Bidirectional counter electromotive force protection circuit of motor

Abstract

The utility model provides a bidirectional counter electromotive force protection circuit for a motor. The bidirectional counter electromotive force protection circuit comprises a power supply module, an MOS tube isolation module, an enabling module and a bidirectional suppression module, the MOS tube isolation module is connected with the positive electrode end of the power supply module; the enabling module is connected with the MOS tube isolation module; the MOS tube isolation module and the bidirectional suppression module are connected with the positive electrode end of the motor, the negative electrode ends of the enabling module, the bidirectional suppression module and the motor are connected with the negative electrode end of the power supply module, and the negative electrode end of the power supply module is grounded; the MOS tube isolation module comprises an NMOS tube and a PMOS tube which are connected in series. The utility model has the advantages that the positive and back electromotive forces generated by the motor can be well isolated and suppressed, so that the positive and back electromotive forces generated by the motor are effectively prevented from influencing the main control board, the motor and other modules, for example, the positive and back electromotive forces are prevented from forming a loop and causing damage or false start of the main control board.

Description

[Technical field]

[0001] The utility model relates to the field of motor protection circuits, in particular to a motor bidirectional back electromotive force protection circuit. [Background technology]

[0002] With the continuous development and progress of science and technology, unmanned electric vehicles have been widely used in many fields such as military and transportation.

[0003] Unmanned electric cars require the use of reduction motors, and reduction motors may generate electromotive force during rotation, which may cause the main control board to power on and start incorrectly or damage the main control board. In order to solve the impact of electromotive force on the main control board, the Chinese utility model patent with application number CN202120495740.2 discloses a back-electromotive force suppression isolation circuit and motor, but the isolation circuit uses a reverse cutoff module, specifically a diode. However, the above existing isolation circuits can only realize a unidirectional suppression function, and therefore cannot effectively avoid the impact of the generated electromotive force on the main control board. In view of the above-mentioned problems, the inventor of this case conducted an in-depth study on the problem, and thus this case came into being. [Contents of the utility model]

[0004] The technical problem to be solved by the utility model is to provide a motor bidirectional back electromotive force protection circuit to solve the problem that the existing isolation circuit can only realize a unidirectional suppression function and cannot effectively avoid the generated electromotive force from affecting the main control board.

[0005] The utility model is implemented as follows: a motor bidirectional back electromotive force protection circuit, comprising a power supply module, a MOS tube isolation module, an enabling module and a bidirectional suppression module;

[0006] The MOS tube isolation module is connected to the positive terminal of the power module; the enabling module is connected to the MOS tube isolation module, and the MOS tube isolation module is driven to work by the enabling module; the MOS tube isolation module and the bidirectional inhibition module are both connected to the positive terminal of the motor, and the enabling module, the bidirectional inhibition module and the negative terminal of the motor are all connected to the negative terminal of the power module, and the negative terminal of the power module is grounded; the MOS tube isolation module includes an NMOS tube and a PMOS tube connected in series.

[0007] Furthermore, it also includes a motor danger signal IMU identification module, and the motor danger signal IMU identification module is connected to the enabling module.

[0008] Furthermore, it also includes a bypass circuit; the bypass circuit includes a first capacitor and a second capacitor, the first capacitor and the second capacitor are arranged in parallel, and one end of the first capacitor and the second capacitor are both connected to the positive terminal of the motor, and the other end of the first capacitor and the second capacitor are both connected to the negative terminal of the motor.

[0009] Furthermore, it also includes other modules, one end of which is connected to the positive terminal of the power module, and the other end of which is connected to the negative terminal of the power module.

[0010] Furthermore, the bidirectional suppression module adopts a bidirectional transient suppression diode.

[0011] Furthermore, the S pole of the PMOS tube is connected to the positive terminal of the power module, the G pole of the PMOS tube and the G pole of the NMOS tube are both connected to the enable module, the D pole of the PMOS tube is connected to the S pole of the NMOS tube, and the D pole of the NMOS tube is connected to the positive terminal of the motor.

[0012] Furthermore, the enabling module includes a main control MCU, a transistor and a boost circuit;

[0013] The S pole of the PMOS tube is connected to the G pole of the PMOS tube through a first resistor, and the G pole of the PMOS tube is connected to the C pole of the triode through a second resistor; the b pole of the triode is connected to the main control MCU through a third resistor, the b pole of the triode is connected to the e pole of the triode through a fourth resistor, and the e pole of the triode is grounded;

[0014] The motor danger signal IMU identification module and the boost circuit are both connected to the main control MCU, and the boost circuit is connected to the G pole of the NMOS tube.

[0015] Further, the boost circuit includes a boost chip, an inductor, a diode, a fifth resistor, a sixth resistor, a seventh resistor and a third capacitor;

[0016] The boost chip has an IN pin, an NC pin, an EN pin, an LX pin, an FB pin and a GND pin. The IN pin of the boost chip is connected to the power module, and the IN pin and the LX pin of the boost chip are connected through the inductor and the diode; the EN pin of the boost chip is connected to the main control MCU, one end of the fifth resistor is grounded, and the other end of the fifth resistor is connected to the EN pin of the boost chip; the G pole of the NMOS tube, one end of the third capacitor and one end of the sixth resistor are all connected to the LX pin of the boost chip, the other end of the sixth resistor and one end of the seventh resistor are connected to the FB pin of the boost chip, and the other end of the third capacitor, the other end of the seventh resistor and the GND pin of the boost chip are all connected to the negative terminal of the power module.

[0017] By adopting the technical solution of the utility model, at least the following beneficial effects are achieved:

[0018] 1. The MOS tube isolation module is composed of NMOS tubes and PMOS tubes, and a bidirectional suppression module is also provided. In specific use, the MOS tube isolation module can be used to bidirectionally isolate the circuit, and the bidirectional suppression module can also be used to bidirectionally suppress the circuit. Through the cooperation between the MOS tube isolation module and the bidirectional suppression module, the positive and reverse electromotive forces generated by the motor can be well isolated and suppressed, thereby effectively preventing the positive and reverse electromotive forces generated by the motor from affecting the main control board, the motor itself, and other modules, such as preventing the positive and reverse electromotive forces from forming a loop and causing damage to the main control board or false start-up.

[0019] 2. The protection circuit also includes a motor danger signal IMU identification module. When the motor danger signal IMU identification module determines that the entire vehicle is in a dangerous state, it can control the MOS tube isolation module to close the circuit loop and put the motor in a power-off state, thereby reducing damage to the internal structure of the motor due to impact, that is, it can protect the motor.

[0020] 3. By setting the first capacitor and the second capacitor between the bidirectional suppression module and the motor, on the one hand, the voltage output can be made uniform and the load voltage fluctuation can be reduced; on the other hand, the decoupling effect can be achieved to avoid the noise of the coupled motor.

Brief Description of the Drawings

[0021] The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

[0022] Figure 1 This is a circuit principle block diagram of a motor bidirectional back electromotive force protection circuit of the utility model;

[0023] Figure 2 The utility model discloses a specific circuit structure diagram of a motor bidirectional back electromotive force protection circuit. [Specific implementation method]

[0024] In order to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] It should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing these embodiments and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. In addition, the terms "first", "second", etc., etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0026] See also Figure 1 to Figure 2 As shown, the utility model is a motor bidirectional back electromotive force protection circuit, including a power module 200, a MOS tube isolation module 300, an enabling module 700 and a bidirectional suppression module 400; wherein, the power module 200 is used to provide the required power to the entire circuit, and the power module 200 can specifically adopt a 12V power supply; the MOS tube isolation module 300 is used to play a bidirectional isolation role to ensure that the positive and back electromotive forces generated by the motor 600 cannot form a loop; the enabling module 700 is used to drive the MOS tube isolation module 300 to work; the bidirectional suppression module 400 is used to play a bidirectional suppression role to ensure that the positive and back electromotive forces generated by the motor 600 cannot form a loop.

[0027] The MOS tube isolation module 300 is connected to the positive terminal of the power module 200; the enabling module 700 is connected to the MOS tube isolation module 300 to drive the MOS tube isolation module 300 to work through the enabling module 700; the MOS tube isolation module 300 and the bidirectional suppression module 400 are both connected to the positive terminal of the motor 600, and the negative terminals of the enabling module 700, the bidirectional suppression module 400 and the motor 600 are all connected to the negative terminal of the power module 200, and the negative terminal of the power module 200 is grounded; the MOS tube isolation module 300 includes an NMOS tube Q1 and a PMOS tube Q2 connected in series to ensure that the entire MOS tube isolation module 300 can achieve a good isolation effect.

[0028] In some embodiments of the utility model, the protection circuit also includes a motor danger signal IMU identification module 800, and the motor danger signal IMU identification module 800 is connected to the enabling module 700. When the utility model is implemented, the motor danger signal IMU identification module 800 is specifically an inertial sensor. An inertial sensor is a device used to respond to physical movement, such as linear displacement or angular rotation, and convert this response into an electrical signal, and amplify and process it through an electronic circuit. Inertial sensors have been widely used in the prior art, such as gyroscopes, accelerometers, etc. are all common inertial sensors; the motor danger signal IMU identification module 800 of the utility model is mainly used to identify whether the whole car is in a falling (weightlessness) state, therefore, the inertial sensor in the prior art can be directly used, so the motor danger signal IMU identification module 800 will not be introduced in detail here. During specific operation, when the motor danger signal IMU identification module 800 determines that the entire vehicle is in a dangerous state (such as falling), it can control the MOS tube isolation module 300 to close the circuit loop, so that the motor 600 is in a power-off state, thereby reducing damage to the internal structure of the motor 600 due to impact.

[0029] By adopting the above technical solution of the utility model, at least the following beneficial effects are achieved:

[0030] 1. The MOS tube isolation module 300 is composed of an NMOS tube Q1 and a PMOS tube Q2, and a bidirectional suppression module 400 is also provided. In specific use, the MOS tube isolation module 300 can be used to bidirectionally isolate the circuit, and the bidirectional suppression module 400 can also be used to bidirectionally suppress the circuit. Through the mutual cooperation of the MOS tube isolation module 300 and the bidirectional suppression module 400, the positive and reverse electromotive forces generated by the motor 600 can be well isolated and suppressed, thereby effectively preventing the positive and reverse electromotive forces generated by the motor 600 from affecting the main control board, the motor itself, and other modules 100, such as preventing the positive and reverse electromotive forces from forming a loop and causing damage to the main control board or erroneous start-up.

[0031] 2. The protection circuit also includes a motor danger signal IMU identification module 800. When the motor danger signal IMU identification module 800 determines that the entire vehicle is in a dangerous state (such as falling), it can control the MOS tube isolation module 300 to close the circuit loop, so that the motor 600 is in a power-off state, thereby reducing the damage to the internal structure of the motor 600 due to impact, that is, it can protect the motor 600.

[0032] In some embodiments of the present invention, the protection circuit further includes a bypass circuit 500; the bypass circuit 500 includes a first capacitor C1 and a second capacitor C2, the first capacitor C1 and the second capacitor C2 are arranged in parallel, and one end of the first capacitor C1 and the second capacitor C2 are both connected to the positive terminal of the motor 600, and the other end of the first capacitor C1 and the second capacitor C2 are both connected to the negative terminal of the motor 600. The present invention can make the voltage output uniform and reduce the load voltage fluctuation on the one hand by arranging the first capacitor C1 and the second capacitor C2 between the bidirectional suppression module 400 and the motor 600; on the other hand, it can also achieve a decoupling effect to avoid coupling the noise of the motor 600.

[0033] In some embodiments of the present invention, the protection circuit further includes another module 100, one end of the other module 100 is connected to the positive terminal of the power module 200, and the other end of the other module 100 is connected to the negative terminal of the power module 200. Figure 1 As shown, with the 12V power module 200 as the boundary, the left side is other modules 100, and the right side is the motor 600 and the MOS tube isolation module 300, the enabling module 700, and the bidirectional suppression module 400 for isolation and suppression. In this way, the positive and reverse electromotive forces generated by the motor 600 can be effectively prevented from affecting the other modules 100 on the left, and can also avoid affecting the motor itself and the main control board.

[0034] In some embodiments of the utility model, the bidirectional suppression module 400 adopts a bidirectional transient suppression diode D1. Transient suppression diode, referred to as TVS, is a high-efficiency protection device in the form of a diode; when the two poles of the TVS diode are subjected to a reverse transient high-energy impact, the high impedance between the two poles can be changed to a low impedance at a speed of 10 to the negative 12th power of seconds, and the surge power of up to several kilowatts can be absorbed, so that the voltage between the two poles is clamped at a predetermined value, thereby effectively protecting the precision components in the electronic circuit from damage by various surge pulses; the utility model can play a bidirectional suppression role by adopting a bidirectional transient suppression diode D1.

[0035] As a specific implementation of the utility model, in order to enable the NMOS tube Q1 and the PMOS tube Q2 to play a bidirectional isolation role, the S pole of the PMOS tube Q2 is connected to the positive terminal of the power module 200, and the G pole of the PMOS tube Q2 and the G pole of the NMOS tube Q1 are both connected to the enabling module 700, so as to drive the PMOS tube Q2 and the NMOS tube Q1 through the enabling module 700; the D pole of the PMOS tube Q2 is connected to the S pole of the NMOS tube Q1, and the D pole of the NMOS tube Q1 is connected to the positive terminal of the motor 600.

[0036] In some embodiments of the utility model, in order to drive the MOS tube isolation module 300 to work, the enabling module 700 includes a main control MCU, a transistor Q3 and a boost circuit; wherein the main control MCU is a microcontroller, also known as a single-chip microcomputer, which is used to play a control role; the transistor Q3 is a driving switch, which is used to drive the MOS tube isolation module 300; the boost circuit is used to play a boost role to obtain the required voltage.

[0037] The S pole of the PMOS tube Q2 is connected to the G pole of the PMOS tube Q2 through a first resistor R1, and the G pole of the PMOS tube Q2 is connected to the C pole of the transistor Q3 through a second resistor R2; the b pole of the transistor Q3 is connected to the main control MCU through a third resistor R3, the b pole of the transistor Q3 is connected to the e pole of the transistor Q3 through a fourth resistor R4, and the e pole of the transistor Q3 is grounded;

[0038] The motor danger signal IMU identification module 800 and the boost circuit are both connected to the main control MCU, so that the motor danger signal IMU identification module 800 can transmit the identified signal to the main control MCU, and at the same time enable the main control MCU to control the NMOS tube Q1; the boost circuit is connected to the G pole of the NMOS tube Q1 to provide the required voltage for the NMOS tube Q1 through the boost circuit.

[0039] More specifically, in order to achieve the boost function, the boost circuit includes a boost chip U2, an inductor L1, a diode D2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a third capacitor C3;

[0040] The boost chip U2 has an IN pin, an NC pin, an EN pin, an LX pin, an FB pin and a GND pin. The IN pin of the boost chip U2 is connected to the power module 200 so that the power module 200 provides a 12V voltage to the boost chip U2. The IN pin and the LX pin of the boost chip U2 are connected through the inductor L1 and the diode D2, and the inductor L1 plays a boosting role. The EN pin of the boost chip U2 is connected to the main control MCU, one end of the fifth resistor R5 is grounded, and the other end of the fifth resistor R5 is connected to the EN pin of the boost chip U2. The G pole of the NMOS tube Q1, one end of the third capacitor C3 and one end of the sixth resistor R6 are all connected to the LX pin of the boost chip U2, the other end of the sixth resistor R6 and one end of the seventh resistor R7 are connected to the FB pin of the boost chip U2, and the other end of the third capacitor C3, the other end of the seventh resistor R7 and the GND pin of the boost chip U2 are all connected to the negative terminal of the power module 200.

[0041] When the protection circuit of the utility model is in specific operation, when the whole vehicle is in a falling (weightlessness) state, a signal can be sent to the main control MCU through the motor danger signal IMU identification module 800. When the main control MCU determines that the whole vehicle is in a dangerous state (such as falling), the MOS tube isolation module 300 is controlled to close the circuit loop, so that the motor 600 is in a power-off state, thereby reducing the damage to the internal structure of the motor 600 due to impact; when the NMOS tube Q1 and the PMOS tube Q2 of the MOS tube isolation module 300 are not enabled, the bidirectional transient suppression diode D1 can be relied on to make the power supply completely disconnected. At this time, the positive and reverse electromotive forces generated by the motor 600 cannot form a loop, so as not to affect the main control board, other modules 100, and the motor itself.

[0042] Although the specific implementation methods of the present invention are described above, those skilled in the art should understand that the specific embodiments described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A motor bidirectional back electromotive force protection circuit, comprising a power module; characterized in that: It also includes a MOS tube isolation module, an enabling module, and a bidirectional inhibition module; The MOS tube isolation module is connected to the positive terminal of the power module; the enabling module is connected to the MOS tube isolation module, and the MOS tube isolation module is driven to work by the enabling module; the MOS tube isolation module and the bidirectional inhibition module are both connected to the positive terminal of the motor, and the enabling module, the bidirectional inhibition module and the negative terminal of the motor are all connected to the negative terminal of the power module, and the negative terminal of the power module is grounded; the MOS tube isolation module includes an NMOS tube and a PMOS tube connected in series.

2. A motor bidirectional back electromotive force protection circuit as claimed in claim 1, characterized in that: It also includes a motor danger signal IMU identification module, and the motor danger signal IMU identification module is connected to the enabling module.

3. A motor bidirectional back electromotive force protection circuit as claimed in claim 1, characterized in that: It also includes a bypass circuit; the bypass circuit includes a first capacitor and a second capacitor, the first capacitor and the second capacitor are arranged in parallel, and one end of the first capacitor and the second capacitor are both connected to the positive terminal of the motor, and the other end of the first capacitor and the second capacitor are both connected to the negative terminal of the motor.

4. A motor bidirectional back electromotive force protection circuit as claimed in claim 1, characterized in that: It also includes other modules, one end of which is connected to the positive terminal of the power module, and the other end of which is connected to the negative terminal of the power module.

5. A motor bidirectional back electromotive force protection circuit as claimed in claim 1, characterized in that: The bidirectional suppression module adopts a bidirectional transient suppression diode.

6. A motor bidirectional back electromotive force protection circuit as claimed in claim 1, characterized in that: The S pole of the PMOS tube is connected to the positive terminal of the power module, the G pole of the PMOS tube and the G pole of the NMOS tube are both connected to the enabling module, the D pole of the PMOS tube is connected to the S pole of the NMOS tube, and the D pole of the NMOS tube is connected to the positive terminal of the motor.

7. A motor bidirectional back electromotive force protection circuit as claimed in claim 2, characterized in that: The enabling module includes a main control MCU, a triode and a boost circuit; The S pole of the PMOS tube is connected to the G pole of the PMOS tube through a first resistor, and the G pole of the PMOS tube is connected to the C pole of the triode through a second resistor; the b pole of the triode is connected to the main control MCU through a third resistor, the b pole of the triode is connected to the e pole of the triode through a fourth resistor, and the e pole of the triode is grounded; The motor danger signal IMU identification module and the boost circuit are both connected to the main control MCU, and the boost circuit is connected to the G pole of the NMOS tube.

8. A motor bidirectional back electromotive force protection circuit as claimed in claim 7, characterized in that: The boost circuit includes a boost chip, an inductor, a diode, a fifth resistor, a sixth resistor, a seventh resistor and a third capacitor; The boost chip has an IN pin, an NC pin, an EN pin, an LX pin, an FB pin and a GND pin. The IN pin of the boost chip is connected to the power module, and the IN pin and the LX pin of the boost chip are connected through the inductor and the diode; the EN pin of the boost chip is connected to the main control MCU, one end of the fifth resistor is grounded, and the other end of the fifth resistor is connected to the EN pin of the boost chip; the G pole of the NMOS tube, one end of the third capacitor and one end of the sixth resistor are all connected to the LX pin of the boost chip, the other end of the sixth resistor and one end of the seventh resistor are connected to the FB pin of the boost chip, and the other end of the third capacitor, the other end of the seventh resistor and the GND pin of the boost chip are all connected to the negative terminal of the power module.

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