Motor driving protection circuit and motor assembly

Abstract

The utility model discloses a motor drive protection circuit and a motor assembly, and belongs to the technical field of motor drive, the motor drive protection circuit comprises a drive circuit, a sampling circuit, a voltage comparison circuit and a reset circuit, the drive circuit is connected with a servo motor, and the sampling circuit is connected with the servo motor. The voltage comparison circuit comprises a voltage stabilizing loop and an optical coupling loop which are connected with each other, one end, far away from the optical coupling loop, of the voltage stabilizing loop is connected with the sampling circuit, and one end, far away from the voltage stabilizing loop, of the optical coupling loop is connected with the reset circuit; a monitoring circuit is also connected between the sampling circuit and the voltage stabilizing loop, and the monitoring circuit is used for monitoring the current change of the motor loop; and the reset circuit is used for automatically trying to recover normal power supply after the motor is short-circuited. The motor driving protection circuit can cut off a power supply in time after a short circuit fault occurs in the circuit so as to protect the motor; and after the external fault is removed, protection can be automatically closed, so that the motor recovers a normal working state.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor drive technical field, specifically, relate to a motor drive protection circuit and motor assembly. BACKGROUND

[0002] For the equipment using direct current motor drive, in order to improve the safety of motor control, the current of direct current motor needs to be monitored in the process of motor driving, and the main purpose is to ensure the safety and stability of motor operation, if sudden situation occurs, such as motor locked-rotor (current is too large), motor failure (no current) and the like, the abnormal situation of motor can be found through monitoring motor current, and then the motor is protected.

[0003] At present, the mainstream test mode of motor current monitoring is that the shunt is used to sample motor current, and the sampled signal reaches the analog-to-digital converter (ADC) after filtering and amplification, and the current signal sampled by the analog-to-digital converter (ADC) is analyzed and processed by the main control chip, so as to obtain the running state of the motor.

[0004] However, the time required in the links of filtering, amplification, ADC sampling and conversion is relatively long, if the instantaneous positive and negative short circuit condition occurs on the motor power supply loop, the conventional current sampling circuit often cannot react in time, the circuit power supply cannot be immediately disconnected, and then the circuit is damaged. UTILITY MODEL CONTENTS

[0005] Therefore, the purpose of the utility model is to overcome the technical problem that the existing current sampling circuit test time is long and the motor is easily damaged in the background art, so as to provide a motor drive protection circuit and motor assembly.

[0006] In order to solve the above problems, the first purpose of the utility model is to provide a motor drive protection circuit, the motor drive protection circuit includes a drive circuit, the drive circuit is connected with a servo motor, and the motor drive protection circuit further includes a sampling circuit, a voltage comparison circuit and a reset circuit connected in sequence.

[0007] The voltage comparison circuit includes a voltage stabilizing loop and an optocoupler loop connected with each other, one end of the voltage stabilizing loop away from the optocoupler loop is connected with the sampling circuit, and one end of the optocoupler loop away from the voltage stabilizing loop is connected with the reset circuit.

[0008] The monitoring circuit is further connected between the sampling circuit and the voltage stabilizing loop, and the monitoring circuit is used for monitoring the current size change of the motor loop.

[0009] The reset circuit is used for automatically attempting to restore normal power supply after motor short circuit.

[0010] Preferably, the sampling circuit comprises a current sampling amplifier and a patch resistor, the patch resistor is connected in series between the positive input terminal and the negative input terminal of the current sampling amplifier, the power supply pin of the current sampling amplifier is connected with an external power supply, the ground pin of the current sampling amplifier is grounded, and the output pin of the current sampling amplifier is connected with the voltage stabilizing loop through a first resistor.

[0011] Preferably, the voltage stabilizing loop comprises a voltage stabilizer, a first capacitor, a second capacitor and a second resistor, the reference voltage pin of the voltage stabilizer is connected on the first resistor, the ground pin of the voltage stabilizer is grounded, the first capacitor, the second capacitor and the second resistor are all connected in parallel between the reference voltage pin and the ground pin of the voltage stabilizer, and the output voltage pin of the voltage stabilizer is connected with the optocoupler loop.

[0012] Preferably, the optocoupler loop comprises a high-speed optocoupler, the output end cathode of the high-speed optocoupler is connected to the output voltage pin of the voltage stabilizer, the input end anode of the high-speed optocoupler is connected with an external power supply, the ground pin of the high-speed optocoupler is connected with the earth, and the output pin of the high-speed optocoupler is connected with the reset circuit.

[0013] Preferably, the reset circuit comprises a reset chip, a third capacitor, a fourth capacitor and a fourth resistor, the power failure voltage monitoring input pin of the reset chip is connected with the output end of the high-speed optocoupler through a third resistor, the manual reset input pin of the reset chip is connected with the power failure voltage monitoring output pin, the third capacitor and the fourth capacitor are connected in parallel between the power supply voltage pin and the ground pin of the reset chip, the fourth resistor is connected between the power supply voltage pin and the power failure voltage monitoring input pin of the reset chip, and the reset output pin of the reset chip is connected with an external power supply and a motor pin respectively.

[0014] Preferably, one end of the third capacitor and the fourth capacitor is connected with an external power supply, and the other end is grounded.

[0015] Preferably, a fifth capacitor is further connected in series between the power failure voltage monitoring input pin of the reset chip and the ground pin of the high-speed optocoupler, and one end of the fifth capacitor away from the reset chip is grounded.

[0016] Preferably, a fifth resistor is further connected in series between the input end anode of the high-speed optocoupler and the external power supply.

[0017] Preferably, a transistor is connected in series between the reset output pin of the reset chip and the external power supply.

[0018] The second purpose of the utility model discloses a motor assembly, including above-mentioned motor drive protection circuit, motor and current signal detection port, the motor sets up in motor drive protection circuit, and the current signal detection port is set up between motor drive protection circuit with the motor.

[0019] Compared with the prior art, the motor drive protection circuit has the following beneficial effects:

[0020] The motor drive protection circuit mainly comprises a driving circuit, a sampling circuit, a voltage comparison circuit and a reset circuit, wherein the driving circuit is responsible for controlling the operation of the servo motor, the sampling circuit is used for monitoring the current change of the motor, the voltage comparison circuit realizes voltage comparison and isolation through a voltage stabilizing loop and an optocoupler loop, and the reset circuit automatically attempts to restore normal power supply after the motor short-circuit; the voltage stabilizing loop is used for ensuring voltage stability and avoiding control failure caused by voltage fluctuation; the optocoupler loop provides electrical isolation and protects the subsequent circuit from the influence of high voltage or transient voltage; the monitoring circuit monitors the current change in the motor loop in real time and can timely discover overcurrent condition. When the current exceeds the set threshold, the voltage comparison circuit triggers the protection mechanism to prevent the motor or the driving circuit from being damaged. After detecting short-circuit or overcurrent, the reset circuit automatically attempts to restore normal power supply of the motor, ensures that the motor can quickly recover work after failure occurs, reduces downtime and improves the availability of the system. Through integrated overcurrent, overtemperature and undervoltage protection functions, the motor drive protection circuit can effectively prevent the motor from being damaged under extreme conditions and ensure safe and stable operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structure schematic view of the motor drive protection circuit in the utility model embodiment.

[0022] MARK NUMBER EXPLANATION:

[0023] Among them:

[0024] 1-sampling circuit; 11-current sampling amplifier; a-output pin; b-ground pin; c-positive input end; d-negative input end; e-power supply pin; 12-surface mount resistor;

[0025] 2-voltage comparison circuit;

[0026] 21-voltage stabilizing loop; 211-voltage stabilizer; 212-first capacitor; 213-second capacitor; 214-second resistor;

[0027] 22-optocoupler loop; 221-high-speed optocoupler;

[0028] 3 - reset circuit; 31 - reset chip; 32 - third capacitor; 33 - fourth capacitor; 34 - fourth resistor; 35 - fifth capacitor;

[0029] 4 - first resistor; 5 - third resistor; 6 - fifth resistor; 7 - transistor. DETAILED DESCRIPTION

[0030] The technical solutions of the utility model will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without making creative efforts fall within the protection scope of the utility model.

[0031] In the description of the utility model, it should be explained that, unless explicitly defined and limited, the terms "mounting", "connection" and "connection" should be understood broadly. According to the example, it can be fixedly connected, or it can be detachably connected, or integrally connected. It can be mechanically connected, or it can be electrically connected. It can be directly connected, or it can be indirectly connected through an intermediate medium. It can be the communication between two elements, or it can be wireless connection, or it can be wired connection. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0032] Please refer to Figure 1 The utility model embodiment provides a motor drive protection circuit, the motor drive protection circuit includes drive circuit and sampling circuit 1, voltage comparison circuit 2 and reset circuit 3 connected in sequence, wherein:

[0033] The drive circuit is connected with a servo motor, the voltage comparison circuit 2 includes mutually connected voltage stabilizing loop 21 and opto-coupler loop 22, and one end of the voltage stabilizing loop 21 away from the opto-coupler loop 22 is connected with the sampling circuit 1, and one end of the opto-coupler loop 22 away from the voltage stabilizing loop 21 is connected with the reset circuit 3;There is also a monitoring circuit connected between the sampling circuit 1 and the voltage stabilizing loop 21, and the monitoring circuit is used for monitoring the current size change of the motor loop;The reset circuit 3 is used for automatically attempting to restore normal power supply after the motor short circuit.

[0034] Specific to the embodiment, the motor drive protection circuit is mainly composed of drive circuit, sampling circuit 1, voltage comparison circuit 2 and reset circuit 3, wherein the drive circuit is responsible for controlling the operation of the servo motor, the sampling circuit 1 is used for monitoring the current change of the motor, the voltage comparison circuit 2 realizes the comparison and isolation of voltage through the voltage stabilizing loop 21 and the opto-coupler loop 22, and the reset circuit 3 automatically attempts to restore normal power supply after the motor short circuit.

[0035] Specifically, the voltage stabilizing circuit 21 is used to ensure voltage stability and avoid control failure caused by voltage fluctuations. The optocoupler circuit 22 provides electrical isolation to protect the subsequent circuit from high voltage or transient voltage. The monitoring circuit monitors the current change in the motor circuit in real time and can timely discover overcurrent conditions. When the current exceeds the set threshold, the voltage comparison circuit 2 triggers the protection mechanism to prevent the motor or drive circuit from being damaged. The reset circuit 3 automatically attempts to restore normal power supply to the motor after detecting a short circuit or overcurrent, ensuring that the motor can quickly recover after a fault occurs, reducing downtime and improving system availability.

[0036] Thus, with the integrated overcurrent, overtemperature and undervoltage protection functions, the motor drive protection circuit can effectively prevent the motor from being damaged under extreme conditions and ensure the safe and stable operation of the system.

[0037] Further, please refer to Figure 1 As shown, the sampling circuit 1 includes a current sampling amplifier 11 and a chip resistor 12, the chip resistor 12 is connected in series between the positive input end c and the negative input end d of the current sampling amplifier 11, the power supply pin e of the current sampling amplifier 11 is connected with an external power supply, the ground pin b of the current sampling amplifier 11 is grounded, and the output pin a of the current sampling amplifier 11 is connected with the voltage stabilizing circuit 21 through the first resistor 4.

[0038] In this embodiment, the current sampling amplifier 11 is the core part of the sampling circuit 1, which converts the current signal in the motor circuit into a voltage signal. This conversion process usually involves converting the current signal through a known resistor (chip resistor 12) into a voltage signal, and then amplifying it for subsequent circuit processing. The chip resistor 12 is used to convert the current in the motor circuit into a voltage signal. According to Ohm's law (V=IR), the current flowing through the resistor can be calculated by measuring the voltage across the resistor.

[0039] The power supply pin e of the current sampling amplifier 11 is connected with an external power supply to ensure that the amplifier has a stable power supply; the ground pin b is grounded to provide a common reference point for the circuit, ensuring stable and accurate operation of the circuit; the output pin a of the current sampling amplifier 11 is connected with the voltage stabilizing circuit 21 through the first resistor 4. This connection ensures that the output signal of the sampling circuit 1 can be correctly received and processed by the voltage comparison circuit 2. The voltage stabilizing circuit 21 is used to stabilize the output voltage of the sampling circuit 1, ensuring that the voltage comparison circuit 2 can accurately compare the voltage.

[0040] Thus, the sampling circuit 1 can accurately monitor the current change in the motor loop. When the current exceeds the preset safety threshold, the output voltage of the current sampling amplifier 11 will increase accordingly, which is transmitted to the voltage stabilization loop 21 through the first resistor 4, triggering the protection mechanism of the voltage comparison circuit 2, thereby protecting the motor and the driving circuit from damage.

[0041] It should be noted that the specific model of the patch resistor 12 in this embodiment is SEWF3920F2L00P9, which is a precision alloy patch resistor produced by RESI, with the characteristics of low temperature drift and high precision, suitable for direct current sampling circuit. The resistance of this resistor is 2 milliohms, the precision is ±1%, and the power is 6W, which is particularly suitable for current detection.

[0042] Preferably, the current sampling amplifier 11 in this embodiment is selected as CSA230MASOT235, which is a high-precision current sampling amplifier. It has an input offset voltage of less than 8 microvolts (typical value) and a gain error of less than 0.1% (maximum value). The common-mode input voltage range of this amplifier is wide, from 0V to 76V, and the bandwidth is 90kHz.

[0043] In addition, this model of amplifier provides different gain options, including 10V / V, 20V / V, 50V / V and 100V / V, and adopts SOT23-5 package.

[0044] Further, please refer to Figure 1 As shown in the figure, the voltage stabilization loop 21 includes a voltage regulator 211, a first capacitor 212, a second capacitor 213 and a second resistor 214. The reference voltage pin of the voltage regulator 211 is connected to the first resistor 4, the ground pin of the voltage regulator 211 is grounded, the first capacitor 212, the second capacitor 213 and the second resistor 214 are connected in parallel between the reference voltage pin and the ground pin of the voltage regulator 211, and the output voltage pin of the voltage regulator 211 is connected to the optocoupler loop 22.

[0045] Specifically in this embodiment, the voltage regulator 211 is used to provide a stable reference voltage, which is the basis for the voltage comparison circuit 2 to compare, ensuring the accuracy of voltage comparison. The first capacitor 212, the second capacitor 213 and the second resistor 214 are connected in parallel between the reference voltage pin and the ground pin of the voltage regulator 211. This configuration provides a filter network to smooth the noise and transient voltage changes on the power line. Capacitors can store and release energy, reducing voltage fluctuations, while resistors provide a stable voltage drop, helping to further stabilize the voltage.

[0046] Preferably, the model of the voltage regulator 211 in this embodiment is selected as ME432AXG, which is a low voltage three-terminal programmable precision voltage regulator produced by M ICRONE. It provides stable performance in the full temperature range, similar to a low temperature coefficient Zener diode. The working current range of this voltage regulator is wide, from 70uA to 100mA, suitable for various applications such as switching power supply, charge management, operational amplifier circuit, etc., and can replace Zener diode.

[0047] Further, please refer to Figure 1 As shown in FIG. 2, the optocoupler circuit 22 includes a high-speed optocoupler 221, the output cathode of the high-speed optocoupler 221 is connected to the output voltage pin of the voltage regulator 211, the input anode of the high-speed optocoupler 221 is connected to the external power supply, the ground pin of the high-speed optocoupler 221 is connected to the ground, and the output pin of the high-speed optocoupler 221 is connected to the reset circuit 3.

[0048] Specifically, the preferred model of the high-speed optocoupler 221 in this embodiment is OR-M601-TP-G, which is composed of a high-efficiency gallium arsenide light-emitting diode and a high-speed optical detector, providing good AC and DC isolation. This model provides good AC and DC isolation at the input and output of the optocoupler, suitable for various applications.

[0049] The high-speed optocoupler 221 is an optoelectronic isolation device that realizes electrical isolation between input and output through internal light-emitting diodes (LEDs) and photosensitive transistors (or photosensitive integrated circuits). This isolation can effectively suppress sharp pulses and various noise disturbances, improving signal-to-noise ratio.

[0050] The input anode of the high-speed optocoupler 221 is connected to the external power supply, the output cathode is connected to the output voltage pin of the voltage regulator 211, and the ground pin is connected to the ground. This makes the input and output of the high-speed optocoupler 221 completely isolated electrically, avoiding the problem of common ground loop and improving the safety and reliability of the system.

[0051] The output pin of the high-speed optocoupler 221 is connected to the reset circuit 3, so that the stable voltage signal provided by the voltage regulator 211 will be transmitted to the reset circuit 3 through the high-speed optocoupler 221. In addition, since there is no electrical connection between the input circuit and the output circuit of the high-speed optocoupler 221, the transmission of interference signals can be avoided, ensuring stable transmission of signals.

[0052] The isolation function of the high-speed optocoupler 221 can prevent damage to the system caused by external device failure or short-circuiting of the input signal line. The input circuit and the output circuit of the optocoupler device can withstand several thousand volts of high voltage, providing safety protection for the system.

[0053] Therefore, the optical coupling circuit 22 realizes electrical isolation and fast and stable signal transmission through the high-speed optocoupler 221, thereby improving the safety, reliability and anti-interference ability of the motor drive protection circuit. This design effectively protects the motor and the drive circuit, and ensures that the motor system can operate stably under various working conditions.

[0054] It should be explained that the OR-M601-TP-G is a high-speed optocoupler produced by Orenda Company, which has 1-channel logic output and the package form is SOP-5.

[0055] Further, please refer to Figure 1 As shown in the figure, the reset circuit 3 includes a reset chip 31, a third capacitor 32, a fourth capacitor 33 and a fourth resistor 34. The power failure voltage monitoring input pin of the reset chip 31 is connected with the output end of the high-speed optocoupler 221 through the third resistor 5, the manual reset input pin of the reset chip 31 is connected with the power failure voltage monitoring output pin, the third capacitor 32 and the fourth capacitor 33 are connected in parallel between the power supply voltage pin and the ground pin of the reset chip 31, the fourth resistor 34 is connected between the power supply voltage pin and the power failure voltage monitoring input pin of the reset chip 31, and the reset output pin of the reset chip 31 is connected with the external power supply and the motor pin respectively.

[0056] In order to ensure that the motor drive protection circuit can automatically recover to normal working state in the case of power failure or other abnormal conditions, the reset chip 31 is set to monitor the power voltage and output a reset signal to restart the circuit when detecting power failure. The power failure voltage monitoring input pin of the reset chip 31 is connected with the output end of the high-speed optocoupler 221 through the third resistor 5, so that the reset chip can respond in time when the power voltage drops below the preset threshold.

[0057] The third capacitor 32 and the fourth capacitor 33 are connected in parallel between the power supply voltage pin and the ground pin of the reset chip 31. This configuration provides a filtering effect, which can reduce the noise and transient voltage change on the power line and ensure the stable operation of the reset chip. The fourth resistor 34 is connected between the power supply voltage pin and the power failure voltage monitoring input pin of the reset chip 31, which may be used to adjust the response threshold of the reset chip to ensure that the reset action is triggered at an appropriate voltage.

[0058] The manual reset input pin of the reset chip 31 is connected with the power failure voltage monitoring output pin, which means that in addition to automatic reset, the reset can also be triggered manually, increasing the flexibility and controllability of the system.

[0059] The reset output pin of the reset chip 31 is connected with the external power supply and the motor pin respectively, so as to ensure that the motor and the external power supply can receive the reset signal at the same time when the reset signal is triggered, and the synchronous restart of the system is realized.

[0060] Therefore, the reset circuit 3 realizes the fast response to the power failure and the automatic restart of the system by the cooperation of the reset chip 31, the capacitor and the resistor, improves the reliability and stability of the system, and ensures that the motor can safely and quickly recover to the normal working state under the abnormal power supply condition.

[0061] It should be particularly pointed out that the model of the reset chip 31 in the embodiment is SGM708-SYS8G, which is a microprocessor monitoring circuit produced by SGMICRO, and has multiple functions, including watchdog timer, power-on automatic reset, manual reset and low voltage alarm. This chip is used to improve the stability and accuracy of the system, and can reset in the case of power-on, power-off or voltage reduction, and even when the supply voltage is as low as 1V, the reset output can still work. It also provides a 1.25V threshold detector for monitoring power failure, low battery or additional power supply to be monitored.

[0062] Further, please refer to Figure 1 As shown in FIG. 5, one end of the third capacitor 32 and the fourth capacitor 33 is connected with the external power supply, and the other end is grounded.

[0063] Therefore, this capacitor configuration can absorb and smooth the noise and fluctuations on the power line, thereby maintaining the stability of the power supply. Since the motor may generate large current fluctuations during startup and operation, if these fluctuations are not filtered, they may affect the stability of the circuit and the performance of the motor.

[0064] Further, please refer to Figure 1 As shown in FIG. 5, the fifth capacitor 35 is further connected in series between the power failure voltage monitoring input pin of the reset chip 31 and the ground pin of the high-speed optocoupler 221, and one end of the fifth capacitor 35 away from the reset chip 31 is grounded.

[0065] Specifically, the fifth capacitor 35 acts as a decoupling capacitor, which can effectively filter high-frequency noise in the circuit by using its AC pass and DC isolation characteristics, prevent these noises from interfering with the normal operation of the reset chip 31, and ensure the stability of the circuit.

[0066] In addition, since the capacitor also has the function of energy storage, when the motor starts and stops, the sudden change of current may cause voltage fluctuations on the power line, and the fifth capacitor 35 can smooth the transient voltage fluctuations on the power line, reducing the influence of power supply noise on the reset chip 31.

[0067] Further, please refer to Figure 1As shown, the input anode of the high-speed optocoupler 221 is also connected in series with the external power supply through a fifth resistor 6.

[0068] In the embodiment, the fifth resistor 6 is used as a current limiting resistor to limit the current flowing through the input of the high-speed optocoupler 221, preventing the current from being too large to damage the light-emitting diode of the high-speed optocoupler 221, especially during circuit startup or in abnormal situations.

[0069] In addition, by selecting an appropriate resistance value for the fifth resistor 6, the on and off states of the high-speed optocoupler 221 can be controlled. When the input voltage exceeds a certain threshold, the light-emitting diode of the high-speed optocoupler 221 begins to conduct, triggering the conduction of the phototriode; when the input voltage is below the threshold, the light-emitting diode is turned off, and the phototriode is also turned off.

[0070] Further, please refer to Figure 1 As shown, the reset output pin of the reset chip 31 is connected in series with the external power supply through a transistor 7.

[0071] The transistor 7 serves as a driving element to enhance the driving capability of the reset output pin of the reset chip 31. When the reset chip 31 needs to output a high-level signal to reset the external circuit, the transistor 7 can provide sufficient current driving capability to ensure that the external circuit can reliably receive the reset signal.

[0072] In addition, the transistor 7 can serve as a protection element to prevent abnormal states of the external circuit from damaging the reset chip 31. For example, if there is a high voltage or current surge in the external circuit, the transistor 7 can limit the impact of these abnormal states on the reset chip, improving the safety of the system.

[0073] In addition, through the switching control of the transistor 7, the output of the reset signal can be more flexible. The transistor 7 can be designed as a switch, and by controlling its on and off states, the output time of the reset signal can be controlled, achieving precise control of the external circuit.

[0074] Preferably, the transistor 7 is a DS14W model, which is a Schottky diode.

[0075] Another embodiment of the utility model also provides a motor assembly, the motor assembly includes motor drive protection circuit, motor and current signal detection port, motor is arranged in motor drive protection circuit, current signal detection port is set between motor drive protection circuit and motor.

[0076] Therefore, the motor assembly improves the safety and reliability of the motor by integrating the motor drive protection circuit and the current signal detection port, enhances the monitoring and maintenance capability of the motor, and makes the motor system more efficient and stable.

[0077] Although the utility model discloses according to above, but the protection scope of the utility model disclosed is not limited to this only. The person skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the utility model.

Claims

1. A motor drive protection circuit, comprising a drive circuit connected to a servo motor, characterized in that: The sampling circuit (1), the voltage comparison circuit (2) and the reset circuit (3) are sequentially connected. The voltage comparison circuit (2) comprises a voltage stabilizing circuit (21) and an optical coupling circuit (22) which are connected with each other, and the voltage stabilizing circuit (21) is connected with the sampling circuit (1) at one end away from the optical coupling circuit (22), and the optical coupling circuit (22) is connected with the reset circuit (3) at one end away from the voltage stabilizing circuit (21). The monitoring circuit is further connected between the sampling circuit (1) and the voltage stabilizing circuit (21), and is used for monitoring the current size change of the motor circuit. The reset circuit (3) is used for automatically attempting to restore normal power supply after the motor short circuit.

2. The motor drive protection circuit of claim 1, wherein, The sampling circuit (1) comprises a current sampling amplifier (11) and a patch resistor (12), the patch resistor (12) is connected in series between the positive input end (c) and the negative input end (d) of the current sampling amplifier (11), the power supply pin (e) of the current sampling amplifier (11) is connected with an external power supply, the ground pin (b) of the current sampling amplifier (11) is grounded, and the output pin (a) of the current sampling amplifier (11) is connected with the voltage stabilizing circuit (21) through the first resistor (4).

3. The motor drive protection circuit of claim 2, wherein, The voltage stabilizing circuit (21) comprises a voltage stabilizer (211), a first capacitor (212), a second capacitor (213) and a second resistor (214), the reference voltage pin of the voltage stabilizer (211) is connected on the first resistor (4), the ground pin of the voltage stabilizer (211) is grounded, the first capacitor (212), the second capacitor (213) and the second resistor (214) are all connected in parallel between the reference voltage pin and the ground pin of the voltage stabilizer (211), and the output voltage pin of the voltage stabilizer (211) is connected with the optical coupling circuit (22).

4. The motor drive protection circuit of claim 3, wherein, The optical coupling circuit (22) comprises a high-speed optical coupling device (221), the output end cathode of the high-speed optical coupling device (221) is connected to the output voltage pin of the voltage stabilizer (211), the input end anode of the high-speed optical coupling device (221) is connected with an external power supply, the ground pin of the high-speed optical coupling device (221) is connected with the ground, and the output pin of the high-speed optical coupling device (221) is connected with the reset circuit (3).

5. The motor drive protection circuit of claim 4, wherein, The reset circuit (3) comprises a reset chip (31), a third capacitor (32), a fourth capacitor (33) and a fourth resistor (34), a power failure voltage monitoring input pin of the reset chip (31) is connected with an output end of the high-speed optocoupler (221) through a third resistor (5), a manual reset input pin of the reset chip (31) is connected with a power failure voltage monitoring output pin, the third capacitor (32) and the fourth capacitor (33) are connected in parallel between a power supply voltage pin and a ground pin of the reset chip (31), the fourth resistor (34) is connected between the power supply voltage pin and the power failure voltage monitoring input pin of the reset chip (31), and a reset output pin of the reset chip (31) is connected with an external power supply and a motor pin respectively.

6. The motor drive protection circuit of claim 5, wherein, One end of the third capacitor (32) and the fourth capacitor (33) is connected with an external power supply, and the other end is grounded.

7. The motor drive protection circuit of claim 5, wherein, A fifth capacitor (35) is further connected in series between the power failure voltage monitoring input pin of the reset chip (31) and a ground pin of the high-speed optocoupler (221), and one end of the fifth capacitor (35) far from the reset chip (31) is grounded.

8. The motor drive protection circuit of claim 4, wherein, A fifth resistor (6) is further connected in series between an input end anode of the high-speed optocoupler (221) and an external power supply.

9. The motor drive protection circuit of claim 5, wherein, A transistor (7) is connected in series between the reset output pin of the reset chip (31) and an external power supply.

10. An electric machine assembly characterized by The motor drive protection circuit, the motor and the current signal detection port are included, the motor is arranged in the motor drive protection circuit, and the current signal detection port is arranged between the motor drive protection circuit and the motor.

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