shutdown detection circuit

Abstract

This invention relates to the field of motor control technology and discloses a shutdown detection circuit, comprising: a control module that outputs a switching signal to switch between short-circuit detection mode and open-circuit detection mode; a function switching module connected to a first power supply terminal, a thyristor, and the control module, receiving the switching signal and performing the switching; a short-circuit detection module connected to the first power supply terminal, the thyristor, and the control module, adjusting the input power supply voltage before outputting; an open-circuit detection module connected to the control terminal of the thyristor, a detection resistor, and the control module, receiving an enable signal, driving the thyristor to conduct, and collecting and outputting the detected current; and a switching module connected to the control module and the motor control circuit, receiving a disable signal before disabling. This solves the problem of not being able to ensure the quality of the thyristor, which could lead to safety hazards.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and more specifically to a stop detection circuit. Background Technology

[0002] With the development of technology, motors have been widely used, and the motor's shutdown function is related to safety issues.

[0003] The thyristor in the shutdown circuit is a key component of the shutdown function. The quality of the thyristor determines whether the shutdown function is normal. In order to ensure the quality of the thyristor, it is necessary to test it. Summary of the Invention

[0004] In view of this, the present invention provides a shutdown detection circuit to solve the problem that the existing technology cannot ensure the quality of the thyristor, which leads to potential safety hazards.

[0005] In a first aspect, the present invention provides a shutdown detection circuit, which is connected to a shutdown control circuit. The shutdown control circuit includes a thyristor and a motor control circuit. The shutdown detection circuit includes:

[0006] The control module is used to output a switching signal, which is used to switch between short-circuit detection mode and open-circuit detection mode.

[0007] A function switching module is connected to a first power supply terminal, a first terminal of the thyristor, and a control module, respectively, and is used to receive the switching signal and perform switching.

[0008] A short-circuit detection module is connected to a first power supply terminal, a first terminal of the thyristor, and a control module. The short-circuit detection module is used to adjust the input power supply voltage before outputting it.

[0009] The control module is also used to receive the regulated input power supply voltage. In short-circuit detection mode, when the regulated input power supply voltage is detected to be less than the first preset voltage value, the thyristor is confirmed to be short-circuited.

[0010] The control module is also used to output an enable signal;

[0011] The circuit breaker detection module is connected to the control terminal of the thyristor, the detection resistor and the control module respectively. It is used to receive the turn-on signal, drive the thyristor to conduct, and collect the detection current flowing through the detection resistor and output it.

[0012] The control module receives the detection current. In the open circuit detection mode, when the adjusted input power supply voltage is greater than the second preset voltage value and the detection current is the preset current value, the thyristor is confirmed to be open circuit.

[0013] The control module is also used to output a shutdown signal when a short circuit or open circuit of the thyristor is detected, so as to control the motor control circuit to stop running;

[0014] A switch module is connected to both the control module and the motor control circuit, and is used to turn off the circuit after receiving the shutdown signal.

[0015] In one optional implementation, the function switching module includes:

[0016] A first switching transistor, the control terminal of the first switching transistor is connected to the control module, the first end of the first switching transistor is connected to the first power supply terminal, and the second end of the first switching transistor is connected to the first end of the first diode. The first switching transistor is used to supply power to the short circuit detection module in the short circuit detection mode.

[0017] The second switch has its first end connected to the stop control terminal and its second end connected to the first end of the thyristor. The second switch is used to prevent voltage from being transmitted to the motor in short-circuit detection mode.

[0018] In one optional implementation, the short-circuit detection module includes:

[0019] A first resistor, the first end of which is connected to a first power supply terminal, and the second end of which is connected to the first end of the thyristor;

[0020] The second resistor has its first end connected to the first end of the thyristor and its second end connected to the control module.

[0021] The third resistor has its first end connected to the second end of the second resistor, and the second end of the third resistor is grounded.

[0022] In one optional implementation, the short-circuit detection module further includes:

[0023] A fourth resistor, the first end of which is connected to the second end of the second resistor, and the second end of which is connected to the control module;

[0024] A clamping diode, wherein the first terminal of the clamping diode is connected to a preset reference voltage, the second terminal of the clamping diode is grounded, and the third terminal of the clamping diode is connected to the second terminal of the second resistor.

[0025] In one optional implementation, the circuit breaker detection module includes:

[0026] A drive unit is connected to the control module and the thyristor respectively. The drive unit is used to receive the turn-on signal and drive the thyristor.

[0027] A current detection unit is connected to both the control module and the detection resistor, and is used to collect the current of the detection resistor and transmit the detected current to the control module.

[0028] In one alternative implementation, the drive unit includes:

[0029] The first transistor has its control terminal connected to the control module, and its first terminal is grounded.

[0030] The second transistor has its control terminal connected to the second terminal of the first transistor, its first terminal connected to a preset reference voltage, and its second terminal connected to the control terminal of the thyristor.

[0031] In one alternative implementation, the drive unit includes:

[0032] The fifth resistor has its first end connected to the control terminal of the first transistor and its second end connected to the control module.

[0033] The sixth resistor has its first end connected to the control terminal of the first transistor, and its second end grounded.

[0034] The seventh resistor has its first end connected to the second end of the first transistor, and its second end connected to the control terminal of the second transistor.

[0035] The eighth resistor has its first end connected to the control terminal of the second transistor and its second end connected to a preset reference voltage.

[0036] The ninth resistor has its first end connected to the second end of the second transistor, and its second end connected to the control terminal of the thyristor.

[0037] The tenth resistor has its first end connected to the second end of the thyristor, and its second end connected to the second end of the ninth resistor.

[0038] In one optional implementation, the current detection unit includes:

[0039] The eleventh resistor, the first end of which is connected to the first end of the detection resistor;

[0040] The twelfth resistor, wherein the first end of the twelfth resistor is connected to the second end of the detection resistor;

[0041] An operational amplifier, wherein the first terminal of the operational amplifier is connected to the second terminal of the eleventh resistor, the second terminal of the operational amplifier is connected to the second terminal of the twelfth resistor, the positive power supply terminal of the operational amplifier is connected to the preset reference voltage, and the negative power supply terminal of the operational amplifier is grounded;

[0042] The thirteenth resistor has its first end connected to the first end of the operational amplifier and its second end connected to a preset reference voltage.

[0043] The fourteenth resistor has its first end connected to the second end of the operational amplifier, and its second end connected to the output end of the operational amplifier.

[0044] The fifteenth resistor has its first end connected to the output terminal of the operational amplifier and its second end connected to the control module.

[0045] In one optional embodiment, the shutdown control circuit includes: a start relay and a fuse, and the switching module includes:

[0046] The third switch has its first end connected to the start relay, its second end connected to the fuse, and its control end connected to the control module.

[0047] In one optional implementation, the shutdown detection circuit further includes:

[0048] A first varistor, wherein a first end of the first varistor is connected to a first end of a first diode, and a second end of the first varistor is connected to a first end of the thyristor;

[0049] The second varistor has its first end connected to the first end of the thyristor and its second end connected to the second end of the thyristor. Attached Figure Description

[0050] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a structural diagram of a shutdown detection circuit according to an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of a three-phase motor application of a shutdown detection circuit according to an embodiment of the present invention.

[0053] Figure 3 This is a schematic diagram of a single-phase motor application of another shutdown detection circuit according to an embodiment of the present invention;

[0054] Figure 4 This is a detailed structural diagram of a shutdown detection circuit according to an embodiment of the present invention;

[0055] Figure 5 This is a structural diagram of another shutdown detection circuit according to an embodiment of the present invention. Detailed Implementation

[0056] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0058] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0059] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0060] This embodiment provides a shutdown detection circuit, such as Figure 1 As shown, the shutdown detection circuit is connected to the shutdown control circuit. The shutdown control circuit includes a thyristor T1 and a motor control circuit B1. The shutdown detection circuit includes:

[0061] Control module 20, the control module 20 is used to output a switching signal, the switching signal is used to switch between short circuit detection mode and open circuit detection mode;

[0062] Specifically, the shutdown detection circuit can be applied to both three-phase and single-phase motors. The shutdown detection circuit performs a test on thyristor T1 before the motor starts running, or it can perform a test on thyristor T1 during motor shutdown control when the shutdown circuit is activated. The control module 20 can be a control chip. A short-circuit detection mode is used to detect whether thyristor T1 is short-circuited, and an open-circuit detection mode is used to detect whether thyristor T1 is open-circuited. Furthermore, the control module 20 is also used to switch the motor running mode by outputting a switching signal when the thyristor T1 test is completed.

[0063] Specifically, after the entire machine is powered on, the control module 20 performs a self-test of the program code. The control module 20 determines whether the controller is normal by reading and writing registers, operating the program pointer PC (Personal Computer), clock calibration, and performing CRC (Cyclic Redundancy Check) checks on the RAM (Random Access Memory) and ROM (Read-Only Memory). If the control module 20's self-test is normal, a short-circuit test is performed.

[0064] Function switching module 10 is connected to the first power supply terminal, the first terminal of the thyristor T1 and the control module 20 respectively, and is used to receive the switching signal and perform switching.

[0065] Specifically, the function switching module 10 is used to switch between short-circuit detection mode and open-circuit detection mode. Optionally, the function switching module 10 can be a switching device. The first power supply terminal can be any one of the three input power supplies in a three-phase motor, or any one of the input power supplies in a unidirectional motor.

[0066] A short-circuit detection module 30 is connected to a first power supply terminal, the first terminal of the thyristor T1, and the control module 20. The short-circuit detection module 30 is used to adjust the input power supply voltage and then output it.

[0067] The control module 20 is also used to receive the regulated input power supply voltage. In the short circuit detection mode, when the regulated input power supply voltage is detected to be less than the first preset voltage value, the thyristor T1 is confirmed to be short-circuited.

[0068] Specifically, when the function switching module 10 switches to short-circuit detection mode, the short-circuit detection module 30 detects whether the thyristor T1 is broken down. Specifically, when the thyristor T1 is in the off state, the voltage at the first terminal of the thyristor T1 is detected. If the voltage is less than the first preset voltage value, it indicates that the thyristor T1 is broken down and conducting.

[0069] The control module 20 is also used to output an enable signal;

[0070] The circuit breaker detection module 40 is connected to the control terminal of the thyristor T1, the detection resistor Rs1 and the control module 20 respectively. After receiving the turn-on signal, the module 40 drives the thyristor T1 to turn on and collects the detection current flowing through the detection resistor and outputs it.

[0071] The control module 20 receives the detection current. In the open circuit detection mode, when the adjusted input power supply voltage is greater than the second preset voltage value and the detection current is the preset current value, the thyristor T1 is confirmed to be open circuit.

[0072] It should be noted that the open circuit test is performed after the short circuit test. After confirming that the thyristor T1 is not short-circuited, the open circuit test of the thyristor T1 is then performed.

[0073] Specifically, when the function switching module 10 switches to the open circuit detection mode, the open circuit detection module 40 detects whether the thyristor T1 is open or damaged. Specifically, when the thyristor T1 is in the on state, if the voltage at the first terminal of the thyristor T1 is greater than a second preset voltage value, and the current flowing through the detection resistor is zero, it indicates that the thyristor T1 is open or damaged. The preset current value can specifically be zero, meaning no current flows through the detection resistor. Optionally, the open circuit detection module 40 includes a circuit for driving the thyristor T1 and a circuit for detecting the current.

[0074] The control module 20 is also used to output a turn-off signal when a short circuit or open circuit is detected in the thyristor T1, so as to control the motor control circuit B1 to stop running;

[0075] The switch module 50 is connected to the control module 20 and the motor control circuit B1 respectively, and is used to turn off after receiving the shutdown signal.

[0076] Specifically, when the control module 20 detects a short circuit or open circuit in the thyristor T1, it outputs a turn-off signal to the switch module 50. At this time, the switch module 50 turns off, causing the motor control circuit B1 to disconnect, preventing the motor control circuit B1 from conducting under fault conditions.

[0077] The shutdown detection circuit provided by this invention outputs a switching signal to the function switching module through the control module. When the function switching module switches to short-circuit detection mode, it receives the regulated input power supply voltage sent by the short-circuit detection module. When the regulated input power supply voltage is detected to be less than a first preset voltage value, the thyristor is confirmed to be short-circuited. Furthermore, when the function switching module switches to open-circuit detection mode through the control module, it controls the open-circuit detection module to drive the thyristor to conduct, simultaneously collecting the detection current flowing through it and transmitting it to the control module. When the control module detects that the regulated input power supply voltage is greater than a second preset voltage value and the detection current is a preset current value, the thyristor is confirmed to be open-circuited. When the control module detects a short circuit or open circuit in the thyristor, it controls the switching module to disconnect the motor control circuit, preventing the motor control circuit from conducting under fault conditions. In other words, by detecting whether the thyristor is damaged before the motor runs, safety hazards are greatly reduced.

[0078] In some alternative implementations, such as Figure 2 and Figure 3 As shown, the function switching module includes:

[0079] The first switch K1 has its control terminal connected to the control module 20, its first end connected to the first power supply terminal, and its second end connected to the first end of the first diode D1. The first switch K1 is used to supply power to the short circuit detection module 30 in the short circuit detection mode.

[0080] The second switch K2 has its first end connected to the stop control terminal and its second end connected to the first end of the thyristor T1. The second switch K2 is used to prevent voltage from being transmitted to the motor in short-circuit detection mode.

[0081] refer to Figure 2 and Figure 3 RL1a, RL1b, and RL1c are the linkage switches for the start relay RL1. When the start button SB1 is pressed, the start relay RL1 is energized and conducts. At this time, RL1a, RL1b, and RL1c also operate simultaneously: the normally open switch RL1a closes, the normally closed switch RL1b opens, and the normally open switch RL1c closes. RL1c is also a stop switch. When the stop switch SB2 or SB3 is pressed, RL1 is disconnected, causing RL1c to return to its closed state. At this time, current flows through RL1c, thyristor T1, and sensing resistor RS1 before reaching ground, thus stopping the motor. The first terminal of the second switch K2 is connected to the stop switch RL1c, and the second terminal of the second switch K2 is connected to the first terminal of the thyristor T1. The first diode D1 is a freewheeling diode, meaning that when the motor stops, current can quickly flow through the first diode D1 to ground.

[0082] In short-circuit detection mode, the first switch K1 and the second switch K2 are closed, and short-circuit detection is performed by the short-circuit detection module 30. In open-circuit detection mode, the first switch K1 and the second switch K2 are open, and open-circuit detection is performed by the open-circuit detection module 40.

[0083] In some alternative implementations, such as Figure 2 , Figure 3 and Figure 4 As shown, the short-circuit detection module 30 includes:

[0084] A first resistor R1, the first end of the first resistor R1 is connected to the first power supply terminal, and the second end of the first resistor R1 is connected to the first end of the thyristor T1.

[0085] The second resistor R2 has its first end connected to the first end of the thyristor T1 and its second end connected to the control module 20.

[0086] The third resistor R3 has its first end connected to the second end of the second resistor R2, and its second end is grounded.

[0087] Specifically, the current from the first power supply terminal is transmitted to the first terminal of the thyristor T1 through the first resistor R1. If the thyristor T1 is short-circuited, the current through the first resistor R1 flows to ground through the thyristor T1 and the detection resistor RS1. If the thyristor T1 is short-circuited, the current is transmitted to the control module 20 after being divided by the second resistor R2 and the third resistor R3. The voltage of the PWR CN2 signal can be detected by the control module 20. If the voltage of the PWR CN2 signal is less than the first preset voltage value, it is confirmed that the thyristor T1 is short-circuited.

[0088] Optionally, the control module 20 can detect the level signal of PWR CN2. If the PWR CN2 signal is high, it indicates that the PWR CN1 signal is also high, confirming that the thyristor T1 is not short-circuited. If the control module 20 detects that the PWR CN2 signal is low, it indicates that the PWR CN1 signal is also low, confirming that the thyristor T1 is short-circuited.

[0089] It should be noted that the first resistor R1 is a high-value resistor. A weak signal is provided through the first resistor R1. At this time, if the thyristor T1 is truly short-circuited, the current is less than 1mA, which will not cause the motor to start suddenly.

[0090] In some alternative implementations, such as Figure 4 As shown, the short-circuit detection module 30 further includes:

[0091] The fourth resistor R4 has its first end connected to the second end of the second resistor R2, and its second end connected to the control module 20.

[0092] Clamping diode D2, the first terminal of clamping diode D2 is connected to a preset reference voltage VCC, the second terminal of clamping diode D2 is grounded, and the third terminal of clamping diode D2 is connected to the second terminal of the second resistor R2.

[0093] Specifically, the fourth resistor R4 is a coupling resistor used to match the control module 20, and the clamping diode D2 is used to clamp the value assigned to PWR CN2. It should be noted that the first capacitor C1 is the filter capacitor for the PWR CN2 signal.

[0094] In some alternative implementations, such as Figure 5 As shown, the circuit breaker detection module 40 includes:

[0095] The drive unit 41 is connected to the control module 20 and the thyristor T1 respectively. The drive unit 41 is used to receive the turn-on signal and drive the thyristor T1.

[0096] Specifically, during the open circuit detection, the first switch K1 and the second switch K2 are closed, and the drive unit 41 is used to drive the thyristor T1, thereby turning on the thyristor T1. After driving the thyristor T1, the open circuit detection is further performed.

[0097] The current detection unit 42 is connected to the control module 20 and the detection resistor RS1 respectively, and is used to collect the current of the detection resistor RS1 and transmit the detected current to the control module 20.

[0098] Specifically, after driving the thyristor T1, the control module 20 collects the current of the detection resistor RS1. If the PWR CN1 signal is detected to be high level through the PWR CN2 signal, it indicates that power is being supplied to the first terminal of the thyristor T1. If the current of the detection resistor RS1 is detected to be 0 at this time, it indicates that the thyristor T1 has an open circuit fault.

[0099] In some alternative implementations, such as Figure 4 As shown, the drive unit 41 includes:

[0100] The first transistor Q1 has its control terminal connected to the control module 20, and its first terminal is grounded.

[0101] The control terminal of the second transistor Q2 is connected to the second terminal of the first transistor Q1, the first terminal of the second transistor Q2 is connected to the preset reference voltage VCC, and the second terminal of the second transistor Q2 is connected to the control terminal of the thyristor T1.

[0102] Specifically, the control module 20 outputs a BRK DRV signal to the first transistor Q1. When the BRK DRV signal is a high-level signal, the first transistor Q1 is turned on and pulls down the voltage at the control terminal of the second transistor Q2, so that after the second transistor Q2 is turned on, it drives the thyristor T1 based on the preset reference voltage VCC.

[0103] In some alternative implementations, such as Figure 4 As shown, the drive unit 41 includes:

[0104] The fifth resistor R5 has its first end connected to the control terminal of the first transistor Q1, and its second end connected to the control module 20.

[0105] The sixth resistor R6 has its first end connected to the control terminal of the first transistor Q1, and its second end grounded.

[0106] The seventh resistor R7 has its first end connected to the second end of the first transistor Q1, and its second end connected to the control terminal of the second transistor Q2.

[0107] The eighth resistor R8 has its first end connected to the control terminal of the second transistor Q2, and its second end connected to the preset reference voltage VCC.

[0108] The ninth resistor R9 has its first end connected to the second end of the second transistor Q2, and its second end connected to the control terminal of the thyristor T1.

[0109] The tenth resistor R10 has its first end connected to the second end of the thyristor T1, and its second end connected to the second end of the ninth resistor R9.

[0110] Specifically, resistors R5 and R6 are the driving resistors for the first transistor Q1, resistors R7 and R8 are the driving resistors for the second transistor Q2, and resistors R9 and R10 are the driving resistors for the thyristor T1. It should be noted that capacitor C2 is the filter capacitor for the signal driving thyristor T1.

[0111] In some alternative implementations, such as Figure 4 As shown, the current detection unit 42 includes:

[0112] The eleventh resistor R11, the first end of which is connected to the first end of the detection resistor RS1;

[0113] The twelfth resistor R12, the first end of which is connected to the second end of the detection resistor RS1;

[0114] Operational amplifier A1, the first terminal of operational amplifier A1 is connected to the second terminal of the eleventh resistor R11, the second terminal of operational amplifier A1 is connected to the second terminal of the twelfth resistor R12, the positive power supply terminal of operational amplifier A1 is connected to the preset reference voltage VCC, and the negative power supply terminal of operational amplifier A1 is grounded;

[0115] The thirteenth resistor R13 has its first end connected to the first end of the operational amplifier A1, and its second end connected to the preset reference voltage VCC.

[0116] The fourteenth resistor R14, the first end of the fourteenth resistor R14 is connected to the second end of the operational amplifier A1, and the second end of the fourteenth resistor R14 is connected to the output end of the operational amplifier A1;

[0117] The fifteenth resistor R15 has its first end connected to the output terminal of the operational amplifier A1, and its second end connected to the control module 20.

[0118] Specifically, the eleventh resistor R11, the twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15 and the operational amplifier A1 collect the current of the detection resistor RS1, amplify it and transmit it to the control module 20, that is, transmit the BRK CUR signal to the control module 20.

[0119] It should be noted that when the shutdown circuit is started, the control module 20 continuously collects the BRK CUR signal and determines the state of the thyristor T1 by detecting the magnitude of the BRK CUR signal.

[0120] In some alternative implementations, such as Figure 2 and Figure 3 As shown, the shutdown control circuit includes: a start relay RL1 and a fuse F1, and the switch module 50 includes:

[0121] The third switch K3 has its first end connected to the start relay RL1, its second end connected to the fuse F1, and its control end connected to the control module 20.

[0122] Specifically, when the control module 20 detects a short circuit or open circuit in the thyristor T1, it outputs a turn-off signal to the third switch K3. Upon receiving the turn-off signal, the third switch K3 disconnects, preventing the start relay RL1 from closing, thus preventing the motor from running in case of a fault. Additionally, if the fuse F1, as the overall protection device for the control and shutdown circuits, opens during an overcurrent event, any operation, such as starting or stopping the motor, will be impossible.

[0123] In some alternative implementations, the shutdown detection circuit further includes:

[0124] A first varistor VR1, the first end of the first varistor VR1 is connected to the first end of the first diode D1, and the second end of the first varistor VR1 is connected to the first end of the thyristor T1.

[0125] The second varistor VR2 has its first end connected to the first end of the thyristor T1, and its second end connected to the second end of the thyristor T1.

[0126] Specifically, the first varistor VR1 and the second varistor VR2 are used to limit the voltage of the thyristor T1 when it is working, thereby protecting the thyristor T1.

[0127] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A shutdown detection circuit, characterized in that, The shutdown detection circuit is connected to the shutdown control circuit. The shutdown control circuit includes a thyristor and a motor control circuit. The shutdown detection circuit includes: The control module is used to output a switching signal, which is used to switch between short-circuit detection mode and open-circuit detection mode. A function switching module is connected to a first power supply terminal, a first terminal of the thyristor, and a control module, respectively, and is used to receive the switching signal and perform switching. A short-circuit detection module is connected to a first power supply terminal, a first terminal of the thyristor, and a control module. The short-circuit detection module is used to adjust the input power supply voltage before outputting it. The control module is also used to receive the regulated input power supply voltage. In short-circuit detection mode, when the regulated input power supply voltage is detected to be less than the first preset voltage value, the thyristor is confirmed to be short-circuited. The control module is also used to output an enable signal; The circuit breaker detection module is connected to the control terminal of the thyristor, the detection resistor and the control module respectively. It is used to receive the turn-on signal, drive the thyristor to conduct, and collect the detection current flowing through the detection resistor and output it. The control module receives the detection current. In the open circuit detection mode, when the adjusted input power supply voltage is greater than the second preset voltage value and the detection current is the preset current value, the thyristor is confirmed to be open circuit. The control module is also used to output a shutdown signal when a short circuit or open circuit of the thyristor is detected, so as to control the motor control circuit to stop running; A switch module, which is connected to both the control module and the motor control circuit, is used to turn off the circuit after receiving the off signal. The function switching module includes: A first switching transistor, the control terminal of the first switching transistor is connected to the control module, the first end of the first switching transistor is connected to the first power supply terminal, and the second end of the first switching transistor is connected to the first end of the first diode. The first switching transistor is used to supply power to the short circuit detection module in the short circuit detection mode. The second switch has a first end connected to the stop control terminal and a second end connected to the first end of the thyristor. The second switch is used to prevent voltage from being transmitted to the motor in short-circuit detection mode. The short-circuit detection module includes: A first resistor, the first end of which is connected to a first power supply terminal, and the second end of which is connected to the first end of the thyristor; The second resistor has its first end connected to the first end of the thyristor and its second end connected to the control module. A third resistor, the first end of which is connected to the second end of the second resistor, and the second end of the third resistor is grounded; The short-circuit detection module also includes: A fourth resistor, the first end of which is connected to the second end of the second resistor, and the second end of which is connected to the control module; A clamping diode, wherein the first terminal of the clamping diode is connected to a preset reference voltage, the second terminal of the clamping diode is grounded, and the third terminal of the clamping diode is connected to the second terminal of the second resistor.

2. The shutdown detection circuit according to claim 1, characterized in that, The circuit breaker detection module includes: A drive unit is connected to the control module and the thyristor respectively. The drive unit is used to receive the turn-on signal and drive the thyristor. A current detection unit is connected to both the control module and the detection resistor, and is used to collect the current of the detection resistor and transmit the detected current to the control module.

3. The shutdown detection circuit according to claim 2, characterized in that, The driving unit includes: The first transistor has its control terminal connected to the control module, and its first terminal is grounded. The second transistor has its control terminal connected to the second terminal of the first transistor, its first terminal connected to a preset reference voltage, and its second terminal connected to the control terminal of the thyristor.

4. The shutdown detection circuit according to claim 3, characterized in that, The driving unit includes: The fifth resistor has its first end connected to the control terminal of the first transistor and its second end connected to the control module. The sixth resistor has its first end connected to the control terminal of the first transistor, and its second end grounded. The seventh resistor has its first end connected to the second end of the first transistor, and its second end connected to the control terminal of the second transistor. The eighth resistor has its first end connected to the control terminal of the second transistor and its second end connected to a preset reference voltage. The ninth resistor has its first end connected to the second end of the second transistor, and its second end connected to the control terminal of the thyristor. The tenth resistor has its first end connected to the second end of the thyristor, and its second end connected to the second end of the ninth resistor.

5. The shutdown detection circuit according to claim 4, characterized in that, The current detection unit includes: The eleventh resistor, the first end of which is connected to the first end of the detection resistor; The twelfth resistor, wherein the first end of the twelfth resistor is connected to the second end of the detection resistor; An operational amplifier, wherein the first terminal of the operational amplifier is connected to the second terminal of the eleventh resistor, the second terminal of the operational amplifier is connected to the second terminal of the twelfth resistor, the positive power supply terminal of the operational amplifier is connected to a preset reference voltage, and the negative power supply terminal of the operational amplifier is grounded. The thirteenth resistor has its first end connected to the first end of the operational amplifier and its second end connected to a preset reference voltage. The fourteenth resistor has its first end connected to the second end of the operational amplifier, and its second end connected to the output end of the operational amplifier. The fifteenth resistor has its first end connected to the output terminal of the operational amplifier and its second end connected to the control module.

6. The shutdown detection circuit according to claim 1, characterized in that, The shutdown control circuit includes a start relay and a fuse; the switching module includes: The third switch has its first end connected to the start relay, its second end connected to the fuse, and its control end connected to the control module.

7. The shutdown detection circuit according to claim 1, characterized in that, The shutdown detection circuit also includes: A first varistor, wherein a first end of the first varistor is connected to a first end of a first diode, and a second end of the first varistor is connected to a first end of the thyristor; The second varistor has its first end connected to the first end of the thyristor and its second end connected to the second end of the thyristor.

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