Grid-connected testing device

Abstract

The utility model discloses a grid-connected testing device, and belongs to the technical field of new energy. The grid-connected testing device comprises a plurality of box bodies and a plurality of electronic devices, the electronic devices are installed in the box bodies respectively, the electronic devices are electrically connected to form a testing circuit, the testing circuit is provided with an input end and an output end, the input end is used for being electrically connected with a power grid, and the output end is used for being electrically connected with power generation equipment. Each box body and the electronic equipment in the corresponding box body jointly form a transportation unit, the weight difference value of the transportation unit with the largest weight and the transportation unit with the smallest weight in the multiple transportation units is T, and T is larger than or equal to 0 and smaller than or equal to 2t, so that the system is more convenient to transport and install, the weight difference of the multiple transportation units can be reduced, and the transportation efficiency is improved. The weights of the multiple conveying units are close, the situation that the weight of a single conveying unit is too large, and consequently conveying is inconvenient can be avoided, and conveying is easy.

Description

Technical Field

[0001] The present application belongs to the field of new energy technology, and in particular, relates to a grid-connected testing device. Background Art

[0002] In recent years, with the rapid development of photovoltaic, energy storage power station, wind power generation and other industries, the adaptability of power generation equipment to the power grid has gradually improved. Power generation equipment is generally located in remote areas with harsh and complex road conditions or deserted areas, which greatly restricts transportation. Existing large-capacity grid-connected test devices generally contain transformers with large volume and weight. This makes the grid-connected test device heavy, resulting in difficulties in transportation of the grid-connected test device at the mobile test site, and even the grid-connected test device cannot be delivered to some test sites with complex terrain. Utility Model Content

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a grid-connected test device, which divides the grid-connected test device into multiple conveying units, which can reduce the weight of a single conveying unit and make the weight difference of multiple conveying units not large, which is convenient for transportation.

[0004] In the first aspect, the present application provides a grid-connected test device, comprising multiple boxes and multiple electronic devices, wherein the multiple electronic devices are respectively installed in the multiple boxes, and the multiple electronic devices are electrically connected to form a test circuit, wherein the test circuit has an input end and an output end, wherein the input end is used to electrically connect to a power grid, and the output end is used to electrically connect to a power generation device, and each of the boxes and the electronic devices in the corresponding boxes together constitute a transport unit, and the weight difference between the transport unit with the largest weight and the transport unit with the smallest weight among the multiple transport units is T, wherein 0≤T≤2t.

[0005] According to the grid-connected test device of the present application, each box and the electronic equipment in the box are combined to form a transport unit. Such a design makes the system more convenient during transportation and installation, and multiple transport units can be disassembled and assembled as needed, reducing transportation costs and installation difficulties. In addition, since the weight difference between the transport unit with the heaviest weight and the transport unit with the smallest weight among the multiple transport units is T, where 0≤T≤2t, the weight difference of the multiple transport units can be reduced, making the weights of the multiple transport units closer, which can avoid the inconvenience of transportation caused by the excessive weight of a single transport unit, making transportation simple, and also can meet the use requirements of customers and on-site.

[0006] According to one embodiment of the present application, the plurality of boxes include a first box, the plurality of electronic devices include a switch cabinet, at least one of a power unit assembly and a main control cabinet, and a multi-winding transformer, and the switch cabinet, at least one of the power unit assembly and the main control cabinet, and the multi-winding transformer are all installed in the first box; and / or,

[0007] The plurality of boxes include a second box, the plurality of electronic devices include a plurality of single-phase transformers, and the plurality of single-phase transformers are installed in the second box; and / or,

[0008] The plurality of boxes include a third box, the plurality of electronic devices include an input switch cabinet, a bypass switch cabinet, an output cabinet, at least one of the output switch cabinets, an auxiliary power transformer and a step-down transformer, and the input switch cabinet, the bypass switch cabinet, the output cabinet, at least one of the output switch cabinets, the auxiliary power transformer and the step-down transformer are all installed in the third box; and / or,

[0009] The grid-connected testing device further comprises a plurality of heat dissipation devices, which are respectively installed in a plurality of the boxes, and each of the heat dissipation devices is used to cool down the electronic equipment in the corresponding box.

[0010] According to one embodiment of the present application, the multiple boxes include a first box, a second box and a third box, the first box is installed with a switch cabinet, a multi-winding transformer, a power unit assembly and a main control cabinet, the second box is installed with a plurality of single-phase transformers, the third box is installed with an input switch cabinet, a bypass switch cabinet, an output cabinet, an output switch cabinet, an auxiliary power transformer and a step-down transformer, and the test circuit is formed between the switch cabinet, the multi-winding transformer, the power unit assembly, the main control cabinet, the plurality of single-phase transformers, the input switch cabinet, the bypass switch cabinet, the output cabinet, the output switch cabinet, the auxiliary power transformer and the step-down transformer.

[0011] According to one embodiment of the present application, the switch cabinet, the multi-winding transformer, and the power unit assembly are sequentially arranged in series;

[0012] The low voltage ends of the plurality of single-phase transformers are electrically connected to the output end of the power unit assembly;

[0013] The input end of the input switch cabinet, the input end of the auxiliary power transformer and the input end of the bypass switch cabinet are all used to be electrically connected to the power grid, the output end of the input switch cabinet is electrically connected to the high voltage end of the step-down transformer, the low voltage end of the step-down transformer is electrically connected to the input end of the switch cabinet, the output end of the bypass switch cabinet is used to be electrically connected to the power generation equipment, one end of the output cabinet is electrically connected to the high voltage ends of multiple single-phase transformers, the other end of the output cabinet is electrically connected to the output switch cabinet, and the output end of the output switch cabinet is used to be electrically connected to the power generation equipment.

[0014] According to an embodiment of the present application, the switch cabinet, the multi-winding transformer, the power unit assembly and the main control cabinet are arranged in sequence along the length direction of the first box; and / or,

[0015] The auxiliary power transformer, the input switch cabinet, the bypass switch cabinet, the step-down transformer, the output cabinet and the output switch cabinet are arranged in sequence along the length direction of the third box.

[0016] According to one embodiment of the present application, the power cell assembly includes multiple cascaded power cells and multiple reactors, the multiple cascaded power cells are arranged in one-to-one correspondence with the multiple reactors, each power cell is electrically connected to the corresponding reactor, the multiple reactors are electrically connected to the secondary winding of the multi-winding transformer, and the multiple cascaded power cells are electrically connected to the low-voltage side of the multiple single-phase transformers.

[0017] According to one embodiment of the present application, the third box is provided with an input adapter terminal and an output adapter terminal, the input adapter terminal is used to be electrically connected to the power grid, and the output adapter terminal is used to be electrically connected to the power generation equipment;

[0018] The input end of the input switch cabinet, the input end of the auxiliary power transformer and the input end of the bypass switch cabinet are all electrically connected to the output transfer terminal;

[0019] The output end of the bypass switch cabinet and the output end of the output switch cabinet are both electrically connected to the output transfer terminal.

[0020] According to an embodiment of the present application, a first detection device is provided in the input switch cabinet, and the first detection device is used to detect the current flowing through the input switch cabinet; and / or,

[0021] A second detection device is provided in the output cabinet, and the second detection device is used to detect and monitor the voltage and current flowing through the output cabinet.

[0022] According to one embodiment of the present application, the auxiliary power transformer is installed with a fuse, one end of the fuse is connected to the high voltage input end of the auxiliary power transformer, and the other end is used to be electrically connected to the power grid.

[0023] According to an embodiment of the present application, the auxiliary power transformer is further equipped with a third detection device, which is located below the fuse and is used to detect the voltage flowing through the auxiliary power transformer.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] Figure 1 is a structural schematic diagram of a grid-connected test device provided in an embodiment of the present application;

[0027] Figure 2 yes Figure 1 A schematic diagram of the structure of a first box and a plurality of electronic devices installed in the first box;

[0028] Figure 3 yes Figure 1 A schematic diagram of the structure of the second box and multiple electronic devices installed in the first box;

[0029] Figure 4 yes Figure 1 A schematic structural diagram of a third box and multiple electronic devices installed in the first box.

[0030] Reference numerals:

[0031] Grid-connected test device 100;

[0032] Box 110, first box 110a, second box 110b, third box 110c;

[0033] Input transfer terminal 1111, output transfer terminal 1112;

[0034] Switch cabinet 1211, input switch cabinet 1212, bypass switch cabinet 1213, output cabinet 1214, output switch cabinet 1215, power unit assembly 122, power unit 1221, reactor 1222, main control cabinet 123, multi-winding transformer 124, single-phase transformer 125, auxiliary power transformer 126, step-down transformer 127. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0036] Reference below Figure 1-Figure 4 A grid-connected testing device according to an embodiment of the present application is described.

[0037] Reference Figures 1 to 4 The grid-connected test device 100 includes a plurality of boxes 110 and a plurality of electronic devices, wherein the plurality of electronic devices are respectively installed in the plurality of boxes 110, and the plurality of electronic devices are electrically connected to form a test circuit, wherein the test circuit has an input end and an output end, wherein the input end is used to be electrically connected to a power grid, and the output end is used to be electrically connected to a power generation device, and each of the boxes 110 and the electronic devices in the corresponding boxes 110 together constitute a transport unit, and the weight difference between the transport unit with the largest weight and the transport unit with the smallest weight among the plurality of the transport units is T, wherein 0≤T≤2t.

[0038] It should be noted that t stands for ton, which is one of the units of weight. The weight of 2t means the weight is 2 tons, or 2000 kilograms.

[0039] According to the grid-connected test device 100 of the present application, each box 110 and the electronic equipment in the box 110 are combined to form a transport unit. Such a design makes the system more convenient to transport and install, and multiple transport units can be disassembled and assembled as needed, reducing transportation costs and installation difficulties. In addition, since the weight difference between the transport unit with the heaviest weight and the transport unit with the smallest weight among the multiple transport units is T, where 0≤T≤2t, the weight difference of the multiple transport units can be reduced, making the weights of the multiple transport units closer, which can avoid the inconvenience of transportation caused by the excessive weight of a single transport unit, making transportation simple, and also can meet the use requirements of customers and on-site.

[0040] Reference Figure 1 and Figure 2In one embodiment, the plurality of boxes 110 include a first box 110a, and the plurality of electronic devices include a switch cabinet 1211, at least one of a power unit assembly 122 and a main control cabinet 123, and a multi-winding transformer 124. The switch cabinet 1211, at least one of the power unit assembly 122 and the main control cabinet 123, and the multi-winding transformer 124 are all installed in the first box 110a, so that a high degree of integration is achieved. Such a design makes the structure of the entire grid-connected test device 100 more compact, reduces space occupation, and facilitates transportation and installation. The switch cabinet 1211, at least one of the power unit assembly 122 and the main control cabinet 123, and the multi-winding transformer 124 are all centrally installed in the first box 110a, making maintenance and overhaul work more convenient. If a certain electronic device fails, it can be quickly located and repaired, thereby improving maintenance efficiency. Since all electronic devices are installed in the first box 110a, the heat dissipation and cooling of the equipment can be better achieved, which helps to reduce energy consumption. At the same time, the centralized equipment layout also helps to reduce line losses and further reduce system energy consumption. The switch cabinet 1211, the power unit assembly 122, at least one of the main control cabinet 123 and the multi-winding transformer 124 are centrally installed in the first box 110a, which can better achieve the sealing and protection of the corresponding multiple electronic devices and improve the safety of the grid-connected test device 100. By integrating multiple electronic devices in the first box 110a, the number of external connection lines and interfaces can be reduced, thereby reducing the cost of the grid-connected test device 100.

[0041] Reference Figure 1 and Figure 3In one embodiment, the plurality of boxes 110 include a second box 110b, and the plurality of electronic devices include a plurality of single-phase transformers 125, and the plurality of single-phase transformers 125 are installed in the second box 110b. In this way, the plurality of single-phase transformers 125 are centrally installed in the second box 110b, making management and maintenance more convenient. All the single-phase transformers 125 are in a specific box 110, which is convenient for the staff to check, debug and repair, thereby improving work efficiency. By centrally installing the plurality of single-phase transformers 125 in the second box 110b, space resources can be more effectively utilized, making the entire grid-connected test device 100 more compact. This helps to reduce the floor space and reduce the demand for space, which is especially important in an environment with limited space. Centrally installing the plurality of single-phase transformers 125 in the second box 110b can better ensure the safety of the equipment. The second box 110b can provide a certain degree of protection to prevent external environmental factors (such as dust, moisture, etc.) from damaging the plurality of single-phase transformers 125. At the same time, centralized installation also helps prevent accidents and improves the safety of the overall grid-connected test device 100. By centrally installing and managing the single-phase transformer 125, unnecessary equipment and connecting cables can be reduced, thereby reducing the cost of the entire system. At the same time, centralized installation also helps reduce energy consumption and maintenance costs, and helps achieve the goal of energy conservation and emission reduction.

[0042] Reference Figure 1 and Figure 4In one embodiment, the plurality of boxes 110 include a third box 110c, and the plurality of electronic devices include an input switch cabinet 1212, a bypass switch cabinet 1213, an output cabinet 1214, and at least one of the output switch cabinet 1215, an auxiliary power transformer 126, and a step-down transformer 127. The input switch cabinet 1212, the bypass switch cabinet 1213, the output cabinet 1214, and at least one of the output switch cabinet 1215, the auxiliary power transformer 126, and the step-down transformer 127 are all installed in the third box 110c, which helps to achieve the compactness and integration of the entire grid-connected test device 100. This design method can reduce the number of external connections and cables, and improve the overall efficiency and reliability of the system. The input switch cabinet 1212, the bypass switch cabinet 1213, the output cabinet 1214, and at least one of the output switch cabinet 1215, the auxiliary power transformer 126, and the step-down transformer 127 are installed in the third box 110c, so that the maintenance and management of the corresponding plurality of electronic devices become more convenient. The staff can conveniently inspect, debug and repair each electronic device, which improves work efficiency and system availability. By installing the corresponding multiple electronic devices in the third box 110c, the corresponding multiple electronic devices can be better sealed and protected, and the safety of the entire system can be improved. This design method can reduce the impact of external environmental factors on the corresponding multiple devices and reduce the possibility of accidents.

[0043] In one embodiment, the plurality of boxes 110 include a first box 110a, a second box 110b, and a third box 110c. The first box 110a is provided with the switch cabinet 1211, the multi-winding transformer 124, the power unit assembly 122, and the main control cabinet 123. The second box 110b is provided with a plurality of single-phase transformers 125. The third box 110c is provided with an input switch cabinet 1212, a bypass switch cabinet 1213, an output cabinet 1214, an output cabinet 1215, and a power supply cabinet 1216. The output switch cabinet 1215, the auxiliary power transformer 126 and the step-down transformer 127 are provided, and the test circuit is formed between the switch cabinet 1211, the multi-winding transformer 124, the power unit assembly 122, the main control cabinet 123, the multiple single-phase transformers 125, the input switch cabinet 1211, the bypass switch cabinet 1213, the output cabinet 1214, the output switch cabinet 1215, the auxiliary power transformer 126 and the step-down transformer 127. In this way, the existence of the test circuit can ensure the stability of the entire system. In the power system, stability is very important because sudden voltage or current changes may cause equipment damage or affect the operation of the entire system. The test circuit can help maintain the stability of the system and reduce problems caused by voltage or current fluctuations. Through the test circuit, faults in the system can be more easily detected and located. When a part fails, the test circuit can provide clear instructions to help maintenance personnel quickly find the problem and take corresponding solutions. This greatly improves the maintainability and reliability of the system. In addition, the entire grid-connected test device 100 can be made more compact and efficient. This design reduces the number of external connections and cables, and improves the integration and overall performance of the grid-connected test device 100. In addition, the transportation and installation of the entire grid-connected test device 100 can be made more convenient, and the transportation and installation costs can be reduced. This design can also facilitate the staff to inspect, debug and repair each device more quickly, and improve the availability and stability of the grid-connected test device 100. This design can also better achieve the sealing and protection of multiple electronic devices, and improve the safety of the entire grid-connected test device 100. This design can reduce the impact of external environmental factors on the equipment and reduce the possibility of accidents. This design can also reduce unnecessary connecting cables, thereby reducing the cost of the entire system. At the same time, the integrated design also helps to reduce energy consumption and maintenance costs, and helps to achieve the goal of energy conservation and emission reduction.

[0044] It should be noted that the grid-connected test device 100 can simulate power supply to the grid, so the main control cabinet 123 provides control and communication functions for the entire simulated power supply, and monitors the operation of the grid-connected test device 100 in real time. In addition, in the embodiment of the present application, the single-phase transformer 125 is set to three. Of course, in other embodiments, the number of the single-phase transformer 125 can be selected as needed, and the present application does not limit this.

[0045] Reference Figure 1 and Figure 2 In one embodiment, the switch cabinet 1211, the multi-winding transformer 124, and the power unit assembly 122 are sequentially arranged in series. In this way, the main function of the switch cabinet 1211 is to open and close, control and protect the electrical equipment in the process of power generation, transmission, distribution and power conversion in the power system. The multi-winding transformer 124 and the power unit assembly 122 are also important components of the power system and have certain control and protection functions. By arranging them in series, the continuity and stability of system control and protection can be better achieved. The multi-winding transformer 124 and the power unit assembly 122 are key equipment for energy conversion. By arranging them in series with the switch cabinet 1211, the energy conversion and transmission process can be better coordinated and controlled, the energy conversion efficiency can be improved, and the energy loss can be reduced. Arranging the switch cabinet 1211, the multi-winding transformer 124 and the power unit assembly 122 in series can simplify the structure of the entire system, reduce the number of equipment and connecting lines, and reduce the complexity and cost of the system. At the same time, this arrangement also helps to improve the reliability and stability of the system and reduce the possibility of failure. In addition, this design can conveniently perform centralized maintenance and management of the switch cabinet 1211, the multi-winding transformer 124, and the power unit assembly 122. Once a fault occurs, the problem can be quickly located and repaired, thereby improving the availability and maintenance efficiency of the system. By connecting the switch cabinet 1211, the multi-winding transformer 124, and the power unit assembly 122 in series, the safety control and protection of the system can be better achieved. In the event of an abnormal situation, the power supply can be quickly cut off or other safety measures can be taken to protect the safety of equipment and personnel.

[0046] Reference Figure 1 The low voltage ends of the multiple single-phase transformers 125 are electrically connected to the output end of the power unit assembly 122. Thus, by directly connecting the low voltage end of the single-phase transformer 125 to the output end of the power unit assembly 122, the intermediate links and cables can be reduced, thereby simplifying the overall structure of the system. Direct connection avoids possible energy loss and ensures efficient power transmission. Reducing the intermediate links reduces the risk of failure caused by intermediate connection problems and improves the stability of the system. Since the system structure is simpler, when maintenance or debugging is required, the problem can be located more quickly.

[0047] The low-voltage ends of the multiple single-phase transformers 125 are connected to the output ends of the power cell components 122 through cables, so that the cable connection provides greater flexibility. If the connection needs to be changed or adjusted, the cable can be easily disconnected and reconnected without making major changes to the entire system. Through cable connection, the single-phase transformer 125 and the power cell component 122 can be easily maintained and debugged. Cable connection provides the possibility for future expansion and upgrading. If the number of single-phase transformers 125 needs to be increased or reduced, it can be achieved by simply adding or removing cables without making major changes to the entire system. Using cable connection can reduce material costs and installation costs. In addition, if components need to be replaced or upgraded, cables are usually cheaper than other connection methods. Through cable connection, the single-phase transformer 125 can be easily connected to the power cell component 122. This connection method makes the installation and configuration of the system simpler and more convenient.

[0048] The input end of the input switch cabinet 1212, the input end of the auxiliary power transformer 126, and the input end of the bypass switch cabinet 1213 are all used to be electrically connected to the power grid, so that the power grid can be easily connected to obtain the required electrical energy. This design simplifies the access process and improves the availability and efficiency of the input switch cabinet 1212, the auxiliary power transformer 126, and the bypass switch cabinet 1213. Electrical connection with the power grid can ensure a continuous and stable energy supply. When the equipment needs to run, it can quickly obtain the required electrical energy from the power grid, reducing the risks caused by energy interruptions. Through the connection with the power grid, the equipment can flexibly adjust the acquisition and use of energy. According to actual needs and operating modes, the equipment can dynamically adjust the connection status with the power grid to achieve efficient energy management.

[0049] The output end of the input switch cabinet 1212 is electrically connected to the high voltage end of the step-down transformer 127, and the low voltage end of the step-down transformer 127 is electrically connected to the input end of the switch cabinet 1211. In this way, by using the step-down transformer 127, the system can adjust the input voltage to meet the voltage requirements of subsequent equipment. This voltage regulation function ensures the normal operation of the equipment and reduces problems caused by voltage fluctuations. This design can control the transmission and distribution of current. This current control function helps to reduce energy consumption and reduce equipment load, thereby improving the efficiency and stability of the system. Reasonable voltage and current regulation can reduce energy loss and improve the energy conversion efficiency of the system. This helps to save energy and reduce operating costs. By controlling voltage and current, the system can reduce potential hazards to equipment and personnel.

[0050] The output end of the bypass switch cabinet 1213 is used to electrically connect to the power generation equipment. In this way, through the connection between the bypass switch cabinet 1213 and the power generation equipment, the system can flexibly access the power generation equipment, thereby providing additional energy supply or serving as a backup energy source for the main power grid. This flexibility helps to ensure a reliable supply of energy and reduce the risk of interruption. The bypass switch cabinet 1213 can quickly connect the power generation equipment to the system or disconnect it from the system. During a main power grid failure or maintenance, the bypass switch cabinet 1213 can ensure the normal operation of the power generation equipment, thereby improving the reliability and efficiency of the entire system. Through the bypass switch cabinet 1213, the power generation equipment can be more easily integrated into the existing system. This integration method simplifies the connection and communication between devices and reduces the integration cost and complexity. In addition, when a test device fails, the input switch cabinet 1212 and the output switch cabinet 1215 are disconnected, and the bypass switch cabinet 1213 is closed, thereby bypassing the entire device.

[0051] One end of the output cabinet 1214 is electrically connected to the high-voltage end of the plurality of single-phase transformers 125, and the other end of the output cabinet 1214 is electrically connected to the output switch cabinet 1215. In this way, the output cabinet 1214 receives the power input from the step-down transformer 127 and the switch cabinet 1211. According to the preset parameters or real-time requirements, the output cabinet 1214 can adjust the input voltage and current through the internal electrical components (such as relays, circuit breakers, etc.) to meet the power demand of the subsequent equipment. When multiple single-phase transformers 125 are connected at the same time, the output cabinet 1214 can realize the load balancing function. It will automatically adjust the energy distribution between each transformer according to the load conditions of each single-phase transformer 125 to ensure the stable operation of the system. In addition, through precise voltage and current regulation, the output cabinet 1214 can ensure a stable and reliable power supply for downstream equipment. It avoids equipment failure or performance degradation caused by voltage fluctuations or excessive / small current. The output cabinet 1214 can dynamically adjust the distribution of energy according to actual needs to avoid unnecessary energy waste. This helps reduce operating costs and improve the energy efficiency of the entire system. In the event of an abnormal situation (such as overload, short circuit, etc.), the output cabinet 1214 can quickly cut off the connection with the faulty equipment to prevent damage to the equipment. At the same time, it also has a fault warning function to report abnormal conditions to the operator or control system in a timely manner for timely processing. Due to the flexible design of the output cabinet 1214, when the system needs to add new equipment or functions in the future, it only needs to simply modify or expand the output cabinet 1214, which reduces the cost of system transformation.

[0052] The output end of the output switch cabinet 1215 is used to electrically connect to the power generation equipment. In this way, the output switch cabinet 1215 receives the electric energy input from the output cabinet 1214, and further distributes and adjusts the electric energy according to the preset parameters or real-time requirements. This ensures that the electric energy can meet the access requirements of various power generation equipment. The output switch cabinet 1215 is usually equipped with an intelligent control system, which can automatically control the working state of the switch cabinet 1211 according to the real-time state of the power grid, the operating state of the power generation equipment and the parameters preset by the system. When an abnormal situation occurs (such as overload, short circuit, etc.), the output switch cabinet 1215 can quickly cut off the connection with the faulty equipment to prevent the equipment from being damaged. At the same time, it also has a fault warning function, and promptly reports abnormal situations to the operator or control system for timely processing. In addition, this design can also improve the stability of the system.

[0053] Reference Figure 1 and Figure 2 In one embodiment, the switch cabinet 1211, the multi-winding transformer 124, the power unit assembly 122 and the main control cabinet 123 are arranged in sequence along the length direction of the first box 110a, so that the connection lines between the switch cabinet 1211, the multi-winding transformer 124, the power unit assembly 122 and the main control cabinet 123 can be short and direct. This helps to reduce the complexity of the connection and potential fault points. The side wall of the first box 110a can be used for heat dissipation to improve the heat dissipation efficiency of the corresponding electronic equipment. This layout method makes full use of the internal space of the first box 110a, so that the corresponding multiple electronic devices can be compactly integrated together, reducing the volume of the entire system. The operator can quickly and conveniently maintain and inspect each electronic device, improving the maintenance efficiency. The compact layout design reduces the impact of external factors (such as vibration, temperature changes, etc.) on the stability of the system. Since this layout method simplifies the design, production and maintenance process, the manufacturing cost and maintenance cost of the entire system can be reduced. The compact layout design helps to reduce the space occupied by the equipment, making the system more suitable for use in a limited space, etc.

[0054] Reference Figure 1 and Figure 4In one embodiment, the auxiliary transformer 126, the input switch cabinet 1212, the bypass switch cabinet 1213, the step-down transformer 127, the output cabinet 1214 and the output switch cabinet 1215 are arranged in sequence along the length direction of the third box 110c, so that the connection lines between the auxiliary transformer 126, the input switch cabinet 1212, the bypass switch cabinet 1213, the step-down transformer 127, the output cabinet 1214 and the output switch cabinet 1215 can be short and direct. This helps to reduce the complexity of connection and potential fault points. Arrangement along the length direction of the third box 110c makes the electronic equipment relatively concentrated, which is convenient for operators to perform maintenance and overhaul work. This layout method makes full use of the internal space of the third box 110c, so that the components can be compactly integrated together, reducing the volume of the entire system. Since the electronic equipment is arranged in the same direction, the operator can quickly and conveniently maintain and inspect the second equipment, thereby improving the maintenance efficiency of the system. The compact layout design reduces the impact of external factors (such as vibration, temperature changes, etc.) on system stability. The optimized layout helps to reduce the operating temperature of each electronic device and further reduce the energy consumption required for heat dissipation. Since this layout method simplifies the design, production and maintenance process, it can reduce the manufacturing cost and maintenance cost of the entire system. The compact layout design helps to reduce the space occupied by the equipment, making the system more suitable for use in limited spaces, such as outdoor box-type substations.

[0055] Reference Figure 1 and Figure 2In one embodiment, the power cell assembly 122 includes a plurality of cascaded power cells 1221 and a plurality of reactors 1222, the cascaded plurality of power cells 1221 and the plurality of reactors 1222 are arranged one-to-one, each of the power cells 1221 is electrically connected to the corresponding reactor 1222, the plurality of reactors 1222 are electrically connected to the secondary winding of the multi-winding transformer 124, and the cascaded plurality of power cells 1221 are electrically connected to the low-voltage side of the plurality of single-phase transformers 125, so that the plurality of power cells 1221 are cascaded together to jointly complete the efficient conversion of electric energy. Each power cell 1221 works independently, but cooperates with each other to form a powerful electric energy conversion system. The reactor 1222 plays a key role in the power cell assembly 122. Each power cell 1221 is arranged one-to-one with a reactor 1222. The main function of the reactor 1222 is to control the phase and amplitude of the current to ensure the stable operation of the power unit 1221. In addition, the reactor 1222 can also filter out harmonics in the system and improve the quality of electric energy. Multiple reactors 1222 are electrically connected to the secondary winding of the multi-winding transformer 124. This connection method ensures the efficient transmission and conversion of electric energy, and also provides a stable energy supply for the power unit 1221. The cascaded multiple power units 1221 are electrically connected to the low-voltage side of multiple single-phase transformers 125. This connection method enables the power unit 1221 to obtain the required electric energy from the single-phase transformer 125 and adjust it appropriately to meet the needs of system operation. This design achieves high-efficiency electric energy conversion through the coordinated work of multiple cascaded power units 1221 and multiple reactors 1222. This helps to reduce energy losses and improve the energy utilization efficiency of the entire system. The introduction of the reactor 1222 ensures the stable operation of the power unit 1221. It precisely controls the phase and amplitude of the current, reducing the failure or performance degradation of electronic equipment caused by current fluctuations. The reactor 1222 can filter out harmonics in the system, improve the quality of the output electric energy, and ensure high-quality power supply. When a power unit 1221 fails, it can be easily replaced; when the capacity of the system needs to be increased, a new power unit 1221 can also be easily added. This design enables the power unit assembly 122 to be compatible with various types of single-phase transformers 125, improving the flexibility and adaptability of the system. In addition, this design can also reduce costs, achieve energy conservation and environmental protection, reduce the impact on the environment, conform to the social development trend of energy conservation and environmental protection, and can also improve the reliability of the entire system. Multiple cascaded power units and reactors are directly installed inside the first box, which reduces the size of the entire first box, facilitates transportation, and reduces costs.

[0056] It should be noted that in the embodiment of the present application, the secondary winding of the multi-winding transformer 124 is connected to the reactor 132 through a three-phase high-voltage cable. And the reactor 1222 and the corresponding power unit 1221 are connected to each other through a high-voltage cable. After the power unit of each phase is cascaded, it passes through the insulating plate on the side plate and is connected to the transfer terminal through a high-voltage cable, and is connected to the transfer terminal of the second box through a high-voltage cable, and then connected to the low-voltage side of the single-phase transformer through a cable.

[0057] Reference Figure 1 and Figure 4 In one embodiment, the third box 110c is provided with an input transfer terminal 1111 and an output transfer terminal 1112. The input transfer terminal 1111 is used to electrically connect to the power grid, and the output transfer terminal 1112 is used to electrically connect to the power generation equipment. In this way, in addition to accommodating other components, the third box 110c is also provided with an input transfer terminal 1111 and an output transfer terminal 1112. The input transfer terminal 1111 is mainly used to electrically connect to the power grid, while the output transfer terminal 1112 is used to electrically connect to the power generation equipment. This means that the third box 110c plays the role of an intermediate hub in the system. The input end of the input switch cabinet 1212, the input end of the auxiliary transformer 126, and the input end of the bypass switch cabinet 1213 are all electrically connected to the output transfer terminal 1112, and the output end of the bypass switch cabinet 1213 and the output end of the output switch cabinet 1215 are all electrically connected to the output transfer terminal 1112. In this way, the third box 110c is used as an intermediate hub to simplify the connection lines between the electronic devices, reduce the probability of failure and maintenance costs. Due to the use of the third box 110c as an intermediate hub, electric energy can be efficiently transmitted between the components, reducing energy losses. Through simplified connections and efficient design, the manufacturing cost and maintenance cost of the system are reduced. Due to the simplified connection and stable component layout, the reliability of the entire system is improved.

[0058] In one embodiment, the input switch cabinet 1212 is provided with a first detection device, and the first detection device is used to detect the current flowing through the input switch cabinet 1212. In this way, the first detection device can monitor the current flowing through the input switch cabinet 1212 in real time to ensure that the current is within a safe range. When the current exceeds the preset threshold, the input switch cabinet 1212 can automatically cut off or reduce the current to protect multiple electronic devices in the test circuit and the grid-connected test device 100 from damage. By detecting the current, the first detection device can promptly detect abnormal conditions in the power grid, such as overload, short circuit, etc. Early warning can help operators to deal with them in time to avoid the expansion of faults or damage to equipment. Real-time current detection data can provide a basis for energy management, help enterprises or institutions to reasonably allocate power resources, and achieve energy saving and consumption reduction. Accurate current detection helps prevent equipment failures caused by abnormal current and improve the reliability and stability of the entire grid-connected test device 100. The first detection device can provide detailed data on the grid current, providing strong support for the maintenance and commissioning of the equipment. Operators can optimize and adjust the equipment based on these data to ensure its normal operation. Real-time monitoring of the grid current helps to ensure the safety of operators. In abnormal situations, the first detection device can take measures quickly to avoid harm to personnel. Through effective current management, unnecessary wear and aging of multiple electronic devices in the grid-connected test device 100 can be reduced, thereby extending the service life of the grid-connected test device 100. Accurate current data can help operators quickly locate problems, reduce troubleshooting time, and thus improve work efficiency.

[0059] It should be noted that the first detection device may include a current transformer, a Hall effect current sensor, a Rogowski coil or a shunt. A current transformer is a common current detection device, and its working principle is based on Lenz's law, and it measures by converting a large current into a small current. A current transformer is usually composed of a primary winding, a secondary winding and an iron core. The primary winding is connected to the circuit under test, and the secondary winding is connected to a load such as a measuring instrument or a relay. Since the number of turns of the primary winding is much less than the number of turns of the secondary winding, the large current in the circuit under test can be converted into a small current, which is convenient for the measurement and protection device to be connected. The Hall effect current sensor uses the Hall effect to measure current. When current passes through a conductor in a magnetic field, a voltage difference is generated at both ends of the conductor, and this voltage difference is proportional to the current in the conductor. The Hall effect current sensor uses this principle to infer the current value in the conductor by measuring the voltage difference at both ends of the conductor. A Rogowski coil is a sensor for measuring alternating current, and its working principle is based on the law of electromagnetic induction. The coil is wound around an insulating material and connected to a measuring instrument or controller. When the current to be measured passes through the Rogowski coil, the magnetic flux in the coil changes, thereby inducing an electromotive force. By measuring the magnitude of the electromotive force, the magnitude of the current to be measured can be inferred. A shunt is a resistor used to measure current. When current passes through a shunt, a voltage difference is generated across it, and this voltage difference is proportional to the current passing through the shunt. Therefore, by measuring the voltage difference across the shunt, the current value in the circuit to be measured can be calculated.

[0060] In one embodiment, the output cabinet 1214 is provided with a second detection device, and the voltage and current flowing through the output cabinet 1214 are detected and monitored by the second detection device. In this way, the second detection device can monitor the voltage and current of the output cabinet 1214 in real time to ensure that it is within the normal working range. This is very important for ensuring stable output and preventing equipment overload or short circuit. Through continuous voltage and current detection, the second detection device can detect potential faults or problems in time, so as to take measures in advance to prevent or repair them. This helps to reduce unexpected downtime and improve the reliability of the system. Through accurate detection of voltage and current, the second detection device can help enterprises or institutions manage energy use more effectively and achieve energy saving goals. By adjusting voltage and current, the operating efficiency of the equipment can be optimized. Real-time monitoring of voltage and current helps to ensure that multiple electronic devices operate within a safe range, thereby preventing potential electrical accidents or damage. This is crucial to ensure the safety of operators and the integrity of equipment. The voltage and current data provided by the second detection device can provide detailed information for the maintenance and commissioning of equipment. By analyzing these data, operators can diagnose problems more accurately and perform targeted maintenance to improve work efficiency.

[0061] It should be noted that, in the embodiments of the present application, the second detection device includes a current detection device and a voltage detection device. There are many types of current detection devices, which may include a current transformer, a Hall effect current sensor, a Rogowski coil or a shunt. There are many types of voltage detection devices, which may include a voltage sensor or a voltmeter. Specifically, the present application does not limit the types of the current detection device and the voltage detection device.

[0062] In one embodiment, the auxiliary transformer 126 is integrated with a fuse, one end of which is connected to the high voltage input end of the auxiliary transformer 126, and the other end is used to be electrically connected to the power grid. In this way, when a short circuit fault occurs in the circuit, the current will increase rapidly and reach the set value of the fuse. The fuse will immediately blow, thereby cutting off the circuit and preventing the short circuit fault from causing greater damage to the circuit. When the load in the circuit is too large, the current will also increase accordingly. The fuse can monitor the current in the circuit. When the current exceeds its set value, the fuse will gradually blow, thereby reducing the current in the circuit and preventing the equipment from being damaged due to overload. Through the short-circuit protection function of the fuse, safety accidents such as equipment damage and fire caused by circuit short circuit can be effectively prevented. Through the overload protection function of the fuse, safety accidents such as equipment damage and fire caused by equipment overload can be effectively prevented. The integrated design of the auxiliary transformer 126 and the fuse simplifies the circuit structure and improves the reliability and safety of the equipment. The integrated design of the auxiliary transformer 126 and the fuse also makes the maintenance of the equipment more convenient and quick. When the fuse needs to be replaced, it can be done directly on the device without disassembling the entire circuit or transformer. By integrating the fuse in the auxiliary power transformer 126, additional circuit protection components and connection lines can be reduced, thereby reducing the cost of the entire device. The integrated design can reduce unnecessary energy loss and improve the working efficiency of the entire circuit.

[0063] In one embodiment, a third detection device is also installed on the auxiliary power transformer 126. The third detection device is located below the fuse and is used to detect the voltage flowing through the auxiliary power transformer 126. In this way, the third detection device can monitor the voltage flowing through the auxiliary power transformer 126 in real time to ensure that the voltage fluctuates within the allowable range, thereby ensuring the stable operation of the entire system. Through real-time monitoring of the voltage, the third detection device can promptly detect voltage anomalies, such as overvoltage or undervoltage, so as to take corresponding protective measures to avoid equipment failure or damage caused by voltage problems. An appropriate voltage range is one of the key factors to ensure normal and stable operation of equipment. Through the monitoring of the voltage by the third detection device, it can be ensured that the equipment works in a suitable voltage environment, thereby extending its service life. When the voltage is abnormal, the third detection device can quickly issue an alarm or record abnormal data. Maintenance personnel can quickly locate and solve the fault based on this information to improve maintenance efficiency. Voltage anomalies may cause safety risks such as equipment damage or fire. Through real-time monitoring by the third detection device, these risks can be reduced to ensure the safety of operators and the integrity of equipment. The third detection device can provide a large amount of real-time data to help enterprises make more informed decisions. Through data analysis, we can gain in-depth understanding of the performance, energy consumption and operating status of the equipment, thereby optimizing the system's operating efficiency and management strategy.

[0064] It should be noted that there are many types of the third detection device, and the third detection device may include a voltage sensor and a voltmeter. A voltage sensor is a device that can convert a voltage signal into a measurable or processable electrical signal. It usually consists of a resistor divider and an operational amplifier, converts a high voltage signal into a low voltage signal, and then measures the low voltage signal through a measuring circuit. The working principle of the voltage sensor is to divide the high voltage signal by a certain ratio through a resistor divider, then amplify the divided signal through an operational amplifier, and finally output it to the measuring circuit. Since the resistor divider and the operational amplifier have high accuracy and stability, the measurement accuracy of the voltage sensor is also high. A voltmeter is an instrument that can directly measure the voltage value in a circuit. A voltmeter usually consists of a magnetoelectric ammeter and a voltage divider, and the total voltage in the circuit is calculated by measuring the output voltage of the voltage divider. The working principle of the voltmeter is to measure the output voltage of the voltage divider through a magnetoelectric ammeter, and then calculate the total voltage in the circuit by calculating the proportional relationship between the total voltage and the output voltage of the voltage divider. Since the magnetoelectric ammeter has high accuracy and stability, the measurement accuracy of the voltmeter is also high.

[0065] In one embodiment, the grid-connected test device 100 further includes a plurality of heat sinks, which are respectively installed in a plurality of boxes 110. Each heat sink is used to cool the electronic device in the corresponding box 110. In this way, the electronic device generates heat during operation. If the heat is not dissipated in time, the device will overheat, affect its normal operation, and may even damage the device. Cooling the electronic device by the heat sink can ensure that it operates within a suitable temperature range and improve the stability and reliability of the device. Proper temperature management can extend the life of the electronic device. The heat sink can effectively take away the heat generated during the operation of the device, reduce the temperature inside the device, and thus reduce the aging or damage of the device caused by overheating. The cooling effect of the heat sink can ensure that the electronic device is always in the best working state, thereby improving the efficiency of the entire grid-connected test device 100. When the operating temperature of the device is reduced, its performance and efficiency are improved, which is very critical for the overall performance optimization of the system. High temperature may cause safety risks such as equipment failure and fire. Cooling the electronic device by the heat sink can reduce these risks and ensure the safety of operators and the integrity of the equipment.

[0066] It should be noted that there are many types of heat sinks, for example, forced cooling heat sinks, liquid cooling heat sinks, heat pipe heat sinks or phase change material heat sinks. Forced cooling heat sinks take away the heat generated by the device by forced convection heat exchange. This type of heat sink is usually composed of a radiator, a fan, a heat pipe, etc., and is suitable for application scenarios with high heat flux density. Liquid cooling heat sinks use liquid (such as water, oil, etc.) to take away the heat generated by the device and transfer the heat to the environment through circulation. This type of heat sink is usually composed of a radiator, a circulation system, etc., and is suitable for scenarios with high power density and high heat dissipation requirements. Heat pipe heat sinks use the heat pipe principle to transfer heat through the liquid medium inside the heat pipe during evaporation and condensation, thereby achieving efficient heat conduction. This type of heat sink is usually composed of a heat pipe, a heat sink, a fan, etc., and is suitable for application scenarios with high heat transfer and high heat flux density. Phase change material heat sinks use the phase change characteristics of phase change materials to absorb and release heat during the phase change process, thereby achieving efficient heat storage and heat dissipation. This type of heat sink is usually composed of phase change materials, heat sinks, a circulation system, etc., and is suitable for scenarios requiring efficient thermal management. Among other cooling methods, natural cooling methods (such as ventilation, heat sinks, etc.) can also be used instead of energy-consuming air conditioners or fans. This helps save energy and reduce operating costs.

[0067] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0068] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0069] In the description of this application, "first feature" or "second feature" may include one or more of the features.

[0070] In the description of the present application, “plurality” means two or more.

[0071] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0072] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0073] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0074] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A grid-connected test device, characterized in that: It includes multiple boxes and multiple electronic devices, which are respectively installed in the multiple boxes. The multiple electronic devices are electrically connected to form a test circuit. The test circuit has an input end and an output end. The input end is used to electrically connect to a power grid, and the output end is used to electrically connect to a power generation device. Each box and the electronic device in the corresponding box together constitute a transport unit. The weight difference between the transport unit with the largest weight and the transport unit with the smallest weight among the multiple transport units is T, where 0≤T≤2t.

2. The grid-connected test device according to claim 1, characterized in that: The plurality of boxes include a first box, the plurality of electronic devices include a switch cabinet, at least one of a power unit assembly and a main control cabinet, and a multi-winding transformer, and the switch cabinet, at least one of the power unit assembly and the main control cabinet, and the multi-winding transformer are all installed in the first box; and / or, The plurality of boxes include a second box, the plurality of electronic devices include a plurality of single-phase transformers, and the plurality of single-phase transformers are installed in the second box; and / or, The plurality of boxes include a third box, the plurality of electronic devices include an input switch cabinet, a bypass switch cabinet, an output cabinet, at least one of the output switch cabinets, an auxiliary power transformer and a step-down transformer, and the input switch cabinet, the bypass switch cabinet, the output cabinet, at least one of the output switch cabinets, the auxiliary power transformer and the step-down transformer are all installed in the third box; and / or, The grid-connected testing device further comprises a plurality of heat dissipation devices, which are respectively installed in a plurality of the boxes, and each of the heat dissipation devices is used to cool down the electronic equipment in the corresponding box.

3. The grid-connected test device according to claim 1, characterized in that: The multiple boxes include a first box, a second box and a third box. The first box is equipped with a switch cabinet, a multi-winding transformer, a power unit assembly and a main control cabinet. The second box is equipped with multiple single-phase transformers. The third box is equipped with an input switch cabinet, a bypass switch cabinet, an output cabinet, an output switch cabinet, an auxiliary power transformer and a step-down transformer. The test circuit is formed between the switch cabinet, the multi-winding transformer, the power unit assembly, the main control cabinet, multiple single-phase transformers, the input switch cabinet, the bypass switch cabinet, the output cabinet, the output switch cabinet, the auxiliary power transformer and the step-down transformer.

4. The grid-connected test device according to claim 3, characterized in that: The switch cabinet, the multi-winding transformer, and the power unit assembly are sequentially arranged in series; The low voltage ends of the plurality of single-phase transformers are electrically connected to the output end of the power unit assembly; The input end of the input switch cabinet, the input end of the auxiliary power transformer and the input end of the bypass switch cabinet are all used to be electrically connected to the power grid, the output end of the input switch cabinet is electrically connected to the high voltage end of the step-down transformer, the low voltage end of the step-down transformer is electrically connected to the input end of the switch cabinet, the output end of the bypass switch cabinet is used to be electrically connected to the power generation equipment, one end of the output cabinet is electrically connected to the high voltage ends of multiple single-phase transformers, the other end of the output cabinet is electrically connected to the output switch cabinet, and the output end of the output switch cabinet is used to be electrically connected to the power generation equipment.

5. The grid-connected test device according to claim 4, characterized in that: The switch cabinet, the multi-winding transformer, the power unit assembly and the main control cabinet are arranged in sequence along the length direction of the first box; and / or, The auxiliary power transformer, the input switch cabinet, the bypass switch cabinet, the step-down transformer, the output cabinet and the output switch cabinet are arranged in sequence along the length direction of the third box.

6. The grid-connected test device according to claim 4, characterized in that: The third box is provided with an input adapter terminal and an output adapter terminal, the input adapter terminal is used to be electrically connected to the power grid, and the output adapter terminal is used to be electrically connected to the power generation equipment; The input end of the input switch cabinet, the input end of the auxiliary power transformer and the input end of the bypass switch cabinet are all electrically connected to the output transfer terminal; The output end of the bypass switch cabinet and the output end of the output switch cabinet are both electrically connected to the output transfer terminal.

7. The grid-connected test device according to any one of claims 3 to 6, characterized in that: The power cell assembly includes multiple cascaded power cells and multiple reactors. The multiple cascaded power cells are arranged in one-to-one correspondence with the multiple reactors. Each power cell is electrically connected to the corresponding reactor. The multiple reactors are electrically connected to the secondary winding of the multi-winding transformer. The multiple cascaded power cells are electrically connected to the low-voltage side of the multiple single-phase transformers.

8. The grid-connected test device according to any one of claims 3 to 6, characterized in that: A first detection device is provided in the input switch cabinet, and the first detection device is used to detect the current flowing through the input switch cabinet; and / or, A second detection device is provided in the output cabinet, and the second detection device is used to detect and monitor the voltage and current flowing through the output cabinet.

9. The grid-connected test device according to any one of claims 2 to 6, characterized in that: The auxiliary power transformer is equipped with a fuse, one end of which is connected to the high voltage input end of the auxiliary power transformer, and the other end of which is electrically connected to the power grid.

10. The grid-connected test device according to claim 9, characterized in that: The auxiliary power transformer is also equipped with a third detection device, which is located below the fuse and is used to detect the voltage flowing through the auxiliary power transformer.

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