Inverter test system

Abstract

This application discloses an inverter testing system. The inverter testing system includes a main control module, a level conversion module, and a power drive module. The inverter and the power drive module form a test loop. The main control module is configured to control the level conversion module to change its operating state, thereby further adjusting the load inductance, load resistance, or load capacitance of the power drive module. This application enables simulated testing of the inverter by connecting the inverter and the power drive module in series to form a test loop. By adjusting the load inductance in the test loop, the load inductance / resistance / capacitance state of the inverter in a weak power grid is simulated, thus achieving simulated testing of the inverter. Compared to methods that test inverters through wiring, the solution disclosed in this application effectively simplifies the testing process and improves testing efficiency and flexibility.

Description

Technical Field

[0001] This application relates to the field of low-voltage control technology, specifically to an inverter testing system. Background Technology

[0002] To improve the grid-friendliness of photovoltaic system products and reduce the potential adverse effects of products on weak grids, and to verify the adaptability of weak grids using the short-circuit capacity ratio (SCR) as an indicator, the test requires transporting the inverter to the field grid environment and connecting it to the transformer for grid-connected testing over long distances via power cables. This requires separate wiring and complex deployment before field testing. Furthermore, it is impossible to accurately simulate and modify the parasitic parameters of the grid-connected power cables during the testing process, or to investigate the impact of parasitic parameters such as cable length, diameter, and wiring method on the inverter's performance. This method faces problems such as long cycle time, low efficiency, complex environment, difficult implementation, high cost, and safety risks. Summary of the Invention

[0003] This application provides an inverter testing system.

[0004] The inverter testing system involved in the embodiments of this application includes a main control module, a level conversion module, and a power drive module, wherein the inverter and the power drive module form a test circuit;

[0005] The main control module is configured to control the level conversion module to change its operating state in order to further adjust and control the load inductance, load resistance or load capacitance of the power drive module.

[0006] Thus, this application can simulate the inverter by connecting the inverter and the power drive module in series to form a test circuit, and by adjusting the load inductance in the test circuit to simulate the load inductance / resistance / capacitance state of the inverter in a weak power grid, thereby realizing the simulation test of the inverter. Compared with the solution of testing the inverter by construction wiring, this can effectively simplify the test process and improve test efficiency and flexibility.

[0007] In some embodiments, the power drive module includes multiple load devices having the same electrical parameters.

[0008] Thus, this application can simulate the load inductance, load resistance, or load capacitance in a circuit by setting multiple load devices.

[0009] In some embodiments, the load device is an inductor, which is arranged in series and has the same inductance value.

[0010] Thus, this application can simulate the load inductance by setting multiple inductor devices and connecting them in series in the test circuit.

[0011] In some embodiments, the level conversion module includes a boost converter and a relay device. The boost converter is configured to adjust the electrical signal provided by the main control module to control the relay device. The relay device is configured to control the connection and disconnection of the inductor in the test circuit.

[0012] Thus, this application can also indirectly control the connection of each inductor in the test circuit through relay devices by setting the level conversion module, thereby realizing the adjustment of the load inductance in the test circuit.

[0013] In some embodiments, the level conversion module includes a first relay and at least one second relay, the first relay being configured to control the on / off state of the test circuit, and the second relay being configured to control the connection and disconnection of the corresponding inductor in the test circuit.

[0014] Thus, this application can also control the overall on / off state of the test circuit by configuring relays, and can also control whether each load inductor is connected in the test circuit.

[0015] In some implementations, the main control module includes a control core device, and the level conversion module is connected to the control core device via a general-purpose input / output interface.

[0016] Thus, this application can also control the level conversion module by setting the main control module, thereby indirectly controlling the on / off state of the test circuit and the connection or disconnection of the relay, thereby controlling the simulation process of the inverter.

[0017] In some embodiments, the main control module further includes a power supply device and a communication device, both of which are electrically connected to the control core device. The power supply device is configured to supply power to the level conversion module and the main control module, and the communication device is configured to control wired or wireless communication between the external environment and the control core device.

[0018] Thus, this application can also enable the control core device to communicate with other external devices by setting up a communication device, and can provide power to the main control module and the level conversion module by using a power supply device.

[0019] In some embodiments, the main control module further includes a switch control device, which is electrically connected to the control core device and is configured to control the operating state of the relay device.

[0020] Thus, this application can also control the switching of the working state of each relay device by setting a switch control device, thereby indirectly controlling the on / off state of the test circuit and whether each load inductor is connected in the test circuit.

[0021] In some embodiments, the switch control device includes a physical switch and / or an electronic switch.

[0022] Therefore, this application also provides a variety of switching control devices to facilitate stable control of relay devices in different scenarios.

[0023] In some embodiments, the main control module further includes a display device, which is electrically connected to the control core device;

[0024] The display device is touch-sensitive and is configured to control the electronic switch to change its operating state or to act as the electronic switch.

[0025] Thus, this application can also display the status of the inverter test system through a display device, and can also achieve the effect of electronic switch control of relay devices through touch.

[0026] In some embodiments, the load device is a capacitor, which is arranged in parallel and has the same capacitance value.

[0027] In some embodiments, the load device is a resistor, which is arranged in series and has the same resistance value.

[0028] In some implementations, the test loop further includes a photovoltaic simulator configured to perform photovoltaic simulation tests on the inverter.

[0029] In some implementations, the test loop further includes a grid simulator configured to perform grid simulation tests on the inverter.

[0030] Thus, this application can also enable inverter testing in different power grids by connecting a photovoltaic simulator or a power grid simulator in series in the test circuit.

[0031] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0032] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic diagram of the inverter testing system in the embodiments of this application;

[0034] Figure 2 This is a schematic diagram of the circuit structure of the test circuit in the embodiments of this application;

[0035] Figure 3 This is a schematic diagram of the level conversion module in the embodiment of this application;

[0036] Figure 4 This is a schematic diagram of the main control module in the embodiment of this application;

[0037] Figure 5 This is a schematic diagram of the main control module in one example of this application.

[0038] The components are as follows: 11. Inverter; 12. Power drive module; 13. Main control module; 131. Control core device; 132. Power supply device; 133. Communication device; 134. Display device; 135. Switch control device; 14. Level conversion module; 141. First relay; 1421. Second relay A; 1422. Second relay B; 14211. Second relay K; 143. Control core device; 1441. Boost converter A; 1442. Boost converter B; 1443. Boost converter C; 14412. Boost converter L; 15. Photovoltaic simulator; 16. Grid simulator. Detailed Implementation

[0039] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0040] Please see Figure 1 The inverter 11 test system in this application includes a main control module 13, a level conversion module 14 and a power drive module 12, and the inverter 11 and the power drive module 12 form a test circuit.

[0041] The main control module 13 is configured to control the level conversion module 14 to change its operating state in order to further adjust the load inductance, load resistance or load capacitance of the power drive module 12.

[0042] Specifically, a weak grid refers to a power grid exhibiting lower stability and dynamic response capabilities under specific conditions, particularly pronounced in distributed generation and remote areas. The IEEE std 1204-1997 standard defines a short-circuit ratio (SCR) of less than 3 as the criterion for classifying a weak grid. Under the combined influence of nonlinear loads and line impedance, the behavior of a weak grid becomes complex, causing power sources to no longer be ideal voltage sources but exhibit a degree of inductive behavior. Under weak grid conditions, increased grid impedance lowers the system's resonant frequency, slows down the dynamic response, and affects system stability. Increasing the number of parallel inverters lowers the resonant frequency, generates additional resonant spikes, and with an increasing number of inverters, the dynamic response slows down, making the system unstable. In a weak grid environment, the inverter's control loop may become unstable due to the presence of grid impedance. Grid voltage distortion is also a significant characteristic of weak grids, reflecting the instability and imbalance of the grid under suboptimal conditions. With lower SCR (Signal Response Rate), higher grid impedance means any disturbance injected by the inverter will be amplified by the weak grid, making it more difficult for the power plant to maintain steady-state operation, complete transient fault ride-through, and maintain power quality under weak grid conditions. Substandard performance may lead to problems or accidents such as grid disconnection, oscillations, significantly increased harmonics, or even equipment damage.

[0043] To improve the grid-friendliness of photovoltaic system products and reduce their adverse impact on the grid, and to verify the adaptability of weak grids using the short-circuit ratio (SCR) as an indicator, the test requires transporting the inverter to the field grid environment and connecting it to the transformer via long-distance power cables for grid-connected testing. This requires separate wiring and complex deployment before field testing. Furthermore, it is impossible to accurately simulate and modify the parasitic parameters of the grid-connected power cables during the test, or to investigate the impact of parasitic parameters such as cable length and diameter, as well as the wiring method, on the inverter's performance. This method faces problems such as long cycle time, low efficiency, complex environment, difficult implementation, high cost, and safety risks.

[0044] To address the numerous issues encountered during grid connection testing, this application discloses a test system for inverter 11. The main idea is to form a test circuit by connecting a power drive module 12 in series with the inverter 11. The power drive module 12 is used to simulate the load inductance, load resistance, or load capacitance present in the power grid based on the properties of the inverter 11 itself, thereby creating a simulated load environment similar to the actual application scenario. In this simulated load environment, the actual performance of the inverter 11 in the power grid can be tested.

[0045] Specifically, the inverter 11 testing system in this application mainly includes three modules: a power drive module 12, a main control module 13, and a level conversion module 14. As described above, the power drive module 12 is connected in series with the inverter 11 under test to form a test circuit, and its main function is to simulate the load inductance / resistance / capacitance in the power grid. The main control module 13 is directly connected to the level conversion module 14, and the level conversion module 14 is directly connected to the power drive module 12. The function of the main control module 13 is to control the working state of the level conversion module 14, thereby indirectly controlling the working state of the power drive module 12, and thus adjusting the inductance / resistance / capacitance values ​​exhibited by the power drive module 12 in the test circuit to meet the different testing requirements of the inverter 11 under different load inductance conditions. The control of the level conversion module 14 by the main control module 13 can be achieved by manual operation by maintenance personnel on site, or by remote operation via wired or wireless communication through a computer, mobile phone, or dedicated control terminal equipment. This effectively enhances the application scenarios and flexibility of inverter 11 testing, while also improving the safety of testing through remote control technology.

[0046] Thus, this application can simulate the test of inverter 11 by connecting inverter 11 and power drive module 12 in series to form a test circuit, and by adjusting the load inductance in the test circuit to simulate the load inductance / resistance / capacitance state of inverter 11 in a weak power grid. Compared with the method of testing inverter 11 by construction wiring, this can effectively simplify the test process and improve test efficiency and flexibility.

[0047] In some embodiments, the power drive module 12 includes multiple load devices having the same electrical parameters.

[0048] Specifically, based on the above embodiments, the power drive module 12 simulates the load inductance, load resistance, or load capacitance in a weak power grid. Therefore, exemplarily, the power drive module 12 includes multiple load devices with the same electrical parameters. These electrical parameters can be one of inductance, resistance, or capacitance. Furthermore, since the power drive module 12 includes multiple load devices, the simulated inductance, resistance, or capacitance can be adjusted by changing the number of load devices connected to the test circuit.

[0049] Thus, this application can simulate the load inductance, load resistance, or load capacitance in a circuit by setting multiple load devices.

[0050] Please see Figure 2In some implementations, the load device is an inductor, which is arranged in series and has the same inductance value.

[0051] Specifically, based on the above embodiments, for ease of description, in the following examples, the adjustment value used for the power drive module 12 is the load inductance of the power drive module 12. The same applies to the load capacitor and load resistor, which can be replaced and adjusted according to the actual situation.

[0052] For example, the power drive module 12 includes multiple inductors connected in series; see [link to relevant documentation]. Figure 2 , Figure 2 The example shown includes eleven inductors, L1 to L11, connected in series. When all eleven inductors are connected in series in the test circuit, the load inductance exhibited by the power drive module 12 in the test circuit is the sum of the inductance values ​​of these eleven inductors. Furthermore, each inductor has the same inductance value. This allows the main control module 13 to indirectly control the number of inductors connected to the test circuit by controlling the operating state of the level conversion module 14, thus easily controlling the load inductance exhibited by the power drive module 12. For example, if the inductance value of the inductors is 0.35mH, then the load inductance exhibited by the power drive module 12, controlled by the main control module 13, can be an integer multiple of 0.35mH within the range of 0 to 11. The number of inductors included in the power drive module 12 and the specific inductance value of each inductor can be adjusted according to the test requirements and the attribute parameters of the inverter 11 itself. This application is only for illustrative purposes and does not make any specific limitations.

[0053] Thus, this application can simulate the load inductance by setting multiple inductor devices and connecting them in series in the test circuit.

[0054] In some embodiments, the level conversion module 14 includes a boost converter and a relay device. The boost converter is configured to adjust the electrical signal provided by the main control module 13 to control the relay device, which is configured to control the connection and disconnection of the inductor device in the test circuit.

[0055] Specifically, based on the above embodiments, the level conversion module 14, exemplarily, includes two parts: a boost converter and a relay. The main function of the relay is to switch whether the inductor in the above embodiments is connected to the test circuit by changing its own operating state under the control of the main control module 13. The boost converter is connected to both the main control module 13 and the relay. When the main control module 13 controls the power drive module 12, it sends a control signal. After receiving the control signal, the boost converter adjusts the control signal to make its signal strength, signal attributes, and other parameters conform to those of the relay. After adjusting the control signal, it sends the control signal back to the relay to achieve the switching control of the relay's operating state.

[0056] Thus, this application can also indirectly control the connection of each inductor in the test circuit through the relay device by setting the level conversion module 14, thereby realizing the adjustment of the load inductance in the test circuit.

[0057] Please see Figure 2 as well as Figure 3 In some embodiments, the level conversion module 14 includes a first relay 141 and at least one second relay. The first relay 141 is configured to control the on / off state of the test circuit, and the second relay is configured to control the connection and disconnection of the corresponding inductor in the test circuit.

[0058] Specifically, based on the above embodiments, and exemplarily, the relay device described above is divided into two types: a first relay 141 and a second relay. Please refer to [link to relevant documentation]. Figure 2 The first relay 141 is directly connected in series in the test circuit and mainly acts as a switch for the test circuit. Under the control of the main control module 13, it can realize the control of the overall on / off of the test circuit, thereby playing the role of starting the test, ending the test, and cutting off the test circuit in an emergency.

[0059] Besides the first relay 141, the second relay is connected one-to-one with each inductor in the power drive module 12. Its main function is the same as in the example above: when the main control module 13 controls the power drive module 12, it changes the connection state of the load device corresponding to the second relay in the test circuit by changing the operating state of the second relay. For some examples, please refer to... Figure 3 The boost converter and relay devices included in the level conversion module 14 have a one-to-one correspondence. For example, Figure 3In the illustrated configuration, the level conversion module 14 includes a total of 12 boost converters, one first relay 141, and 11 second relays. Each boost converter is connected to a corresponding relay device. One boost converter is connected to the first relay 141, and each of the remaining 11 boost converters is connected to a corresponding second relay. For example, according to... Figure 3 Boost converter A1441 is connected to the first relay 141; boost converter B1442 is connected to inductor L1 via the second relay A1421; boost converter C1443 is connected to inductor L2 via the second relay B1422; and so on, with boost converter L14412 connected to inductor L11 via the second relay K14211. In this configuration, the main control module 13 can send two different control signals when controlling the level conversion module 14. One signal controls the first relay 141 to change its operating state, thereby controlling the on / off state of the test circuit. The other signal controls a specific second relay to change its operating state, thereby controlling whether the inductor corresponding to that second relay is connected in the test circuit.

[0060] Thus, this application can also control the overall on / off state of the test circuit by configuring relays, and can also control whether each load inductor is connected in the test circuit.

[0061] In some implementations, the main control module 13 includes a control core device 143131, and the level conversion module 14 is connected to the control core device 143131 via a general-purpose input / output interface.

[0062] In some embodiments, the main control module 13 further includes a power supply device 132 and a communication device 133, both of which are electrically connected to the control core device 143131. The power supply device 132 is configured to supply power to the level conversion module 14 and the main control module 13, and the communication device 133 is configured to control wired or wireless communication between the outside world and the control core device 143131.

[0063] In some embodiments, the main control module 13 further includes a switch control device 135, which is electrically connected to the control core device 143131 and is configured to control the operating state of the relay device.

[0064] In some implementations, the switch control device 135 includes a physical switch and / or an electronic switch.

[0065] In some embodiments, the main control module 13 further includes a display device 134, which is electrically connected to the control core device 143131.

[0066] The display device 134 is touch-sensitive and is configured to control the electronic switch to change its operating state or to act as an electronic switch.

[0067] Specifically, based on the above implementation methods, please refer to the example provided. Figure 4 The main control module 13 includes at least a control core device 143131, a power supply device 132, a communication device 133, a display device 134, and a switch control device 135. The control core device 143131 is the core of the main control module 13, and its main function is to integrate the power supply, communication, information display, and control functions for the level conversion module of the main control module 13 through electrical connections with other devices. Considering that the main control module 13 controls the level conversion module through control signals, for example, the level conversion module and the control core device 143131 are electrically connected through a preset general-purpose input / output interface (hereinafter referred to as the GPIO interface). For example, please refer to... Figure 3 as well as Figure 4 For an overall view, please refer to Figure 4 The level conversion module 14 is connected to the control core device 143131 through the GPIO interface. Specifically, the control core device 143131 is equipped with multiple GPIO interfaces. In the level conversion module 14, each boost converter can be connected to a GPIO interface. In this way, the main control module 13 can be connected to each relay through the GPIO interface to realize the control of the test circuit and each inductor device.

[0068] The power supply device 132 is electrically connected to the control core device 143131, typically through a power port reserved on the control core device 143131. The function of the power supply device 132 is to supply power to the various devices in the main control module 13, the boost converter in the level conversion module 14, and the relay devices.

[0069] The electrical connection between the communication device 133 and the control core device 143131 is generally achieved through a communication port reserved on the control core device 143131. The function of the communication device 133 is to provide a wired communication channel and / or a wireless communication channel for the main control module 13. The type of communication channel used can be adjusted and installed according to the actual situation, and this application does not make specific limitations.

[0070] The electrical connection between the display device 134 and the control core device 143131 is generally achieved through a reserved display device connection port on the control core device 143131. The function of the display device is to provide information display so as to provide users with the current working status of each module or device in the inverter 11 test system in real time.

[0071] Unlike the aforementioned devices, the switch control device 135 is directly connected to the level conversion module 14. Its main function is to activate and control the process of the control core device 143131 sending control signals to each relay. In terms of test execution, whenever the user manually operates the corresponding switch control device 135, the control core device 143131 sends a control signal to the corresponding boost converter. After processing the control signal, the boost converter sends the processed signal to the corresponding relay device, thereby controlling the corresponding relay device to change its own working state, thereby realizing the control of the on / off state of the test circuit or the control of whether the corresponding inductor device is connected in the test circuit.

[0072] Specifically, the aforementioned switch control device 135 includes a physical switch and / or an electronic switch, wherein the reliability of the physical switch is higher than that of the electronic switch, and conversely, the accuracy of the electronic switch is better than that of the physical switch. The specific selection of one or both physical and electronic switches can be adjusted according to the actual situation, and this application does not impose specific limitations.

[0073] Alternatively, the display device 134 described above can also be a touch screen. When the display device 134 is a touch screen, it can also act as the electronic switch described above. Users can directly achieve the control effect described above by operating the display device 134 without the need to set up an additional electronic switch.

[0074] In addition, by way of example, the display device 134 is also provided with an operation indicator ( Figure 4 (Not shown in the image), wherein the above-mentioned operation indicator generally includes one or more LEDs or other types of light-emitting devices, the main purpose of which is to indicate the current working status of each device in the system by means of light, which can effectively improve the efficiency of the display device 134 in indicating the corresponding working status, and enable the user to grasp the current operating status of each module and device in the system as quickly as possible, so as to deal with faults or other emergencies in a timely manner.

[0075] Please see Figure 5 , Figure 5 This is a specific example of the structure of the main control module 13. The core control device 143131 is a microprocessor unit (hereinafter referred to as MCU), which has a total of 8 ports.

[0076] P0 is a power port that connects to a 5V3A Type-C power adapter and either a 5V or 3.3V power supply. The 5V3A Type-C power adapter and either a 5V or 3.3V power supply correspond to the power supply device 132 mentioned above.

[0077] P1, P4, P5, and P7 are communication ports. P1 is a network port for wired network connection of the MCU. Users can program test signals to the MCU via the internet or local area network, allowing the MCU to send control signals to the level conversion module 14 according to the test program. P4 is a Bluetooth port, and P5 is a Wi-Fi port, connecting to Bluetooth and Wi-Fi adapters respectively. These adapters are used to establish wireless communication for the MCU, enabling external devices to connect and communicate with it via Bluetooth or Wi-Fi. Additionally, P7 is a Universal Serial Bus (USB) port. The MCU can connect to USB storage devices or other USB-compliant devices through this port, expanding its functionality and allowing for additional user control. The Bluetooth and Wi-Fi adapters correspond to the communication device 133.

[0078] Furthermore, P2 is a display device connection port, for example, Figure 5 The main control module 13 shown uses a 7-inch touch screen as the display device 134 and also serves as the electronic switch in the switch control device 135.

[0079] Finally, 10 GPIO sub-ports are set in port P3, and GPIO sub-ports are also reserved in port P6. Each boost converter in the level conversion module is connected to the above-mentioned GPIO sub-ports to form a 270A relay driver circuit, wherein the operating voltage of the above-mentioned 270A relay driver circuit is 3.3V.

[0080] in addition, Figure 5 In the main control module 13 shown, the switch control module also includes a compatible physical switch. This physical switch is directly connected to the 270A relay drive circuit to directly control the operating status of each boost converter device. Furthermore, Figure 5 The main control module 13 shown is also equipped with a running indicator device to indicate the running status of each device in the 270A relay drive circuit and each device in the main control module 13.

[0081] Thus, this application can also control the level conversion module 14 by setting the main control module 13, thereby indirectly controlling the on / off state of the test circuit and the connection of relays, and thus controlling the simulation process of the inverter 11. Simultaneously, this application can also enable the control core device 143131 to communicate with other external devices by setting the communication device 133, and power supply to the main control module 13 and the level conversion module 14 by the power supply device 132; it can control the switching of the working state of each relay device by setting the switch control device 135, thereby indirectly controlling the on / off state of the test circuit and the connection of each load inductor in the test circuit; it also provides multiple switch control devices 135 to facilitate stable control of relay devices in different scenarios; it can also display the status of the inverter 11 test system by the display device 134, and can also achieve the effect of electronic switch control of relay devices by touch.

[0082] In some embodiments, the load device is a capacitor, which is arranged in parallel and has the same capacitance value.

[0083] In some implementations, the load device is a resistor, which is arranged in series and has the same resistance value.

[0084] Specifically, based on the above embodiments, the load device can be used not only to simulate load inductance but also to simulate load capacitance or load resistance. Therefore, exemplarily, the load device can be a capacitor or a resistor, thereby simulating load capacitance or load resistance. The specific simulation logic is similar to the simulation logic for load inductance in the above embodiments. Wherein, according to the superposition rule of resistance, when the load device is a resistor, the resistors are arranged in series, and the specific arrangement can follow the established method. Figure 2 The arrangement of each inductor in the circuit. However, unlike the above method, according to the superposition rule of capacitance, if we want to achieve the same superposition logic as the inductors and resistors mentioned above, for example, when the load device is a capacitor, all capacitors should be arranged in parallel. In this way, even if the capacitance of all capacitors is the same, the load capacitance can be easily controlled to be an integer multiple of the capacitance value of each capacitor by controlling the number of capacitors connected to the test circuit.

[0085] Please see Figure 1 as well as Figure 2 In some implementations, the test loop also includes a photovoltaic simulator 15, which is configured to perform photovoltaic simulation tests on the inverter 11.

[0086] Furthermore, in some embodiments, the test loop also includes a grid simulator 16, which is configured to perform grid simulation tests on the inverter 11.

[0087] Specifically, based on the above implementation method, and considering the diversity of current weak grids, the testing requirements for inverter 11 are also diverse. Therefore, exemplarily, the test circuit also includes a photovoltaic simulator 15 and a grid simulator 16. Their function is to simulate photovoltaic and grid application scenarios, thereby simulating the application environment of inverter 11 under either photovoltaic or conventional weak grid application scenarios. This allows for different tests of inverter 11 under either photovoltaic or grid application scenarios. The specific photovoltaic simulator 15 and grid simulator 16 included in the test circuit can be adjusted according to actual conditions. Figure 1 as well as Figure 2 This is merely an illustrative example and should not be construed as a limitation that the two sets of simulators must necessarily coexist.

[0088] In the description of this specification, the references to terms such as "some embodiments," "in one example," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0089] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0090] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An inverter testing system, characterized in that, The system includes a main control module, a level conversion module, and a power drive module, and the inverter and the power drive module form a test circuit. The main control module is configured to control the level conversion module to change its operating state in order to further adjust and control the load inductance, load resistance or load capacitance of the power drive module.

2. The system according to claim 1, characterized in that, The power drive module includes multiple load devices, all of which have the same electrical parameters.

3. The system according to claim 2, characterized in that, The load device is an inductor, which is arranged in series and has the same inductance value.

4. The system according to claim 3, characterized in that, The level conversion module includes a boost converter and a relay device. The boost converter is configured to adjust the electrical signal provided by the main control module to control the relay device. The relay device is configured to control the connection and disconnection of the inductor device in the test circuit.

5. The system according to claim 4, characterized in that, The level conversion module includes a first relay and at least one second relay. The first relay is configured to control the on / off state of the test circuit, and the second relay is configured to control the connection and disconnection of the corresponding inductor in the test circuit.

6. The system according to claim 1, characterized in that, The main control module includes a control core device, and the level conversion module is connected to the control core device through a general-purpose input / output interface.

7. The system according to claim 6, characterized in that, The main control module also includes a power supply device and a communication device, both of which are electrically connected to the control core device. The power supply device is configured to supply power to the level conversion module and the main control module, and the communication device is configured to control wired or wireless communication between the external environment and the control core device.

8. The system according to claim 6, characterized in that, The main control module also includes a switch control device, which is electrically connected to the level conversion module and is configured to control the operating state of the relay device.

9. The system according to claim 8, characterized in that, The switch control device includes physical switches and / or electronic switches.

10. The system according to claim 9, characterized in that, The main control module also includes a display device, which is electrically connected to the control core device; The display device is touch-sensitive and is configured to control the electronic switch to change its operating state or to act as the electronic switch.

11. The system according to claim 2, characterized in that, The load device is a capacitor, which is arranged in parallel and has the same capacitance value.

12. The system according to claim 2, characterized in that, The load device is a resistor, which is arranged in series and has the same resistance value.

13. The system according to claim 1, characterized in that, The test circuit also includes a photovoltaic simulator configured to perform photovoltaic simulation tests on the inverter.

14. The system according to claim 1, characterized in that, The test circuit also includes a grid simulator configured to perform grid simulation tests on the inverter.

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