Test protection circuit based on power supply output voltage, motor driving system and test system

Abstract

The invention provides a test protection circuit based on a power supply output voltage, a motor driving system and a test system, the test protection circuit comprises a control module and a protection module, the control module is connected with the protection module, the input end of the control module is connected with a power supply and a voltage-stabilized power supply, and the output end of the protection module is connected with a tested device. Wherein the control module outputs a control signal according to the output voltage of the power supply in both the first power-on mode and the second power-on mode; wherein in the first power-on mode and the second power-on mode, the power-on sequences of the power supply and the voltage-stabilized power supply are different; the control signal is used for indicating the protection module to turn off the output of the power supply or indicating the protection module, the power supply and the tested equipment to form an electrified loop. The invention solves the problems that the test protection circuit has strict requirements on the power sequence of the power supply and the stabilized voltage, and is lack of corresponding anti-false-triggering design.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic circuits, and in particular to a test protection circuit based on a power supply output voltage, a motor drive system, and a test system. Background Art

[0002] Power supplies are commonly used in the testing and screening of motor drive products, providing power and voltage to the device under test. To mitigate safety hazards during testing, a protection circuit and control circuit are typically added between the power supply and the device under test to protect against short-circuit and overload conditions.

[0003] In the control circuits described above, comparators are very commonly used electronic components, especially in situations where fast response and high-precision voltage / current monitoring are required. Therefore, ensuring the proper functioning of the comparators is a prerequisite for achieving effective circuit protection. Whether the comparators in the control circuits function properly is closely related to the power-up sequence. If the power-up sequence is incorrect, the following problems may occur:

[0004] 1. The comparator is not initialized. Specifically, if the regulated power supply is not providing power, the comparator will not function. The power supply output may exceed the safe range, but the protection circuitry may not detect or respond, causing damage to the device under test (DUT). For example, the inrush current during power supply startup may not be detected by the comparator, causing the overcurrent protection to fail to trigger.

[0005] 2. The reference voltage is not stable. Specifically, the comparator's reference voltage (e.g., provided by a voltage divider or reference source from a regulated power supply) requires time to stabilize. If the power supply is turned on before the reference voltage stabilizes, it can cause a misjudgment. For example, if the reference voltage falls below the designed value due to power supply delays, the comparator can trigger protection prematurely.

[0006] 3. Ground potential offset: Specifically, if the power supply ground wire and the protection circuit ground wire are not isolated, the ground noise when the power supply is started may interfere with the input signal of the comparator, causing malfunction. Summary of the Invention

[0007] In response to the deficiencies in the prior art, the present invention provides a test protection circuit, a motor drive system and a test system based on the output voltage of a power supply, which solves the problem that the test protection circuit in the prior art has strict requirements on the power-on sequence of the power supply and the regulated voltage, and lacks a corresponding anti-false triggering design.

[0008] According to an embodiment of the present invention, a first aspect provides a test protection circuit based on the output voltage of a power supply, comprising a control module and a protection module, wherein the control module is connected to the protection module, the input end of the control module is connected to the power supply and the voltage regulator, and the output end of the protection module is connected to the device under test, wherein:

[0009] The control module outputs a control signal according to the output voltage of the power supply in both the first power-on mode and the second power-on mode; wherein the power-on sequence of the power supply and the regulated power supply is different in the first power-on mode and the second power-on mode; the control signal is used to instruct the protection module to shut down the output of the power supply or to instruct the protection module, the power supply and the device under test to form a power-on loop.

[0010] Optionally, after the control signal instructs the protection module to shut down the output of the power supply, the control module is put back into the first power-on mode or the second power-on mode and outputs a new control signal.

[0011] Optionally, the control module includes a voltage comparator, a first resistor to a seventh resistor, a first diode, a second diode, a third diode and a first thyristor;

[0012] One end of the first resistor is connected to a power supply, and the other end is connected to one end of the second resistor and the gate of the first thyristor, and the other end of the second resistor and the cathode of the first thyristor are grounded;

[0013] One end of the third resistor is connected to a power supply, one end of the fourth resistor is connected to a voltage-stabilized power supply, the other end of the third resistor is connected to the input end of the first diode, the other end of the fourth resistor is connected to the input end of the second diode, the output end of the first diode, the output end of the second diode, and the output end of the third diode are connected to the inverting input end of the voltage comparator, the output end of the second diode is also connected to one end of the fifth resistor, the input end of the second diode is also connected to the anode of the first thyristor, and the other end of the fifth resistor and the input end of the third diode are grounded;

[0014] One end of the sixth resistor and one end of the seventh resistor are connected to the non-inverting input terminal of the voltage comparator, the other end of the sixth resistor is grounded, and the other end of the seventh resistor is connected to a regulated power supply;

[0015] The power supply input terminal of the voltage comparator is connected to the regulated power supply, the power supply ground terminal of the voltage comparator is grounded, and the output terminal of the voltage comparator is connected to the protection module as the output terminal of the control module.

[0016] Optionally, the voltage signal of one end of the seventh resistor connected to the non-inverting input end of the voltage comparator is a non-inverting control end voltage signal;

[0017] The positive phase control terminal voltage signal is a preset reference threshold voltage signal.

[0018] Optionally, the control module further includes a first capacitor;

[0019] The first capacitor is connected in parallel across the third diode.

[0020] Optionally, the protection module includes a light emitting diode for indicating the working status of the protection control circuit.

[0021] Optionally, the protection module includes an eighth resistor to an eleventh resistor, a second thyristor, a light emitting diode, a field effect transistor and a relay;

[0022] One end of the eighth resistor and one end of the ninth resistor are connected to the control module, the other end of the eighth resistor and one end of the tenth resistor are connected to a voltage-regulated power supply, the other end of the ninth resistor is grounded, the other end of the tenth resistor is connected to the anode of the second thyristor, the cathode of the second thyristor is grounded, and the gate of the second thyristor is connected to one end of the eighth resistor, one end of the ninth resistor, and the control module;

[0023] The other end of the tenth resistor and the anode of the second thyristor are further connected to one end of the eleventh resistor and the gate of the field effect transistor, the drain of the field effect transistor is connected to the output end of the light emitting diode, and the other end of the eleventh resistor and the source of the field effect transistor are grounded;

[0024] The relay includes a first coil control end, a second coil control end, a first power interface and a second power interface. The input end of the light-emitting diode is connected to the first coil control end of the relay, and the second coil control end of the relay is connected to a voltage-stabilized power supply; the first power interface of the relay is connected to the power supply, and the second power interface of the relay is the output end of the protection module connected to the device under test.

[0025] Optionally, the protection module further includes a second capacitor;

[0026] One end of the second capacitor is connected to the gate of the second thyristor, and the other end of the second capacitor is grounded.

[0027] A second aspect of the present invention provides a motor drive system, comprising a power supply, a voltage-stabilized power supply, and the above-mentioned test protection circuit based on the output voltage of the power supply.

[0028] A third aspect of the present invention provides a test system, comprising a real-time data acquisition and monitoring unit and the motor drive system as described above; a device under test is connected to the motor drive system and the real-time data acquisition and monitoring unit.

[0029] Compared with the prior art, the beneficial effects of the present invention are: providing a control module that outputs a control signal according to the output voltage of the power supply, regardless of whether it is in the first power-on mode or the second power-on mode, that is, regardless of the power-on sequence of the medium power supply and the regulated power supply, the control module can normally instruct the protection module to shut down the output of the power supply to achieve circuit protection, or instruct the protection module, the power supply and the device under test to form a power-on loop for normal testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of a test protection circuit based on the output voltage of a power supply according to an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of the circuit structure of a test protection circuit based on the output voltage of a power supply according to an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the circuit structure of a test protection circuit based on the output voltage of a power supply according to an embodiment of the present invention;

[0033] Figure 4 Schematic diagram of the circuit structure of a test protection circuit based on the output voltage of a power supply according to an embodiment of the present invention;

[0034] Figure 5 Schematic diagram of the circuit structure of a test protection circuit based on the output voltage of a power supply according to an embodiment of the present invention;

[0035] Figure 6 The figure is a schematic diagram of the circuit structure of a test protection circuit based on the output voltage of a power supply according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0037] like Figure 1 As shown, an embodiment of the present invention provides a test protection circuit based on power supply output voltage, comprising a control module 10 and a protection module 20. The control module 10 is connected to the protection module 20, with the input of the control module 10 connected to the power supply VP and the voltage-regulated power supply VCC, and the output of the protection module 20 connected to the device under test. Furthermore, in both the first power-on mode and the second power-on mode, the control module 10 outputs a control signal based on the output voltage of the power supply VP.

[0038] It should be noted that the power-on order of the power supply VP and the regulated power supply VCC is different in the first power-on mode and the second power-on mode. For example, in the first power-on mode, the power supply VP is powered on first and the regulated power supply VCC is powered on later; in the second power-on mode, the regulated power supply VCC is powered on first and the power supply VP is powered on later.

[0039] The detailed operating process of this embodiment of the present invention is as follows: After power supply VP and regulated power supply VCC are powered on, the control circuit outputs a control signal to instruct protection module 20 to shut down the output of power supply VP in the event of a short circuit, overload, or other fault condition in the device under test. Under normal operating conditions, the control circuit outputs a control signal to instruct protection module 20, power supply VP, and the device under test to form a power-on circuit, allowing testing to proceed normally. Because control module 10 outputs control signals based solely on the output voltage of power supply VP, it is unaffected by the power-up sequence of power supply VP and regulated power supply VCC, achieving a simple and effective design for preventing false triggering.

[0040] It should be noted that the control signal output by the voltage comparator N1 is a high-level signal or a low-level signal, and in the embodiment of the present invention, the control signal is used to instruct the protection module 20 to turn off the output of the power supply VP or to instruct the protection module 20, the power supply VP and the device under test to form a power-on loop. By way of example, it means that the protection circuit turns off the output of the power supply VP according to the high-level signal, and forms a power-on loop among the protection module 20, the power supply VP and the device under test according to the low-level signal.

[0041] In another embodiment of the present invention, a single-shot protection mechanism is employed to ensure that normal control can only be restored after the fault is resolved and power is restored. Therefore, after the control signal instructs the protection module 20 to shut down the output of the power supply VP, the control module 10 returns to the first power-on mode or the second power-on mode and outputs a new control signal.

[0042] In another embodiment of the present invention, the specific circuit structure of the control module 10 in the test protection circuit based on the power supply output voltage shown in the above embodiment is described. Figure 2As shown, the control module 10 includes a voltage comparator N1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first diode D1, a second diode D2, a third diode D3, a first thyristor T1, and a sixth resistor R6 and a seventh resistor R7 located on the side of the non-inverting input terminal IN+. The first diode D1 and the second diode D2 are switching diodes, the third diode D3 is a voltage regulator diode, and the control signal output by the voltage comparator N1 includes a high-level signal and a low-level signal. The connection relationship of the above-mentioned structures is as follows: one end of the first resistor R1 is connected to the power supply VP, and the other end is connected to one end of the second resistor R2 and the gate of the first thyristor T1. The other end of the second resistor R2 and the cathode of the first thyristor T1 are grounded; one end of the third resistor R3 is connected to the power supply VP, one end of the fourth resistor R4 is connected to the voltage regulator VCC, the other end of the third resistor R3 is connected to the input end of the first diode D1, and the other end of the fourth resistor R4 is connected to the input end of the second diode D2. The output ends of the first diode D1, the second diode D2, and the third diode D3 are connected to the inverting input terminal IN- of the voltage comparator N1. The output end of the second diode D2 is also connected to one end of the fifth resistor R5, the input end of the second diode D2 is also connected to the anode of the first thyristor T1, and the other end of the fifth resistor R5 and the input end of the third diode D3 are grounded; one end of the sixth resistor R6 and one end of the seventh resistor R7 are connected to the non-inverting input terminal IN+ of the voltage comparator N1, the other end of the sixth resistor R6 is grounded, and the other end of the seventh resistor R7 is connected to the regulated power supply VCC; the power supply input terminal V+ of the voltage comparator N1 is connected to the regulated power supply VCC, the power supply ground terminal V- of the voltage comparator N1 is grounded, and the output end of the voltage comparator N1 is connected to the protection module 20 as the output end of the control module 10.

[0043] In specific applications, the voltage V t Determines whether to trigger the protection mechanism. The voltage V0 of the positive input terminal IN+ is used to compare with the voltage V of the negative input terminal IN- t For comparison. Figure 2 In the detailed circuit structure of the control module 10 shown in FIG, the voltage signal at one end of the seventh resistor R7 connected to the non-inverting input terminal IN+ of the voltage comparator N1 is a preset reference threshold voltage signal.

[0044] like Figure 3 As shown, in one embodiment, the control module 10 further includes a first capacitor C1; the first capacitor C1 is connected in parallel across the third diode D3. In a specific application, the first capacitor C1 can prevent the voltage of the inverting input terminal IN- from suddenly changing and causing the protection mechanism to be falsely triggered.

[0045] based on Figure 2 and Figure 3 , in the embodiment of the present invention, the anti-mis-trigger design of the control module 10 for the power-on sequence of the power supply VP and the regulated power supply VCC has the following principle:

[0046] First, under normal working conditions, it is necessary to always ensure that the voltage V at the inverting terminal of the voltage comparator N1 t > the voltage V0 at the non-inverting terminal.

[0047] Second, assume that in the first power-on mode, the regulated power supply VCC is powered on first and the power supply VP is powered on later. At this time, the voltage at the inverting input terminal IN- of the voltage comparator N1 is V t , (ignoring the on-voltage drop of the second diode D2), the voltage at the non-inverting input terminal IN+ of the voltage comparator N1 is V0, and it is set that It can be seen that V t > V0 is satisfied. After the power supply VP is powered on, the voltage at the gate of the control terminal of the first thyristor T1 changes from low level to high level, and the first thyristor T1 conducts (self-locking conduction). At this time, the regulated power supply VCC forms a loop through the fourth resistor R4 and the first thyristor T1, and the regulated power supply VCC no longer passes through the second diode D2 and the fifth resistor R5, so that the regulated power supply VCC loses the control effect on the inverting input terminal IN- of the voltage comparator N1. Therefore, the voltage at the inverting input terminal IN- of the voltage comparator N1 is self-locked and changed to (ignoring the on-voltage drop of the first diode D1), it can be seen that V t > V0 can still be satisfied. And V t is always determined by the power supply VP. Thus, if V t < V0, it will indicate that it is in an abnormal working condition, and the control signal output by the voltage comparator N1 will cause the protection circuit to turn off the output of the power supply VP according to the high-level signal, playing a protection and control role.

[0048] Then, assume that in the second power-on mode, the power supply VP is powered on first and the regulated power supply VCC is powered on later. The first thyristor T1 conducts (self-locking conduction), and the voltage at the inverting input terminal IN- of the voltage comparator N1 is always The voltage at the non-inverting input terminal IN+ of the voltage comparator N1 is (when VCC is not powered on, VCC = 0V), and V t > V0 is satisfied. After the regulated power supply VCC is powered on, the voltage at the non-inverting input terminal IN+ of the voltage comparator N1 changes from 0V to It also satisfies V t > V0. And, even if the regulated power supply VCC is powered on later, V t is still determined by the power supply VP. Thus, if V t<V0 indicates that in the abnormal working condition, the control signal output by the voltage comparator N1 will cause the protection circuit to cut off the output of the power supply VP according to the high-level signal, playing a protection and control role.

[0049] It should be noted that when V t > V0, the control signal output by the voltage comparator N1 is a low-level signal; otherwise, the control signal output by the voltage comparator N1 is a high-level signal. In the embodiment of the present invention, the control signal is used to instruct the protection module 20 to cut off the output of the power supply VP or to instruct the protection module 20, the power supply VP, and the DUT to form a powered loop. It means that the protection circuit cuts off the output of the power supply VP according to the high-level signal and forms a powered loop for the protection module 20, the power supply VP, and the DUT according to the low-level signal.

[0050] In another embodiment of the present invention, the specific circuit structure implementation of the protection module 20 in the test protection circuit based on the output voltage of the power supply shown in the above embodiment is described. As Figure 4 shown, the protection module 20 includes a light-emitting diode L1 for indicating the working state of the protection control circuit. Exemplarily, when the light-emitting diode L1 is on, it indicates that the DUT is working normally; when the light-emitting diode L1 is off, it indicates that the DUT has a fault condition and triggers the protection mechanism. In the detailed circuit structure of the protection module 20, the protection module 20 includes the eighth resistor R8 to the eleventh resistor R11, the second thyristor T2, the light-emitting diode L1, the field-effect transistor Q1, and the relay J; the connection relationships of the above structures are as follows: one end of the eighth resistor R8 and one end of the ninth resistor R9 are connected to the control module 10, the other end of the eighth resistor R8 and one end of the tenth resistor R10 are connected to the regulated power supply VCC, the other end of the ninth resistor R9 is grounded, the other end of the tenth resistor R10 is connected to the anode of the second thyristor T2, the cathode of the second thyristor T2 is grounded, and the gate of the second thyristor T2 is connected to one end of the eighth resistor R8, one end of the ninth resistor R9, and the control module 10; the other end of the tenth resistor R10 and the anode of the second thyristor T2 are also connected to one end of the eleventh resistor R11 and the gate of the field-effect transistor Q1, the drain of the field-effect transistor Q1 is connected to the output end of the light-emitting diode L1, and the other end of the eleventh resistor R11 and the source of the field-effect transistor Q1 are grounded; the relay J includes a first coil control terminal J1, a second coil control terminal J2, a first power interface J3, and a second power interface J4. The input end of the light-emitting diode L1 is connected to the first coil control terminal J1 of the relay J, and the second coil control terminal J2 of the relay J is connected to the regulated power supply VCC; the first power interface J3 of the relay J is connected to the power supply VP, and the second power interface J4 of the relay J is the output end of the protection module 20 and is connected to the DUT.

[0051] As Figure 5As shown, in one embodiment, the protection module 20 further includes a second capacitor C2; one end of the second capacitor C2 is connected to the gate of the second thyristor T2, and the other end of the second capacitor C2 is grounded. In a specific application, the second capacitor C2 is used to prevent ringing at the output of the voltage comparator N1, which could lead to false triggering of the protection mechanism.

[0052] It is understandable that based on Figure 3 The detailed circuit structure of the control module 10 is shown, and Figure 5 The specific circuit structure of the protection module 20 shown in FIG. Figure 6 The test protection circuit based on the power supply output voltage is shown. In this regard, the embodiment of the present invention also provides Figure 6 Optimal implementation parameters for each structure. For example, the first capacitor C1 and the second capacitor C2 can be 1μF / 50V ceramic capacitors. The first resistor R1 and the third resistor R3 can be 39kΩ resistors. The second resistor R2, the fourth resistor R4, the fifth resistor R5, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the eleventh resistor R11 can be 10kΩ resistors. The sixth resistor R6 can be 2kΩ. The first diode D1 and the second diode D2 can be BAS21H diodes. The third diode D3 can be MM3Z12V diode. The first thyristor T1 and the second thyristor T2 can be MCR100-6 thyristors. The light-emitting diode L1 can be a high-power light-emitting diode with an IF=2A parameter. The voltage comparator N1 can be an FX193 voltage comparator. The field-effect transistor Q1 can be an IPD068N10N3G field-effect transistor. Relay J can adopt G9EC-1 type relay.

[0053] In addition, the embodiments of the present invention are based on Figure 6 The test protection circuit based on the power supply output voltage shown in the figure explains its working principle: First, VP out Then, under normal working conditions, it is necessary to always ensure that the voltage V t > the voltage V0 of the positive input terminal IN+, then the voltage V1 of the output terminal of the voltage comparator N1 is 0V, the second thyristor T2 is not conducting, and the gate voltage of the field effect tube Q1 is The field effect tube Q1 is normally turned on, the first coil control terminal J1 and the second coil control terminal J2 of the relay J form a power circuit, the relay J is in a closed state, the first power interface J3 and the second power interface J4 are turned on, and the power supply VP supplies power to the device under test normally (VP out=VP). When the device under test experiences a short circuit or overload fault, the output voltage amplitude of the power supply VP is often sharply pulled down due to insufficient power output capacity, causing V t <V0, at this time V1 changes from low level to high level The second thyristor T2 is turned on (once the thyristor is turned on, it will be in a self-locking continuous conduction state, and the control end loses its control function), the gate voltage of the field effect tube Q1 changes from a high level to a self-locking low level state, and the field effect tube Q1 changes from an on state to a self-locking off state. The first coil control terminal J1 and the second coil control terminal J2 of the relay J are in a self-locking off state, and the first power interface J3 and the second power interface J4 of the relay J are self-locking and shut off. Therefore, the power supply VP always stops supplying power to the device under test (VP out =0V), normal control can be restored only when the fault is removed and the voltage regulator power supply VCC and the power supply VP are powered on again, thus playing the role of load short circuit overload protection.

[0054] Therefore, on the one hand, the present invention adopts a single-trigger protection mechanism to ensure that normal control can be restored only after the fault is eliminated and power is re-applied. On the other hand, the test protection circuit based on the power supply output voltage provided by the present invention must have a good anti-false triggering design, that is, under normal working conditions, regardless of the power-on sequence of the power supply VP and the regulated power supply VCC, it is always ensured that the voltage of the inverting input terminal IN- of the voltage comparator N1 is greater than the voltage of the non-inverting input terminal IN+.

[0055] In yet another embodiment of the present invention, a motor drive system is provided, including a power supply VP, a voltage-stabilized power supply VCC, and the above-mentioned test protection circuit based on the output voltage of the power supply.

[0056] In yet another embodiment of the present invention, a test system is provided, comprising a real-time data acquisition and monitoring unit and the above-mentioned motor drive system; a device under test is connected to the motor drive system and the real-time data acquisition and monitoring unit.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A test protection circuit based on the output voltage of a power supply, comprising a control module and a protection module, wherein the control module is connected to the protection module, the input end of the control module is connected to the power supply and the voltage-regulated power supply, and the output end of the protection module is connected to the device under test, characterized in that: The control module outputs a control signal according to the output voltage of the power supply in both the first power-on mode and the second power-on mode; wherein the power-on sequence of the power supply and the regulated power supply is different in the first power-on mode and the second power-on mode; the control signal is used to instruct the protection module to shut down the output of the power supply or to instruct the protection module, the power supply and the device under test to form a power-on loop.

2. The test protection circuit based on the power supply output voltage according to claim 1, characterized in that: After the control signal instructs the protection module to shut down the output of the power supply, the control module is put back into the first power-on mode or the second power-on mode and outputs a new control signal.

3. The test protection circuit based on the power supply output voltage according to claim 1 or 2, characterized in that: The control module includes a voltage comparator, a first resistor to a seventh resistor, a first diode, a second diode, a third diode and a first thyristor; One end of the first resistor is connected to a power supply, and the other end is connected to one end of the second resistor and the gate of the first thyristor, and the other end of the second resistor and the cathode of the first thyristor are grounded; One end of the third resistor is connected to a power supply, one end of the fourth resistor is connected to a voltage-stabilized power supply, the other end of the third resistor is connected to the input end of the first diode, the other end of the fourth resistor is connected to the input end of the second diode, the output end of the first diode, the output end of the second diode, and the output end of the third diode are connected to the inverting input end of the voltage comparator, the output end of the second diode is also connected to one end of the fifth resistor, the input end of the second diode is also connected to the anode of the first thyristor, and the other end of the fifth resistor and the input end of the third diode are grounded; One end of the sixth resistor and one end of the seventh resistor are connected to the non-inverting input terminal of the voltage comparator, the other end of the sixth resistor is grounded, and the other end of the seventh resistor is connected to a regulated power supply; The power supply input terminal of the voltage comparator is connected to the regulated power supply, the power supply ground terminal of the voltage comparator is grounded, and the output terminal of the voltage comparator is connected to the protection module as the output terminal of the control module.

4. The test protection circuit based on the power supply output voltage according to claim 3, characterized in that: The voltage signal at one end of the seventh resistor connected to the non-inverting input end of the voltage comparator is a preset reference threshold voltage signal.

5. The test protection circuit based on the power supply output voltage according to claim 4, characterized in that: The control module further includes a first capacitor; The first capacitor is connected in parallel across the third diode.

6. The test protection circuit based on power supply output voltage according to claim 1 or 2, characterized in that: The protection module includes a light emitting diode for indicating the working state of the protection control circuit.

7. The test protection circuit based on the power supply output voltage according to claim 6, characterized in that: The protection module includes an eighth resistor to an eleventh resistor, a second thyristor, a light emitting diode, a field effect transistor and a relay; One end of the eighth resistor and one end of the ninth resistor are connected to the control module, the other end of the eighth resistor and one end of the tenth resistor are connected to a voltage-regulated power supply, the other end of the ninth resistor is grounded, the other end of the tenth resistor is connected to the anode of the second thyristor, the cathode of the second thyristor is grounded, and the gate of the second thyristor is connected to one end of the eighth resistor, one end of the ninth resistor, and the control module; The other end of the tenth resistor and the anode of the second thyristor are further connected to one end of the eleventh resistor and the gate of the field effect transistor, the drain of the field effect transistor is connected to the output end of the light emitting diode, and the other end of the eleventh resistor and the source of the field effect transistor are grounded; The relay includes a first coil control end, a second coil control end, a first power interface and a second power interface. The input end of the light-emitting diode is connected to the first coil control end of the relay, and the second coil control end of the relay is connected to a voltage-stabilized power supply; the first power interface of the relay is connected to the power supply, and the second power interface of the relay is the output end of the protection module connected to the device under test.

8. The test protection circuit based on the power supply output voltage according to claim 7, characterized in that: The protection module further includes a second capacitor; One end of the second capacitor is connected to the gate of the second thyristor, and the other end of the second capacitor is grounded.

9. A motor drive system, characterized in that: The device comprises a power supply, a voltage-stabilized power supply, and a test protection circuit based on the output voltage of the power supply as claimed in any one of claims 1 to 8.

10. A testing system, characterized in that: It comprises a real-time data acquisition and monitoring unit and the motor drive system according to claim 9; the device under test is connected to the motor drive system and the real-time data acquisition and monitoring unit.

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