阅读说明：本技术 马达断电剎车系统及方法 (Motor power-off brake system and method ) 是由 洪银树 郭俊谷 于 2018-08-27 设计创作，主要内容包括：一种马达断电剎车系统及方法，用以解决现有马达断电剎车的开关操作引发突波破坏马达线圈绕组的问题，其包括：一个电源；一个驱动电路，与该电源电性连接；一个马达线圈，与该驱动电路电性连接；一个电压感测模块，与该电源电性连接，用于测量该电源的电压，并产生一个监测电压值；及一个控制模块，分别与该驱动电路及该电压感测模块电性连接，并接收该监测电压值，该控制模块根据该监测电压值判断该电源即将断电，通过该控制模块产生一个控制信号，切换该驱动电路及该马达线圈形成断路并维持一段持续时间，再切换该驱动电路及该马达线圈形成封闭回路。(A motor power-off brake system and method are used for solving the problem that the switching operation of the existing motor power-off brake causes a sudden wave to damage a motor coil winding, and comprise the following steps: a power source; a driving circuit electrically connected to the power supply; a motor coil electrically connected to the driving circuit; the voltage sensing module is electrically connected with the power supply and is used for measuring the voltage of the power supply and generating a monitoring voltage value; and the control module is electrically connected with the driving circuit and the voltage sensing module respectively and receives the monitoring voltage value, judges that the power supply is about to be powered off according to the monitoring voltage value, generates a control signal through the control module, switches the driving circuit and the motor coil to form an open circuit and maintains the open circuit for a period of time, and then switches the driving circuit and the motor coil to form a closed loop.)

1. A motor braking system, comprising:

a power supply, the power supply generating a drive current;

the driving circuit is electrically connected with the power supply;

a motor coil electrically connected to the driving circuit, the driving circuit guiding the driving current to pass through the motor coil;

the voltage sensing module is electrically connected with the power supply and is used for measuring the voltage of the power supply and generating a monitoring voltage value; and

the control module is electrically connected with the driving circuit and the voltage sensing module respectively and receives the monitoring voltage value, judges that the power supply is about to be powered off according to the monitoring voltage value, generates a control signal through the control module, switches the driving circuit and the motor coil to form an open circuit and maintains for a period of time, and then switches the driving circuit and the motor coil to form a closed loop.

2. The motor braking system of claim 1, wherein the power supply is further electrically connected to a plurality of rectifying elements, respectively.

3. The motor braking system of claim 2, wherein the rectifying element is connected in parallel with an energy storage element.

4. The motor braking system of claim 1, wherein the driving circuit is an H-bridge, the driving circuit has two upper bridge cells and two lower bridge cells, and the two upper bridge cells and the two lower bridge cells are MOSFETs.

5. The system of claim 4, wherein the upper bridge unit is electrically connected to a voltage divider circuit, the voltage divider circuit being electrically connected to the power source and serially connected to a transistor switch.

6. The motor braking system of claim 1, wherein the voltage sensing module has a voltage sensor and a voltage divider circuit, the voltage divider circuit is electrically connected to the voltage sensor, and the voltage divider circuit is electrically connected to the power source.

7. The system of claim 6, wherein the voltage sensor is coupled in parallel with an energy storage device.

8. The system of claim 6, wherein the voltage sensor and the control module are integrated into a microcontroller.

9. The system of claim 6, wherein the voltage sensor and the control module are electrically connected to the power supply.

10. A motor power-off braking method is characterized by comprising the following steps:

a running stage, leading the driving current of a power supply to enter a motor coil through a driving circuit, measuring the power supply through a voltage sensing module to obtain a monitoring voltage value, comparing whether the monitoring voltage value is greater than the working voltage, if the comparison result is yes, maintaining the running stage, if the comparison result is no, increasing the number of times of reading the monitoring voltage value in unit time by the voltage sensing module, continuously comparing whether the monitoring voltage value is greater than the stop voltage, and if the comparison result is yes, maintaining the running stage; and

and a cut-off stage, wherein the monitoring voltage value of the running stage is not more than the stop voltage, and an open circuit is formed by the driving circuit to stop current passing through the motor coil and maintain for a period of time.

11. The method of claim 10, further comprising a deceleration phase, wherein the deceleration phase is entered after the off-phase is maintained for the duration, and a closed loop is formed by the driving circuit and the motor coil.

Technical Field

The present invention relates to a protection method for an electrical power system, and more particularly, to a system and method for braking a motor during power failure to prevent damage to circuit components due to a surge.

Background

In an electric power system, a Switching Surge (Switching Surge) caused by a Switching operation is an instantaneous voltage wave or an instantaneous current wave caused by an energy storage component (inductor and capacitor) in a circuit at the moment of Switching off or Switching on the circuit, the Surge usually exists in the circuit for a plurality of microseconds (μ s), and the amplitude of the Surge is often hundreds and tens of times of the normal amplitude, so that the instantaneous high-energy impact of the Surge can cause overload of the circuit and is not timely responded by a general circuit protection component,

the coil winding and the coupling core of a typical motor include insulation components, and when the motor is turned off and the brake stops to generate a switching surge, high voltage or current exceeding the specification of the motor may damage the insulation components on the components, resulting in short circuit of the coil winding. Therefore, the motor is repeatedly switched between start and stop to receive the surge interference for a long time, which may cause damage to the coil winding of the motor and reduce the service life of the circuit assembly.

In view of the above, there is a need for an improved system for a motor-generator brake.

Disclosure of Invention

To solve the above problems, an objective of the present invention is to provide a system and method for braking a motor in a power-off state, which can predict the occurrence of a surge and prevent the surge from entering a winding of a motor coil.

The invention discloses a motor power-off braking system, which comprises: a power supply that generates a drive current; the driving circuit is electrically connected with the power supply; a motor coil electrically connected to the driving circuit, the driving circuit guiding the driving current to pass through the motor coil; the voltage sensing module is electrically connected with the power supply and is used for measuring the voltage of the power supply and generating a monitoring voltage value; and the control module is electrically connected with the driving circuit and the voltage sensing module respectively and receives the monitoring voltage value, judges that the power supply is about to be powered off according to the monitoring voltage value, generates a control signal through the control module, switches the driving circuit and the motor coil to form an open circuit and maintains for a period of time, and then switches the driving circuit and the motor coil to form a closed loop.

The invention discloses a motor power-off braking method, which comprises the following steps: a running stage, leading the driving current of a power supply to enter a motor coil through a driving circuit, measuring the power supply through a voltage sensing module to obtain a monitoring voltage value, comparing whether the monitoring voltage value is greater than the working voltage, if the comparison result is yes, maintaining the running stage, if the comparison result is no, increasing the number of times of reading the monitoring voltage value in unit time by the voltage sensing module, continuously comparing whether the monitoring voltage value is greater than the stop voltage, and if the comparison result is yes, maintaining the running stage; and a cut-off stage, when the monitoring voltage value of the operation stage is not greater than the stop voltage, the drive circuit forms a cut-off circuit to stop current passing through the motor coil and maintain a period of time.

Therefore, the motor power-off brake system and the motor power-off brake method predict the occurrence of the surge by monitoring the voltage change of the power supply, and stop the driving circuit to block the surge from entering the motor coil, so as to reduce the interference of the surge on the coil winding and the circuit component, and have the technical effects of avoiding the damage of the motor component and prolonging the service life of the motor.

The power supply is also electrically connected with the plurality of rectifying components respectively. Therefore, the rectifying component can prevent current from flowing back to the power supply, and has the technical effect of protecting the power supply.

Wherein, this rectification subassembly connects in parallel an energy storage component. Therefore, the energy storage component can be a capacitor, and the capacitor is charged when the voltage is high and discharged when the voltage is low, so that the technical effect of stabilizing the voltage is achieved.

The drive circuit is an H bridge and is provided with two upper bridge units and two lower bridge units, wherein the two upper bridge units and the two lower bridge units are metal oxide semiconductor field effect transistors. Therefore, the two upper bridge units and the two lower bridge units can be switched to be connected or disconnected by controlling the voltage of the gate, and the technical effect of switching the states of current forward, reverse, short circuit or disconnection and the like is achieved.

The upper bridge unit is electrically connected with a voltage division loop, and the voltage division loop is electrically connected with the power supply and is connected with a transistor switch in series. Therefore, the technical effect of respectively controlling the two upper bridge units to be conducted or disconnected is achieved.

The voltage sensing module is provided with a voltage sensor and a voltage division loop, the voltage division loop is electrically connected with the voltage sensor, and the voltage division loop is electrically connected with the power supply. Therefore, the voltage sensor can measure the reduced power supply voltage through the voltage division loop, and the technical effect of auxiliary voltage monitoring is achieved.

Wherein, this voltage sensor connects in parallel an energy storage component. Therefore, the energy storage assembly can stabilize the voltage to avoid the voltage oscillation to influence the measurement, and has the technical effect of reducing the misjudgment probability of voltage monitoring.

Wherein, the voltage sensor and the control module are a microcontroller. Therefore, the control system has the technical effects of integrating the control function and saving the installation space.

Wherein, the voltage sensor and the control module are electrically connected with the power supply. Therefore, the power supply can supply the power used by the control module and the voltage sensor, and the technical effect of saving the installation space is achieved.

The motor power-off braking method also comprises a deceleration stage, wherein the deceleration stage is entered after the cut-off stage maintains the duration, and a closed loop is formed by the driving circuit and the motor coil. Therefore, the motor rotates by inertia, and the motor coil can generate a reverse induction magnetic field, so that the technical effect of braking is achieved.

Drawings

FIG. 1 is a system block diagram of a preferred embodiment of the present invention.

Fig. 2 is a circuit diagram of a preferred embodiment of the present invention.

FIG. 3 is a flowchart of a method according to a preferred embodiment of the present invention.

Description of the reference numerals

1 Power supply

11 rectification subassembly 12 energy storage component

2 drive circuit

21. 22 upper bridge unit 23, 24 lower bridge unit

25 ground terminal 26 voltage division loop

27 transistor switch

3 Motor coil

3a, 3b electric connection terminal

4 voltage sensing module

41 voltage sensor 42 voltage division loop

43 energy storage assembly

5 control module

Vcc direct current supply source M microcontroller

D drive current V monitoring voltage value

C control signal S1 operation stage

S2 cut-off stage S3 deceleration stage

V1 operating voltage V2 stop voltage

Duration of T.

Detailed Description

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below:

referring to fig. 1, a brake system according to a preferred embodiment of the present invention includes a power source 1, a driving circuit 2, a motor coil 3, a voltage sensing module 4 and a control module 5, wherein the power source 1 is electrically connected to the driving circuit 2 and the voltage sensing module 4, the driving circuit 2 is electrically connected to the motor coil 3, and the control module 5 is electrically connected to the driving circuit 2 and the voltage sensing module 4.

Referring to fig. 2, the power supply 1 includes a dc power supply Vcc, the power supply 1 may further include a plurality of rectifying devices 11, the dc power supply Vcc is electrically connected to the plurality of rectifying devices 11, the rectifying devices 11 may be rectifying diodes, and the plurality of rectifying devices 11 may prevent a current from flowing back to the dc power supply Vcc; each rectifying component 11 may also be connected in parallel with an energy storage component 12, and the energy storage component 12 may be a capacitor, which has a technical effect of stabilizing voltage.

The driving circuit 2 may be an H-bridge (H-bridge), the driving circuit 2 has two upper bridge units 21, 22 and two lower bridge units 23, 24, the two upper bridge units 21, 22 and the two lower bridge units 23, 24 may be Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs), sources of the two upper bridge units 21, 22 are electrically connected to the power supply 1, and sources of the two lower bridge units 23, 24 are electrically connected to a ground 25. In addition, the gates of the two upper bridge units 21, 22 may also be electrically connected to a voltage dividing loop 26, and each voltage dividing loop 26 is electrically connected to the power supply 1 and is connected to a transistor switch 27 in series, so that the power supply 1, the voltage dividing loop 26 and the transistor switch 27 can control the voltage of the gate, and have the technical effect of controlling the two upper bridge units 21, 22 to be turned on or off.

The motor coil 3 is wound by a metal wire to form a plurality of winding groups, and the motor coil 3 has two electrical terminals 3a and 3b in the embodiment, which are used for a single-phase motor, however, the invention can also be applied to motors with two phases, three phases, etc., without being limited thereto. The connecting terminal 3a of the motor coil 3 is electrically connected to the drain of the upper bridge unit 21 and the drain of the lower bridge unit 23, the connecting terminal 3b is electrically connected to the drain of the upper bridge unit 22 and the drain of the lower bridge unit 24, and the motor coil 3 is energized by the driving circuit 2 to generate an electromagnetic field, which can act on a permanent magnet to generate a magnetic force to drive the motor to rotate.

The voltage sensing module 4 is electrically connected to a voltage dividing loop 42 through a voltage sensor 41, the voltage dividing loop 42 is electrically connected to the power supply 1, the voltage sensor 41 can monitor the voltage change of the power supply 1, in addition, the voltage sensor 41 can be further connected to an energy storage component 43 in parallel, and the energy storage component 43 can be a capacitor, and has the technical effect of stabilizing the voltage.

The control module 5 is electrically connected to the bases of the two transistor switches 27 and the gates of the two lower bridge units 23 and 24, respectively, and the control module 5 can control the two transistor switches 27 and the lower bridge units 23 and 24 to be on or off respectively, so as to switch the states of the motor coil 3, such as on, closed, and off, in different current directions through the driving circuit 2. In addition, the control module 5 and the voltage sensor 41 are preferably integrated into a Micro Control Unit (MCU) M, and the MCU M is electrically connected to the power supply 1, so that the power used by the control module 5 and the voltage sensor 41 can be supplied by the power supply 1.

Referring to fig. 1, with the above structure, the power supply 1 generates a driving current D, the driving circuit 2 guides the driving current D to pass through the motor coil 3, the voltage sensing module 4 is configured to measure a voltage of the power supply 1 and generate a monitoring voltage value V, the control module 5 receives the monitoring voltage value V, the control module 5 generates a control signal C according to the monitoring voltage value V, and then receives the control signal C through the driving circuit 2, and the driving circuit 2 switches the conduction state of the motor coil 3 according to the control signal C.

Referring to fig. 1 and 2, the driving circuit 2 can make the upper bridge unit 21 and the lower bridge unit 24 be on and the upper bridge unit 22 and the lower bridge unit 23 be off according to the control signal C, so that the driving current D passes through the motor coil 3 in a direction from the electrical connection terminal 3a to the electrical connection terminal 3 b; or the upper bridge unit 22 and the lower bridge unit 23 are turned on, and the upper bridge unit 21 and the lower bridge unit 24 are turned off, so that the driving current D passes through the motor coil 3 in a direction from the power connection terminal 3b to the power connection terminal 3 a. Thus, the driving circuit 2 alternately switches the current direction on the motor coil 3 according to the control signal C, so that the magnetic poles generated by the motor coil 3 can be changed to continuously push the rotor of the motor to rotate.

The driving circuit 2 can also open the two upper bridge units 21 and 22 and the two lower bridge units 23 and 24 according to the control signal C, so as to turn off the motor coil 3. Thus, the switching surge caused by the switching operation cannot enter the motor coil 3, and the technical effect of preventing the winding from being damaged by the surge is achieved, and the rotor of the motor can continue to rotate due to the inertia effect.

The driving circuit 2 can also open the two upper bridge units 21 and 22 according to the control signal C, so that the two lower bridge units 23 and 24 and the motor coil 3 form a closed loop, and thus, when the rotor of the motor rotates due to inertia and changes the magnetic flux passing through the motor coil 3, the motor coil 3 generates a reverse induction magnetic field for canceling the change of the magnetic flux passing through the motor coil 3, and the reverse magnetic field has the technical effect of braking the motor.

Fig. 3 is a flowchart of a method for powering-off and braking a motor according to a preferred embodiment of the invention, which includes an operation phase S1, a stop phase S2 and a deceleration phase S3.

The operation stage S1 is to guide the driving current D of the power supply 1 to enter the motor coil 3 through the driving circuit 2, and the voltage sensing module 4 reads the monitoring voltage V, and then the control module 5 compares whether the monitoring voltage V is greater than the working voltage V1, if yes, the operation stage S1 is maintained, if no, the voltage sensing module 4 increases the number of times of reading the monitoring voltage V per unit time, and continues to compare whether the monitoring voltage V is greater than the stopping voltage V2, if yes, the operation stage S1 is maintained, and if no, the stopping stage S2 is performed. Wherein the operating voltage V1 is greater than the stop voltage V2.

The cut-off stage S2 is to switch the driving circuit 2 to an open circuit by the control module 5 with the control signal C, so that the current cannot enter the motor coil 3, and the cut-off stage S2 is maintained for a duration T and then enters the deceleration stage S3. In the cut-off stage S2, a surge cannot enter the motor coil 3, which has the technical effect of preventing the winding of the motor coil 3 from being damaged by the surge.

In the deceleration stage S3, the control module 5 switches the driving circuit 2 and the motor coil 3 with the control signal C to form a closed loop. The motor coil 3 generates a reverse induction magnetic field according to the inertial rotation, and has the technical effect of braking the motor to rotate.

In summary, the system and method for braking a motor during power failure of the present invention predict the occurrence of a surge by monitoring the voltage variation of the power supply, and stop the driving circuit to block the surge from entering the motor coil, so as to reduce the interference of the surge to the coil winding and the circuit assembly, thereby having the technical effects of avoiding the damage of the motor assembly and prolonging the service life of the motor.

Although the present invention has been disclosed with reference to the above preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.