Motor overcurrent dual protection circuit and protection device

Abstract

The utility model relates to a motor over-current dual protection circuit and a protection device, which solve the problems in the prior art that software code execution of a single-chip microcomputer is not reliable enough, and over-current protection is easy to fail due to only one over-current protection, and adopts the technical scheme that the motor over-current dual protection circuit comprises a first over-current protection circuit and a second over-current protection circuit, the first overcurrent protection circuit is provided with a comparison circuit, a controller and an IPM module in communication connection with the controller, and the IPM module is in control connection with the motor; the second overcurrent protection circuit comprises a control circuit and a driving turn-off circuit; the control circuit is connected with the comparison circuit; and the driving turn-off circuit is connected with the control circuit. The motor over-current protection circuit has the advantages that the second over-current protection circuit (a hardware circuit) is additionally arranged on the basis that the first over-current protection circuit (a single chip microcomputer monitors motor current) carries out over-current protection, over-current dual protection is achieved, and once control of the first over-current protection circuit fails, the second over-current protection circuit can carry out timely and effective protection.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, in particular to a motor overcurrent double protection circuit and a protection device. Background Art

[0002] Permanent magnet variable frequency water pumps are widely used in industrial and civil fields. Permanent magnet variable frequency water pumps are composed of variable frequency controllers and permanent magnet DC synchronous motors. During operation, their operating currents must be closely monitored to prevent motor demagnetization caused by excessive currents. Therefore, when the permanent magnet DC synchronous motor works abnormally due to short circuits, it is necessary to be able to provide timely overcurrent protection for the variable frequency controller and the permanent magnet DC synchronous motor. The existing overcurrent protection circuit is: the three-phase current of the motor is sampled through a sampling resistor, and then the sampled electrical signal is amplified, and then the signal is compared through a comparator, and a high and low level signal is output to the single-chip microcomputer, which is program-identified by the single-chip microcomputer and forms a shutdown drive enable signal, which controls the variable frequency controller and the permanent magnet DC synchronous motor to stop in time. However, this overcurrent protection scheme still has some shortcomings: 1. The overcurrent protection of the permanent magnet DC synchronous motor is realized by the microcontroller generating a shutdown drive enable signal. The process of the microcontroller generating a shutdown drive enable signal is a software code execution process, and the software code is unreliable; 2. There is only one level of overcurrent protection, and once it fails, it cannot effectively protect the frequency converter and the permanent magnet DC synchronous motor (referred to as the motor in this article). Summary of the invention

[0003] The purpose of the utility model is to solve the above-mentioned problems existing in the prior art and to provide a motor overcurrent dual protection circuit and protection device. On the basis of the first overcurrent protection circuit performing overcurrent protection on the frequency conversion controller and the permanent magnet DC synchronous motor, a second overcurrent protection circuit is additionally provided. On the basis of the second overcurrent protection circuit receiving the shutdown drive enable signal to perform overcurrent protection on the frequency conversion controller and the permanent magnet DC synchronous motor, the first overcurrent protection circuit mainly performs overcurrent protection by analyzing the shutdown drive enable signal by software code on a controller (such as a single-chip microcomputer). The second overcurrent protection circuit is a hardware circuit, and the components thereon perform overcurrent protection according to the shutdown drive enable signal, thereby achieving dual overcurrent protection for the frequency conversion controller and the permanent magnet DC synchronous motor.

[0004] The above technical objectives of the utility model are mainly solved by the following technical solutions: The technical solution of the first technical subject is: a motor overcurrent double protection circuit, characterized in that:

[0005] including a first overcurrent protection circuit and a second overcurrent protection circuit;

[0006] A first overcurrent protection circuit is provided with a comparison circuit, a controller, and an IPM module (i.e., an intelligent power module) communicatively connected to the controller, wherein the IPM module is connected to the motor control and is used to shut down the permanent magnet DC motor due to overcurrent;

[0007] The comparison circuit is used to sample, amplify and compare the motor current signal and generate a shutdown drive enable signal for shutting down the motor;

[0008] The controller receives a shutdown drive enable signal and implements motor overcurrent protection through the IPM module. When the shutdown drive enable signal received by the controller is a low level signal, the motor is shut down through the IPM module;

[0009] The second overcurrent protection circuit includes a control circuit and a drive shutdown circuit;

[0010] The control circuit is connected to the comparison circuit and receives a shutdown drive enable signal;

[0011] The drive shutdown circuit is connected to the control circuit, receives a shutdown drive enable signal, and implements motor overcurrent protection through the IPM module. When the shutdown drive enable signal received by the drive shutdown circuit is a low-level signal, the motor is shut down through the IPM module.

[0012] In the present technical solution, regardless of whether the software code in the controller (such as a single-chip microcomputer) in the first overcurrent protection circuit accurately analyzes the shutdown drive enable signal, the second overcurrent protection circuit (i.e., the hardware circuit) can receive the shutdown drive enable signal generated by the comparison circuit, and can accurately determine whether the shutdown drive enable signal is a low level or a high level. When the shutdown drive enable signal is a low level, the control circuit causes the drive shutdown circuit to shut down the motor through the IPM module, thereby achieving the purpose of double overcurrent protection, which is further beneficial to ensure that the frequency conversion controller and the permanent magnet DC synchronous motor operate normally within the appropriate current range.

[0013] The purpose of this technical solution is that when the first overcurrent protection circuit works normally, the first overcurrent circuit and the second overcurrent circuit do not interfere with each other and are used to protect the motor from overcurrent. When the first overcurrent protection circuit fails, the second overcurrent protection circuit is a hardware circuit with high working stability and reliability. The second overcurrent protection circuit can still protect the motor from overcurrent, thereby achieving the purpose of dual overcurrent protection for the motor and avoiding overcurrent of the motor.

[0014] As a further improvement and supplement to the above technical solution, the utility model adopts the following technical measures: the second overcurrent protection circuit also includes a reset circuit, which is connected to the control circuit and is used to operate the motor through the control circuit and the drive shutdown circuit. When the overcurrent fault is eliminated, the reset circuit enables the control circuit to obtain a high-level signal, cuts off the pre-circuit in the control circuit, makes the base of the control transistor high-level, turns on the control transistor, and makes the base of the start-stop transistor low-level and turns on again, thereby restarting the motor and allowing the motor to operate normally.

[0015] Preferably, three parallel start-stop transistor circuits are arranged on the drive shutdown circuit, each of which includes a start-stop transistor, a diode connected in series with the base of the start-stop transistor, and the collector and emitter of the start-stop transistor are connected to the controller and the IPM module respectively. The diode is arranged to make the start-stop transistor unidirectionally conductive to the control circuit.

[0016] In the present technical solution, there are two technical solutions in which the collector and emitter of the start-stop transistor are connected to the controller and the IPM module respectively.

[0017] The first technical solution: when the start-stop transistor is a PNP transistor and the control transistor is an NPN transistor, the emitter of the start-stop transistor is connected to the corresponding signal port on the controller (such as the emitter of the start-stop transistor Q9 is connected to the UH signal terminal, the emitter of the start-stop transistor Q10 is connected to the VH signal terminal, and the emitter of the start-stop transistor Q11 is connected to the WH signal terminal), the collector of the start-stop transistor is connected to the corresponding signal port on the IPM module (such as the collector of the start-stop transistor Q9 is connected to the UH_O signal terminal, the collector of the start-stop transistor Q10 is connected to the VH_O signal terminal, and the collector of the start-stop transistor Q11 is connected to the WH_O signal terminal), and the base of the start-stop transistor is connected to the control circuit through corresponding diodes.

[0018] The second technical solution: when the start-stop transistor is an NPN transistor and the control transistor is a PNP transistor, the collector of the start-stop transistor is connected to the corresponding signal port on the controller (such as the collector of the start-stop transistor Q9 is connected to the UH signal terminal, the collector of the start-stop transistor Q10 is connected to the VH signal terminal, and the collector of the start-stop transistor Q11 is connected to the WH signal terminal), the emitter of the start-stop transistor is connected to the corresponding signal port on the IPM module (such as the emitter of the start-stop transistor Q9 is connected to the UH_O signal terminal, the emitter of the start-stop transistor Q10 is connected to the VH_O signal terminal, and the emitter of the start-stop transistor Q11 is connected to the WH_O signal terminal), and the base of the start-stop transistor is connected to the control circuit through corresponding diodes.

[0019] Preferably, the control circuit includes a pre-circuit, a control transistor connected to the pre-circuit, the pre-circuit is connected to the comparison circuit, the control transistor is connected to the start-stop transistor through the corresponding diode, and the diode makes the start-stop transistor conduct to the control transistor. The pre-circuit is used to turn on or off the control transistor, and the control transistor is used to control the conduction of the start-stop transistor. The shutdown drive enable signal (I_OC signal) is connected to the pre-circuit, and the diode is correspondingly set between the control transistor and each start-stop transistor, and the diode makes the start-stop transistor unidirectionally conduct to the control transistor.

[0020] Preferably, the start-stop transistor is a PNP transistor, and the control transistor is an NPN transistor; or, the start-stop transistor is an NPN transistor, and the control transistor is a PNP transistor.

[0021] Preferably, the reset circuit is connected to a preamplifier circuit on the control circuit.

[0022] Preferably, the reset circuit is also connected to the controller.

[0023] Preferably, the controller is a single-chip microcomputer, and the reset circuit is connected to a reset RESTART terminal of the single-chip microcomputer.

[0024] The technical solution of the second technical subject involved in the utility model: a motor overcurrent dual protection device, characterized in that the aforementioned motor overcurrent dual protection circuit is provided therein, and the motor overcurrent dual protection circuit includes a first overcurrent protection circuit and a second overcurrent protection circuit;

[0025] Preferably, the first overcurrent protection circuit is provided with a comparison circuit, a controller, and an IPM module communicatively connected to the controller;

[0026] The IPM module is connected to the motor control, and the comparison circuit is used to

[0027] Sampling, amplifying and comparing the motor current signal, and generating a shutdown drive enable signal for shutting down the motor;

[0028] The controller receives a shutdown drive enable signal and implements motor overcurrent protection through the IPM module;

[0029] The second overcurrent protection circuit includes a control circuit and a drive shutdown circuit;

[0030] The control circuit is connected to the comparison circuit and receives a shutdown drive enable signal;

[0031] The drive shutdown circuit is connected to the control circuit, receives a shutdown drive enable signal, and implements motor overcurrent protection through the IPM module.

[0032] The second overcurrent protection circuit also includes a reset circuit, which is connected to the control circuit and the IPM module. The controller is a single-chip microcomputer, and the reset circuit is connected to a reset RESTART terminal of the single-chip microcomputer.

[0033] The utility model has the following beneficial effects: 1. On the basis of the first overcurrent protection circuit for overcurrent protection of the frequency conversion controller and the permanent magnet DC synchronous motor, a second overcurrent protection circuit is added, and the second overcurrent protection circuit receives the shutdown drive enable signal to perform overcurrent protection on the frequency conversion controller and the permanent magnet DC synchronous motor. 2. The first overcurrent protection circuit mainly implements overcurrent protection by analyzing the shutdown drive enable signal by the software code on the controller (single-chip microcomputer), and the second overcurrent protection circuit is a hardware circuit, and the components on it implement overcurrent protection according to the shutdown drive enable signal, thereby realizing double overcurrent protection for the frequency conversion controller and the permanent magnet DC motor. 3. When the first overcurrent protection circuit works normally, the first overcurrent circuit and the second overcurrent circuit do not interfere with each other, and each is used to perform overcurrent protection on the motor. When the first overcurrent protection circuit fails, the second overcurrent protection circuit is a hardware circuit, and its working stability and reliability are high. The second overcurrent protection circuit can still perform overcurrent protection on the motor, thereby achieving the purpose of double overcurrent protection for the motor and avoiding overcurrent of the motor. 4. A reset circuit is set to conveniently and efficiently restore the normal working state of the motor. 5. The second overcurrent protection circuit is a hardware circuit with better stability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the utility model.

[0035] Figure 2 It is a structural schematic diagram of the second overcurrent protection circuit involved in the utility model.

[0036] Figure 3 This is another structural schematic diagram of the second overcurrent protection circuit involved in the utility model. DETAILED DESCRIPTION

[0037] The technical solution of the utility model is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0038] Example 1: Figure 1-Figure 2 As shown, the technical solution of the first technical subject of the utility model is: a motor overcurrent double protection circuit:

[0039] including a first overcurrent protection circuit and a second overcurrent protection circuit;

[0040] A first overcurrent protection circuit is provided with a comparison circuit, a controller, and an IPM module communicatively connected to the controller;

[0041] The IPM module is connected to the motor control, and the comparison circuit is used to

[0042] Sampling, amplifying and comparing the motor current signal, and generating a shutdown drive enable signal for shutting down the motor;

[0043] The controller receives a shutdown drive enable signal and implements motor overcurrent protection through the IPM module;

[0044] The second overcurrent protection circuit includes a control circuit and a drive shutdown circuit;

[0045] The control circuit is connected to the comparison circuit and receives a shutdown drive enable signal;

[0046] The drive shutdown circuit is connected to the control circuit, receives a shutdown drive enable signal, and implements motor overcurrent protection through the IPM module.

[0047] In practical applications, when the shutdown drive enable signal received by the drive shutdown circuit is a low level signal, the motor is shut down through the IPM module.

[0048] In the present technical solution, regardless of whether the software code in the controller (such as a single-chip microcomputer) in the first overcurrent protection circuit accurately analyzes the shutdown drive enable signal, the second overcurrent protection circuit (i.e., the hardware circuit) can receive the shutdown drive enable signal generated by the comparison circuit, and can accurately determine whether the shutdown drive enable signal is a low level or a high level. When the shutdown drive enable signal is a low level, the control circuit causes the drive shutdown circuit to shut down the motor through the IPM module, thereby achieving the purpose of double overcurrent protection, which is further beneficial to ensure that the frequency conversion controller and the permanent magnet DC synchronous motor operate normally within the appropriate current range.

[0049] The purpose of this technical solution is that when the first overcurrent protection circuit works normally, the first overcurrent circuit and the second overcurrent circuit do not interfere with each other and are used to protect the motor from overcurrent. When the first overcurrent protection circuit fails, the second overcurrent protection circuit is a hardware circuit with high working stability and reliability. The second overcurrent protection circuit can still protect the motor from overcurrent, thereby achieving the purpose of double overcurrent protection for the motor and avoiding overcurrent of the motor.

[0050] In practical applications, the comparison circuit includes an adopting circuit, an amplifying circuit and a triggering circuit. The adopting circuit is used to obtain a current sampling signal. The amplifying circuit is used to amplify the obtained current acquisition signal. The amplification factor is preferably 5-10 times. A comparator is provided on the triggering circuit. The current protection point is set by the comparator. When the current sampling signal exceeds the current protection point of the comparator after being amplified by the amplifying circuit, a shutdown drive enable signal (i.e., I_OC signal, such as a low-level signal) is generated. The controller on the first overcurrent protection circuit or the second overcurrent protection circuit stops the motor according to the shutdown drive enable signal, thereby achieving the purpose of double overcurrent protection.

[0051] Three parallel start-stop transistor circuits are arranged on the driving shutdown circuit, each of the start-stop transistor circuits includes a start-stop transistor (i.e., start-stop transistor Q9, start-stop transistor Q10, start-stop transistor Q11, referred to as start-stop transistors Q9-Q11), a diode connected in series with the base of the start-stop transistor, and the collector and emitter of the start-stop transistor are respectively connected to the controller and the IPM module.

[0052] like Figure 2 The start-stop transistor is a PNP transistor, the control transistor is an NPN transistor, the emitter of the start-stop transistor is connected to the corresponding signal port on the controller (such as the emitter of the start-stop transistor Q9 is connected to the UH signal terminal, the emitter of the start-stop transistor Q10 is connected to the VH signal terminal, and the emitter of the start-stop transistor Q11 is connected to the WH signal terminal), the collector of the start-stop transistor is connected to the corresponding signal port on the IPM module (such as the collector of the start-stop transistor Q9 is connected to the UH_O signal terminal, the collector of the start-stop transistor Q10 is connected to the VH_O signal terminal, and the collector of the start-stop transistor Q11 is connected to the WH_O signal terminal), and the base of the start-stop transistor is connected to the control circuit through corresponding diodes.

[0053] That is to say, the emitter of the start-stop transistor Q9 is connected to the UH signal terminal of the microcontroller, then the collector of the start-stop transistor Q9 is connected to the UH_O signal terminal on the IPM module, and the output UH_O signal terminal is connected to the frequency converter on the motor; under normal working conditions, the emitter of the start-stop transistor Q9 is at a high level and the base is at a low level, then the emitter and collector of the start-stop transistor Q9 are connected, the UH signal terminal is connected to the UH_O signal terminal, and the motor works normally; when the UH signal terminal and the UH_O signal terminal are not connected, similarly, for the start-stop transistors Q10 and Q11, the VH signal terminal and the VH_O signal terminal, and the WH signal terminal and the WH_O signal terminal are also not connected, and the motor stops.

[0054] The control circuit includes a pre-circuit, a control transistor (i.e., a start-stop transistor Q8) connected to the pre-circuit, the pre-circuit is connected to the comparison circuit, the control transistor is connected to the start-stop transistor through the corresponding diode, and the diode makes the start-stop transistor conduct to the control transistor.

[0055] The front circuit on the control circuit receives the shutdown drive enable signal. When the first overcurrent protection circuit does not work, the I_OC signal is low level. The base of the control transistor Q8 is low level through the front circuit, so that the control transistor Q8 is turned off, and the emitter and base of the start-stop transistor are both high level. At this time, the start-stop transistor is in the cut-off state, and the motor stops. Therefore, by driving the shutdown circuit and the control circuit, it can be ensured that the first overcurrent protection circuit and the second overcurrent protection circuit can both receive the I_OC signal. When the first overcurrent protection circuit works normally, the first overcurrent circuit and the second overcurrent circuit do not interfere with each other, and each is used to protect the motor from overcurrent. When the first overcurrent protection circuit fails, the second overcurrent protection circuit can still protect the motor from overcurrent, thereby achieving the purpose of double overcurrent protection for the motor and avoiding overcurrent of the motor.

[0056] In practical applications, the second overcurrent protection circuit further includes a reset circuit, and the reset circuit is connected to the control circuit and the IPM module.

[0057] When the I_OC signal is a low-level signal, the trigger control circuit controls the drive shutdown circuit to stop the motor, and the second overcurrent protection circuit can be restored through the reset circuit to restore the motor to normal operation; the reset circuit is connected to the RESTART terminal of the single-chip microcomputer; when the start-stop transistor is a PNP transistor, when the single-chip microcomputer outputs a high level of RESTART, the pre-circuit in the control circuit is cut off, so that the base of the control transistor Q8 is a high level, and the control transistor Q8 is turned on, so that the bases of the start-stop transistors Q9~Q11 are all low and turned on again. When the motor is restarted, the signals of the UH_O port, VH_O port, and WH_O port are all output normally, so that the motor can work normally.

[0058] In practical applications, the reset circuit is connected to the preamplifier circuit on the control circuit.

[0059] In practical applications, the reset circuit is also connected to the controller.

[0060] In practical applications, the controller is a single-chip microcomputer, and the reset circuit is connected to a reset RESTART terminal of the single-chip microcomputer.

[0061] In practical applications, the single chip microcomputer has six driving signals, namely UH, VH, WH, UL, VL, and WL, which respectively drive transistors Q4 to Q11, thereby controlling the reset circuit, the control circuit, and the drive shutdown circuit, and realizing the second overcurrent protection circuit to protect the motor from overcurrent.

[0062] Example 2: Figure 3 As shown, the difference from Example 1 is that the start-stop transistor is an NPN transistor, and the control transistor is a PNP transistor. The collector of the start-stop transistor is connected to the corresponding signal port on the controller (such as the collector of the start-stop transistor Q9 is connected to the UH signal terminal, the collector of the start-stop transistor Q10 is connected to the VH signal terminal, and the collector of the start-stop transistor Q11 is connected to the WH signal terminal), the emitter of the start-stop transistor is connected to the corresponding signal port on the IPM module (such as the emitter of the start-stop transistor Q9 is connected to the UH_O signal terminal, the emitter of the start-stop transistor Q10 is connected to the VH_O signal terminal, and the emitter of the start-stop transistor Q11 is connected to the WH_O signal terminal), and the base of the start-stop transistor is connected to the control circuit through the corresponding diodes.

[0063] When the first over-current protection circuit does not work, the I_OC signal is at a low level, and the base of the control transistor Q8 is at a low level through the pre-circuit, so that the control transistor Q8 is turned on, and the emitter of the start-stop transistor is at a high level, and the base is at a low level at the same time. At this time, the start-stop transistor is in a cut-off state, and the motor stops; at the same time, if the first over-current protection circuit is normal, the emitter of the start-stop transistor is at a low level and is still in a cut-off state, and the second over-current protection circuit can also work normally to protect the motor from over-current.

[0064] Embodiment 3: The technical solution of the second technical subject involved in the utility model: a motor overcurrent dual protection device, which is provided with the motor overcurrent dual protection circuit described in Embodiment 1 or Embodiment 2, and the motor overcurrent dual protection circuit includes a first overcurrent protection circuit and a second overcurrent protection circuit;

[0065] A first overcurrent protection circuit is provided with a comparison circuit, a controller, and an IPM module communicatively connected to the controller;

[0066] The IPM module is connected to the motor control, and the comparison circuit is used to

[0067] Sampling, amplifying and comparing the motor current signal, and generating a shutdown drive enable signal for shutting down the motor;

[0068] The controller receives a shutdown drive enable signal and implements motor overcurrent protection through the IPM module;

[0069] The second overcurrent protection circuit includes a control circuit and a drive shutdown circuit;

[0070] The control circuit is connected to the comparison circuit and receives a shutdown drive enable signal;

[0071] The drive shutdown circuit is connected to the control circuit, receives a shutdown drive enable signal, and implements motor overcurrent protection through the IPM module.

[0072] The second overcurrent protection circuit also includes a reset circuit, which is connected to the control circuit and the IPM module. The controller is a single-chip microcomputer, and the reset circuit is connected to a reset RESTART terminal of the single-chip microcomputer.

[0073] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. In the above embodiments, the utility model can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A motor overcurrent dual protection circuit, characterized in that: including a first overcurrent protection circuit and a second overcurrent protection circuit; A first overcurrent protection circuit is provided with a comparison circuit, a controller, an IPM module connected to the controller in communication, and the IPM module is connected to the motor control; The comparison circuit is used to sample, amplify and compare the motor current signal and generate a shutdown drive enable signal for shutting down the motor; The controller receives a shutdown drive enable signal and implements motor overcurrent protection through the IPM module; The second overcurrent protection circuit includes a control circuit and a drive shutdown circuit; The control circuit is connected to the comparison circuit and receives a shutdown drive enable signal; The drive shutdown circuit is connected to the control circuit, receives a shutdown drive enable signal, and implements motor overcurrent protection through the IPM module.

2. The motor overcurrent dual protection circuit according to claim 1 is characterized in that The second overcurrent protection circuit also includes a reset circuit, which is connected to the control circuit and is used to drive the shutdown circuit to operate the motor through the control circuit.

3. The motor overcurrent dual protection circuit according to claim 1 or 2, characterized in that Three parallel start-stop transistor circuits are arranged on the driving shutdown circuit, each of the start-stop transistor circuits includes a start-stop transistor, a diode connected in series with the base of the start-stop transistor, and the collector and emitter of the start-stop transistor are respectively connected to the controller and the IPM module.

4. The motor overcurrent dual protection circuit according to claim 3 is characterized in that The control circuit includes a pre-circuit, a control transistor connected to the pre-circuit, the pre-circuit is connected to the comparison circuit, the control transistor is connected to the start-stop transistor through the corresponding diode, and the diode makes the start-stop transistor conduct to the control transistor.

5. The motor overcurrent dual protection circuit according to claim 4 is characterized in that The start-stop transistor is a PNP transistor, and the control transistor is an NPN transistor; or, the start-stop transistor is an NPN transistor, and the control transistor is a PNP transistor.

6. The motor overcurrent dual protection circuit according to claim 2 is characterized in that The reset circuit is connected to the front circuit on the control circuit.

7. The motor overcurrent dual protection circuit according to claim 6 is characterized in that The reset circuit is also connected to the controller.

8. The motor overcurrent dual protection circuit according to claim 7 is characterized in that The controller is a single chip microcomputer, and the reset circuit is connected to a reset RESTART terminal of the single chip microcomputer.

9. A motor overcurrent dual protection device, characterized in that The motor overcurrent dual protection circuit according to any one of claims 1 to 8 is provided therein, and the motor overcurrent dual protection circuit comprises a first overcurrent protection circuit and a second overcurrent protection circuit; A first overcurrent protection circuit is provided with a comparison circuit, a controller, and an IPM module communicatively connected to the controller; The IPM module is connected to the motor control, and the comparison circuit is used to Sampling, amplifying and comparing the motor current signal, and generating a shutdown drive enable signal for shutting down the motor; The controller receives a shutdown drive enable signal and implements motor overcurrent protection through the IPM module; The second overcurrent protection circuit includes a control circuit and a drive shutdown circuit; The control circuit is connected to the comparison circuit and receives a shutdown drive enable signal; The drive shutdown circuit is connected to the control circuit, receives a shutdown drive enable signal, and implements motor overcurrent protection through the IPM module.

10. The motor overcurrent dual protection device according to claim 9 is characterized in that The second overcurrent protection circuit further includes a reset circuit, which is connected to the control circuit. The controller is a single-chip microcomputer, and the reset circuit is connected to a reset RESTART terminal of the single-chip microcomputer.

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