CN113702858B - A dynamic response test device for switching power supply - Google Patents

Abstract

The invention provides a dynamic response testing device of a switching power supply, which considers that the efficiency and the accuracy of manual testing are low. Through the device, manual operation is not needed, so that the labor cost is reduced, the test time is saved, and the efficiency and the accuracy of the dynamic response test of the switching power supply can be effectively improved.

Description

A dynamic response test device for switching power supply

Technical field

The invention relates to the technical field of automated testing of switching power supplies, and in particular to an automatic testing system for switching power supplies.

Background technique

Switching power supply is a high-frequency switching power conversion device. It has many advantages such as small size, light weight, wide voltage stabilization range, and good filtering effect. It is often used as a power supply for electronic equipment. With the increase in the working speed and current demand of electronic equipment, when the current of electronic equipment changes transiently, the output voltage of the switching power supply must be maintained within a specific tolerance range to ensure the stable operation of the circuit. Therefore, the switching power supply is required to operate stably. The dynamic response test of the power supply is particularly important.

In the existing technology, the dynamic response test of the switching power supply can only be carried out manually, and the test must be carried out by manually controlling the oscilloscope. After obtaining the test results, the stored data must be manually copied and organized into a record table, which consumes a lot of manpower. and time, test efficiency and accuracy are lower.

Contents of the invention

The purpose of the present invention is to provide a dynamic response testing device for a switching power supply that does not require manual operation, reduces labor costs, saves testing time, and can effectively improve the efficiency and accuracy of dynamic response testing of the switching power supply.

In order to solve the above technical problems, the present invention provides a dynamic response testing device for a switching power supply, which includes:

A load module, the input end of the load module is connected to the output end of the switching power supply under test, and is used to change the load current based on the threshold value of the load current and the change mode of the load current;

A power module, the output end of the power module is connected to the input end of the switching power supply under test, and is used to supply power to the switching power supply under test;

An acquisition module, the input end of the acquisition module is connected to the output end of the switching power supply under test, and is used to test the output voltage value of the switching power supply under test when the load current of the load module changes;

A control module, the control module is connected to the control end of the load module and the acquisition module respectively, and is used to determine the threshold value of the load current of the load module and the change mode of the load current based on user instructions, and determine the Whether the output voltage value of the tested switching power supply is within the preset output voltage range, if so, it is determined that the dynamic response of the tested switching power supply meets the requirements.

Preferably, the power module is a DC power supply, and the output end of the DC power supply is connected to the input end of the switching power supply under test for supplying power to the switching power supply under test.

Preferably, the switching power supply under test is arranged on the motherboard;

The power module also includes:

PSU, the PSU is used to supply power to the switching power supply under test through the mainboard.

Preferably, it also includes a controllable switch, the first end of the controllable switch is connected to the mains, the second end of the controllable switch is connected to the input end of the PSU, and the control end of the controllable switch is connected to the mains. The DC power supply connection;

The control module is also used to control the DC power supply to supply power to the switching power supply under test, or to send a closing instruction of the controllable switch to the DC power supply;

The DC power supply is also used to control the controllable switch to close after receiving a closing instruction of the controllable switch, so that the PSU supplies power to the tested switching power supply through the mainboard.

Preferably, the controllable switch is a relay.

Preferably, the user instruction includes the input voltage value of the switching power supply under test;

Controlling the DC power supply to supply power to the switching power supply under test includes:

The DC power supply is controlled to output the input voltage value to supply power to the switching power supply under test.

Preferably, the acquisition module is also used to test the load current value of the load module and display the waveform of the output voltage value of the tested switching power supply as the load current value of the load module changes.

Preferably, it also includes a display module; the control module is also used to control the display module to display the determination result of whether the dynamic response of the tested switching power supply meets the requirements.

Preferably, the user instruction also includes the designed output voltage value of the switching power supply under test;

The preset output voltage range is from the designed output voltage value of the tested switching power supply * 0.97 to the designed output voltage value of the tested switching power supply * 1.03.

Preferably, the user instruction includes the full load output current value;

Determining the threshold of the load current based on user instructions includes:

When the full load output current value is less than the standard current threshold, the large current threshold of the load current is determined to be 90% of the full load output current value, and the small current threshold is 10% of the full load output current value;

When the full load output current value is not less than the standard current threshold, the first large current threshold of the load current is determined to be 50% of the full load output current value, and the first small current threshold is the full load output current value. 0%; the second large current threshold is 100% of the full load output current value, and the second small current threshold is 50% of the full load output current value.

The present invention provides a dynamic response testing device for a switching power supply. The control module first determines the load current threshold of the load module and the changing mode of the load current based on user instructions. The load module can perform testing based on the threshold value of the load current and the changing mode of the load current. When the load current changes, the power module can supply power to the switching power supply under test. The acquisition module can test the output voltage value of the switching power supply under test when the load current changes. Then the control module determines whether it is in the predetermined state based on the output voltage value of the switching power supply under test. Assuming that the output voltage range is within the range, it can be determined whether the dynamic response of the tested switching power supply meets the requirements. It can be seen that the control module, the load module, the power module and the acquisition module work together to realize the test of the dynamic response of the switching power supply under test without manual operation, which reduces labor costs, saves test time, and can effectively improve Efficiency and accuracy of dynamic response testing of switching power supplies.

Description of the drawings

In order to explain the technical solutions in the embodiments of the present invention more clearly, the prior art and the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the drawings of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic structural diagram of a dynamic response testing device for a switching power supply provided by this application;

Figure 2 is a schematic structural diagram of another dynamic response testing device of a switching power supply provided by this application;

Figure 3 is a flow chart of a dynamic response test of a switching power supply provided by this application.

Detailed ways

The core of the invention is to provide a dynamic response testing device for a switching power supply, which does not require manual operation, reduces labor costs, saves testing time, and can effectively improve the efficiency and accuracy of dynamic response testing of the switching power supply.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Please refer to Figure 1, which is a schematic structural diagram of a dynamic response testing device for a switching power supply provided by this application.

The invention provides a dynamic response testing device for a switching power supply, which includes:

Load module 1, the input end of the load module 1 is connected to the output end of the switching power supply under test, and is used to change the load current based on the threshold value of the load current and the change mode of the load current;

Power module 2, the output end of the power module 2 is connected to the input end of the switching power supply under test, and is used to supply power to the switching power supply under test;

Acquisition module 3, the input end of the acquisition module 3 is connected to the output end of the switching power supply under test, and is used to test the output voltage value of the switching power supply under test when the load current of the load module 1 changes;

The control module 4 is connected to the control terminals of the load module 1 and the acquisition module 3 respectively, and is used to determine the threshold value of the load current of the load module 1 and the change mode of the load current based on user instructions, and determine the output voltage of the tested switching power supply. Whether the value is within the preset output voltage range, if so, determine that the dynamic response of the tested switching power supply meets the requirements.

Considering that when testing the dynamic response of a switching power supply, manual operation consumes more manpower and time and the test efficiency and accuracy are low. In order to solve this technical problem, this application provides a dynamic response testing device of the switching power supply. The dynamic response test device of the switching power supply includes a load module 1, a power module 2, an acquisition module 3 and a control module 4. Specifically, when the dynamic response test device of the switching power supply is operating, the control module 4 determines the threshold value of the load current of the load module 1 and the change pattern of the load current of the load module 1 based on user instructions, and sends control instructions to the load module 1 . Load module 1 will simulate the impact of different loads on the performance of the switching power supply under test. Load module 1 receives the threshold value of the load current and the way the load current changes, and changes the load current based on the threshold value of the load current and the way the load current changes, so that Subsequently, the dynamic response of the switching power supply under test is obtained when the load current changes dynamically. The power module 2 can supply power to the switching power supply under test. Among them, after the switching power supply under test receives the input voltage provided by the power supply module 2, it will perform DC conversion on the input voltage based on the switching frequency Fsw to obtain the output voltage. The acquisition module 3 will test when the load current of the load module 1 changes. The output voltage value of the switching power supply. The control module 4 reads the output voltage value of the tested switching power supply tested by the acquisition module 3, and determines whether the output voltage value of the tested switching power supply is within the preset output voltage range by comparing it with the preset output voltage range. If so, determines whether the output voltage value of the tested switching power supply is within the preset output voltage range. The dynamic response of the tested switching power supply meets the requirements; otherwise, it is determined that the dynamic response of the tested switching power supply does not meet the requirements.

In addition, the load module 1 can obtain the threshold value of the load current and the change mode of the load current through USB-GPIB (Universal Serial-General Bus-Purpose Interface Bus, Universal Serial Bus-General Interface Bus). The control module 4 can read the output voltage value of the tested switching power supply tested by the acquisition module 3 through USB-GPIB. Of course, the load module 1 and the control module 4, and the control module 4 and the acquisition module 3 can also communicate in other ways, and this application is not particularly limited here.

In addition, the load module 1 here can be, but is not limited to, a load meter. The load meter is connected to the switching power supply under test through a load line, which has the advantages of flexible use and energy saving.

The acquisition module 3 can be, but is not limited to, an oscilloscope.

The power module 2 may be a DC power supply obtained by converting commercial power, or may be a DC power supply 21 or the like, which is not particularly limited in this application.

In summary, in the dynamic response test device of the switching power supply of the present application, the control module 4, the load module 1, the power module 2 and the acquisition module 3 work together to realize the test of the dynamic response of the switching power supply under test without manual labor. Performing it manually reduces labor costs, saves testing time, and can effectively improve the efficiency and accuracy of dynamic response testing of switching power supplies.

Based on the above embodiments:

Please refer to FIG. 2 , which is a schematic structural diagram of another dynamic response testing device of a switching power supply provided by this application.

As a preferred embodiment, the power module 2 is a DC power supply 21, and the output end of the DC power supply 21 is connected to the input end of the switching power supply under test for supplying power to the switching power supply under test.

In order to achieve the accuracy of the dynamic response test of the switching power supply, in this embodiment, the power module 2 can use a DC power supply 21. The output terminal of the DC power supply 21 is directly connected to the input terminal of the switching power supply under test, and the DC voltage can be directly applied. to the input terminal of the switching power supply, so that when the load current changes, the output voltage value of the switching power supply under test is stable within the preset output voltage range, ensuring the accuracy of the test.

As a preferred embodiment, the switching power supply under test is installed on the motherboard;

Power module 2 also includes:

PSU22, PSU22 is used to power the switching power supply under test through the motherboard.

In order to simulate the test requirements when the switching power supply is working normally, in this embodiment, the switching power supply under test is set on the main board. The main board is a PCB (Printed Circuit Board) board. The power module 2 can also choose PSU22 (Power Supply Module 2). Supply Unit (power supply device). During the test process, PSU22 can output voltage to the mainboard. PSU22 applies the output voltage to the mainboard. After the mainboard converts the voltage into the voltage required for the normal operation of the switching power supply under test, the converted The voltage is provided to the switching power supply under test to realize power supply to the switching power supply under test.

In addition, this example sets two power supply modes to facilitate the user to select the power supply mode of the power module 2 according to actual test requirements.

As a preferred embodiment, it also includes a controllable switch 23, the first end of the controllable switch 23 is connected to the mains, the second end of the controllable switch 23 is connected to the input end of the PSU 22, and the control end of the controllable switch 23 Connected to DC power supply 21;

The control module 4 is also used to control the DC power supply 21 to supply power to the switching power supply under test, or to send a closing instruction of the controllable switch 23 to the DC power supply 21;

The DC power supply 21 is also used to control the controllable switch 23 to close after receiving the closing instruction of the controllable switch 23, so that the PSU 22 supplies power to the switching power supply under test through the main board.

In order to realize automatic control of the power supply of the switching power supply under test by the power supply module 2, in this embodiment, the dynamic response testing device of the switching power supply also includes a controllable switch 23. The first end of the controllable switch 23 is connected to the mains power. The second end of the switch 23 is connected to the input end of the PSU 22 , and the control end of the controllable switch 23 is connected to the DC power supply 21 . The user selects the power supply mode of the switching power supply under test in the control module 4. If it is the DC power supply 21 mode, the control module 4 controls the DC power supply 21 to power the switching power supply under test; if it is the PSU22 mode, the control module 4 sends a controllable switch The closing command of 23 is sent to the DC power supply 21. After receiving the closing command of the controllable switch 23, the DC power supply 21 controls the controllable switch 23 to close, thereby realizing that the PSU22 supplies power to the switching power supply under test through the main board.

In addition, PSU22 can be an AC-DC (Alternating Current-Direct current) power supply, used to convert mains power into direct current.

As a preferred embodiment, the controllable switch 23 is a relay.

In this embodiment, the controllable switch 23 can be a relay, which is an automatic switch that uses a smaller current to control a larger current. During actual operation, the control module 4 controls the DC power supply 21 to output a 5V voltage to control the relay. The pull-in enables PSU22 to supply power to the switching power supply under test through the motherboard, and the circuit structure is simple.

As a preferred embodiment, the user instruction includes the input voltage value of the switching power supply under test;

Control the DC power supply 21 to supply power to the switching power supply under test, including:

The DC power supply 21 is controlled to output an input voltage value to supply power to the switching power supply under test.

In this embodiment, when the dynamic response test device of the switching power supply starts to work, the user will input user instructions into the control module 4. The user instructions include the input voltage value of the switching power supply under test; the control module 4 is based on the input of the switching power supply under test. The voltage value is to set the DC power supply 21 so that the output voltage value of the DC power supply 21 is the input voltage value of the switching power supply under test in the user instruction.

In addition, the control module 4 can be, but is not limited to, a PC controller. The PC controller has the advantages of strong data processing capabilities, strong network communication functions, the ability to execute relatively complex control algorithms, and its nearly unlimited storage capacity. The PC controller and the DC power supply 21 can communicate through USB-GPIB. Of course, other methods can also be used for communication, which is not specifically limited in this application.

As a preferred embodiment, the acquisition module 3 is also used to test the load current value of the load module 1 and display the waveform of the output voltage value of the tested switching power supply changing with the load current value of the load module 1 .

In order to realize the automated recording of the dynamic response test process of the switching power supply, in this embodiment, the acquisition module 3 can also be used to test the load current value of the load module 1, and change the output voltage value of the tested switching power supply with the load module 1 The waveform of the load current value change is displayed, so that the control module 4 can capture and record the waveform of the acquisition module 3, and determine whether the dynamic response of the tested switching power supply meets the requirements based on the test data.

In addition, the acquisition module 3 can be, but is not limited to, an oscilloscope. The oscilloscope includes a CH1 interface and a CH2 interface. The oscilloscope's CH1 interface reads the output voltage value Vout' of the switching power supply under test through a differential carbon rod, and the oscilloscope's CH2 interface reads the load current through a current gun. Value Iout'.

A capacitor can also be provided on the main board, and the capacitor is connected to the output end of the switching power supply under test. By welding two flying wires at both ends of the capacitor, connect the flying wires to the positive and negative ends of the acquisition module 3. Then the acquisition module 3 The detected voltage value across the capacitor is the output voltage value of the switching power supply under test. In addition, during the dynamic response test of the switching power supply, the capacitor can be charged and discharged quickly. When the current of the load module 1 changes instantaneously, the capacitor can also quickly provide a part of the current, making the response faster and stabilizing the output voltage of the switching power supply under test.

As a preferred embodiment, it also includes a display module; the control module 4 is also used to control the display module to display the determination result of whether the dynamic response of the tested switching power supply meets the requirements.

In this embodiment, the dynamic response testing device of the switching power supply also includes a display module. The control module 4 controls the display module to display the determination result of whether the dynamic response of the tested switching power supply meets the requirements. If the output voltage of the tested switching power supply is within If the output voltage is within the preset range, the display module displays pass; if the output voltage of the switching power supply under test is outside the preset output voltage range, the display module displays fail.

As a preferred embodiment, the user instruction includes the designed output voltage value of the switching power supply under test;

The preset output voltage range is the design output voltage value of the switching power supply under test *0.97 to the design output voltage value of the switching power supply under test *1.03.

In this embodiment, when the dynamic response testing device of the switching power supply under test starts to work, the user will input user instructions into the control module 4, and the user instructions include the designed output voltage value Vout of the switching power supply under test;

The preset output voltage range in this application is "the designed output voltage value of the switching power supply under test Vout*0.97 ≦ the output voltage value of the switching power supply under test Vout' ≦ the design output voltage value of the switching power supply under test Vout * 1.03", in This preset output voltage range can ensure the normal operation of the switching power supply under test.

As a preferred embodiment, the user instruction also includes the full load output current value Imax;

Determine the load current threshold based on user instructions, including:

When the full load output current value Imax is less than the standard current threshold, the large current threshold for determining the load current is 90% of the full load output current value Imax, and the small current threshold is 10% of the full load output current value Imax;

When the full load output current value Imax is not less than the standard current threshold, the first large current threshold value of the load current is determined to be 50% of the full load output current value Imax, and the first small current threshold value is 0% of the full load output current value Imax; The second large current threshold is 100% of the full load output current value Imax, and the second small current threshold is 50% of the full load output current value Imax.

In this embodiment, when the dynamic response test device of the switching power supply under test starts to work, the user will input user instructions into the control module 4. The user instructions also include the full load output current value; the control module 4 determines the threshold value of the load current based on the user instructions. and how the load current changes.

Specifically, set the working mode of load module 1 to CCDH (Constant Current Dynamic Highmode, constant current dynamic high mode);

The tested switching power supply has different dynamic responses to normal operation depending on the full-load output current. In this application, the standard current threshold I is used as the basis for judging the current size.

When the full-load output current value Imax of the tested switching power supply is less than the standard current threshold I, it is usually a power supply that directly drives the load at the end. This type of power supply is characterized by frequent starts and stops. When the load is not working, it will remain in the standby state and remain in a very small load state. During the test, it can be recognized as the load current with a small current threshold of a load with a full load output current value of Imax*10%. When working normally at full load, a peak current will form when the current changes rapidly. If it reaches full load directly, the peak current may cause damage to the switching power supply under test, so the large current threshold of the load current will be set to the full load output. Current value Imax*90%, then slowly compensate to full load. Therefore, when testing this type of switching power supply, the load current threshold is set to the high current threshold High of the load current = full load output current value Imax*90%, and the low current threshold Low of the load current = full load output current value Imax*10%.

When the full-load output current value Imax of the switching power supply under test is not less than the standard current threshold I, if the load current changes from 0 to Imax, such a drastic instantaneous current change may easily damage the switching power supply under test. In this case, the switching power supply under test will have a state change when the load current changes to an intermediate value, making it different between the high current operating state and the low current operating state. In other words, it is necessary to test the switching power supply when the first small current threshold is the full load output current value Imax*0% to the first large current threshold is the full load output current value Imax*50%, and the second small current threshold is the full load output The dynamic response from the current value Imax*50% to the second large current threshold is the full load output current value Imax*100%. Therefore, when testing this type of switching power supply, the load current threshold is set so that the first large current threshold of the load current is 50% of the full load output current value Imax, and the first small current threshold is 0% of the full load output current value Imax; The second large current threshold is 100% of the full load output current value Imax, and the second small current threshold is 50% of the full load output current value Imax.

In addition, the standard current threshold may be 20A current, which is not specifically limited in this application.

The load current can change at a certain frequency, and its change method can be based on the above-set large current threshold, small current threshold, large current threshold duration, small current threshold duration, change rate from large current threshold to small current threshold, and small current The rate of change from threshold to high current threshold is determined.

For example, the large current threshold duration CCDHT1=0.5ms, the small current threshold duration CCDHT2=0.5ms, the change rate from the large current threshold to the small current threshold CCDH1=2.5A/us, and the change rate from the small current threshold to the large current threshold CCDH2= 2.5A/us, this application does not make special limitations here.

The user instruction also includes the switching frequency Fsw so that the user can know the working status of the switching power supply under test.

Please refer to Figure 3, which is a flow chart of a dynamic response test of a switching power supply provided by this application.

In order to facilitate the understanding of the test process of the dynamic response test device of the switching power supply provided by this application, the process of the dynamic response test of the switching power supply is explained in detail below:

1. Enter the information of the switching power supply under test on the test report template, including the input voltage value Vin of the switching power supply under test, the designed output voltage value Vout of the switching power supply under test, the switching frequency Fsw, and the full-load output current Iout.

2. Connect the PC controller to the oscilloscope, DC power supply 21, and load meter using USB-GPIB.

3. The output end of the switching power supply under test is connected to the load meter through the load line, the input end of the switching power supply under test is connected to the DC power supply 21 or PSU, and the differential line is welded to the remote output capacitor.

4. Oscilloscope CH1 reads the output voltage value Vout’ of the switching power supply under test through the differential probe, and CH2 reads the load current value Iout’ through the current gun.

5. Start the compiled application and display the software user interface.

6. Select the report to read and save waveform data in the user interface, and select the power supply method (DC power supply 21 or PSU). If the DC power supply 21 is directly powered, the PC controller will directly control the DC power supply 21 to output the input voltage Vin of the switching power supply under test; if it is powered by a PSU, the PSU is connected to the output end of the relay, and the control end of the relay is connected to the DC power supply. At both ends of the power supply 21, the PC controller controls the DC power supply 21 to output a 5V voltage to control the relay to close and complete the power supply.

7. Read the input voltage value Vin of the switching power supply under test, the designed output voltage value Vout of the switching power supply under test, the switching frequency Fsw, and the full-load output current Iout in the report, determine the preset output voltage range, and determine the load of the load meter. The current threshold and the way the load current changes. When the full-load output current value is less than 20A, the load current threshold setting is: High=Imax*90%, Low=Imax*10%; when the full-load output current value is not less than 20A, it needs to be tested twice in sections, the first load Current threshold setting: High=Imax*50%, Low=Imax*0%; Second load current threshold setting: High=Imax*100%, Low=Imax*50%.

8. Click "RUN" on the user interface to start running the program and run it according to the determined power supply mode and load meter settings. After the oscilloscope completes the operation according to the program, it will return the waveform and test data to the PC controller.

9. The program analyzes and processes the data and compares the output voltage value of the tested switching power supply with the preset output voltage range to determine whether the dynamic response of the tested switching power supply meets the requirements.

10. Import the test results and waveforms into the test report, and display the test result pass or fail. Turn off the DC power supply 21 and the load meter to complete the test.

It should be noted that in this specification, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements not only includes those elements , but also includes other elements not expressly listed or inherent in such process, method, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes the stated element.

The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be practiced in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. A dynamic response test device for a switching power supply, which is characterized in that it includes: A load module, the input end of the load module is connected to the output end of the switching power supply under test, and is used to change the load current based on the threshold value of the load current and the change mode of the load current; A power module, the output end of the power module is connected to the input end of the switching power supply under test, and is used to supply power to the switching power supply under test; An acquisition module, the input end of the acquisition module is connected to the output end of the switching power supply under test, and is used to test the output voltage value of the switching power supply under test when the load current of the load module changes; A control module, the control module is connected to the control end of the load module and the acquisition module respectively, and is used to determine the threshold value of the load current of the load module and the change mode of the load current based on user instructions, and determine the Whether the output voltage value of the tested switching power supply is within the preset output voltage range, and if so, determine that the dynamic response of the tested switching power supply meets the requirements; The user instruction includes a full load output current value; determining the load current threshold based on the user instruction includes: When the full load output current value is less than the standard current threshold, the large current threshold of the load current is determined to be 90% of the full load output current value, and the small current threshold is 10% of the full load output current value; When the full load output current value is not less than the standard current threshold, the first large current threshold of the load current is determined to be 50% of the full load output current value, and the first small current threshold is the full load output current value. 0%; the second large current threshold is 100% of the full load output current value, and the second small current threshold is 50% of the full load output current value. 2. The dynamic response testing device of a switching power supply as claimed in claim 1, wherein the power module is a DC power supply, and the output end of the DC power supply is connected to the input end of the switching power supply under test. Provide power to the switching power supply under test. 3. The dynamic response testing device of the switching power supply according to claim 2, wherein the switching power supply under test is arranged on the motherboard; The power module also includes: PSU, the PSU is used to supply power to the switching power supply under test through the mainboard. 4. The dynamic response testing device of the switching power supply according to claim 3, further comprising a controllable switch, the first end of the controllable switch being connected to the mains, and the second end of the controllable switch being connected to the mains. It is connected to the input end of the PSU, and the control end of the controllable switch is connected to the DC power supply; The control module is also used to control the DC power supply to supply power to the switching power supply under test, or to send a closing instruction of the controllable switch to the DC power supply; The DC power supply is also used to control the controllable switch to close after receiving a closing instruction of the controllable switch, so that the PSU supplies power to the tested switching power supply through the mainboard. 5. The dynamic response testing device of a switching power supply according to claim 4, wherein the controllable switch is a relay. 6. The dynamic response testing device of a switching power supply according to claim 4, wherein the user instruction includes the input voltage value of the switching power supply under test; Controlling the DC power supply to supply power to the switching power supply under test includes: The DC power supply is controlled to output the input voltage value to supply power to the switching power supply under test. 7. The dynamic response testing device of the switching power supply according to claim 1, wherein the acquisition module is also used to test the load current value of the load module and display the output voltage value of the tested switching power supply. The waveform changes with the load current value of the load module. 8. The dynamic response testing device of the switching power supply according to claim 1, further comprising a display module; The control module is also used to control the display module to display the determination result of whether the dynamic response of the tested switching power supply meets the requirements. 9. The dynamic response testing device of a switching power supply as claimed in claim 1, wherein the user instruction further includes the designed output voltage value of the switching power supply under test; The preset output voltage range is from the designed output voltage value of the tested switching power supply * 0.97 to the designed output voltage value of the tested switching power supply * 1.03.