the power module 110 can output a power supply lower than the normal operating voltage (e.g., from 220V to 150V) to observe whether the inverter's operation under undervoltage conditions meets the design requirements.

[0049] The acquisition module 120 is responsible for detecting the output electrical signals and response time of the inverter under test 200 in real time and accurately during the test. It includes components such as sensors, amplifiers, and analog-to-digital converters (ADCs), which convert the detected physical quantities into electrical signals and transmit them to the control module 140 for analysis. When the inverter under test 200 responds to abnormal operating conditions (such as cutting off the output, adjusting the output voltage, or adjusting the output frequency), the acquisition module 120 detects these changes and outputs the corresponding acquisition signals to the control module 140. Taking overvoltage protection testing as an example, when the inverter cuts off the output under overvoltage conditions, the acquisition module 120 can detect changes in electrical performance parameters and other electrical signals indicating the inverter's response, and record the time interval from the output overvoltage test power supply to the inverter's response (e.g., detecting a 1-second time for the output cut-off action).

[0050] Optionally, the communication module 130 is electrically connected to the inverter under test 200 when it is connected to the testing device. The communication module 130 serves as an information exchange channel between the power supply module 110, the acquisition module 120, the control module 140, and the inverter under test 200. It supports multiple communication protocols and interface standards, and is responsible for receiving and transmitting the operating signals of the inverter under test 200. Specifically, the communication module 130 can be a collection of various communication buses, such as RS485 or Ethernet. It enables signal transmission between the modules, allowing the control module 140 to control the operating status of the power supply module 110 and the acquisition module 120, while also enabling the acquisition module 120 to transmit data to the control module 140. Furthermore, the communication module 130 can also communicate with the inverter under test 200 to obtain its necessary status information.

[0051] Optionally, the control module 140 may specifically control the power supply module 110 to operate and output test power to the inverter under test 200 after receiving the operating signal (such as power-on signal, power-off signal) from the inverter under test 200. The control module 140 is a computer device used for detection, control, and data processing in an automation or industrial control system, typically including a microcontroller unit (MCU) or other types of controllers. It encompasses functional modules such as signal processing, comparison, and calculation modules. Users can input control signals or adjust parameters through input devices, and the control module 140 receives, processes, and analyzes signals from the lower-level machine to detect the system status. The comparison module compares signal levels and outputs a comparison signal to set thresholds and generate control logic; the calculation module performs data calculations and determines whether to control the power supply module 110 to operate based on the operating signal of the inverter under test 200, controls the acquisition module 120 to acquire the response time of the inverter under test 200 based on the comparison signal, and judges the test result (normal or abnormal) based on the signal output by the acquisition module 120. The control module 140 controls the power supply module 110 to output the corresponding test power through preset logic or algorithms, and mainly controls the devices connected to the communication module 130 through protocols such as SCPI (Standard Commands for Programmable Instruments). Then, the control module 140 receives data such as electrical signals and response times of the inverter under abnormal operating conditions such as over-voltage, under-voltage, and under-frequency from the acquisition module 120. After analysis and judgment, it outputs test results such as "Inverter overvoltage protection function is normal" or "Abnormal" to help evaluate whether the inverter's protection mechanism is working as expected.

[0052] The control module 140 is communicatively connected to the power supply module 110, the acquisition module 120, and the inverter under test 200 via the communication module 130. The control module 140 controls the operating state of the power supply module 110, enabling it to output stable test power to the inverter under test 200 that meets the test requirements. This test power can simulate different abnormal operating conditions such as overvoltage, undervoltage, overfrequency, and underfrequency, thereby testing the response capability of the inverter under test 200 to different abnormal operating conditions. The acquisition module 120 detects the electrical signals output by the inverter under test 200 and the timing of its response, and converts the detected electrical signals and the inverter under test 200's response time into data. The timing of the corresponding response action is output to the control module 140 in the form of a data acquisition signal. The control module 140 receives the data acquisition signal from the data acquisition module 120 and outputs the corresponding test results. These test results can intuitively demonstrate the test status of the abnormal protection capability of the inverter under test 200, effectively realizing the automatic control of the test process for over-frequency and over-voltage abnormal operating conditions, significantly reducing the test time and improving test efficiency. At the same time, through automatic control testing, the error of manual operation can also be reduced, improving the accuracy and reliability of test results, and providing strong support for evaluating the performance of the inverter under test 200.

[0053] Compared to other testing devices in related technologies, the testing device of this application can obtain more accurate and predictable fault protection time results, avoiding testing errors caused by the need for manual intervention in time location. By optimizing the system structure and control strategy, it can also reduce testing time and improve testing efficiency, with testing time reduced by up to approximately 50%. Furthermore, it possesses a high level of digitalization, automatically outputting test results through the control module 140, and enabling traceability and recording of test results, such as test logs, by connecting to terminal devices or other digital platforms.

[0054] Reference Figure 1 , Figure 2 , Figure 4 In one embodiment, the inverter under test 200 includes an AC side 201 and a DC side 202, and the power module 110 includes an AC source 111 and a DC source 112. The AC source 111 is connected to the AC side 201 of the inverter under test 200, and the DC source 112 is connected to the DC side 202 of the inverter under test 200.

[0055] An inverter, as a device that converts DC power to AC power, requires a stable DC power supply as input to drive its internal modules for energy conversion during operation. Simultaneously, the inverter also needs to be connected to the AC power grid or load to output the converted AC power. Therefore, during testing, it is essential to ensure that the inverter under test 200 is connected to both the DC source 112 and the AC source 111 to simulate its actual operating environment and verify its conversion efficiency and fault protection functions. The DC source 112 is connected to the DC side of the inverter under test 200 to verify its performance and stability under DC input conditions, and optionally, to further test its protection capabilities in the event of DC input abnormalities (such as overvoltage or undervoltage). AC source 111 is connected to the AC side of inverter under test 200 to verify the working performance and stability of inverter under test 200 under AC output conditions, and to test its protection capability when AC output is abnormal (such as overvoltage, undervoltage, overfrequency, underfrequency, short circuit, etc.).

[0056] The acquisition module 120 can optionally be configured to correspond to at least one of the DC side 202 and AC side 201 of the inverter under test 200, to detect the output electrical signals of the inverter under test 200 during the test process (including but not limited to the voltage, current, and frequency of the AC side 201, and the voltage and current of the DC side 202) and the time when the inverter under test 200 makes corresponding response actions. When the inverter under test 200 responds under abnormal operating conditions (such as cutting off the output, adjusting the output voltage, adjusting the output frequency, issuing an alarm, etc.), the acquisition module 120 will detect these changes and output the corresponding acquisition signal to the control module 140. In this way, a comprehensive evaluation of the performance of the inverter under test 200 under different operating conditions can be achieved. By simulating abnormal operating conditions, abnormal operating condition testing of the inverter before it leaves the factory can be realized, ensuring that it can work stably and reliably in actual applications.

[0057] Taking undervoltage protection testing as an example, the DC source 112 outputs DC power lower than the normal operating voltage (e.g., the normal operating voltage is 220V, but the output is 150V). The acquisition module 120 detects the time it takes for the inverter under test 200 to respond accordingly. The control module 140 presets a target undervoltage protection time (e.g., 0.1s, 1s, 1.5s, etc.). If the response time of the inverter under test 200 is not greater than the preset target undervoltage protection time, then it is determined that the abnormal protection of the inverter under test 200 under undervoltage conditions meets the design requirements.

[0058] Taking overvoltage protection testing as an example, AC source 111 outputs AC voltage higher than the normal operating voltage (e.g., the normal operating voltage is 220V, but the output is 250V). Acquisition module 120 detects electrical signals such as changes in electrical performance parameters of the inverter under test (UDT) in response, and detects the time it takes for UDT 200 to respond. Control module 140 presets a target overvoltage protection time (e.g., 0.1s, 1s, 1.5s, etc.). If the response time of UDT 200 is not greater than the preset target overvoltage protection time, then it is determined that the abnormal protection of UDT 200 under overvoltage conditions meets the design requirements.

[0059] Depending on the actual usage requirements, the target parameter range of the inverter under test 200 can be further preset to determine whether the undervoltage (overvoltage) protection of the inverter under test 200 is qualified when the detected voltage does not exceed the target parameter range.

[0060] The implementation examples for testing over- and under-frequency protection can be referred to the aforementioned examples of over- and under-voltage protection, and will not be repeated here.

[0061] This application primarily uses the abnormal operating conditions of the power grid, such as overvoltage, undervoltage, overfrequency, and underfrequency conditions on the AC side 201, as examples. It mainly focuses on the fault protection time of the inverter under test responding abnormally and triggering power outages and other protective actions. The abnormal operating conditions on the DC side 202 can be referred to accordingly and will not be elaborated upon further.

[0062] Reference Figure 1 , Figure 4 In one embodiment, the control module 140 is connected to the AC source 111. The control module 140 is used to control the AC source 111 to output test power of different magnitudes to simulate overvoltage, undervoltage, overfrequency and underfrequency conditions.

[0063] Taking overvoltage testing as an example:

[0064] When the normal operating voltage is 220V, the AC source 111 can be controlled to output a 250V test power supply during overvoltage testing. The control module 140 determines whether the response time of the inverter under test 200 under overvoltage conditions meets the design requirements based on the electrical signal (such as the acquired voltage value) acquired by the acquisition module 120 and the time when the inverter under test 200 makes a corresponding response action (e.g., the time from controlling the AC source 111 to output the test power supply to the inverter under test 200 cutting off the output, and the time from controlling the AC source 111 to output the test power supply to the inverter under test 200 making other overvoltage protection actions), and outputs the test results.

[0065] The implementation of the undervoltage test can be referred to the overvoltage test described above, and the test power output of the control AC source 111 is adjusted to 150V (undervoltage) or other test power during the test; it will not be described in detail here.

[0066] Taking over-frequency testing as an example:

[0067] When the normal operating frequency is 50Hz, the AC source 111 can be controlled to output a test power of 51.5Hz during overfrequency testing. The control module 140 outputs the test results based on the electrical signal (such as the acquired frequency value) acquired by the acquisition module 120 and the time when the inverter under test 200 makes a corresponding response action (for example, the time from controlling the AC source 111 to outputting the test power to the inverter under test 200 cutting off the output, and the time from controlling the AC source 111 to outputting the test power to the inverter under test 200 making other overfrequency protection actions).

[0068] The implementation of the underfrequency test can be referred to the above-mentioned overfrequency test, and the test power output of the control AC source 111 is adjusted to 47.5Hz (underfrequency) or other test power during the test; it will not be described in detail here.

[0069] Optionally, the control module 140 is used to control the AC source 111 to output test power of different magnitudes to simulate abnormal operating conditions such as overvoltage, undervoltage, overfrequency, and underfrequency. Specifically, it can be implemented in any one or more of the following ways:

[0070] The testing device is electrically connected to input devices such as buttons, touch screens, keyboards, and mice to receive control signals transmitted by the user and control the execution of different abnormal operating condition tests such as overvoltage, undervoltage, overfrequency, and underfrequency based on the received control signals. Alternatively, different test items can be preset for different types of inverters under test 200, so that when the inverter under test 200 is connected to the testing device, the corresponding abnormal operating condition tests are automatically executed in the order of the preset test items without the need for multiple manual operations. Alternatively, instances of components such as the power module 110, communication module 130, and inverter under test 200 can be displayed on the display interface of the host computer or other display devices. The instances serve as illustrative virtual devices to simulate the connections between the components. The host computer software controls the connections and operations between the components and manages the test items and test processes to simulate different operating conditions such as overvoltage, undervoltage, overfrequency, and underfrequency, and to realize the corresponding abnormal operating condition tests. When a test is required, the user outputs control signals by clicking the corresponding instance or the test item option to control the testing device to execute the corresponding test item. The specific settings can be customized according to actual conditions and are not limited here.

[0071] Reference Figure 4In one embodiment, the acquisition module 120 includes an AC acquisition module 121 and an oscilloscope 122. The AC acquisition module 121 is electrically connected to the AC source 111 and the inverter under test 200, respectively. The oscilloscope 122 is electrically connected to the AC source 111, the AC acquisition module 121, and the communication module 130, respectively. The oscilloscope 122 is used to detect the test power output by the AC source 111 and also to output the acquisition signal.

[0072] The AC acquisition module 121 is electrically connected to the AC source 111 and the inverter under test 200. When the AC acquisition module 121 receives the test power signal output by the AC source 111, it performs preprocessing operations such as amplification and filtering, and mainly converts the analog signal into a digital signal through an analog-to-digital converter (ADC) to improve the signal-to-noise ratio and accuracy of the signal, which facilitates subsequent signal processing.

[0073] The oscilloscope 122, as an instrument for measuring and displaying electrical signal waveforms, can accurately capture high-speed, high-frequency signal changes. In this system, the oscilloscope 122 is used not only to detect the test power output from the power module 110, but also to receive electrical signals (including parameters such as voltage, current, frequency, and phase, and their waveforms) detected by the AC acquisition module 121. Furthermore, the oscilloscope 122 transmits the acquired signals to the controller via the communication module 130 and has the function of displaying the test power waveform, which helps technicians to intuitively observe and analyze signal changes. The digital signal sampled by the acquisition module 120 is transmitted to the control module 140 or other control devices via the communication module 130 and stored in the memory for subsequent traceability analysis. The waveforms and fault protection times displayed by the oscilloscope 122 can be saved in the form of images, etc., which is not limited here.

[0074] Reference Figure 4 In one embodiment, the control module 140 is electrically connected to the oscilloscope 122 via the communication module 130, and is used to control the oscilloscope 122 to display the electrical signal output by the inverter under test 200 and the time when the inverter under test 200 makes a corresponding response action.

[0075] The control module 140 controls the oscilloscope 122 through a preset program. Specific functions include, but are not limited to, setting the display parameters of the oscilloscope 122 (such as time axis scaling and voltage axis scaling), trigger conditions (such as setting trigger level and trigger mode), and locating feature points on the waveforms (parameters) displayed by the oscilloscope 122. When the inverter under test 200 is connected to the testing device, the control module 140 controls the oscilloscope 122 to display the electrical signals output by the inverter under test 200 and the time it takes for the inverter under test to make a corresponding response. Specifically, the time for the inverter under test to make a corresponding response is the fault protection time. In related technologies, it is usually impossible to directly obtain the test time under abnormal operating conditions, or the fault protection time needs to be manually determined on the oscilloscope 122, which increases the uncertainty and error of the test. In this application, the control module 140 uses the SCPI (Standard Commands for Programmable Instruments) protocol and a self-developed algorithm to locate feature points on the waveform displayed by the oscilloscope 122. Specifically, this involves automatically calibrating the timing of the output test power supply and the timing of the inverter under test's response. SCPI, as a text-based standardized command language, is used to control programmable test and measurement instruments. By calculating the time interval from the output overvoltage test power supply to the inverter's response, the fault protection time of the inverter under test 200 in the corresponding test item can be determined. This method effectively reduces reliance on manual intervention, avoids inaccurate test results that may result from manual operation, and significantly shortens test time, improving test efficiency.

[0076] Reference Figure 2 In one embodiment, the testing device further includes a switch module 150, through which the power module 110 is connected to an external power supply; and a control module 140 is electrically connected to the switch module 150 and is used to control the connection between the power module 110 and the external power supply.

[0077] Optionally, the switching module 150 includes one or more electronic switches (such as relays, MOSFETs, IGBTs, etc.), whose main function is to control the connection between the power module 110 and the external power supply. Under the control of the control module 140, the switching module 150 can quickly switch states to change the on / off state of the module, thereby realizing the connection or disconnection between the power module 110 and the external power supply. The specific functions are as follows: When the inverter under test 200 is connected to the test device, the control module 140 controls the switch module 150 to connect the power module 110 to the external power supply, so that the power module 110 converts the electrical energy provided by the external power supply into the test power required for testing the inverter under test 200; during the test, the switch module 150 allows the control module 140 to flexibly control the connection and disconnection of the power supply according to the test requirements, which is suitable for test scenarios that require switching different external power supplies at different test stages; when encountering abnormal or even fault conditions (such as overvoltage, overcurrent, etc.) or needing to stop the test urgently during the test, the control module 140 quickly disconnects the connection between the power module 110 and the external power supply through the switch module 150 to protect the test equipment and the inverter under test 200 from damage; during non-test periods, the control module 140 disconnects the connection between the power module 110 and the external power supply through the switch module 150 to reduce unnecessary energy consumption.

[0078] In this application, AC source 111 is used to be electrically connected to AC side 201 of inverter under test 200, and DC source 112 is used to be electrically connected to DC side 202 of inverter under test 200. Both DC source 112 and AC source 111 are electrically connected to an external power supply through switch module 150.

[0079] Reference Figure 2 In one embodiment, the switch module 150 includes an AC contactor KM1 and a circuit breaker QF1 connected to each other. The AC contactor KM1 is electrically connected to the power module 110, and the circuit breaker QF1 is used to be electrically connected to an external power supply.

[0080] The AC contactor mainly consists of an electromagnetic system (including coil and iron core) and a contact system (including normally open and normally closed contacts), making it particularly suitable for applications requiring frequent operation and remote control. The QF1 circuit breaker provides multiple protection functions, including overload protection and short-circuit protection, ensuring the safety and reliability of the testing process. This not only improves the flexibility and safety of the testing equipment but also reduces unnecessary energy consumption.

[0081] In the switch module 150, the AC contactor KM1 and circuit breaker QF1 cooperate to control the connection status between the power module 110 and the external power supply. The specific workflow is as follows: When power needs to be connected, the control module 140 sends a signal to the attraction coil of the AC contactor KM1, causing it to attract and connect the module; simultaneously, the circuit breaker QF1 is closed, allowing current to flow. During testing, if abnormal current or voltage occurs in the module, the circuit breaker QF1 will quickly disconnect the module, protecting the module and connected equipment from damage. When the test ends or power needs to be disconnected, the control module 140 sends a disconnect signal to the attraction coil of the AC contactor KM1, causing it to release and disconnect the module; additionally, the circuit breaker QF1 can also be manually or automatically disconnected to achieve complete module disconnection. Through the AC contactor KM1 and circuit breaker QF1, the switch module 150 can more flexibly control the connection between the power module 110 and the external power supply, realizing start / stop control and protection functions for the power module 110. This not only improves the flexibility and safety of the testing device but also helps reduce unnecessary energy consumption.

[0082] Optionally, the switch module 150 includes multiple circuits corresponding to the three-phase power lines and the neutral line. The multiple switch modules 150 are connected in parallel. Each switch module 150 corresponding to the three-phase power lines includes an AC contactor KM1 and a circuit breaker QF1 connected to each other through a straight-through terminal X3. The AC source 111 and the DC source 112 are electrically connected to the AC contactor KM1 through a straight-through terminal X2, and the circuit breaker QF1 is electrically connected to an external power supply through a straight-through terminal X1.

[0083] Reference Figure 4 In one embodiment, the testing device further includes a display screen 160, which is electrically connected to a control module 140. The control module 140 is used to receive the product target signal input by the user and control the display screen 160 to output an electrical signal and the inverter under test 200 to make a corresponding response action based on the collected signal, the product target signal, or at least one of these.

[0084] Users input target signals (including the product model, product parameters, test parameters, target voltage, target frequency, and target fault protection time of the inverter under test 200) through external input devices (such as buttons, touch screens, keyboards, mice, etc.) or input devices located in the control module 140. After receiving these signals, the control module 140 processes them according to a preset program and generates corresponding control signals. Simultaneously, the control module 140 locates the waveform characteristic points displayed on the oscilloscope 122, automatically calibrates the time point of the output test power supply and the time point of the inverter's response action, thereby calculating the fault protection time. The control module 140 determines the test results based on the acquired electrical signals, target signals, and fault protection time, and sends these test results (including the parameters of the inverter under test, fault protection time, etc.) to the display screen 160 for display. The display screen 160 not only displays the acquired real-time status and test results but also helps users understand the operation of the testing device. Specifically, when receiving a signal containing the target fault protection time, the control module 140 compares the target fault protection time with the actual fault protection time and outputs test results such as "Inverter overvoltage protection function is normal" or "Abnormal". The display screen 160 makes the interaction between the test device and the user more convenient and accurate, helping the user to easily view and control the test process, making the test process more flexible and controllable.

[0085] Reference Figure 3 In one embodiment, the testing device is provided with a wiring strip 170, and the control module 140, the acquisition module 120, and the display screen 160 are respectively connected to an external power supply through the wiring strip 170; an emergency stop button J1 is provided between the wiring strip 170 and the external power supply.

[0086] The wiring strip 170 is mainly used in the testing device and is configured on the outer casing or other suitable location of the testing device. It connects components such as the control module 140, data acquisition module 120, and display screen 160 to the external power supply via sockets and outlets, simplifying wiring complexity and directly powering these components to maintain the normal operation of the testing device. The use of the wiring strip 170 makes power supply and connection of modules more convenient and faster. Furthermore, to ensure safety during equipment operation, an emergency stop button J1 is provided. In case of emergency or abnormal situation, closing the emergency stop button J1 can quickly cut off the power supply or stop the equipment operation, thereby preventing accidents.

[0087] Optionally, the wiring strip 170 is electrically connected to the protective grounding wire of the external power supply via a ground wire to ensure that the equipment casing is grounded and to provide safety protection; the wiring strip 170 is electrically connected to the phase wire of the external power supply via a live wire to provide power; the wiring strip 170 is electrically connected to the neutral wire of the external power supply via a neutral wire for current return; the live wire is electrically connected to the neutral wire via an emergency stop button J1, a selector switch S1 (2-position selector switch), and an AC contactor KM2 connected in sequence, for emergency stop via the emergency stop button J1, which quickly cuts off the power supply in an emergency to ensure the safety of equipment and personnel; the live wire is electrically connected to the neutral wire via an AC contactor KM3 and an indicator light H1 connected in sequence, and the indicator light H1 lights up when the wiring strip 170 is connected to the external power supply to indicate the power connection status.

[0088] Furthermore, when the circuit breaker QF1 and the position selection switch S1 are in the closed state by being successively placed in the "ON" position, the AC contactors KM1, KM2, and KM3 are closed to control the AC source 111 and the DC source 112 to be powered on.

[0089] Reference Figure 4 In one embodiment, the communication module 130 includes a switch 131. The switch 131 is mainly used to forward and switch data packets, and ensures efficient, secure, and reliable data transmission in the network by supporting various security policies such as port security and access control lists (ACLs).

[0090] Taking the control module 140, which includes an industrial computer 141, as an example, the industrial computer 141 is connected to the display screen 160 via a VGA / HDMI interface or other connection interface. The display screen 160 is used to display the operation interface and test results of the industrial computer 141. The industrial computer 141 is connected to the switch 131 via a network cable for network communication and data transmission. The industrial computer 141 is connected to the DC source 112 via a USB-to-485 cable (or other compatible communication interface and protocol) for controlling the output of the DC source 112 or reading its status information; and is also connected to the inverter under test 200 via a USB-to-485 cable (or other means) for controlling the operation of the inverter under test 200, detecting its performance, or collecting data. The oscilloscope 122 is connected to the AC acquisition module 121 via a dedicated signal line (such as a BNC cable) for detecting and analyzing the waveform and electrical performance parameters of AC signals. The AC acquisition module 121 is connected to the AC source 111 and is used to acquire signals from the AC source 111 and perform preprocessing (such as amplification and filtering). The processed electrical signal is then transmitted to the oscilloscope 122, which outputs the acquired signal to the industrial computer 141 via a network cable. The industrial computer 141 uses a preset algorithm to locate feature points on the waveform (parameters) displayed by the oscilloscope 122 to determine the fault protection time. The DC source 112 is connected to an external power supply via a power cord to power itself and is connected to the industrial computer 141 via a USB-to-485 cable (or other communication interface) to receive control signals from the industrial computer 141 and provide status feedback. The inverter under test 200 is connected to the DC source 112 via a power cord to convert DC power to AC power output.

[0091] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A testing device, characterized in that, include: A power module is used to connect to the inverter under test. The power module is used to output test power to the inverter under test so that the inverter under test can make a corresponding response action according to the received test power. The acquisition module is connected to the inverter under test. The acquisition module is used to detect the electrical signal output by the inverter under test, the time when the inverter under test makes a corresponding response action, and output the corresponding acquisition signal. The communication module is electrically connected to the power module and the acquisition module respectively, and the communication module is electrically connected to the inverter under test connected to the test device; The control module is communicatively connected to the power supply module, the acquisition module, and the inverter under test via the communication module. The control module is used to control the power supply module to output test power to the inverter under test, and to receive and output corresponding test results based on the acquisition signals output by the acquisition module.

2. The testing apparatus as described in claim 1, characterized in that, The inverter under test includes an AC side and a DC side, and the power module includes an AC source and a DC source. The AC source is connected to the AC side of the inverter under test, and the DC source is connected to the DC side of the inverter under test.

3. The testing apparatus as described in claim 2, characterized in that, The control module is connected to the AC source and is used to control the AC source to output test power of different magnitudes to simulate overvoltage, undervoltage, overfrequency, and underfrequency conditions.

4. The testing apparatus as described in claim 2, characterized in that, The acquisition module includes an AC acquisition module and an oscilloscope. The AC acquisition module is electrically connected to the AC source and the inverter under test, respectively. The oscilloscope is electrically connected to the AC source, the AC acquisition module, and the communication module, respectively. The oscilloscope is used to detect the test power output by the AC source and also to output the acquisition signal.

5. The testing apparatus as described in claim 4, characterized in that, The control module is electrically connected to the oscilloscope through the communication module, and is used to control the oscilloscope to display the electrical signal output by the inverter under test and the time when the inverter under test makes the corresponding response action.

6. The testing apparatus as described in claim 2, characterized in that, The testing device also includes a switch module, and the power module is connected to an external power supply through the switch module; The control module is electrically connected to the switch module and is used to control the connection between the power supply module and the external power supply.

7. The testing apparatus as described in claim 6, characterized in that, The switching module includes an AC contactor and a circuit breaker that are connected to each other. The AC contactor is electrically connected to the power supply module, and the circuit breaker is used to connect to an external power supply.

8. The testing apparatus as described in any one of claims 1-7, characterized in that, The testing device also includes a display screen, which is electrically connected to the control module. The control module is used to receive the product target signal input by the user and control the display screen to output the electrical signal and the time of the inverter under test to make a corresponding response action based on the acquired signal, the product target signal, or at least one of these.

9. The testing apparatus as described in claim 8, characterized in that, The testing device is equipped with a wiring strip, and the control module, the acquisition module, and the display screen are respectively connected to an external power supply through the wiring strip; An emergency stop button is provided between the power strip and the external power supply.

10. The testing apparatus according to any one of claims 1-7, characterized in that, The communication module includes a switch.

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