A source-load integrated test system and test method

Abstract

The present invention discloses a source-load integrated test system and test method, comprising a power grid, an AC / DC module, a DC / DC module, a first DC / AC / DC module, a second DC / AC / DC module, and a device under test (EUT). The power grid is connected to one end of the ACDC module, the other end of the ACDC module is connected to one end of the DCDC module, and the other end of the DCDC module has two parallel circuits, one connected to one end of the first DC / AC / DC module and the other end of the second DC / AC / DC module. The other ends of the first DC / AC / DC module and the second DC / AC / DCDC module are both connected to the device under test (EUT). By providing the ACDC module, the DCDC module, the first DC / AC / DC module, and the second DC / AC / DCDC module, the present invention provides multiple circuits independently connected to the device under test (EUT). The system is suitable for various applications, including AC source / AC load, AC source / DC load, DC source / DC load, DC source / AC load, and independent or parallel sources or loads. This ensures high integration of the source and load, effectively simplifying the test environment.

Description

Technical Field

[0001] The present invention relates to the technical field of power switching test systems, and in particular to a source-load integrated test system and a test method. Background Art

[0002] Currently, test systems in laboratories or factories for power conversion systems primarily consist of three components: a power supply, a test subject (device under test), and a simulated load. Depending on the device under test, a DC or AC source, and a DC or AC load, may be required. Most medium- and high-power power supplies utilize an AC / DC + DC / DC combination. R&D requires both an AC and a DC source. However, currently available sources and loads are separate devices, and most have a single function: AC source, DC source, AC load, or DC load. Consequently, when the DUT is diverse, the laboratory or factory must build a wide variety of test platforms, limiting the flexibility to adapt the test platforms to the DUT. This is not only inconvenient, but also requires significant costs and space.

[0003] Patent application CN110824275A discloses a microgrid AC / DC bus interface converter demonstration test platform. This platform enables performance testing of small and medium-sized microgrid AC / DC bus interface converters at various voltage levels. However, its matching capabilities with the DUT are limited, preventing high-level integration of carriers and sources. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a test system and a test method with a highly integrated power supply and load.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A source-load integrated test system includes a power grid, an ACDC module, a DCDC conversion module, a first DCAC&DCDC module, and a second DCAC&DCDC module;

[0007] The power grid is connected to one end of the ACDC module, the other end of the ACDC module is connected to one end of the DCDC conversion module, the other end of the DCDC conversion module has two parallel circuits, which are respectively connected to one end of the first DCAC&DCDC module and the second DCAC&DCDC module, and the other ends of the first DCAC&DCDC module and the second DCAC&DCDC module are both connected to the equipment under test (EUT).

[0008] Advantages: By providing an ACDC module, a DCDC conversion module, a first DCAC&DCDC module, and a second DCAC&DCDC module, the present invention provides multiple circuits independently connected to the device under test (EUT). This makes it suitable for various applications, including AC source / AC load, AC source / DC load, DC source / DC load, DC source / AC load, and independent or parallel sources or loads. This ensures high integration of sources and loads, effectively simplifying the test environment. Simultaneously, the system circuitry is simplified, ensuring the compact size and lightweight nature of the test system.

[0009] Preferably, the power grid has power live lines L1, L2 and L3.

[0010] Preferably, the ACDC module includes an inductor group L1, a three-phase PWM rectifier bridge arm RB1, and an output filter capacitor C1;

[0011] The power live wires L1, L2 and L3 of the power grid are connected to the input end of the three-phase PWM rectifier bridge arm RB1 through the inductor group L1, and the output end of the three-phase PWM rectifier bridge arm RB1 is connected to the DCDC conversion module;

[0012] The two ends of the output filter capacitor C1 are connected to the output end of the three-phase PWM rectifier bridge arm RB1.

[0013] Preferably, the DCDC conversion module includes a transformer T1, a rectifier bridge RB2, a rectifier bridge RB3, a resonant inductor L2, a resonant capacitor C2, an input filter capacitor C3, an output filter capacitor C4 and an output filter capacitor C5;

[0014] The transformer T1 has a primary winding N1, a secondary winding N2 and a secondary winding N3;

[0015] The output end of the three-phase PWM rectifier bridge arm RB1 is connected to the primary winding N1 of the transformer T1 through the rectifier bridge RB2, the two ends of the input filter capacitor C3 are connected to the input end of the rectifier bridge RB2, and the resonant inductor L2 and the resonant capacitor C2 are respectively arranged on both sides of the primary winding N1 of the transformer T1;

[0016] The secondary winding N2 of the transformer T1 is connected to the first DCAC&DCDC module through the rectifier bridge RB3, and the two ends of the output filter capacitor C4 are connected to the output end of the rectifier bridge RB3;

[0017] The secondary winding N3 of the transformer T1 is connected to the second DCAC&DCDC module via the rectifier bridge RB4, and both ends of the output filter capacitor C5 are connected to the output end of the rectifier bridge RB4.

[0018] Preferably, the first DCAC&DCDC module includes a rectifier bridge RB5, a filter capacitor C6, a resonant inductor L3, a resistor R1 and a resonant capacitor C8;

[0019] The output end of the rectifier bridge RB3 is connected to the input end of the rectifier bridge RB5. The positive output end of the rectifier bridge RB5 is connected to the negative output end after passing through the series-connected resonant inductor L3, resistor R1 and resonant capacitor C8 in sequence; the two ends of the series-connected resistor R1 and resonant capacitor C8 are connected to the equipment under test (EUT).

[0020] The two ends of the filter capacitor C6 are connected to the input end of the rectifier bridge RB5.

[0021] Preferably, the second DCAC&DCDC module includes a rectifier bridge RB6, a filter capacitor C7, a resonant inductor L4, a resistor R2 and a resonant capacitor C9;

[0022] The output end of the rectifier bridge RB4 is connected to the input end of the rectifier bridge RB6. The positive output end of the rectifier bridge RB6 is connected to the negative output end after passing through the series-connected resonant inductor L4, resistor R2 and resonant capacitor C9. The two ends of the series-connected resistor R2 and resonant capacitor C9 are connected to the equipment under test (EUT).

[0023] The two ends of the filter capacitor C6 are respectively connected to the two input ends of the rectifier bridge RB6.

[0024] Preferably, the power grid is connected to one end of the ACDC module, and the other end of the ACDC module is connected in parallel with three identical test lines, each of which is connected to the equipment under test (EUT);

[0025] Each of the test lines includes a DCDC conversion module, a first DCAC&DCDC module, and a second DCAC&DCDC module.

[0026] The present invention also discloses a source-load integration testing method, comprising the following steps:

[0027] S1. Set the circuit corresponding to the first DCAC&DCDC module as the DC source of the device under test (EUT), and the circuit corresponding to the second DCAC&DCDC module as the DC load of the device under test (EUT);

[0028] S2. Adjust the ACDC module, the DCDC conversion module, the first DCAC&DCDC module, and the second DCAC&DCDC module so that the first DCAC&DCDC module supplies DC power to the EUT and the second DCAC&DCDC module serves as a DC load for the EUT.

[0029] S3. After the entire system is operating normally, turn on the power grid;

[0030] S4. The energy of the power grid is input to the equipment under test (EUT) after passing through the ACDC module, the DCDC conversion module, and the first DCAC&DCDC module in sequence.

[0031] S5. The energy of the equipment under test (EUT) is fed back to the grid after passing through the second DCAC&DCDC module, the DCDC conversion module, and the ACDC module in sequence.

[0032] Preferably, the adjustment of the DCDC conversion module in step 2 is specifically as follows:

[0033] S21, adjusting the rectifier bridge RB2 between the primary winding N1 of the transformer T1 and the output end of the three-phase PWM rectifier bridge arm RB1;

[0034] S22, adjusting the rectifier bridge RB3 between the secondary winding N2 of the transformer T1 and the first DCAC&DCDC module;

[0035] S23 , adjusting the rectifier bridge RB4 between the secondary winding N3 of the transformer T1 and the second DCAC&DCDC module.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) Powerful functions and wide application occasions. It is widely applicable to different application occasions such as AC source AC load, AC source DC load, DC source DC load, DC source AC load, independent or parallel source or load, etc., effectively simplifying the test environment.

[0038] (2) Improve efficiency. Due to the shared primary side of the ACDC module and the DCDC conversion module, the system loss is reduced, which significantly improves the overall efficiency of the test system, saves electricity and reduces emissions, and greatly reduces the power consumption at the user end.

[0039] (3) Due to the simplification of the system power module, the overall volume and mass of the equipment are effectively reduced.

[0040] (4) Economic Benefits: Due to the simplified system circuit, the material consumption is reduced by about one-quarter, which reduces the equipment manufacturing cost, saves electricity, and reduces the electricity cost of the laboratory or factory. The small size and light weight reduce the transportation cost and effectively reduce the space occupied by the test system in the laboratory or factory production line. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the device structure of Example 1 of the present invention;

[0042] Figure 2 Schematic diagram of the principle of the ACDC module of the first embodiment of the present invention;

[0043] Figure 3 Schematic diagram of the principle of the DCDC conversion module of the first embodiment of the present invention;

[0044] Figure 4This is a schematic diagram of the principle of the first DCDC and DCAC module of the first embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of the principle of the second DCDC and DCAC module of the first embodiment of the present invention;

[0046] Figure 6 This is a schematic diagram of the device structure of embodiment 2 of the present invention. DETAILED DESCRIPTION

[0047] To facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described with reference to the accompanying drawings.

[0048] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0049] Example 1

[0050] See Figure 1 This embodiment discloses a source-load integrated test system, including a power grid 1, an ACDC module 2, a DCDC conversion module 3, a first DCAC&DCDC module 4, a second DCAC&DCDC module 5, and a device under test (EUT). The DCAC&DCDC module is a module that can simultaneously perform DC-DC conversion and DC-AC conversion.

[0051] See Figure 2 In this embodiment, the power grid 1 has power live wires L1, L2, and L3. The ACDC module 2 includes an inductor group L1, a three-phase PWM rectifier bridge arm RB1, and an output filter capacitor C1. The power grid 1 is connected to the three-phase PWM rectifier bridge arm RB1 via the inductor group L1. The output filter capacitor C1 is connected to the positive and negative output terminals of the three-phase PWM rectifier bridge arm RB1.

[0052] In this embodiment, the output end of the three-phase PWM rectifier bridge arm RB1 outputs direct current (DC). By controlling the on / off state of the three-phase PWM rectifier bridge arm RB1, bidirectional energy flow between the power grid 1 and the DC power supply (DC) is achieved. The DC power supply (DC) is a stable DC voltage whose value (excluding minor effects of ripple and load regulation) does not vary with the operating status of the power live wires L1, L2, and L3 of the power grid 1 or other modules.

[0053] See Figure 3The DCDC conversion module 3 includes a transformer T1, a rectifier bridge RB2, a rectifier bridge RB3, a resonant inductor L2, a resonant capacitor C2, an input filter capacitor C3; and output filter capacitors C4 and C5.

[0054] The positive and negative output ends of the three-phase PWM rectifier bridge arm RB1 are connected to the primary winding N1 of the transformer T1 through the rectifier bridge RB2. The two ends of the input filter capacitor C3 are connected to the two input ends of the rectifier bridge RB2. The resonant inductor L2 and the resonant capacitor C2 are respectively set on both sides of the primary winding N1 of the transformer T1.

[0055] The secondary winding N2 of the transformer T1 of this embodiment outputs direct current DC1 after passing through the rectifier bridge RB3, and the two terminals of the output filter capacitor C4 are connected to the two output terminals of the rectifier bridge RB3; the secondary winding N3 outputs direct current DC2 after passing through the rectifier bridge RB4, and the two terminals of the output filter capacitor C5 are connected to the two output terminals of the rectifier bridge RB4.

[0056] During the specific implementation of this embodiment, the DCDC conversion module 3 performs an isolation function while enabling energy flow between the direct currents DC, DC1, and DC2. When the corresponding modules are operating, the direct currents DC, DC1, and DC2 are all stable voltages (excluding the subtle effects of ripple and load regulation).

[0057] Transformer T1's primary winding N1 enables bidirectional energy flow through rectifier bridge RB2 and ACDC module 2. Secondary windings N2 and N3 connect to two hardware circuits with identical functionality. When the DC1 side's subsequent stage serves as the input of the EUT, and the DC2 side's subsequent stage serves as the output of the EUT, the host computer controls rectifier bridge RB3 to supply energy from transformer T1 to the EUT, while rectifier bridge RB4 feeds energy from the EUT back to transformer T1. If the energy required by DC1 is greater than that of DC2, the DC side supplements the difference to power DC1. Otherwise, the energy difference on DC2 flows back, and the DC side becomes an output port, feeding energy back to grid 1 through the preceding ACDC module 2.

[0058] On the contrary, when the subsequent stage on the DC1 side serves as the output terminal of the EUT and the subsequent stage on the DC2 side serves as the input terminal of the EUT, the operation process is opposite to the above, which will not be described in detail here.

[0059] Furthermore, the on-off switching of rectifier bridge RB3 in this DC-DC converter module 3 controls the on-off of DC power supply DC1. When rectifier bridge RB3 is off, the secondary winding N2 of transformer T1 is open-circuited. Rectifier bridge RB4 controls the on-off of DC power supply DC2. When rectifier bridge RB4 is off, the secondary winding N3 of transformer T1 is open-circuited. Therefore, both DC power supply DC1 and DC2 can be used independently.

[0060] See Figure 4 The first DCAC&DCDC module 4 includes a rectifier bridge RB5, a filter capacitor C6, a resonant inductor L3, a resistor R1 and a resonant capacitor C8.

[0061] The two ends of the direct current DC1 are respectively connected to the two input ends of the rectifier bridge RB5. The positive output end of the rectifier bridge RB5 passes through the series resonant inductor L3, resistor R1 and resonant capacitor C8 in sequence and then connects to the negative output end. The two ends of the series resistor R1 and resonant capacitor C8 are connected to the equipment under test EUT, outputting direct current DCa or alternating current ACa. The two ends of the filter capacitor C6 are respectively connected to the two input ends of the rectifier bridge RB5.

[0062] See Figure 5 The second DCAC&DCDC module 5 includes a rectifier bridge RB6, a filter capacitor C7, a resonant inductor L4, a resistor R2 and a resonant capacitor C9.

[0063] The two ends of the direct current DC2 are respectively connected to the two input ends of the rectifier bridge RB6. The positive output end of the rectifier bridge RB6 passes through the series resonant inductor L4, resistor R2 and resonant capacitor C9 in sequence and then connects to the negative output end. The two ends of the series resistor R2 and resonant capacitor C9 are connected to the equipment under test EUT, outputting direct current DCb or alternating current ACb. The two ends of the filter capacitor C6 are respectively connected to the two input ends of the rectifier bridge RB6.

[0064] The first DCAC & DCDC module 4 and the second DCAC & DCDC module 5 are two completely independent circuits with identical hardware. Their topologies are identical, enabling bidirectional energy flow. For ease of explanation, we assume that the host computer has defined the first DCDC and DCAC modules as the source of the EUT, with energy flowing from left to right, and the second DCDC and DCAC modules as the source of the EUT, with energy flowing from right to left.

[0065] By controlling the on / off switching of rectifier bridge RB5, the first DCAC & DCDC module 4 outputs either direct current (DCa) or alternating current (ACa). Therefore, the system's source can be either AC or DC. Furthermore, by controlling the on / off switching of rectifier bridge RB6, the second DCAC & DCDC module 5 converts the power of direct current (DCb) or alternating current (ACb) into direct current (DC2). Therefore, the test system's load can be either AC or DC. Since each downstream output is isolated, it can function as a source / load for multiple EUTs simultaneously.

[0066] For ease of explanation, this embodiment still uses the circuit corresponding to DC1 as the source of the device under test (EUT), and the circuit corresponding to DC2 as the load of the device under test (EUT). The working principle of the entire system is as follows:

[0067] This embodiment uses a DC source and a DC load as an example. The rectifier bridge RB5 is adjusted so that the first DCAC & DCDC module 4 converts DC1 into DCa. Similarly, the second DCAC & DCDC module 5 converts DCb into DC2. The rectifier bridges of the entire system are switched on and off so that the entire system is operating normally. When grid 1 is turned on, the energy from grid 1 passes sequentially through ACDC module 2, DCDC conversion module 3, and the first DCAC & DCDC module 4 before outputting DCa. Meanwhile, the DC power DCb output by the device under test (EUT) passes sequentially through the second DCAC & DCDC module 5, DCDC conversion module 3, and ACDC module 2 before being fed back to grid 1.

[0068] Specifically, the DCDC converter module 3 of this embodiment can function solely as a source or a load. When acting as a source, the primary side components of the ACDC module 2 and the DCDC converter module 3 provide power to the EUT. When acting as a load, the primary side components of the ACDC module 2 and the DCDC converter module 3 feed the power provided by the EUT back to the grid 1.

[0069] When the source and the load are used together, the power running on the primary sides of the ACDC module 2 and the DCDC conversion module 3 is the difference in the energy required by the source and the load. Therefore, compared with independent sources and loads of the same power, when the power carried by the source and the load is equivalent, the actual power required by the primary sides of the ACDC module 2 and the DCDC conversion module 3 can be reduced to half of the independent ones. In this way, the current carrying specifications of the power devices in this part are smaller, resulting in a smaller size and lighter weight. Because the power required by this part is reduced, the loss generated by this part will also be greatly reduced. The efficiency when the source and the load are used together is higher than that of an ordinary system with independent sources and loads. In terms of hardware, the system shares the primary sides of the ACDC module 2 and the DCDC conversion module 3. Compared with independent sources and loads, the system saves the components on the primary sides of the ACDC module 2 and the DCDC conversion module 3, so the overall electronic components used are fewer and the volume is smaller.

[0070] In summary, the device of this embodiment has the following advantages: (1) Improved efficiency: Due to the shared primary side of the ACDC module 2 and the DCDC conversion module 3, the system loss is reduced, which significantly improves the overall efficiency of the test system, saves electricity and reduces emissions, and greatly reduces the power consumption of the user end. (2) Due to the simplification of the system power module, the overall volume and weight of the device are effectively reduced. (3) Powerful functions and a wide range of applications. It is widely applicable to different applications such as AC source AC load, AC source DC load, DC source DC load, DC source AC load, independent or parallel source or load, effectively simplifying the test environment. (4) Economic benefits: Due to the simplification of the system circuit, about a quarter of the materials are reduced, which reduces the cost of equipment production, saves electricity, and reduces the electricity cost of the laboratory or factory. The small size and light weight reduce the transportation cost and can also effectively reduce the laboratory or factory production line space occupied by the test system.

[0071] Example 2

[0072] The first embodiment discloses the basic working principle of the present invention in detail. However, when used as an AC load or AC source, it can only provide a source load for the single-phase power device under test (EUT). Therefore, in order to broaden the scope of use of the test system of the present invention, the test system can provide a source load for three-phase power to meet the use of various types of devices under test on the market. Figure 6 As shown, this embodiment improves the test system of the first embodiment.

[0073] In this embodiment, based on the test system of embodiment 1, three identical test circuits are connected in parallel at the output end of the ACDC module 2, and each test circuit is connected to the device under test EUT; wherein, each of the test circuits includes a DCDC conversion module 3, a first DCAC&DCDC module 4, and a second DCAC&DCDC module 5. The connection relationship of the components of each test circuit is the same as that of embodiment 1, and will not be repeated here. At the same time, the energy flow direction in the system can flow in both directions, specifically according to whether the host computer sets source / load 1~6 as source or load, which determines whether the energy flows out of this test device or into this test device.

[0074] like Figure 6 As shown, source / load 1, 3, and 5 are set as the source of the device under test (EUT), and source / load 2, 4, and 6 are set as the load of the device under test (EUT). The method of using the test system of this embodiment is as follows:

[0075] (1) The 6-channel source / load of this test system can be used independently. Since the output of each post-stage is isolated, they can be used as a source / load for one or more EUTs at the same time.

[0076] (2) Short-circuit the common terminals of the three output sources to configure them as a three-phase source. The phase angle between the phases can be set arbitrarily. At the same time, short-circuit the common terminals of the other three outputs to configure them as a three-phase load. When connecting to a three-phase source or three-phase load, you can flexibly use either a triangle or star connection.

[0077] (3) When the three source outputs are used as DC sources, they can be connected in parallel to provide higher currents, or in series to provide higher voltages. At the same time, when the three loads are used as DC loads, they can be connected in parallel to provide a wider load current range, or in series to provide a wider test voltage range.

[0078] It should be noted that the arrows in the accompanying drawings indicate the direction of energy flow. All power modules in this system can control the energy flow direction through the host computer software, automatically achieving bidirectional energy conversion. For ease of explanation, the present invention defaults to the circuit DCAC & DCDC1 corresponding to DC1 as the source of the EUT, and the circuit DCAC & DCDC2 corresponding to DC2 as the load of the EUT.

[0079] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be embraced herein, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0080] The above-mentioned embodiments merely represent the implementation methods of the invention. The protection scope of the present invention is not limited to the above-mentioned embodiments. For those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention, which all fall within the protection scope of the present invention.

Claims

1. A source-load integrated test system, characterized by: It includes a power grid (1), an ACDC module (2), a DCDC conversion module (3), a first DCAC&DCDC module (4), and a second DCAC&DCDC module (5); The power grid (1) is connected to one end of the ACDC module (2), the other end of the ACDC module (2) is connected to one end of the DCDC conversion module (3), the other end of the DCDC conversion module (3) has two parallel circuits, which are respectively connected to one end of the first DCAC&DCDC module (4) and the second DCAC&DCDC module (5), and the other ends of the first DCAC&DCDC module (4) and the second DCAC&DCDC module (5) are both connected to the equipment under test (EUT); The DCDC conversion module (3) includes a transformer T1, a rectifier bridge RB2, a rectifier bridge RB3, a resonant inductor L2, a resonant capacitor C2, an input filter capacitor C3, an output filter capacitor C4 and an output filter capacitor C5; The transformer T1 has a primary winding N1, a secondary winding N2 and a secondary winding N3; The output end of the three-phase PWM rectifier bridge arm RB1 is connected to the primary winding N1 of the transformer T1 through the rectifier bridge RB2, the two ends of the input filter capacitor C3 are connected to the input end of the rectifier bridge RB2, and the resonant inductor L2 and the resonant capacitor C2 are respectively arranged on both sides of the primary winding N1 of the transformer T1; The secondary winding N2 of the transformer T1 is connected to the first DCAC&DCDC module (4) via the rectifier bridge RB3, and the two ends of the output filter capacitor C4 are connected to the output end of the rectifier bridge RB3; The secondary winding N3 of the transformer T1 is connected to the second DCAC&DCDC module (5) through the rectifier bridge RB4, and the two ends of the output filter capacitor C5 are connected to the output end of the rectifier bridge RB4.

2. The source-load integrated test system according to claim 1, characterized in that: The power grid (1) has power live lines L1, L2 and L3.

3. The source-load integrated test system according to claim 2, characterized in that: The ACDC module (2) comprises an inductor group L1, a three-phase PWM rectifier bridge arm RB1, and an output filter capacitor C1; The power live wires L1, L2 and L3 of the power grid (1) are connected to the input end of the three-phase PWM rectifier bridge arm RB1 through the inductor group L1, and the output end of the three-phase PWM rectifier bridge arm RB1 is connected to the DCDC conversion module (3); The two ends of the output filter capacitor C1 are connected to the output end of the three-phase PWM rectifier bridge arm RB1.

4. The source-load integrated test system according to claim 1, characterized in that: The first DCAC&DCDC module (4) and the second DCAC&DCDC module (5) are two complete and independent circuits with completely identical hardware, and the topologies of the two parts are completely consistent.

5. The source-load integrated test system according to claim 4, characterized in that: The first DCAC&DCDC module (4) comprises a rectifier bridge RB5, a filter capacitor C6, a resonant inductor L3, a resistor R1 and a resonant capacitor C8; The output end of the rectifier bridge RB3 is connected to the input end of the rectifier bridge RB5. The positive output end of the rectifier bridge RB5 is connected to the negative output end after passing through the series-connected resonant inductor L3, resistor R1 and resonant capacitor C8 in sequence; the two ends of the series-connected resistor R1 and resonant capacitor C8 are connected to the equipment under test (EUT). The two ends of the filter capacitor C6 are connected to the input end of the rectifier bridge RB5.

6. The source-load integrated test system according to claim 4, characterized in that: The second DCAC&DCDC module (5) comprises a rectifier bridge RB6, a filter capacitor C7, a resonant inductor L4, a resistor R2 and a resonant capacitor C9; The output end of the rectifier bridge RB4 is connected to the input end of the rectifier bridge RB6. The positive output end of the rectifier bridge RB6 is connected to the negative output end after passing through the series-connected resonant inductor L4, resistor R2 and resonant capacitor C9. The two ends of the series-connected resistor R2 and resonant capacitor C9 are connected to the equipment under test (EUT). The two ends of the filter capacitor C6 are respectively connected to the two input ends of the rectifier bridge RB6.

7. The source-load integrated test system according to claim 1, characterized in that: The power grid (1) is connected to one end of the ACDC module (2), and the other end of the ACDC module (2) is connected in parallel with three identical test circuits, each of which is connected to the device under test (EUT); Each of the test lines comprises the DCDC conversion module (3), the first DCAC&DCDC module (4), and the second DCAC&DCDC module (5).

8. A method for testing using the source-load integrated test system according to any one of claims 1 to 7, characterized in that: The steps include: S1. Setting the circuit corresponding to the first DCAC&DCDC module (4) as the DC source of the device under test (EUT), and the circuit corresponding to the second DCAC&DCDC module (5) as the DC load of the device under test (EUT); S2, adjusting the ACDC module (2), the DCDC conversion module (3), the first DCAC&DCDC module (4) and the second DCAC&DCDC module (5), so that the first DCAC&DCDC module (4) supplies DC power to the device under test EUT, and the second DCAC&DCDC module (5) serves as a DC load for the device under test EUT; S3. After the entire system is operating normally, turn on the power grid (1); S4, the energy of the power grid (1) is input to the equipment under test (EUT) after passing through the ACDC module (2), the DCDC conversion module (3), and the first DCAC&DCDC module (4); S5. The energy of the equipment under test (EUT) is fed back to the power grid (1) after passing through the second DCAC&DCDC module (5), the DCDC conversion module (3), and the ACDC module (2) in sequence.

9. The method for testing a source-load integrated test system according to claim 8, characterized in that: The adjustment of the DCDC conversion module (3) in step 2 is specifically as follows: S21, adjusting the rectifier bridge RB2 between the primary winding N1 of the transformer T1 and the output end of the three-phase PWM rectifier bridge arm RB1; S22, adjusting the rectifier bridge RB3 between the secondary winding N2 of the transformer T1 and the first DCAC&DCDC module (4); S23, adjusting the rectifier bridge RB4 between the secondary winding N3 of the transformer T1 and the second DCAC&DCDC module (5).

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