A functional test cabinet for a direct current networking system

Abstract

The utility model provides a kind of function test cabinet of direct current networking type system, it is related to power grid test technical field, including function cabinet loop, function cabinet loop is connected with the power supply main loop of outside by parallel operation loop, function cabinet loop is also connected with the power module of outside, and parallel operation loop is used to complete the parallel operation between the module of power module and power supply main loop;Load test loop, access function cabinet loop, for load increase and unload test and droop current sharing test to power module;Short circuit test loop, access function cabinet loop, for short circuit test to power module.Affirmative effect is to integrate multiple independent devices in a device, which can simulate and verify the performance of power modules under various core working conditions such as parallel operation, sudden load increase and unload, and short circuit.Overcomes the problem of single function of test device, and multiple platforms need to be built to verify different working conditions, saving the manpower, material resources and physical space required for experiments, improving test efficiency and convenience.

Description

Technical Field

[0001] This utility model relates to the field of power grid testing technology, and in particular to a functional test cabinet for a DC grid system. Background Technology

[0002] Shipboard DC networking technology, with its topological advantages in improving energy efficiency, reducing emissions, and flexibly connecting to various energy sources, has become a core strategic direction for the development of intelligent ships internationally. In recent years, relevant industrial policies, such as my country's "Intelligent Ship Development Action Plan (2024-2030)" and the EU's "Green Shipping Corridor," have put forward clear requirements and development goals for the application of DC networking technology.

[0003] However, DC grid systems are highly dynamic and complex, requiring full-condition performance verification in a laboratory environment before practical application. Currently, existing experimental setups for such verification suffer from significant technical problems:

[0004] First, the functions are singular and fragmented. Most devices focus only on testing a single function, such as load testing or short-circuit testing, and lack the collaborative verification capability to integrate multiple key operating conditions such as parallel operation, load changes, and short-circuit faults.

[0005] Secondly, testing is costly. To fully simulate all operating conditions of the system, multiple independent real-world test platforms need to be built, which consumes enormous human, material, and spatial resources. Therefore, existing technologies cannot efficiently and economically conduct comprehensive and systematic performance verification of DC grid systems, especially their core power modules, and cannot meet the rapidly developing needs of this technology field. Utility Model Content

[0006] To address the problems existing in the prior art, this utility model provides a functional test cabinet for a DC grid system, comprising:

[0007] The functional cabinet circuit is connected to the external main power supply circuit through a parallel circuit. The functional cabinet circuit is also connected to an external power module. The parallel circuit is used to complete the parallel connection between the power module and the module of the main power supply circuit.

[0008] A load test circuit is connected to the functional cabinet circuit and is used to perform load addition / removal tests and droop current sharing tests on the power module.

[0009] A short-circuit test circuit is connected to the functional cabinet circuit and is used to perform short-circuit tests on the power module.

[0010] Preferably, the paralleling circuit includes:

[0011] The first circuit breaker has its power input and power output lines connected to the main power supply circuit and the functional cabinet circuit, respectively.

[0012] A synchronization table is connected in parallel across the first circuit breaker.

[0013] The first acquisition board is connected to the main power supply circuit and is connected to the signal of the first circuit breaker.

[0014] The second acquisition board is connected to the circuit of the functional cabinet and is connected to the signal of the first circuit breaker.

[0015] A changeover switch is used to connect the first acquisition board and the second acquisition board, respectively.

[0016] Preferably, the load test circuit includes:

[0017] The second circuit breaker has its power input line connected in parallel to the circuit of the functional cabinet, and its power output line is connected to the load box through the first quick-connect connector located on the cabinet surface of the functional test cabinet.

[0018] Preferably, the short-circuit test circuit includes:

[0019] The third circuit breaker has its power input line connected in parallel to the circuit of the functional cabinet, and its power output lines are interconnected via short-circuit copper busbars.

[0020] Preferred, including:

[0021] The fourth circuit breaker has its power input line connected in parallel to the circuit of the functional cabinet, and its power output line is connected to the power module through a second quick-connect connector located on the cabinet surface of the functional test cabinet.

[0022] Preferably, it also includes a pre-charging branch, comprising:

[0023] A three-phase contactor, wherein each phase of the three-phase contactor is connected in series with a pre-charge resistor and then in parallel across the fourth circuit breaker.

[0024] Preferably, the main power supply circuit is connected to an external inverter module or the power grid.

[0025] Preferably, the functional testing cabinet also has the following features on its surface:

[0026] Multiple module indicator lights respectively indicate the on / off status of the parallel circuit, the load test circuit, and the short-circuit test circuit;

[0027] Multiple opening and closing knobs are provided, each of which is used to control the on / off state of the parallel circuit, the load test circuit, and the short-circuit test circuit.

[0028] The above technical solution has the following advantages or beneficial effects: it integrates key functional tests that originally required multiple independent devices into a single platform. Through a unified functional cabinet circuit, it can connect to external power modules for testing and also connect to an external power supply main circuit (such as a simulated power grid). This allows for the simulation and verification of power module performance under various core operating conditions, such as parallel operation, sudden load increase / decrease, and short circuits, all within a single device. This highly integrated structure overcomes the problems of existing technologies where test devices have limited functionality and require multiple platforms to verify different operating conditions. It not only significantly saves on manpower, material costs, and physical space required for experiments but also significantly improves testing efficiency and convenience, providing an efficient, compact, and comprehensive solution for full-condition performance verification of DC grid systems. Attached Figure Description

[0029] Figure 1 A circuit diagram of a functional test cabinet for a DC networking system is shown in a preferred embodiment of this utility model.

[0030] Figure 2 A schematic diagram of the cabinet surface of a functional test cabinet for a DC networking system is shown in a preferred embodiment of this utility model.

[0031] Figure 3 This is a schematic diagram of the internal components of a functional test cabinet for a DC network system, as shown in a preferred embodiment of the present invention. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within its scope.

[0033] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a functional test cabinet for a DC grid system is provided, such as... Figure 1 As shown, it includes:

[0034] Functional cabinet circuit 1 is connected to the external main power supply circuit 3 through parallel circuit 2. Functional cabinet circuit 1 is also connected to the external power module 4. Parallel circuit 2 is used to complete the parallel connection between the power module 4 and the module of the main power supply circuit 3.

[0035] Load test circuit 5 is connected to function cabinet circuit 1 and is used to perform load addition / removal tests and droop current sharing tests on power module 4.

[0036] Short-circuit test circuit 6 is connected to functional cabinet circuit 1 and is used to perform short-circuit tests on power module 4.

[0037] Specifically, this utility model achieves significant beneficial effects by integrating the parallel circuit 2, the load test circuit 5, and the short-circuit test circuit 6 into a single functional test cabinet:

[0038] This system integrates key functional tests that previously required multiple independent devices into a single platform. Through a unified functional cabinet circuit, it can connect to external power modules for testing and also access external power supply main circuits (such as a simulated power grid). This allows for the simulation and verification of power module performance under various core operating conditions, including parallel operation, sudden load increases and decreases, and short circuits, all within a single device. This highly integrated structure overcomes the limitations of existing technologies where test devices are limited in function and require multiple platforms to verify different operating conditions. It significantly saves on manpower, material costs, and physical space, while also substantially improving testing efficiency and convenience. This provides an efficient, compact, and comprehensive solution for full-condition performance verification of DC grid systems.

[0039] In a preferred embodiment of this utility model, it includes:

[0040] The power input line of the fourth circuit breaker QF4 is connected in parallel to circuit 1 of the functional cabinet, and the power output line of the fourth circuit breaker QF4 is connected to the power module 4 through the second quick-connect connector J2 located on the cabinet surface of the functional test cabinet.

[0041] In a preferred embodiment of this invention, the parallel circuit 2 includes:

[0042] The first circuit breaker QF1 has its power inlet and power outlet connected to the main power supply circuit 3 and the functional cabinet circuit 1, respectively.

[0043] Synchronization table PW1 is connected in parallel across the first circuit breaker QF1;

[0044] The first acquisition board PC1 is connected to the main power supply circuit 3 and is connected to the signal of the first circuit breaker QF1;

[0045] The second acquisition board PC2 is connected to the function cabinet circuit 1 and is connected to the signal of the first circuit breaker QF1;

[0046] The changeover switch K is connected to the first acquisition board PC1 and the second acquisition board PC2, respectively.

[0047] In a preferred embodiment of this invention, the main power supply circuit 3 is connected to an external inverter module or the power grid 7.

[0048] Specifically, paralleling is a term in the field of power systems, referring to the process of connecting two or more independent power sources (or power modules) in parallel to the same main circuit (or power grid) to jointly supply power to the load. The reason for verifying the "paralleling" function is to test the performance of power modules when working together with other power sources, such as how they evenly share the load (current sharing test).

[0049] In this embodiment, there are three paralleling methods for connecting the power module and the inverter module or the power grid: direct paralleling, synchronization meter paralleling, and automatic paralleling by the acquisition board.

[0050] like Figure 1 As shown, the power module 4 and the inverter module or the power grid 7 are connected in sequence by the first circuit breaker QF1 and the fourth circuit breaker QF4.

[0051] In the first mode, the first circuit breaker QF1 remains closed and conducting, and then the fourth circuit breaker QF4 closes to directly conduct, thus completing the direct paralleling.

[0052] In the second mode, the fourth circuit breaker QF4 remains on, and whether to parallel the operation is mainly controlled by the first circuit breaker QF1. Since the synchronizing meter PW1 is connected in parallel across the first circuit breaker QF1, it can collect the three-phase voltage output by the inverter module 7 or the voltage of the power grid 7, as well as the voltage of the power module 4. When the phase and amplitude of the two collected voltages are consistent, the synchronizing meter sends a signal to the first circuit breaker QF1 to close and conduct, thus completing the parallel operation of the synchronizing meter.

[0053] In the third mode, the fourth circuit breaker QF4 remains conducting, and whether to parallel the operation is mainly controlled by the first circuit breaker QF1. Two acquisition boards are set in the test cabinet. The first acquisition board PC1 is connected to the main power supply circuit 3 and is connected to the signal of the first circuit breaker QF1; the second acquisition board PC2 is connected to the functional cabinet circuit 1 and is connected to the signal of the first circuit breaker QF1. The first acquisition board PC1 acquires the three-phase voltage output of the inverter module 7 or the voltage of the power grid 7, and the second acquisition board PC2 acquires the voltage of the power module 4. When the phase and amplitude of the voltages acquired by the two acquisition boards are consistent, the first circuit breaker QF1 closes and conducts, completing the parallel operation.

[0054] like Figure 1As shown, the first acquisition board PC1 and the second acquisition board PC2 are switched by a changeover switch K. The top three pins on the left side of the changeover switch K are connected to the first acquisition board PC1, the bottom three pins are connected to the second acquisition board PC2, and the six pins on the right side are interconnected. In the first state of the changeover switch K, the top three pins and the right pins are connected to the first acquisition board PC1 to acquire the three-phase voltage output by the inverter module 7 or the voltage of the power grid 7. In the second state, the changeover switch is empty. In the third state, the bottom three pins and the right pins are connected to the second acquisition board PC2 to acquire the voltage of the power module 4.

[0055] In a preferred embodiment of this invention, the load test circuit 5 includes:

[0056] The second circuit breaker QF2 has its power input line connected in parallel to the functional cabinet circuit 1, and its power output line is connected to the load box 8 through the first quick-connect connector J1 located on the cabinet surface of the functional test cabinet.

[0057] Specifically, in this embodiment, the load test is implemented as follows:

[0058] Connecting the load: The tester connects a load cell to the first quick-connect connector on the functional test cabinet panel via wires. This load cell can simulate various electrical devices in a ship's electrical system.

[0059] Applying and unloading loads:

[0060] Sudden Load Test: When the power modules in the system are operating normally, the operator closes the second circuit breaker QF2. This instantly connects the load of the load box to the main circuit of the functional cabinet, thereby verifying the dynamic response and stability of the power modules when the load suddenly increases.

[0061] Sudden load disconnection test: With the load box already connected, the operator disconnects the second circuit breaker QF2. This instantly disconnects the load, thus testing the power module's voltage recovery capability and system stability when the load suddenly disappears.

[0062] By controlling the on / off state of the second circuit breaker, this load test circuit can conveniently simulate two key operating conditions: sudden increases and decreases in load, to verify the system's performance. Furthermore, this circuit can also be closed when two power modules are running in parallel for droop current sharing tests under load.

[0063] The droop current sharing test is used to verify the effectiveness of droop control strategies. Droop control is a control method widely used in microgrids. Its core idea is to allow parallel distributed power sources (such as multiple power modules) to proportionally distribute active and reactive power according to their rated power, thereby achieving automatic power balance distribution without the need for additional communication.

[0064] Specifically, in this embodiment, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed simultaneously to perform a droop current sharing test between the load module and the power module. During the load operation, the current distribution between the two power modules is observed and verified to confirm whether they can achieve stable and proportional current sharing through the droop control strategy.

[0065] In a preferred embodiment of this invention, the short-circuit test circuit 6 includes:

[0066] The third circuit breaker QF3 has its power input line connected in parallel to the function cabinet circuit, and its power output lines are interconnected via short-circuit copper busbar 9.

[0067] Specifically, the short-circuit test of this invention is achieved through a short-circuit test circuit, which includes a third circuit breaker QF3 and a short-circuiting copper busbar. During the test, the first circuit breaker QF1 is first closed. Then, the third circuit breaker QF3 is electrically closed using a knob, short-circuiting the circuit and thus verifying the system's support capability under short-circuit conditions. The short-circuit support aims to limit the converter's short-circuit current by actively controlling the output current when a short-circuit fault occurs, ensuring stable system operation under conditions such as low-voltage ride-through.

[0068] In a preferred embodiment of this utility model, a pre-charging branch 10 is further included, comprising:

[0069] The three-phase contactor KM1 has a pre-charge resistor R connected in series with each phase and then connected in parallel across the fourth circuit breaker QF4.

[0070] Specifically, the pre-charge circuit in this embodiment includes a quick-connect connector J2, a pre-charge branch contactor KM1, and a pre-charge resistor R. These components are connected in parallel in the main circuit. By closing the pre-charge branch contactor KM1 before the power module 4 is connected, the instantaneous time of current entering the power module 4 can be reduced, avoiding the large current surge when the power module 4 is connected to the functional cabinet circuit 1, thereby protecting the equipment in preparation for subsequent load or parallel operation tests.

[0071] In a preferred embodiment of this utility model, such as Figure 2 As shown, the functional testing cabinet also has the following features on its surface:

[0072] Multiple module indicator LEDs respectively indicate the on / off status of the parallel circuit, load test circuit, and short circuit test circuit;

[0073] Multiple opening and closing knobs M, each used to control the opening and closing of the parallel circuit, load test circuit, and short circuit test circuit respectively.

[0074] Figure 2 In the middle, the first row of LEDs from left to right are the power status indicator, the first circuit breaker QF1 closing indicator, the second circuit breaker QF2 closing indicator, the third circuit breaker QF3 closing indicator, and the fourth circuit breaker QF4 closing indicator.

[0075] The second row of LEDs, from left to right, are the first circuit breaker QF1 trip indicator, the second circuit breaker QF2 trip indicator, the third circuit breaker QF3 trip indicator, and the fourth circuit breaker QF4 trip indicator.

[0076] The third row of LEDs, from left to right, are the enable status indicator for the load module and the on / off status indicator for the external power module.

[0077] The knobs M, from left to right, are the opening and closing knobs for the first circuit breaker QF1, the second circuit breaker QF2, the third circuit breaker QF3, and the fourth circuit breaker QF4.

[0078] J1 is a quick-connect connector for connecting to the load bank, and J2 is a quick-connect connector for connecting to the power module.

[0079] like Figure 3 The diagram shown is a schematic of the components inside the functional test cabinet.

[0080] Specifically, the beneficial effect of this embodiment is that by setting module indicator lights and circuit breaker knobs on the surface of the functional test cabinet, intuitive and convenient control and status monitoring of the performance verification of the DC grid system are realized.

[0081] Specifically, its beneficial effects are reflected in the following aspects:

[0082] Intuitive status display: Multiple module indicator lights can clearly indicate the on / off status of the parallel circuit, load test circuit and short circuit test circuit, allowing users to understand the current working status of the test circuit at a glance.

[0083] Convenient remote or local control: Multiple opening and closing knobs allow users to easily control the on / off state of each test circuit, facilitating various functional verifications, such as short-circuit support, sudden load application and removal, etc.

[0084] Improving testing efficiency and safety: This integrated design concentrates complex testing functions within a single cabinet and provides an intuitive control interface, avoiding the enormous manpower and material resources required to actually build a test platform. At the same time, convenient operation reduces the risk of misoperation during testing, improving overall testing efficiency and safety.

[0085] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A functional test cabinet for a DC grid system, characterized in that, include: The functional cabinet circuit is connected to the external main power supply circuit through a parallel circuit. The functional cabinet circuit is also connected to an external power module. The parallel circuit is used to complete the parallel connection between the power module and the module of the main power supply circuit. A load test circuit is connected to the functional cabinet circuit and is used to perform load addition / removal tests and droop current sharing tests on the power module. A short-circuit test circuit is connected to the functional cabinet circuit and is used to perform short-circuit tests on the power module.

2. The functional testing cabinet according to claim 1, characterized in that, The paralleling circuit includes: The first circuit breaker has its power input and power output lines connected to the main power supply circuit and the functional cabinet circuit, respectively. A synchronization table is connected in parallel across the first circuit breaker. The first acquisition board is connected to the main power supply circuit and is connected to the signal of the first circuit breaker. The second acquisition board is connected to the circuit of the functional cabinet and is connected to the signal of the first circuit breaker. A changeover switch is used to connect the first acquisition board and the second acquisition board, respectively.

3. The functional testing cabinet according to claim 1, characterized in that, The load test circuit includes: The second circuit breaker has its power input line connected in parallel to the circuit of the functional cabinet, and its power output line is connected to the load box through the first quick-connect connector located on the cabinet surface of the functional test cabinet.

4. The functional testing cabinet according to claim 1, characterized in that, The short-circuit test circuit includes: The third circuit breaker has its power input line connected in parallel to the circuit of the functional cabinet, and its power output lines are interconnected via short-circuit copper busbars.

5. The functional testing cabinet according to claim 1, characterized in that, include: The fourth circuit breaker has its power input line connected in parallel to the circuit of the functional cabinet, and its power output line is connected to the power module through a second quick-connect connector located on the cabinet surface of the functional test cabinet.

6. The functional testing cabinet according to claim 5, characterized in that, It also includes a pre-charge branch, including: A three-phase contactor, wherein each phase of the three-phase contactor is connected in series with a pre-charge resistor and then in parallel across the fourth circuit breaker.

7. The functional testing cabinet according to claim 1, characterized in that, The main power supply circuit is connected to an external inverter module or the power grid.

8. The functional testing cabinet according to claim 1, characterized in that, The functional testing cabinet also has the following features on its surface: Multiple module indicator lights respectively indicate the on / off status of the parallel circuit, the load test circuit, and the short-circuit test circuit; Multiple opening and closing knobs are provided, each of which is used to control the on / off state of the parallel circuit, the load test circuit, and the short-circuit test circuit.

Images