Device and method for testing alternating current through-current capability of power electronic rectifier module

Abstract

The invention provides a device and a method for testing the alternating current through-current capability of a power electronic rectifier module in order to solve the problem that the alternating current through-current performance of the rectifier module is not tested in the existing rectifier module testing device. Comprising a three-phase voltage regulator, a transformer, a temperature detection structure, a current detection structure, an adjustable load, a control structure, a timer and a counter, the three-phase voltage regulator is connected with an external power supply, and the three-phase voltage regulator is also connected with primary sides of the three transformers respectively; the secondary sides of the three transformers are respectively connected with the three-phase input of the tested first rectifier module; the output of the first rectifier module is connected with the adjustable load, and the adjustable load is also connected with the current detection structure; the temperature detection structure is arranged close to the three-phase voltage regulator; the current detection structure and the temperature detection structure are respectively connected with the control structure; the timer and the counter are respectively connected with the control structure; and the through-current capability test of the alternating current side of the rectifier module is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of rectifier module testing, and in particular to a device and method for testing the AC current carrying capacity of a power electronic rectifier module. Background Art

[0002] A rectifier module is an electronic component used to convert alternating current (AC) to direct current (DC). It consists of multiple diode chips packaged in various ways according to specific circuits and is widely used in AC-to-DC applications. To verify that the rectifier module meets design requirements, various performance tests are necessary. For example, the content disclosed in patent publication number CN104865513B can be used to test the rectifier module's surge resistance. Additionally, rectifier modules are tested for current flow capacity, among other tests.

[0003] Currently, traditional current-carrying capacity tests in the industry often use a DC constant current. The specific method is to connect the positive pole of the constant current source to the negative pole of the output terminal of the rectifier module, so that current flows into the positive pole of the output terminal of the rectifier module, and the current flows out of the positive pole of the output terminal of the rectifier module and returns to the negative pole of the constant current source. However, in existing inspection methods, because the AC input pole of the rectifier module is floating, it does not pass the test, and therefore, it is impossible to effectively verify whether the AC pole of the rectifier module has defects. To overcome the shortcomings of existing testing methods, a device and method for testing the AC current-carrying capacity of power electronic rectifier modules are proposed. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a device and method for testing the AC current carrying capacity of a power electronic rectifier module.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions: A device for testing the AC current carrying capacity of a power electronic rectifier module comprises a three-phase voltage regulator, a transformer, a temperature detection structure, a current detection structure, an adjustable load, a control structure, a timer, and a counter. The three-phase voltage regulator is connected to an external power supply and is also connected to the primary sides of three transformers respectively. The secondary sides of the three transformers are respectively connected to the three-phase inputs of a first rectifier module to be tested, and a Y-type connection is adopted between the three transformers. The output of the first rectifier module is connected to the adjustable load, which is also connected to the current detection structure to collect the current passing through the adjustable load. The temperature detection structure is arranged near the three-phase voltage regulator and is used to detect the temperature of the three-phase voltage regulator. The current detection structure and the temperature detection structure are respectively connected to the control structure. The timer and the counter are also respectively connected to the control structure. The timer is used to count the test duration, and the counter is used to count the number of cycle tests.

[0006] Furthermore, it also includes a three-phase contactor, which is arranged between the three-phase voltage regulator and the transformer. The control end of the three-phase contactor is also connected to the adjustable load, and the adjustable load controls the conduction and shutdown of the relay according to the temperature feedback of the temperature detection structure.

[0007] Furthermore, it also includes an air switch, wherein the air switch is arranged in series between each phase input of the three-phase voltage regulator from which the external power supply comes, and the air switch is also arranged between the output end of the three-phase voltage regulator and each phase input of the first rectifier module.

[0008] Furthermore, the rotating voltage regulating part of the three-phase voltage regulator is provided with a fixed motor, the output shaft of the motor is transmission-connected to the rotating voltage regulating part of the three-phase voltage regulator to control the voltage output by the three-phase voltage regulator; the motor is also connected to the control structure.

[0009] Furthermore, the adjustable load includes two copper rods arranged in parallel, and a number of corresponding mounting holes for setting resistance wires are respectively provided on the two copper rods. Screws for fixing the resistance wires in the mounting holes are also provided on the copper rods; by changing the number of resistance wires set between the two copper rods, the total resistance value of the load is controlled and changed.

[0010] Furthermore, the output end of the first rectifier module under test is further provided with a second rectifier module for detecting the current carrying capacity, and the DC output end of the second rectifier module is connected in series with the adjustable load and then connected to the output of the first rectifier module.

[0011] Furthermore, it also includes a support frame, which is arranged into a three-layer structure, wherein the first layer is provided with a transformer and a three-phase voltage regulator; the second layer is provided with an adjustable load; the third layer is provided with a rectifier module; and a mounting plate is also provided between the second and third layers; and a control structure, a timer and a counter are fixedly provided on the mounting plate.

[0012] Furthermore, it also includes a heat dissipation structure, which includes a plurality of fans; the fans are respectively arranged on the third layer and the second layer of the support frame.

[0013] A method for testing the AC current carrying capacity of a power electronic rectifier module, based on the above-mentioned testing device, includes the following steps: Step 1: The control structure sets the temperature variation range, current variation range, number of cycles, and running time according to the input parameters; Step 2: The control structure turns on the three-phase voltage regulator and transformer according to the start-up operation instruction to supply power to the first rectifier module on the secondary side of the transformer; Step 3: The current detection structure detects the current output by the first rectifier module to the adjustable load, determines whether the current exceeds the set current variation range, and controls the motor connected to the three-phase voltage regulator by the control structure to adjust the output voltage to control the current of the adjustable load within the current variation range; Step 4: The temperature detection structure detects whether the temperature of the first rectifier module exceeds the temperature variation range; if it exceeds the temperature variation range, the control structure controls the three-phase contactor to disconnect, disconnects the three-phase voltage regulator and the transformer, controls the heat dissipation structure to start, and reduces the temperature of the first rectifier module until the temperature reaches the set lower temperature limit. The counter records this as one cycle and proceeds to the next step; otherwise, the process returns to step 3 and continues to detect temperature and current changes. Step 5: The control structure determines whether the actual number of loops reaches the set number of loops and whether the actual running time reaches the set running time based on the recorded values of the counter and timer; if one of the conditions is met, the test ends; otherwise, it returns to step 2 and continues the test.

[0014] Furthermore, the voltage range of the secondary side output of the transformer is 3V~10V, and the resistance of the adjustable load is 1 milliohm~20 milliohm; the current variation range set in step 1 is 300A~330A.

[0015] The beneficial effects of the present invention are: By setting up the secondary side of the transformer connected to the three-phase input terminal of the rectifier module and coordinating with components such as adjustable load, the current carrying capacity of the AC side of the rectifier module can be tested, and the performance of the rectifier module can be more comprehensively evaluated. Cooperating with the temperature detection structure and the three-phase contactor, the rectifier module can be tested in a cycle. Under the premise of ensuring the safety of the test process, the performance of the rectifier module can be tested multiple times to ensure that the rectifier module that passes the test is safe and reliable. By setting the motor to be connected to the three-phase voltage regulator, the output voltage of the three-phase voltage regulator is adjusted according to the current feedback, and the current at both ends of the adjustable load is controlled within the set range; By setting an adjustable load including a copper rod with a mounting hole and a resistance wire, the equivalent resistance of the adjustable load is controlled to reach the milliohm level, achieving the effect of low voltage and high current, and fully testing the power output load capacity of the rectifier module; By setting up a second rectifier module, the current flow performance test of the output end of other rectifier modules can be realized at the same time, enriching the types of simultaneous tests; By setting up a heat dissipation structure, the rectifier module can be cooled quickly, improving the efficiency of the cycle test; By adopting the test method, the performance stability of the rectifier module after multiple AC to DC cycle output is tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the overall structure of the device of Example 1; Figure 2 This is a schematic diagram of the overall structure of the device of Example 1 from another angle; Figure 3 This is an exploded view of a portion of the structure of the device of Example 1; Figure 4 Schematic diagram of the adjustable resistor of Example 1; Figure 5 Schematic diagram of the circuit structure of the device of Example 1.

[0017] Description of the accompanying drawings: three-phase voltage regulator 1, transformer 2, temperature detection structure 3, current detection structure 4, adjustable load 5, copper rod 51, resistance wire 52, screw 53, control structure 6, timer 7, counter 8, three-phase contactor 9, air switch 10, motor 11, first rectifier module 12, second rectifier module 13, support frame 14, mounting plate 141, heat dissipation structure 15, fan 151, heat dissipation base 152. DETAILED DESCRIPTION

[0018] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. Therefore, the figures only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0020] Example 1: like Figures 1 to 5As shown, a device for testing the AC current carrying capacity of a power electronic rectifier module includes a three-phase voltage regulator 1, a transformer 2, a temperature detection structure 3, a current detection structure 4, an adjustable load 5, a control structure 6, a timer 7, and a counter 8; wherein the three-phase voltage regulator 1 is connected to an external power supply, and the three-phase voltage regulator 1 is also connected to the primary sides of three transformers 2 respectively; the secondary sides of the three transformers 2 are respectively connected to the three-phase inputs of the first rectifier module 12 to be tested, and the three transformers 2 are connected in a Y-type manner; specifically, the N terminals of the three transformers 2 are short-circuited, and each of the other three transformers 2 has a low-voltage output terminal Connected to the AC input end of the rectifier module; the output of the first rectifier module 12 is connected to the adjustable load 5, and the adjustable load 5 is also connected to the current detection structure 4 to collect the current passing through the adjustable load 5; the temperature detection structure 3 is set close to the three-phase voltage regulator 1 and is used to detect the temperature of the three-phase voltage regulator 1; the current detection structure 4 and the temperature detection structure 3 are respectively connected to the control structure 6; the timer 7 and the counter 8 are also respectively connected to the control structure 6, the timer 7 is used to count the test duration, and the counter 8 is used to count the number of cycle tests, and the test is stopped according to the test duration and the number of cycle tests. In this example, the output of the three-phase voltage regulator 1 is also connected to the control structure 6 to realize power supply to the control structure 6. In addition, in this example, the temperature detection structure 3 and the control structure 6 are combined into a temperature controller.

[0021] It also includes a three-phase contactor 9, which is arranged between the three-phase voltage regulator 1 and the transformer 2. The control end of the three-phase contactor 9 is also connected to the adjustable load 5, and the adjustable load 5 controls the conduction and shutdown of the relay according to the temperature feedback of the temperature detection structure 3; it should be noted that the three-phase contactor 9 can also control the disconnection of the three-phase voltage regulator 1 and the transformer 2 when the test is completed, and cooperate with the control structure 6 to control whether the transformer 2 has input according to parameters such as temperature, thereby controlling whether the rectifier module is working or not.

[0022] The system further includes an air switch 10, which is connected in series between each phase input of the three-phase voltage regulator 1, which is the external power source. The air switch 10 is also connected between the output of the three-phase voltage regulator 1 and each phase input of the first rectifier module 12. The air switches 10 in these two positions are used to control the start and stop of the three-phase voltage regulator 1 and the start and stop of the transformer 2, respectively, to cut off power and protect circuit components when an abnormality occurs in the circuit. It should be noted that in this example, a relay is also included, which is connected in series with the circuit to control the on and off of the circuit.

[0023] The rotating voltage regulating part of the three-phase voltage regulator 1 is provided with a fixed motor 11, and the output shaft of the motor 11 is transmission-connected to the rotating voltage regulating part of the three-phase voltage regulator 1 to control the voltage output by the three-phase voltage regulator 1; the motor 11 is also connected to the control structure 6. It should be noted that the control structure controls the forward and reverse rotation of the motor 11 according to the current change using the existing method; in this example, the motor 11 adjusts the output of the three-phase voltage regulator according to the current detected by the current detection structure 4, thereby controlling the current passing through the adjustable load 5 to be stable within a certain range.

[0024] The voltage regulator adopts the specification of 220V:5V, so that the voltage output by the transformer for testing is lower, thereby improving the safety of personnel operation.

[0025] The adjustable load 5 includes two parallel copper rods 51, each of which is provided with a plurality of corresponding mounting holes for setting resistance wires 52. The copper rods 51 are also provided with screws 53 for fixing the resistance wires 52 in the mounting holes. By changing the number of resistance wires 52 arranged in parallel between the two copper rods 51, the equivalent total resistance value of the load is controlled and changed. In this example, the two ends of the copper rods 51 are fixedly mounted on the support frame structure described below through insulating fixing seats. It should be noted that the resistance value of the adjustable load 5 is extremely small, at the milliohm level, while conventional high-power resistance wires 52 are difficult to reach the milliohm level. Therefore, it is necessary to adopt the form of connecting multiple resistance wires 52 in parallel to reduce the equivalent resistance value of the adjustable load 5, so that when the voltage is low, a larger current can be obtained, thereby ensuring the output power of the first rectifier module 12 and achieving the purpose of testing the output power performance. Because the current of the rectifier module is usually large in the application scenario, and the slope resistance of the rectifier module itself is extremely small, at the milliohm level, so when testing the current sharing capacity, if the load end of the rectifier module is directly short-circuited, although it can reduce heat to a certain extent, it is greatly affected by the voltage fluctuation of the external power supply, affecting the test effect. Therefore, an adjustable resistor with a smaller resistance is added so that the voltage drop across the rectifier module and the voltage drop across the adjustable load 5 are at the same level, in this case both are about 1.5V, reducing the impact caused by the power supply voltage fluctuation. In addition, in this example, two groups of adjustable loads 5 are provided in series, one of which has a resistance of about 5 milliohms. When the output voltage of the rectifier module is about 5V, the current value after passing through the two series-connected adjustable loads 5 is about 300A.

[0026] The output end of the first rectifier module 12 to be tested is also provided with a second rectifier module 13 for detecting the current carrying capacity. The DC output end of the second rectifier module 13 is connected in series with the adjustable load 5 and then connected to the output of the first rectifier module 12; in this example, two second rectifier modules 13 are arranged in series, wherein one positive and negative pole of the DC output end of the two second rectifier modules 13 is connected, and the other positive and negative pole is connected to the output of the first rectifier module 12 to form a loop, thereby achieving the purpose of simultaneously testing the current carrying capacity of the second rectifier module 13, improving the test efficiency, and enriching the performance test categories of the rectifier module in different aspects.

[0027] The system also includes a support frame 14, which is a three-layer structure. The first layer is provided with a transformer 2 and a three-phase voltage regulator 1; the second layer is provided with an adjustable load 5; and the third layer is provided with a rectifier module. A mounting plate 141 is also provided between the second and third layers. A control structure 6, a timer 7, and a counter 8 are fixedly provided on the mounting plate 141, and the counter 8 and the timer 7 respectively display the number of cycle tests and the test duration. The transformer 2 on the first layer is connected to the rectifier module on the third layer via a copper busbar. Similarly, the adjustable load 5 on the second layer is also connected to the rectifier module on the third layer via a copper busbar. A grounding wire is also provided on the first layer of the support frame 14, and the grounding wire is connected to the ground terminal of the electronic component.

[0028] In addition, a current display part of the current detection structure 4 is also provided on the mounting plate 141; the current detection structure 4 also includes a current sensor, which is connected in series with the adjustable load 5. The current sensor is also connected to the control structure 6 and the current display part, and transmits the detected and collected current value to the current display part for display, and transmits it to the control structure 6, which controls the action of the motor 11 on the three-phase voltage regulator 1.

[0029] A power switch and a current adjustment button associated with the motor 11 on the three-phase voltage regulator 1 are also provided on the mounting plate 141. The bottom of the support frame 14 is also provided with universal wheels for easy movement.

[0030] It also includes a heat dissipation structure 15, which includes several fans 151; the fans 151 are respectively arranged on the third and second layers of the support frame 14; the fans 151 are connected to the control structure 6, and the control structure 6 controls their start and stop. In this example, two fans 151 are arranged on the third layer, and the two fans 151 are respectively arranged on both sides of the first rectifier module 12 and the second rectifier module 13, forming a one-way air flow channel. The heat dissipation structure 15 also includes a heat dissipation base 152, which includes a heat dissipation plate and several parallel heat dissipation fins, which are vertically arranged below the heat dissipation plate; the other side of the heat dissipation plate is provided with a detachably connected first rectifier module 12 and second rectifier module 13; the direction of the heat dissipation fins in the heat dissipation base 152 is parallel to the air flow channel between the two fans 151, which facilitates the air flow to pass through the gaps between the heat dissipation fins and remove heat.

[0031] A method for testing the AC current carrying capacity of a power electronic rectifier module, based on the above-mentioned testing device, includes the following steps: Step 1: The control structure 6 sets the temperature variation range, current variation range, number of cycles and running time according to the input parameters; Step 2: The control structure 6 connects the three-phase voltage regulator 1 and the transformer 2 according to the start-up operation instruction, and supplies power to the first rectifier module 12 on the secondary side of the transformer 2; Step 3: The current detection structure 4 detects the current output by the first rectifier module 12 to the adjustable load 5, determines whether the current exceeds the set current variation range, and controls the motor 11 connected to the three-phase voltage regulator 1 by the control structure 6 to adjust the output voltage to control the current of the adjustable load 5 within the current variation range; Step 4: The temperature detection structure 3 detects whether the temperature of the first rectifier module 12 exceeds the temperature variation range; if it exceeds the temperature variation range, the control structure 6 controls the three-phase contactor 9 to disconnect, disconnects the connection between the three-phase voltage regulator 1 and the transformer 2, controls the heat dissipation structure 15 to start, and reduces the temperature of the first rectifier module 12 until the temperature reaches the set lower temperature limit. The counter 8 records this as one cycle and proceeds to the next step; otherwise, the process returns to step 3 and continues to detect temperature and current changes. Step 5: The control structure 6 determines whether the actual number of cycles reaches the set number of cycles and whether the actual running time reaches the set running time based on the recorded values of the counter 8 and the timer 7; if one of the conditions is met, the test ends; otherwise, return to step 2 and continue testing.

[0032] The voltage range of the secondary side output of the transformer 2 is 3V~10V, the resistance of the adjustable load 5 is 1 milliohm~20 milliohm, and by adjusting the resistance of the adjustable resistor and the output of the three-phase voltage regulator, the current change range set in step 1 is controlled to be 300A~330A.

[0033] During the implementation process, by setting the secondary side of the transformer 2 connected to the three-phase input end of the rectifier module, and coordinating with components such as the adjustable load 5, the current carrying capacity test of the AC side of the rectifier module is realized; by coordinating with the temperature detection structure 3 and the three-phase contactor 9, a cyclic test of the rectifier module is realized, and the performance of the rectifier module is tested multiple times while ensuring the safety of the test process, so as to ensure that the rectifier module that passes the test is safe and reliable; by setting the motor 11 to be connected to the three-phase voltage regulator 1, the output voltage of the three-phase voltage regulator 1 is adjusted according to the current feedback, and the current at both ends of the adjustable load 5 is controlled within the set range. ; By setting an adjustable load 5 including a copper rod 51 with a mounting through hole, combined with a resistance wire 52, the equivalent resistance of the adjustable load 5 is controlled to reach the milliohm level, achieving the effect of low voltage and high current, and fully testing the power output load capacity of the rectifier module; by setting a second rectifier module 13, the current flow performance test of the output end of other rectifier modules is achieved at the same time, enriching the types of simultaneous tests; by setting a heat dissipation structure 15, the rapid cooling of the rectifier module is achieved, and the efficiency of the cycle test is improved; by adopting a test method, the performance stability of the rectifier module after multiple AC-to-DC cycle outputs is tested.

[0034] Example 2: This embodiment is obtained by improving Example 1. The difference between this embodiment and Example 1 is that the first rectifier module 12 and the second rectifier module 13 are both single-phase rectifier bridges. At this time, the output of any transformer 2 is connected to the input end of the single-phase first rectifier module 12, and the connection method at the output end of the first rectifier module 12 is the same as that in Example 1.

[0035] The above description is merely a specific example of the present invention and does not constitute any limitation thereto. It is apparent to those skilled in the art, after understanding the content and principles of the present invention, that various modifications and alterations in form and detail may be made without departing from the principles and structure of the present invention. However, such modifications and alterations based on the concepts of the present invention remain within the scope of protection of the claims of the present invention.

Claims

1. A device for testing the AC current carrying capacity of a power electronic rectifier module, characterized in that: The invention comprises a three-phase voltage regulator (1), a transformer (2), a temperature detection structure (3), a current detection structure (4), an adjustable load (5), a control structure (6), a timer (7) and a counter (8); wherein the three-phase voltage regulator (1) is connected to an external power supply, and the three-phase voltage regulator (1) is also connected to the primary sides of three transformers (2) respectively; the secondary sides of the three transformers (2) are respectively connected to the three-phase input of the first rectifier module (12) to be measured, and the three transformers (2) are connected in a Y-type manner; the input of the first rectifier module (12) is connected to the secondary sides of the three transformers (2) respectively. The output is connected to the adjustable load (5), and the adjustable load (5) is also connected to the current detection structure (4) to collect the current passing through the adjustable load (5); the temperature detection structure (3) is set close to the three-phase voltage regulator (1) and is used to detect the temperature of the three-phase voltage regulator (1); the current detection structure (4) and the temperature detection structure (3) are respectively connected to the control structure (6); the timer (7) and the counter (8) are also respectively connected to the control structure (6), the timer (7) is used to count the test time, and the counter (8) is used to count the number of cycle tests.

2. A device for testing AC current carrying capacity of a power electronic rectifier module according to claim 1, characterized in that: The invention also includes a three-phase contactor (9), which is arranged between the three-phase voltage regulator (1) and the first rectifier module (12). The control end of the three-phase contactor (9) is also connected to the adjustable load (5), and the adjustable load (5) controls the on and off of the relay according to the temperature feedback of the temperature detection structure (3).

3. The device for testing the AC current carrying capacity of a power electronic rectifier module according to claim 2, characterized in that: It also includes an air switch (10), wherein the air switch (10) is arranged in series between each phase input of the three-phase voltage regulator (1) from which external power is supplied, and the air switch (10) is also arranged between the output end of the three-phase voltage regulator (1) and each phase input of the first rectifier module (12).

4. The device for testing AC current carrying capacity of a power electronic rectifier module according to claim 1, characterized in that: The rotating voltage regulating portion of the three-phase voltage regulator (1) is provided with a fixed motor (11), and the output shaft of the motor (11) is transmission-connected to the rotating voltage regulating portion of the three-phase voltage regulator (1) to control the voltage output by the three-phase voltage regulator (1); the motor (11) is also connected to the control structure (6).

5. The device for testing AC current carrying capacity of a power electronic rectifier module according to claim 1, characterized in that: The adjustable load (5) comprises two copper rods (51) arranged in parallel, each of which is provided with a plurality of corresponding mounting through holes for setting resistance wires (52), and each of which is provided with screws (53) for fixing the resistance wires (52) in the mounting through holes. By changing the number of resistance wires (52) arranged between the two copper rods (51), the total resistance value of the load is controlled and changed.

6. The device for testing AC current carrying capacity of a power electronic rectifier module according to claim 1, characterized in that: The output end of the first rectifier module (12) to be tested is further provided with a second rectifier module (13) for detecting the flow capacity, and the DC output end of the second rectifier module (13) is connected in series with the adjustable load (5) and then connected to the output of the first rectifier module (12).

7. The device for testing AC current carrying capacity of a power electronic rectifier module according to claim 1, characterized in that: The invention also includes a support frame (14), wherein the support frame (14) is arranged as a three-layer structure, wherein the first layer is provided with a transformer (2) and a three-phase voltage regulator (1); the second layer is provided with an adjustable load (5); the third layer is provided with a rectifier module; and a mounting plate (141) is further provided between the second and third layers; and a control structure (6), a timer (7), and a counter (8) are fixedly provided on the mounting plate (141).

8. The device for testing AC current carrying capacity of a power electronic rectifier module according to claim 7, characterized in that: It also includes a heat dissipation structure (15), which includes a plurality of fans (151); the fans (151) are respectively arranged on the third layer and the second layer of the support frame (14).

9. A method for testing the AC current carrying capacity of a power electronic rectifier module, characterized in that: The testing device according to any one of claims 1 to 8 comprises the following steps: Step 1: The control structure (6) sets the temperature variation range, current variation range, number of cycles and running time according to the input parameters; Step 2: The control structure (6) switches on the three-phase voltage regulator (1) and the transformer (2) according to the start-up operation instruction, and supplies power to the first rectifier module (12) on the secondary side of the transformer (2); Step 3: The current detection structure (4) detects the current output from the first rectifier module (12) to the adjustable load (5), determines whether the current exceeds the set current variation range, and the control structure (6) controls the motor (11) connected to the three-phase voltage regulator (1) to adjust the output voltage and control the current of the adjustable load (5) within the current variation range; Step 4: The temperature detection structure (3) detects whether the temperature of the first rectifier module (12) exceeds the temperature variation range; if it exceeds the temperature variation range, the control structure (6) controls the three-phase contactor (9) to disconnect, disconnects the connection between the three-phase voltage regulator (1) and the transformer (2), controls the heat dissipation structure (15) to start, and reduces the temperature of the first rectifier module (12) until the temperature reaches the set lower temperature limit, which is recorded as one cycle by the counter (8), and enters the next step; otherwise, return to step 3 and keep detecting temperature changes and current changes; Step 5: The control structure (6) determines whether the actual number of cycles reaches the set number of cycles and whether the actual running time reaches the set running time based on the recorded values of the counter (8) and the timer (7); if one of the conditions is met, the test ends; otherwise, it returns to step 2 and continues the test.

10. A method for testing the AC current carrying capacity of a power electronic rectifier module according to claim 9, characterized in that: The voltage range of the secondary output of the transformer (2) is 3V~10V, and the resistance of the adjustable load (5) is 1 milliohm~20 milliohm; the current variation range set in step 1 is 300A~330A.

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