CN108923387A - Motor protection device, motor and protection method thereof - Google Patents
Motor protection device, motor and protection method thereof Download PDFInfo
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- CN108923387A CN108923387A CN201810617987.XA CN201810617987A CN108923387A CN 108923387 A CN108923387 A CN 108923387A CN 201810617987 A CN201810617987 A CN 201810617987A CN 108923387 A CN108923387 A CN 108923387A
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
- H02H7/09—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against over-voltage; against reduction of voltage; against phase interruption
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/08—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors
- H02H7/085—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against excessive load
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- Control Of Electric Motors In General (AREA)
- Protection Of Generators And Motors (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
The invention discloses a protection device of a motor, the motor and a protection method thereof, wherein the device comprises: the sampling module (102) is used for acquiring the current voltage of the motor; the first comparison module (104) is used for comparing the current voltage with a preset protection voltage; the switch module (106) is used for triggering a preset overcurrent protection signal if the current voltage is greater than or equal to the protection voltage and the degree that the current voltage is greater than the protection voltage is within a set range; and the first control module (108) is used for adjusting the output power of the motor according to the overcurrent protection signal so as to reduce the current voltage. According to the scheme, the problem of high cost caused by the fact that a peripheral protection circuit is required to be built because the drive module consisting of the overcurrent protection module and the discrete components in the IPM module has no overcurrent protection function in the prior art can be solved, and the effect of reducing the cost is achieved.
Description
Technical Field
The invention belongs to the technical field of motor control, and particularly relates to a motor protection device, a motor and a motor protection method, in particular to an overcurrent protection circuit, a motor with the overcurrent protection circuit and an overcurrent protection method of the motor.
Background
The discrete MOSFET or IGBT controllable component can replace an integrated IPM Module (Intelligent Power Module) driving motor as a low-cost scheme. In the running process of the motor, under the influence of various factors of voltage and current, the discrete component MOSFET or IGBT controllable component has a certain voltage and current bearing range, and the excessive voltage and current can cause the damage and the burning of a module, thereby causing the motor failure.
An overcurrent protection module is arranged in the integrated IPM module, but the hardware cost of the scheme is high.
Disclosure of Invention
The present invention provides a protection apparatus for a motor, a motor and a protection method thereof, to solve the problem of high cost of the IPM module in the prior art, and achieve the effect of reducing the cost.
The invention provides a protection device of a motor, comprising: the device comprises a sampling module, a first comparison module, a switch module and a first control module; the sampling module is used for acquiring the current voltage of the motor; the first comparison module is used for comparing the current voltage with a preset protection voltage; the switch module is used for triggering a preset overcurrent protection signal if the current voltage is greater than or equal to the protection voltage and the degree that the current voltage is greater than the protection voltage is within a set range; and the first control module is used for adjusting the output power of the motor according to the overcurrent protection signal so as to reduce the current voltage.
Optionally, wherein the sampling module includes: sampling a resistor; and/or, the first comparing module comprises: an operational amplifier and a first filter circuit, the first filter circuit being provided at an input side of the operational amplifier; and/or, the switch module comprises: the voltage division module is arranged at the input end of the triode; the switch module triggers a preset first overcurrent protection signal, and comprises: reducing the output voltage of the triode; and/or, the first control module adjusts the output power of the motor, including: and reducing the output power of the motor by adjusting the PWM duty ratio of the driving signal of the motor.
Optionally, the method further comprises: the second comparison module and the second control module; the second comparison module is configured to trigger a preset short-circuit protection signal if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range; the second control module is used for blocking the continuous operation of the motor according to the short-circuit protection signal; and/or the switch module is further configured to trigger a preset shutdown signal if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, or if the current voltage after the output power of the motor is adjusted is still increased; and the first control module is used for stopping the motor according to the stop signal.
Optionally, when the switch module includes a transistor and a voltage division module, the switch module triggers a preset shutdown signal, including: reducing the output voltage of the triode to a preset low level signal and outputting the signal to the first control module; and/or, the second comparing module comprises: the delay circuit is arranged at the output end of the comparator, and the second filter circuit is arranged at the input end of the comparator; the second comparison module triggers a preset short-circuit protection signal, and the method comprises the following steps: the second comparator outputs a preset low level signal to the second control module through the delay circuit; and/or at least one of the first control module and the second control module comprises: MCU; the first control module at least one of disabling operation of the motor and the second control module blocking continued operation of the motor includes: and switching off the driving signal of the motor by the MCU according to a preset low level signal.
Optionally, the method further comprises: setting a module; the setting module is arranged at the input end of the first comparison module and used for setting the protection voltage according to the actual application requirement of the protection device of the motor.
In accordance with another aspect of the present invention, there is provided a motor including: the protection device of the motor is described above.
In another aspect, the present invention provides a method for protecting a motor, including: acquiring the current voltage of the motor through a sampling module; comparing the current voltage with a preset protection voltage through a first comparison module; through a switch module, if the current voltage is greater than or equal to the protection voltage and the degree that the current voltage is greater than the protection voltage is within a set range, triggering a preset overcurrent protection signal; and adjusting the output power of the motor through a first control module according to the overcurrent protection signal so as to reduce the current voltage.
Optionally, the method further comprises: through a second comparison module, if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, triggering a preset short-circuit protection signal; blocking the continuous operation of the motor according to the short-circuit protection signal through a second control module; and/or triggering a preset shutdown signal if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range or if the current voltage after the output power of the motor is adjusted still increases through the switch module; and stopping the motor by the first control module according to the stop signal.
Optionally, the method further comprises: the protection device comprises a first comparison module, a second comparison module and a setting module, wherein the first comparison module is used for comparing the input voltage of the motor with the protection voltage of the motor, and the second comparison module is used for comparing the input voltage of the motor with the protection voltage of the motor.
According to the scheme of the invention, through the design of the peripheral circuit, the overcurrent protection point can be changed according to the actual application condition, effective protection can be realized, and the flexibility of product development is improved.
Further, according to the scheme of the invention, when the current reaches the protection point, the output power of the motor can be automatically adjusted according to the overcurrent point, so that the current of the motor is adjusted back, the motor cannot be shut down immediately, and the experience effect of a user cannot be influenced in product application.
Further, according to the scheme of the invention, when the current of the motor is continuously increased to the limit protection voltage point, the motor is stopped; if the motor is short-circuited and has a large current at the moment, the motor can be stopped immediately, and a second circuit is arranged to lock the motor to operate after being delayed, so that double protection is realized.
Therefore, according to the scheme provided by the invention, the peripheral overcurrent protection circuit of the controllable component is arranged, the motor current protection point can be set automatically, and corresponding overcurrent protection is carried out according to the overcurrent degree of the motor current when the motor current reaches the protection point, so that the problem of high cost of the IPM module in the prior art is solved, the defects of high cost, low reliability and high maintenance difficulty in the prior art are overcome, and the beneficial effects of low cost, high reliability and low maintenance difficulty are realized.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
Fig. 1 is a schematic structural diagram of an embodiment of a protection device for an electric machine according to the present invention;
fig. 2 is a schematic structural diagram of another embodiment of the protection device for the motor of the present invention.
Fig. 3 is a schematic structural diagram of an overcurrent protection circuit according to an embodiment of the motor of the present invention;
FIG. 4 is a schematic flow chart diagram illustrating an embodiment of a method for protecting a motor according to the present invention;
FIG. 5 is a schematic flow chart diagram illustrating an embodiment of short-circuit protection in the method of the present invention;
fig. 6 is a schematic flow chart illustrating an embodiment of continuing short-circuit protection in the method of the present invention.
The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:
102-a sampling module; 104-a first comparison module; 106-a switch module; 108-a first control module; 202-a second comparison module; 204-a second control module; 302-setup module.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A drive circuit module formed by discrete component MOSFET or IGBT controllable components has no overcurrent protection function and needs to build a peripheral protection circuit. According to an embodiment of the present invention, a protection device for an electric motor is provided, as shown in fig. 1, which is a schematic structural diagram of an embodiment of the device of the present invention. The protection apparatus of the motor may include: a sampling module 102, a first comparison module 104, a switching module 106, and a first control module 108.
In an alternative example, the sampling module 102 may be configured to obtain a current voltage (e.g., a sampling current IBUS) of the motor.
The sampling module 102 may include: the resistance is sampled.
Therefore, sampling is performed through the sampling resistor, the cost is low, the structure is simple, and the sampling result is accurate and good.
In an optional example, the first comparing module 104 may be configured to compare the current voltage with a preset protection voltage (e.g., a protection voltage corresponding to an overcurrent protection point of the motor).
The first comparing module 104 may include: an operational amplifier (e.g., operational amplifier U1) and a first filter circuit (e.g., filter capacitor C1) disposed on an input side of the operational amplifier.
Therefore, the current voltage is compared with the preset protection voltage through the adaptive arrangement of the operational amplifier and the first filter circuit, the structure is simple, the cost is low, and the reliability of the comparison result is good.
In an optional example, the switch module 106 may be configured to trigger a preset overcurrent protection signal if the current voltage is greater than or equal to the protection voltage and a degree that the current voltage is greater than the protection voltage is within a set range.
Optionally, if the current voltage is less than a preset protection voltage, a preset first overcurrent protection signal is not triggered, so that the motor operates normally.
For example: as shown in fig. 3, when the input IBUS does not reach the current trigger point, that is, the voltage of the output voltage of the operational amplifier U1 divided by the resistors R8 (e.g., voltage dividing resistors R7 and R8) is applied to the base of the transistor Q1, which is not enough to turn on, the voltage signal received by the main control chip (e.g., MCU) is almost V1, which is a normal operation state.
The switch module 106 may include: the voltage divider comprises a triode (such as a triode Q1) and a voltage dividing module (such as voltage dividing resistors R7 and R8), wherein the voltage dividing module is arranged at the input end of the triode (such as voltage dividing resistors R7 and R8 arranged at the base of a triode Q1).
Specifically, the triggering of the preset first overcurrent protection signal by the switch module 106 may include: the output voltage of the triode is reduced.
From this, set up through the adaptation of triode and partial pressure module and carry out trigger control to first control module, simple structure, with low costs, the reliability is high.
In an optional example, the first control module 108 may be configured to adjust the output power of the motor according to the over-current protection signal, so that the current voltage is decreased.
For example: when the current reaches the protection point, the motor can adjust the output power according to the overcurrent point, so that the motor current is adjusted back, the motor cannot be shut down at once, and the experience effect of a user cannot be influenced in product application.
For example: when the motor current reaches the protection point, the power output can be adjusted according to the overcurrent degree of the motor current, so that the overload capacity of the motor is improved.
Therefore, under the condition that the current voltage of the motor is greater than or equal to the preset protection voltage but the degree that the current voltage is greater than the protection voltage is within the set range, the output power of the motor is adjusted to reduce the current voltage of the motor, so that the motor is protected, and the safety is good; and the normal operation of the motor is conveniently ensured, and the reliability is high.
Wherein the first control module 108 regulates the output power of the motor and may include: and reducing the output power of the motor by adjusting the PWM duty ratio of the driving signal of the motor.
For example: as shown in fig. 3, when voltage fluctuation is increased due to unstable grid voltage or load is increased, the divided voltage of the resistor R8 is increased, when the divided voltage reaches the starting voltage of Q1, Q1 is turned on and enters an amplification state, the voltage received by the MCU is gradually reduced, the main control chip receives a signal and then outputs and adjusts power output by changing the duty ratio of PWM, so that the current of the sampling resistor is adjusted back to be decreased, thereby avoiding thermal breakdown of the MOSFET or IGBT controllable component due to long-time high-power operation, during the period when Q1 is turned on and reaches a saturation state, the voltage at the end of the resistor R7 is always lower than the terminal voltage of the resistor R12, and the comparator U2 is always in a high level state and does not trigger an overcurrent.
Therefore, the output power of the motor is reduced by adjusting the PWM duty ratio of the driving signal of the motor, so that the current voltage is reduced, and the motor driving circuit is simple and convenient in adjustment mode and high in reliability.
In an alternative embodiment, the method may further include: the short-circuit protection process, such as by the following first and/or second scenario, provides a heavy or double short-circuit protection of the motor.
The first case: the protection apparatus for the motor may further include a second comparison module 202 and a second control module 204.
In an optional example, the second comparing module 202 may be configured to trigger a preset short-circuit protection signal if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range.
The second comparing module 202 may include: a comparator (such as a comparator U2), a delay circuit (such as a delay circuit formed by a resistor R13 and a capacitor C4) and a second filter circuit (such as a filter capacitor C2, a filter capacitor C3 and the like), wherein the delay circuit is arranged at the output end of the comparator, and the second filter circuit is arranged at the input end of the comparator.
Specifically, the triggering of the preset short-circuit protection signal by the second comparing module 202 may include: the second comparator outputs a preset low level signal to the second control module 204 through the delay circuit.
Therefore, the second control module is triggered through the adaptive arrangement of the comparator, the delay circuit and the second filter circuit, the triggering mode is simple and convenient, and the timeliness is good.
In an alternative example, the second control module 204 may be configured to block the motor from continuing to operate according to the short-circuit protection signal.
For example: if the motor is short-circuited and has a large current at the moment, the motor can be stopped immediately, and a second circuit is arranged to lock the motor to operate after being delayed, so that double protection is realized.
For example: if the current of the motor reaches the maximum value instantly, the motor is cut off and protected by two circuits successively, so that the controllable components, the motor and the like are prevented from being broken down by large current, high voltage or heat, and the effect of double protection is achieved.
For example: as shown in fig. 3, if an emergency such as a short circuit or a locked rotor occurs, the IBUS voltage is instantaneously increased, so that the terminal voltage of the resistor R7 is greater than the voltage of the resistor R12, at this time, the output end of the comparator U2 outputs a low level signal through a delay circuit formed by the R13 and the C4, the MCU1 level is pulled low, the main control chip can timely turn off the driving module, so that the motor stops running, and the driving module and the motor are prevented from being burned out, while the speed of the comparator is faster than that of the triode Q1, because of the increased voltage of the resistor R7, the Q1 can also reach a saturation state, and a signal for turning off the driving module can also be sent out, so that a dual protection effect can be achieved by.
Therefore, through the adaptive setting of the second comparison module and the second control module, the continuous operation of the motor is blocked under the condition that the degree that the current voltage of the motor is greater than the preset protection voltage exceeds the set range, the motor is protected, and the protection efficiency is high.
At least one of the first control module 108 and the second control module 204 may include: the MCU (e.g., the first control module 108 may comprise an MCU and the second control module 204 may comprise a MUC 1).
Specifically, at least one of the first control module 108 stopping the motor and the second control module 204 blocking the motor from continuing to operate may include: and switching off the driving signal of the motor by the MCU according to a preset low level signal.
Therefore, the driving signal of the motor is controlled through the MCU, and the control accuracy and reliability can be ensured.
The second case: the short circuit protection continues with the switch module 106 and the first control module 108.
In an optional example, the switch module 106 may be further configured to trigger a preset shutdown signal if the current voltage is greater than the protection voltage and the current voltage is greater than the protection voltage by an extent exceeding the set range, or if the current voltage after the output power of the motor is adjusted still increases.
When the switch module 106 may include a transistor and a voltage divider module, the switch module 106 triggers a preset shutdown signal, which may include: the output voltage of the transistor is reduced to a preset low level signal and is output to the first control module 108.
Therefore, the first control module is triggered to cut off the driving signal of the motor in a mode that the output voltage of the triode is reduced to the preset low level signal, so that the motor stops running, and the triggering mode is simple and reliable.
In an alternative example, the first control module 108 may be configured to disable the motor based on the shutdown signal.
For example: when the motor current continuously increases to the limit protection voltage point, the motor is stopped.
For example: and if the current of the motor continuously increases and exceeds the set maximum current value, the motor is immediately stopped.
For example: as shown in fig. 3, if the voltage across the resistor R8 is still increased after the regulated power is decreased, Q1 enters a saturation state, the value of the MCU is pulled down to 0V, the motor stops running, and the motor restarts after the fault is cleared.
Therefore, the motor is stopped to run under the condition that the degree that the current voltage of the motor is greater than the preset protection voltage exceeds the set range through the switch module and the first control module, the protection reliability is high, and the safety is high.
In an alternative embodiment, the protection device for an electric motor may further include: a module 302 is provided (e.g., resistors R2, R4, R5, etc.).
The setting module 302 is disposed at an input end of the first comparing module 104, and may be configured to set the protection voltage according to an actual application requirement of the protection device of the motor.
For example: the overcurrent protection point can be changed according to the actual application condition, effective protection can be realized, and the flexibility of product development is improved.
Therefore, the protection voltage of the motor is set according to the actual application requirement, so that the application flexibility is good, and the universality is high.
Through a large number of tests, the technical scheme of the embodiment is adopted, and through the design of the peripheral circuit, the overcurrent protection point can be changed according to the actual application condition, effective protection can be realized, and the flexibility of product development is improved.
According to an embodiment of the present invention, there is also provided a motor corresponding to a protection device of the motor. The motor may include: the motor protection device is described above.
In an optional embodiment, the invention provides an overcurrent protection peripheral circuit, which has lower cost, high reliability and more convenient and simpler later maintenance compared with an IPM module.
Optionally, according to the scheme of the invention, the overcurrent protection point can be changed according to the actual application condition through the design of the peripheral circuit, effective protection can be realized, and the flexibility of product development is improved.
For example: referring to the example shown in fig. 3, the over-current protection point may be modified by adjusting the amplification of the operational amplifier U1 and/or adjusting the reference voltage of the comparator U2. Such as: by adjusting the resistance values of the resistors R5 and R6, the amplification factor of the operational amplifier U1 can be adjusted. For another example: by adjusting the resistance of the resistors R11 and R12, the reference voltage of the comparator U2 can be adjusted.
Optionally, according to the scheme of the invention, when the current reaches the protection point, the output power of the motor can be automatically adjusted according to the overcurrent point, so that the current of the motor is adjusted back, the motor cannot be shut down immediately, and the experience effect of a user cannot be influenced in product application.
Optionally, according to the scheme of the invention, when the current of the motor is continuously increased to the limit protection voltage point, the motor is stopped; that is, the motor can be immediately stopped when the motor current reaches a protection point. If the motor is short-circuited and has a large current at the moment, the motor can be stopped immediately, and a second circuit is arranged to lock the motor to operate after being delayed, so that double protection is realized.
In an alternative example, the scheme of the invention achieves the function of automatically setting the current protection point of the motor by designing a simple peripheral circuit in a control circuit of the direct current brushless motor. When the motor current reaches a protection point, the power output can be adjusted according to the overcurrent degree of the motor current, so that the overload capacity of the motor is improved; if the current of the motor continuously increases and exceeds the set maximum current value, the motor is immediately stopped: if the current of the motor reaches the maximum value instantly, the motor is cut off and protected by two circuits successively, so that the controllable components, the motor and the like are prevented from being broken down by large current, high voltage or heat, and the effect of double protection is achieved.
Fig. 3 can be a schematic diagram of the overcurrent protection circuit of the present invention. In fig. 3, U1 is an operational amplifier, U2 is a comparator, 13 fixed resistance resistors R1 to R13, C1, C2, and C3 are filter capacitors, R13 and C4 form an RC delay circuit, Q1 is an NPN transistor, V1 is a given analog voltage signal, and VCC is a chip power supply.
For example: the operational amplifier function of the operational amplifier U1 can be adjusted by adjusting the resistance values of the resistors R1-R6; the transistor Q1 can be protected through the resistor R7; the conduction and amplification functions of the triode Q1 can be controlled through voltage division through the resistor R8, and the resistance value of the resistor R8 is generally larger than that of the resistor R7; through the cooperation of resistance R12, electric capacity C3 to and resistance R10, electric capacity C2 etc., can realize the filtering function, can also realize the time delay function.
With reference to the example shown in fig. 3, the specific working principle of the present invention is described as follows:
IBUS is sampling resistance voltage, after being amplified by an operational amplifier U1, one path of the sampling resistance voltage is supplied to OCP (short circuit over-current protection), and the other path of the sampling resistance voltage is supplied to a Q1NPN triode for over-current range protection. For example: the sampling resistor voltage can be a voltage loaded on a sampling resistor between the current output end of the motor winding and the ground.
(1) When the input IBUS does not reach the current trigger point, that is, the voltage of the output voltage of the operational amplifier U1 is divided by the resistors R8 (such as voltage dividing resistors R7 and R8) and applied to the base of the transistor Q1 is not enough to turn on, the voltage signal received by the main control chip (such as MCU) is almost V1, which is a normal operation state.
(2) When the voltage fluctuation is increased due to unstable grid voltage or the load is increased, the divided voltage of the resistor R8 is increased, when the starting voltage of the Q1 is reached, the Q1 is conducted and enters an amplification state, the voltage received by the MCU is gradually reduced, the main control chip outputs and adjusts the power output by changing the duty ratio of the PWM after receiving signals, the current of the sampling resistor is adjusted back and reduced, the phenomenon that a MOSFET or IGBT controllable component runs at high power for a long time and is thermally broken down is avoided, when the Q1 is conducted and reaches a saturation state, the voltage of the resistor R7 end is always lower than the terminal voltage of the resistor R12, the comparator U2 is always in a high level state, and the overcurrent protection function is not triggered.
Optionally, if the terminal voltage of the resistor R8 is still increased after the regulated power is reduced, the Q1 enters a saturation state, the value of the MCU is pulled down to 0V, the motor stops running, and the motor restarts after the fault is cleared.
Optionally, if an emergency such as a short circuit or a locked rotor occurs, the IBUS voltage is instantly increased, so that the terminal voltage of the resistor R7 is greater than the voltage of the resistor R12, at this time, the output end of the comparator U2 outputs a low level signal through a delay circuit formed by the R13 and the C4, the level of the MCU1 is pulled low, the main control chip can turn off the driving module in time, so that the motor stops running, and the driving module and the motor are prevented from being burned out, while the speed of the comparator is faster than that of the triode Q1, so that the Q1 can reach a saturated state due to the increased voltage of the resistor R7, and a signal for turning off the driving module can be sent, thereby achieving the effect of dual protection by matching use.
In an alternative example, Q1 may be replaced by other switching devices that select the same operating principle, and the selection of peripheral devices is redesigned to achieve the same switching action. Q1 may be any switching tube having a switching state and an amplifying state, such as a MOSFET, an IGBT, etc.
Since the processes and functions implemented by the motor of this embodiment substantially correspond to the embodiments, principles and examples of the devices shown in fig. 1 to fig. 2, the description of this embodiment is not detailed, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.
Through a large number of tests, the technical scheme of the invention is adopted, and when the current reaches the protection point, the output power of the motor can be automatically adjusted according to the overcurrent point, so that the current of the motor is adjusted back, the motor cannot be shut down immediately, and the experience effect of a user cannot be influenced in product application.
According to an embodiment of the present invention, there is also provided a method for protecting a motor corresponding to the motor, as shown in fig. 4, which is a schematic flow chart of an embodiment of the method of the present invention. The protection method of the motor may include: step S110 to step S140.
At step S110, the current voltage of the motor is obtained through the sampling module 102.
At step S120, the current voltage is compared with a preset protection voltage by the first comparing module 104.
In step S130, if the current voltage is greater than or equal to the protection voltage and the degree that the current voltage is greater than the protection voltage is within a set range, a preset overcurrent protection signal is triggered through the switch module 106. Optionally, if the current voltage is less than a preset protection voltage, a preset first overcurrent protection signal is not triggered, so that the motor operates normally.
In step S140, the output power of the motor is adjusted by the first control module 108 according to the over-current protection signal, so that the current voltage becomes smaller.
For example: when the current reaches the protection point, the motor can adjust the output power according to the overcurrent point, so that the motor current is adjusted back, the motor cannot be shut down at once, and the experience effect of a user cannot be influenced in product application.
For example: when the motor current reaches the protection point, the power output can be adjusted according to the overcurrent degree of the motor current, so that the overload capacity of the motor is improved.
Therefore, under the condition that the current voltage of the motor is greater than or equal to the preset protection voltage but the degree that the current voltage is greater than the protection voltage is within the set range, the output power of the motor is adjusted to reduce the current voltage of the motor, so that the motor is protected, and the safety is good; and the normal operation of the motor is conveniently ensured, and the reliability is high.
In an alternative embodiment, the method may further include: the short-circuit protection process, such as by the following first and/or second scenario, provides a heavy or double short-circuit protection of the motor.
The first case: the protection apparatus for the motor may further include a second comparison module 202 and a second control module 204.
The following further describes a specific process of short-circuit protection with reference to a schematic flow chart of an embodiment of short-circuit protection in the method of the present invention shown in fig. 5.
Step S210, by the second comparing module 202, if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, triggering a preset short-circuit protection signal.
And step S220, the second control module 204 locks the continuous operation of the motor according to the short-circuit protection signal.
For example: if the motor is short-circuited and has a large current at the moment, the motor can be stopped immediately, and a second circuit is arranged to lock the motor to operate after being delayed, so that double protection is realized.
For example: if the current of the motor reaches the maximum value instantly, the motor is cut off and protected by two circuits successively, so that the controllable components, the motor and the like are prevented from being broken down by large current, high voltage or heat, and the effect of double protection is achieved.
For example: as shown in fig. 3, if an emergency such as a short circuit or a locked rotor occurs, the IBUS voltage is instantaneously increased, so that the terminal voltage of the resistor R7 is greater than the voltage of the resistor R12, at this time, the output end of the comparator U2 outputs a low level signal through a delay circuit formed by the R13 and the C4, the MCU1 level is pulled low, the main control chip can timely turn off the driving module, so that the motor stops running, and the driving module and the motor are prevented from being burned out, while the speed of the comparator is faster than that of the triode Q1, because of the increased voltage of the resistor R7, the Q1 can also reach a saturation state, and a signal for turning off the driving module can also be sent out, so that a dual protection effect can be achieved by.
Therefore, through the adaptive setting of the second comparison module and the second control module, the continuous operation of the motor is blocked under the condition that the degree that the current voltage of the motor is greater than the preset protection voltage exceeds the set range, the motor is protected, and the protection efficiency is high.
The second case: the short circuit protection continues with the switch module 106 and the first control module 108.
The following further describes a specific process of continuing short-circuit protection with reference to a schematic flow chart of an embodiment of continuing short-circuit protection in the method of the present invention shown in fig. 6.
Step S310, through the switch module 106, if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, or if the current voltage after the output power of the motor is adjusted is still increased, a preset shutdown signal is triggered.
And step S320, stopping the motor by the first control module 108 according to the stop signal.
For example: when the motor current continuously increases to the limit protection voltage point, the motor is stopped.
For example: and if the current of the motor continuously increases and exceeds the set maximum current value, the motor is immediately stopped.
For example: as shown in fig. 3, if the voltage across the resistor R8 is still increased after the regulated power is decreased, Q1 enters a saturation state, the value of the MCU is pulled down to 0V, the motor stops running, and the motor restarts after the fault is cleared.
Therefore, the motor is stopped to run under the condition that the degree that the current voltage of the motor is greater than the preset protection voltage exceeds the set range through the switch module and the first control module, the protection reliability is high, and the safety is high.
In an alternative embodiment, the method may further include: the setting module 302 is disposed at an input end of the first comparing module 104, and may be configured to set the protection voltage according to an actual application requirement of the protection device of the motor.
For example: the overcurrent protection point can be changed according to the actual application condition, effective protection can be realized, and the flexibility of product development is improved.
Therefore, the protection voltage of the motor is set according to the actual application requirement, so that the application flexibility is good, and the universality is high.
Since the processing and functions implemented by the method of this embodiment substantially correspond to the embodiments, principles and examples of the motor, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment, which is not described herein.
Through a large number of tests, the technical scheme of the invention is adopted, and when the current of the motor is continuously increased to the limit protection voltage point, the motor is stopped; if the motor is short-circuited and has a large current at the moment, the motor can be stopped immediately, and a second circuit is arranged to lock the motor to operate after being delayed, so that double protection is realized.
In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.
The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.
Claims (9)
1. A protection device for an electric machine, comprising: the device comprises a sampling module (102), a first comparison module (104), a switch module (106) and a first control module (108); wherein,
the sampling module (102) is used for acquiring the current voltage of the motor;
the first comparison module (104) is used for comparing the current voltage with a preset protection voltage;
the switch module (106) is used for triggering a preset overcurrent protection signal if the current voltage is greater than or equal to the protection voltage and the degree that the current voltage is greater than the protection voltage is within a set range;
the first control module (108) is used for adjusting the output power of the motor according to the overcurrent protection signal so as to reduce the current voltage.
2. The apparatus of claim 1, wherein,
the sampling module (102) comprising: sampling a resistor;
and/or the presence of a gas in the gas,
the first comparison module (104) comprising: an operational amplifier and a first filter circuit, the first filter circuit being provided at an input side of the operational amplifier;
and/or the presence of a gas in the gas,
the switch module (106) comprising: the voltage division module is arranged at the input end of the triode;
the switch module (106) triggers a preset first overcurrent protection signal, comprising: reducing the output voltage of the triode;
and/or the presence of a gas in the gas,
the first control module (108) regulates output power of the motor, including: and reducing the output power of the motor by adjusting the PWM duty ratio of the driving signal of the motor.
3. The apparatus of claim 1 or 2, further comprising: a second comparison module (202) and a second control module (204); wherein,
the second comparison module (202) is configured to trigger a preset short-circuit protection signal if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range;
the second control module (204) is used for blocking the continuous operation of the motor according to the short-circuit protection signal;
and/or the presence of a gas in the gas,
the switch module (106) is further configured to trigger a preset shutdown signal if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, or if the current voltage after the output power of the motor is adjusted is still increased;
the first control module (108) is used for stopping the motor according to the stop signal.
4. The apparatus of claim 3, wherein,
when the switch module (106) includes a triode and a voltage divider module, the switch module (106) triggers a preset shutdown signal, including: reducing the output voltage of the triode to a preset low level signal and outputting the signal to the first control module (108);
and/or the presence of a gas in the gas,
the second comparison module (202) comprising: the delay circuit is arranged at the output end of the comparator, and the second filter circuit is arranged at the input end of the comparator;
the second comparing module (202) triggers a preset short-circuit protection signal, including: the second comparator outputs a preset low level signal to the second control module (204) through the delay circuit;
and/or the presence of a gas in the gas,
at least one of the first control module (108), the second control module (204), comprising: MCU;
at least one of the first control module (108) disabling the motor and the second control module (204) blocking continued operation of the motor includes: and switching off the driving signal of the motor by the MCU according to a preset low level signal.
5. The apparatus of any of claims 1-4, further comprising: a setup module (302);
the setting module (302) is arranged at the input end of the first comparison module (104) and is used for setting the protection voltage according to the actual application requirement of the protection device of the motor.
6. An electric machine, comprising: a protection device for an electric machine as claimed in any one of claims 1 to 5.
7. A method of protecting an electric machine according to claim 6, comprising:
acquiring the current voltage of the motor through a sampling module (102);
comparing the current voltage with a preset protection voltage through a first comparison module (104);
through a switch module (106), if the current voltage is greater than or equal to the protection voltage and the degree that the current voltage is greater than the protection voltage is within a set range, triggering a preset overcurrent protection signal;
and adjusting the output power of the motor according to the overcurrent protection signal through a first control module (108) so as to reduce the current voltage.
8. The method of claim 7, further comprising:
through a second comparison module (202), if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, triggering a preset short-circuit protection signal;
blocking the motor from continuing to operate according to the short-circuit protection signal through a second control module (204);
and/or the presence of a gas in the gas,
through the switch module (106), if the current voltage is greater than the protection voltage and the degree that the current voltage is greater than the protection voltage exceeds the set range, or if the current voltage after the output power of the motor is adjusted is still increased, a preset shutdown signal is triggered;
and stopping the motor by the first control module (108) according to the stop signal.
9. The method of claim 7 or 8, further comprising:
the protection voltage is set at the input end of the first comparison module (104) through a setting module (302) and is used for setting the protection voltage according to the actual application requirement of the protection device of the motor.
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| CN201810617987.XA CN108923387B (en) | 2018-06-15 | 2018-06-15 | Motor protection device, motor and protection method thereof |
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| CN201810617987.XA CN108923387B (en) | 2018-06-15 | 2018-06-15 | Motor protection device, motor and protection method thereof |
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| CN110690683A (en) * | 2019-11-05 | 2020-01-14 | 四川虹美智能科技有限公司 | Overcurrent protection circuit and overcurrent protection device of intelligent power module |
| CN112019124A (en) * | 2019-05-29 | 2020-12-01 | 北京新能源汽车股份有限公司 | Motor device and car |
| CN112350644A (en) * | 2020-10-21 | 2021-02-09 | 苏州索斯曼电气有限公司 | Motor controller with short-circuit protection function |
| CN112653093A (en) * | 2019-10-10 | 2021-04-13 | 惠州拓邦电气技术有限公司 | Method and device for preventing AC motor from stalling |
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| CN108923387B (en) | 2020-01-21 |
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