CN116093880A - Overcurrent protection device, drive control circuit and motor assembly - Google Patents

Overcurrent protection device, drive control circuit and motor assembly Download PDF

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Publication number
CN116093880A
CN116093880A CN202310002144.XA CN202310002144A CN116093880A CN 116093880 A CN116093880 A CN 116093880A CN 202310002144 A CN202310002144 A CN 202310002144A CN 116093880 A CN116093880 A CN 116093880A
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China
Prior art keywords
circuit
resistor
sampling
branch
detection
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Pending
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CN202310002144.XA
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Chinese (zh)
Inventor
刘大巍
何震球
柴明
姚宏
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Hollysys Electric Technology Co ltd
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Hollysys Electric Technology Co ltd
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Priority to CN202310002144.XA priority Critical patent/CN116093880A/en
Publication of CN116093880A publication Critical patent/CN116093880A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00—Details of emergency protective circuit arrangements
    • H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/10—Measuring sum, difference or ratio
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
    • 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
    • H02H7/0854—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 responsive to rate of change of current, couple or speed, e.g. anti-kickback protection

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The embodiment of the invention provides an overcurrent protection device, a drive control circuit and a motor assembly, wherein the overcurrent protection device comprises: the sampling circuit is used for connecting the positive electrode of the power supply and the driving circuit; the mirror image current source circuit is connected with the sampling circuit; the detection circuit is connected with the mirror current source circuit, and the mirror current source circuit can control whether the detection circuit is conducted or not according to the sampling value of the sampling circuit; the control circuit is connected with the detection circuit; under the condition that the detection circuit is conducted, the detection circuit sends a conducting signal to the control circuit, so that the control circuit sends out an overcurrent early warning signal according to the conducting signal. The current with the same size can be detected by using the smaller sampling resistor, so that the power consumed by the sampling resistor can be greatly reduced, particularly when the large current is detected, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged. The volume of the sampling resistor can be reduced, and the occupied area of the sampling resistor on the PCB is further reduced.

Description

Overcurrent protection device, drive control circuit and motor assembly
Technical Field
The embodiment of the invention relates to the technical field of overcurrent protection, in particular to an overcurrent protection device, a drive control circuit and a motor assembly.
Background
At present, an overcurrent detection circuit is generally used in occasions such as power device protection of motor drive, overcurrent protection of a switching power supply, power management of a battery and the like. The purpose is to prevent the power device from losing efficacy due to thermal breakdown caused by high current, thereby cutting off an abnormal high-current conduction loop and further protecting the power device.
An economical and low-cost current detection method generally uses a voltage generated by a current flowing through a resistor to detect the current. The related art places a resistor between the driving circuit and ground in a manner called low-side current detection.
However, if there is a problem in the motor winding that leakage occurs, the current flowing from the positive end of the power supply may flow directly back to GND without passing through the current sampling resistor, which may cause an overcurrent but is not detected. In addition, if the current sampling resistor fails or burns out, the voltage at the positive end of the power supply can be directly applied to the overcurrent detection circuit and the driving circuit of the power tube, so that the electronic components at the control end are burnt out in a large area.
In addition, if a relatively large current is to be detected, a resistance with relatively large rated power is required, so that heat generation is relatively large, and the occupied area of the PCB is relatively large.
Disclosure of Invention
Embodiments of the present invention aim to solve at least one of the technical problems existing in the prior art.
To this end, a first aspect of an embodiment of the present invention provides an overcurrent protection device.
A second aspect of an embodiment of the present invention provides a drive control circuit.
A third aspect of embodiments of the present invention provides a motor assembly.
In view of this, according to a first aspect of an embodiment of the present invention, there is provided an overcurrent protection device including: the sampling circuit is used for connecting the positive electrode of the power supply and the driving circuit; the mirror image current source circuit is connected with the sampling circuit; the detection circuit is connected with the mirror current source circuit, and the mirror current source circuit can control whether the detection circuit is conducted or not according to the sampling value of the sampling circuit; the control circuit is connected with the detection circuit; under the condition that the detection circuit is conducted, the detection circuit sends a conducting signal to the control circuit, so that the control circuit sends out an overcurrent early warning signal according to the conducting signal.
The overcurrent protection device provided by the embodiment of the invention comprises a sampling circuit, a mirror current source circuit, a detection circuit and a control circuit, wherein the sampling circuit is connected with the positive electrode of a power supply and the driving circuit, the mirror current source circuit is connected with the sampling circuit, the detection circuit is connected with the mirror current source circuit, and the control circuit is connected with the detection circuit, namely, the overcurrent protection device is arranged between the positive electrode of the power supply and the driving circuit, namely, high-end current detection is performed.
Through setting up overcurrent protection device between the anodal and the drive circuit of power supply, compare in the correlation technique with overcurrent detection circuit setting between drive circuit and ground, because total current is from the anodal outflow of power, can not exist the reposition of redundant personnel condition that low-end current detection exists, ensure carrying out effectual detection to the heavy current, improve the accuracy of current detection.
In addition, since the overcurrent protection device part can bear high-end common-mode voltage, even if the sampling resistor of the sampling circuit fails or burns out, the driving circuit part cannot be burnt out, so that when the overcurrent protection device prevents large current from flowing through the driving circuit to cause thermal breakdown of the power devices to fail, the use safety of the driving control circuit with the overcurrent protection device is further ensured, and the service life of each power device in the driving circuit is prolonged.
The mirror current source circuit can control whether the detection circuit is conducted according to the sampling value of the sampling circuit, for example, when the sampling value of the sampling circuit is smaller than a preset sampling value, that is, a smaller current flows from the positive electrode of the power supply, the mirror current source circuit generates a smaller voltage difference, or the generated voltage difference is zero, so that the detection circuit cannot be conducted, and a detection module of the detection circuit cannot detect a voltage signal or a current signal.
When the sampling value of the sampling circuit is greater than or equal to a preset sampling value, namely, larger current flows out from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of a power device on the driving circuit to fail, the mirror current source circuit generates larger voltage difference, the larger voltage difference can enable the detection circuit to be conducted, so that the detection module can detect a voltage signal or a current signal and send a conducting signal to the control circuit, and the control circuit sends an overcurrent early warning signal according to the conducting signal, so that the driving signal is cut off, namely, the driving circuit does not flow current any more, and the power device on the driving circuit is prevented from being burnt.
In addition, compared with the prior art without the mirror current source circuit, the current detection circuit can utilize the smaller sampling resistor to detect the current with the same size by controlling the conduction state of the detection circuit through the mirror current source circuit, so that the power consumed by the sampling resistor can be greatly reduced, particularly when detecting the large current, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged.
And moreover, the volume of the sampling resistor can be reduced, so that the occupied area of the sampling resistor on the PCB is reduced, and the space utilization rate of the PCB is improved.
In practical application, the sampling circuit comprises a sampling resistor, the mirror current source circuit comprises two PNP triodes with the same parameters, and the bases of the two triodes are connected. The detection circuit comprises a PVP triode, namely, the conduction state of the PVP triode is controlled through the mirror current source circuit.
In addition, the overcurrent protection device provided by the technical scheme of the invention has the following additional technical characteristics:
in one possible technical scheme, when the sampling value is smaller than a preset sampling value, the mirror current source circuit outputs a first voltage difference so as to cut off the detection circuit; when the sampling value is greater than or equal to a preset sampling value, the mirror current source circuit outputs a second voltage difference so as to enable the detection circuit to be conducted; wherein the first voltage difference is less than the second voltage difference.
In the technical scheme, when the sampling value of the sampling circuit is smaller than a preset sampling value, namely smaller current flows out from the positive electrode of the power supply, the mirror current source circuit generates a first voltage difference, wherein the first voltage difference is smaller, or the first voltage difference is zero, so that the detection circuit cannot be conducted, and a detection module of the detection circuit cannot detect a voltage signal or a current signal.
When the sampling value of the sampling circuit is greater than or equal to a preset sampling value, namely, a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of a power device on the driving circuit to fail, the mirror current source circuit generates a second voltage difference, wherein the second voltage difference is greater than the first voltage difference, the larger second voltage difference can enable the detection circuit to be conducted, so that the detection module can detect a voltage signal or a current signal and send a conducting signal to the control circuit, the control circuit sends an overcurrent early warning signal according to the conducting signal, and therefore the driving signal is cut off, namely, the driving circuit does not flow current any more, and the power device on the driving circuit is prevented from being burnt.
In addition, compared with the prior art without the mirror current source circuit, the current detection circuit can utilize the smaller sampling resistor to detect the current with the same size by controlling the conduction state of the detection circuit through the mirror current source circuit, so that the power consumed by the sampling resistor can be greatly reduced, particularly when detecting the large current, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged.
And moreover, the volume of the sampling resistor can be reduced, so that the occupied area of the sampling resistor on the PCB is reduced, and the space utilization rate of the PCB is improved.
In one possible solution, the sampling circuit includes a sampling resistor, and the sampling resistor is used to connect the positive electrode of the power supply and the driving circuit.
In this solution, the sampling circuit comprises a sampling resistor, i.e. the current is detected by means of a voltage generated by the current flowing through the sampling resistor. Further, the sampling resistor is connected between the positive electrode of the power supply and the driving circuit, and compared with the resistor arranged between the driving circuit and the ground in the related art, the total current flows out from the positive electrode of the power supply, so that the current detection device has no shunt condition of low-end current detection, ensures effective detection of large current and improves the accuracy of current detection.
In addition, since the overcurrent protection device part can bear high-end common-mode voltage, even if the sampling resistor fails or burns out, the drive circuit part cannot be burnt out, so that when the overcurrent protection device prevents large current from flowing through the drive circuit to cause thermal breakdown of the power devices to fail, the use safety of the drive control circuit with the overcurrent protection device is further ensured, and the service life of each power device in the drive circuit is prolonged.
In one possible technical scheme, the mirror current source circuit comprises a first branch and a second branch, wherein the first branch is connected with the positive electrode of the power supply and the sampling resistor, the first branch is provided with a first switch element, the second branch is connected with the sampling resistor and the driving circuit and is connected with the first branch in parallel, the second branch is provided with a second switch element, the second switch element is connected with the first switch element, and the detection circuit is connected with the first branch and the second branch.
In the technical scheme, the mirror current source circuit is limited to comprise two parallel first branches and two second branches, the first branches are connected with the positive electrode of the power supply and the sampling resistor, the second branches are connected with the sampling resistor and the driving circuit, the first branches are provided with first switch pieces, the second branches are provided with second switch pieces, the first switch pieces are connected with the second switch pieces, and the detection circuit is connected with the first branches and the second branches.
It can be understood that when the sampling value of the sampling circuit is smaller than the preset sampling value, that is, a smaller current flows from the positive electrode of the power supply, the first switch element and the second switch element are closed, so that the mirror current source circuit generates a smaller voltage difference, or the generated voltage difference is zero, so that the detection circuit cannot be conducted, and the detection module of the detection circuit cannot detect the voltage signal or the current signal.
When the sampling value of the sampling circuit is greater than or equal to a preset sampling value, namely, a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of a power device on the driving circuit to fail, at the moment, the first switch piece is closed, the second switch piece is opened, so that the mirror current source circuit generates a larger voltage difference, the larger voltage difference can enable the detection circuit to be conducted, the detection module can detect a voltage signal or a current signal, and a conducting signal is sent to the control circuit, the control circuit sends an overcurrent early warning signal according to the conducting signal, so that the driving signal is cut off, namely, the driving circuit does not flow current any more, and the power device on the driving circuit is prevented from being burnt.
In addition, compared with the prior art without the mirror current source circuit, the current detection circuit can utilize the smaller sampling resistor to detect the current with the same size by controlling the conduction state of the detection circuit through the mirror current source circuit, so that the power consumed by the sampling resistor can be greatly reduced, particularly when detecting the large current, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged.
And moreover, the volume of the sampling resistor can be reduced, so that the occupied area of the sampling resistor on the PCB is reduced, and the space utilization rate of the PCB is improved.
In practical application, the first switch element and the second switch element are PNP type triodes with the same parameters, and the bases of the PNP type triodes are connected to form a mirror current source circuit.
In one possible technical scheme, the mirror current source circuit further comprises a first resistor and a second resistor, wherein the first resistor is arranged on the first branch, the first resistor is connected with the first switch element, the second resistor is arranged on the second branch, and the second resistor is connected with the second switch element; the resistance of the first resistor is the same as that of the second resistor.
In this technical scheme, it still includes first resistance and second resistance to have limited mirror image current source circuit, and first resistance sets up on first branch, and the second resistance sets up on the second branch, through setting up the resistance respectively on two branches, can play the effect of current-limiting to improve overcurrent protection device's interference killing feature.
The resistance of the first resistor is the same as that of the second resistor, so that the mirror current source circuit can accurately control the on-off of the detection circuit, and the detection of large current is realized.
In one possible technical scheme, the mirror current source circuit further comprises a third resistor and a fourth resistor, wherein the third resistor is arranged on the first branch, the third resistor is connected with the positive electrode of the power supply and the first switch piece, the fourth resistor is arranged on the second branch, and the fourth resistor is connected with the sampling resistor and the second switch piece; the resistance value of the third resistor is the same as that of the fourth resistor, and the resistance value of the third resistor is smaller than that of the first resistor; and/or the resistance value of the fourth resistor is smaller than the resistance value of the second resistor.
In this solution, it is defined that the mirrored current source circuit further comprises a third resistor and a fourth resistor,
specifically, the third resistor is arranged on the first branch, the fourth resistor is arranged on the second branch, and the anti-interference capability of the overcurrent protection device is further improved by 5.
In addition, the resistance of the third resistor is the same as that of the fourth resistor, the third resistor is smaller than that of the first resistor, and the fourth resistor is smaller than that of the second resistor, so that the large current detection is realized, the open-close state of the second switch piece is prevented from being influenced due to excessive voltage division of the fourth resistor, the accuracy of the overcurrent protection device on the large current detection is further improved, and the service life of each power device on the driving circuit is prolonged.
In one possible solution, the detection circuit comprises a third switching element and a detection module, wherein,
the third switch piece is connected with the first branch and the second branch, and the detection module is connected with the third switch piece; when the third switch piece is conducted, the detection module sends a conducting signal to the control circuit, so that the control circuit sends an overcurrent early warning signal according to the conducting signal.
In this technical solution, it is defined that the detection circuit comprises a third switching element and a detection module, in particular, 5 the third switching element is connected with the first branch and the second branch, the detection module is connected with the third switching element, when sampling
When the sampling value of the circuit is smaller than the preset sampling value, namely smaller current flows out from the positive electrode of the power supply, the mirror current source circuit generates smaller voltage difference, or the generated voltage difference is zero, the third switch piece is opened, so that the detection circuit cannot be conducted, and a detection module of the detection circuit cannot detect a voltage signal or a current signal.
0 when the sampling value of the sampling circuit is greater than or equal to the preset sampling value, namely, a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes the power device on the driving circuit to generate thermal breakdown and fail, the mirror current source circuit generates a larger voltage difference, the larger voltage difference can enable the third switch piece to be closed, the detection circuit is conducted, thereby enabling the detection module to detect a voltage signal or a current signal, and
and sending a conduction signal to the control circuit, and sending an overcurrent early warning signal by the control circuit according to the conduction signal, so that the drive signal is cut off 5, namely, no current flows into the drive circuit, and the power device on the drive circuit is prevented from being burnt.
In practical applications, the third switch element is a PNP transistor. The base electrode of the triode is connected with the second branch, and the emitter electrode is connected with the first branch.
In one possible technical scheme, the first switch piece is a PNP triode; and/or the second switch element is a PNP triode; and/or the third switch element is a PNP triode.
In the technical scheme, the first switch piece, the second switch piece and the third switch piece are PNP triodes. The setting can be specifically performed according to actual needs. Simple structure, convenient operation.
According to a second aspect of the present invention, a driving control circuit is provided, which includes the overcurrent protection device provided in any one of the above technical solutions, so that all the beneficial technical effects of the overcurrent protection device are provided, and are not described herein.
Further, the drive control circuit further comprises a power supply and a drive circuit, wherein the overcurrent protection device is connected with the positive electrode of the power supply and the drive circuit.
The drive control circuit provided by the embodiment of the invention comprises the over-current protection device, the power supply and the drive circuit, and particularly, compared with the prior art that the over-current detection circuit is arranged between the drive circuit and the ground by arranging the over-current protection device between the positive electrode of the power supply and the drive circuit, the drive control circuit provided by the embodiment of the invention has the advantages that the total current flows out from the positive electrode of the power supply, the shunt condition existing in low-end current detection is avoided, the effective detection of large current is ensured, and the accuracy of current detection is improved.
In addition, since the overcurrent protection device part can bear high-end common-mode voltage, even if the sampling resistor of the sampling circuit fails or burns out, the driving circuit part cannot be burnt out, so that when the overcurrent protection device prevents large current from flowing through the driving circuit to cause thermal breakdown of the power devices to fail, the use safety of the driving control circuit with the overcurrent protection device is further ensured, and the service life of each power device in the driving circuit is prolonged.
According to a third aspect of the present invention, there is provided a motor assembly, including the driving control circuit provided in any of the above-mentioned technical solutions, so as to have all the beneficial technical effects of the driving control circuit, which are not described herein.
Further, the motor assembly further includes a motor, and the drive control circuit is configured to control operation of the motor.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:
fig. 1 shows a schematic structural view of an overcurrent protection device according to an embodiment of the present invention;
fig. 2 shows a specific structural schematic diagram of an overcurrent protection device according to an embodiment of the present invention.
The correspondence between the reference numerals and the component names in fig. 1 and 2 is:
100 overcurrent protection device, 110 sampling circuit, 120 mirror current source circuit, 121 first branch, 122 first switch element, 123 second branch, 124 second switch element, 125 first resistor, 126 second resistor, 127 third resistor, 128 fourth resistor, 130 detection circuit, 131 third switch element, 132 detection module, 140 control circuit.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced otherwise than as described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.
An overcurrent protection device 100, a drive control circuit, and a motor assembly provided according to some embodiments of the present invention are described below with reference to fig. 1 and 2.
In one embodiment according to the present application, as shown in fig. 1 and 2, an overcurrent protection device 100 is proposed, the overcurrent protection device 100 including: a sampling circuit 110 for connecting the positive electrode of the power supply and the driving circuit; a mirror current source circuit 120 connected to the sampling circuit 110; the detection circuit 130 is connected with the mirror current source circuit 120, and the mirror current source circuit 120 can control whether the detection circuit 130 is conducted or not according to the sampling value of the sampling circuit 110; a control circuit 140 connected to the detection circuit 130; when the detection circuit 130 is turned on, the detection circuit 130 sends an on signal to the control circuit 140, so that the control circuit 140 sends an over-current warning signal according to the on signal.
The overcurrent protection device 100 provided in the embodiment of the invention includes a sampling circuit 110, a current mirror circuit 120, a detection circuit 130 and a control circuit 140, specifically, the sampling circuit 110 is connected to the positive electrode of the power supply and the driving circuit, the current mirror circuit 120 is connected to the sampling circuit 110, the detection circuit 130 is connected to the current mirror circuit 120, and the control circuit 140 is connected to the detection circuit 130, that is, the overcurrent protection device 100 is disposed between the positive electrode of the power supply and the driving circuit, that is, the high-side current detection.
By arranging the overcurrent protection device 100 between the positive electrode of the power supply and the driving circuit, compared with the prior art in which the overcurrent detection circuit is arranged between the driving circuit and the ground, the total current flows out from the positive electrode of the power supply, so that the current detection device can not have the shunt condition of low-end current detection, ensure the effective detection of large current and improve the accuracy of current detection.
In addition, since the over-current protection device 100 can bear a high-end common-mode voltage, even if the sampling resistor of the sampling circuit 110 fails or burns out, the driving circuit is not burned out, so that the over-current protection device 100 prevents a large current from flowing through the driving circuit, and the power devices are thermally broken down to fail, and meanwhile, the use safety of the driving control circuit 140 with the over-current protection device 100 is further ensured, and the service life of each power device in the driving circuit is prolonged.
The current mirror circuit 120 can control whether the detection circuit 130 is turned on according to the sampling value of the sampling circuit 110, for example, when the sampling value of the sampling circuit 110 is smaller than a preset sampling value, that is, a smaller current flows from the positive electrode of the power supply, the current mirror circuit 120 generates a smaller voltage difference, or the generated voltage difference is zero, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.
When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of the power device on the driving circuit to fail, the mirror current source circuit 120 generates a larger voltage difference, and the larger voltage difference can enable the detection circuit 130 to be conducted, so that the detection module 132 can detect a voltage signal or a current signal and send a conducting signal to the control circuit 140, and the control circuit 140 sends an overcurrent early warning signal according to the conducting signal, so that the driving signal is cut off, that is, no current flows into the driving circuit any more, and the power device on the driving circuit is prevented from being burnt.
In addition, compared with the prior art without the mirror current source circuit, the mirror current source circuit 120 controls the on state of the detection circuit 130, and the current with the same magnitude can be detected by using a smaller sampling resistor, so that the power consumed by the sampling resistor can be greatly reduced, particularly when detecting a large current, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged.
And moreover, the volume of the sampling resistor can be reduced, so that the occupied area of the sampling resistor on the PCB is reduced, and the space utilization rate of the PCB is improved.
In practical application, the sampling circuit 110 includes a sampling resistor, the mirror current source circuit 120 includes two PNP transistors with identical parameters, and bases of the two transistors are connected. The detection circuit 130 includes a PVP transistor, i.e., the on state of the PVP transistor is controlled by the mirrored current source circuit 120.
Further, on the basis of the above embodiment, in the case where the sampling value is smaller than the preset sampling value, the mirrored current source circuit 120 outputs the first voltage difference to turn off the detection circuit 130; when the sampling value is greater than or equal to the preset sampling value, the mirror current source circuit 120 outputs a second voltage difference to enable the detection circuit 130 to be conducted; wherein the first voltage difference is less than the second voltage difference.
In this embodiment, when the sampling value of the sampling circuit 110 is smaller than the preset sampling value, that is, a smaller current flows from the positive electrode of the power supply, the mirror current source circuit 120 generates a first voltage difference, where the first voltage difference is smaller, or the first voltage difference is zero, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.
When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, i.e. a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of the power device on the driving circuit to fail, the mirror current source circuit 120 generates a second voltage difference, wherein the second voltage difference is greater than the first voltage difference, and the larger second voltage difference can enable the detection circuit 130 to be conducted, so that the detection module 132 can detect a voltage signal or a current signal and send a conducting signal to the control circuit 140, and the control circuit 140 sends an overcurrent early warning signal according to the conducting signal, so that the driving signal is cut off, i.e. no current flows into the driving circuit any more, and the power device on the driving circuit is prevented from being burnt.
In addition, compared with the prior art without the mirror current source circuit, the mirror current source circuit 120 controls the on state of the detection circuit 130, and the current with the same magnitude can be detected by using a smaller sampling resistor, so that the power consumed by the sampling resistor can be greatly reduced, particularly when detecting a large current, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged.
And moreover, the volume of the sampling resistor can be reduced, so that the occupied area of the sampling resistor on the PCB is reduced, and the space utilization rate of the PCB is improved.
As shown in fig. 2, further, the sampling circuit 110 includes a sampling resistor, which is used to connect the positive electrode of the power supply and the driving circuit.
In this embodiment, the sampling circuit 110 includes a sampling resistor, i.e., a voltage generated by a current flowing through the sampling resistor is used to detect the current. Further, the sampling resistor is connected between the positive electrode of the power supply and the driving circuit, and compared with the resistor arranged between the driving circuit and the ground in the related art, the total current flows out from the positive electrode of the power supply, so that the current detection device has no shunt condition of low-end current detection, ensures effective detection of large current and improves the accuracy of current detection.
In addition, since the over-current protection device 100 can bear the high-end common-mode voltage, even if the sampling resistor fails or burns out, the driving circuit part is not burnt out, so that the over-current protection device 100 prevents the power devices from being failed due to thermal breakdown caused by the large current flowing through the driving circuit, the use safety of the driving control circuit 140 with the over-current protection device 100 is further ensured, and the service life of each power device in the driving circuit is prolonged.
As shown in fig. 2, further, the mirrored current source circuit 120 includes a first branch 121 and a second branch 123, wherein the first branch 121 is connected to the positive electrode of the power supply and the sampling resistor, the first branch 121 is provided with a first switching element 122, the second branch 123 is connected to the sampling resistor and the driving circuit, and is connected in parallel to the first branch 121, the second branch 123 is provided with a second switching element 124, the second switching element 124 is connected to the first switching element 122, and the detection circuit 130 is connected to the first branch 121 and the second branch 123.
In this embodiment, the mirror current source circuit 120 is defined to include two parallel first branches 121 and second branches 123, the first branches 121 are connected to the positive electrode of the power supply and the sampling resistor, the second branches 123 are connected to the sampling resistor and the driving circuit, the first branches 121 are provided with first switching elements 122, the second branches 123 are provided with second switching elements 124, the first switching elements 122 are connected to the second switching elements 124, and the detection circuit 130 is connected to the first branches 121 and the second branches 123.
It can be appreciated that when the sampling value of the sampling circuit 110 is smaller than the preset sampling value, that is, a smaller current flows from the positive electrode of the power supply, the first switch 122 and the second switch 124 are closed, so that the mirror current source circuit 120 generates a smaller voltage difference, or the generated voltage difference is zero, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.
When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of the power device on the driving circuit to fail, at this time, the first switch 122 is closed, and the second switch 124 is opened, so that the mirror current source circuit 120 generates a larger voltage difference, and the larger voltage difference can enable the detection circuit 130 to be turned on, so that the detection module 132 can detect the voltage signal or the current signal, and send an on signal to the control circuit 140, and the control circuit 140 sends an over-current early warning signal according to the on signal, so that the driving signal is cut off, that is, no current flows into the driving circuit any more, and the power device on the driving circuit is prevented from being burned.
In addition, compared with the prior art without the mirror current source circuit, the mirror current source circuit 120 controls the on state of the detection circuit 130, and the current with the same magnitude can be detected by using a smaller sampling resistor, so that the power consumed by the sampling resistor can be greatly reduced, particularly when detecting a large current, the heating of the sampling resistor is reduced, and the service life of the sampling resistor is prolonged.
And moreover, the volume of the sampling resistor can be reduced, so that the occupied area of the sampling resistor on the PCB is reduced, and the space utilization rate of the PCB is improved.
In practical applications, the first switch 122 and the second switch 124 are PNP transistors with the same parameters, and bases of the PNP transistors are connected to form the mirrored current source circuit 120.
As shown in fig. 2, further, the current mirror circuit 120 further includes a first resistor 125 and a second resistor 126, where the first resistor 125 is disposed on the first branch 121, the first resistor 125 is connected to the first switch 122, the second resistor 126 is disposed on the second branch 123, and the second resistor 126 is connected to the second switch 124; the resistance of the first resistor 125 is the same as the resistance of the second resistor 126.
In this embodiment, the mirror current source circuit 120 is defined to further include a first resistor 125 and a second resistor 126, where the first resistor 125 is disposed on the first branch 121, and the second resistor 126 is disposed on the second branch 123, and by disposing resistors on the two branches respectively, the current limiting function can be achieved, so as to improve the anti-interference capability of the overcurrent protection device 100.
The resistance of the first resistor 125 is the same as that of the second resistor 126, so that the mirror current source circuit 120 can accurately control the on-off of the detection circuit 130, and large current detection can be realized.
As shown in fig. 2, based on the above embodiment, the current mirror circuit 120 further includes a third resistor 127 and a fourth resistor 128, where the third resistor 127 is disposed on the first branch 121, the third resistor 127 is connected to the positive electrode of the power supply and the first switching element 122, the fourth resistor 128 is disposed on the second branch 123, and the fourth resistor 128 is connected to the sampling resistor and the second switching element 124; the resistance of the third resistor 127 is the same as the resistance of the fourth resistor 128, and the resistance of the third resistor 127 is smaller than the resistance of the first resistor 125; and/or the resistance of the fourth resistor 128 is smaller than the resistance of the second resistor 126.
In this embodiment, the mirror current source circuit 120 is defined to further include a third resistor 127 and a fourth resistor 128, specifically, the third resistor 127 is disposed on the first branch 121, and the fourth resistor 128 is disposed on the second branch 123, so as to further improve the anti-interference capability of the overcurrent protection device 100.
In addition, the resistance of the third resistor 127 is the same as the resistance of the fourth resistor 128, and the third resistor 127 is smaller than the first resistor 125, and the fourth resistor 128 is smaller than the second resistor 126, so that the open-close state of the second switch 124 is prevented from being influenced due to excessive voltage division of the fourth resistor 128 while the large current detection is realized, the accuracy of the overcurrent protection device 100 in detecting the large current is further improved, and the service life of each power device on the driving circuit is prolonged.
As shown in fig. 2, further, the detection circuit 130 includes a third switching element 131 and a detection module 132, where the third switching element 131 is connected to the first branch 121 and the second branch 123, and the detection module 132 is connected to the third switching element 131; when the third switch 131 is turned on, the detection module 132 sends an on signal to the control circuit 140, so that the control circuit 140 sends an over-current warning signal according to the on signal.
In this embodiment, the detection circuit 130 includes a third switching element 131 and a detection module 132, specifically, the third switching element 131 is connected to the first branch 121 and the second branch 123, the detection module 132 is connected to the third switching element 131, when the sampling value of the sampling circuit 110 is smaller than the preset sampling value, that is, a smaller current flows from the positive electrode of the power supply, the mirror current source circuit 120 generates a smaller voltage difference, or the generated voltage difference is zero, and the third switching element 131 is turned off, so that the detection circuit 130 cannot be turned on, and the detection module 132 of the detection circuit 130 cannot detect the voltage signal or the current signal.
When the sampling value of the sampling circuit 110 is greater than or equal to the preset sampling value, that is, a larger current flows from the positive electrode of the power supply, if the current flows to the driving circuit, the container causes thermal breakdown of the power device on the driving circuit to fail, the mirror current source circuit 120 generates a larger voltage difference, the larger voltage difference can close the third switch member 131, the detection circuit 130 is conducted, so that the detection module 132 can detect a voltage signal or a current signal and send a conducting signal to the control circuit 140, the control circuit 140 sends an overcurrent early warning signal according to the conducting signal, so that the driving signal is cut off, that is, the driving circuit does not flow current any more, and the power device on the driving circuit is prevented from being burnt.
In practical applications, the third switch 131 is a PNP transistor. The base of the transistor is connected to the second branch 123 and the emitter is connected to the first branch 121.
In a specific embodiment, further, the first switch 122 is a PNP transistor; and/or the second switch 124 is a PNP transistor; and/or the third switching element 131 is a PNP transistor.
In this embodiment, the first, second and third switching elements 122, 124 and 131 are PNP transistors. The setting can be specifically performed according to actual needs. Simple structure, convenient operation.
According to a second aspect of the present invention, a driving control circuit 140 is provided, which includes the overcurrent protection device 100 according to any one of the embodiments, so that all the beneficial effects of the overcurrent protection device 100 are provided, and are not described herein.
Further, the driving control circuit 140 further includes a power source and a driving circuit, wherein the overcurrent protection device 100 is connected to the positive electrode of the power source and the driving circuit.
The drive control circuit 140 provided by the embodiment of the invention includes the over-current protection device 100, the power supply and the drive circuit, specifically, by arranging the over-current protection device 100 between the positive electrode of the power supply and the drive circuit, compared with the arrangement of the over-current detection circuit between the drive circuit and the ground in the related art, because the total current flows out from the positive electrode of the power supply, the shunt condition existing in the low-end current detection is avoided, the effective detection of the large current is ensured, and the accuracy of the current detection is improved.
In addition, since the over-current protection device 100 can bear a high-end common-mode voltage, even if the sampling resistor of the sampling circuit 110 fails or burns out, the driving circuit is not burned out, so that the over-current protection device 100 prevents a large current from flowing through the driving circuit, and the power devices are thermally broken down to fail, and meanwhile, the use safety of the driving control circuit 140 with the over-current protection device 100 is further ensured, and the service life of each power device in the driving circuit is prolonged.
According to a third aspect of the present invention, a motor assembly is provided, which includes the driving control circuit 140 provided in any of the above embodiments, so that all the advantages of the driving control circuit 140 are provided, and are not described herein.
Further, the motor assembly also includes a motor, and the drive control circuit 140 is configured to control motor operation.
In the description of the present specification, the terms "connected," "mounted," "secured," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present specification, the terms "one embodiment," "some embodiments," "particular embodiments," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. An overcurrent protection device, comprising:
the sampling circuit is used for connecting the positive electrode of the power supply and the driving circuit;
the mirror image current source circuit is connected with the sampling circuit;
the detection circuit is connected with the mirror current source circuit and can control whether the detection circuit is conducted or not according to the sampling value of the sampling circuit;
the control circuit is connected with the detection circuit;
under the condition that the detection circuit is conducted, the detection circuit sends a conducting signal to the control circuit, so that the control circuit sends out an overcurrent early warning signal according to the conducting signal.
2. The overcurrent protection device according to claim 1, wherein,
when the sampling value is smaller than a preset sampling value, the mirror current source circuit outputs a first voltage difference so as to cut off the detection circuit;
when the sampling value is greater than or equal to the preset sampling value, the mirror current source circuit outputs a second voltage difference so as to conduct the detection circuit;
wherein the first voltage difference is less than the second voltage difference.
3. The overcurrent protection device of claim 1, wherein the sampling circuit comprises:
and the sampling resistor is used for connecting the power supply anode and the driving circuit.
4. The overcurrent protection apparatus according to claim 3, wherein the mirrored current source circuit comprises:
the first branch is connected with the positive electrode of the power supply and the sampling resistor, and is provided with a first switch piece;
the second branch circuit is connected with the sampling resistor and the driving circuit and is connected with the first branch circuit in parallel, the second branch circuit is provided with a second switch piece, the second switch piece is connected with the first switch piece, and the detection circuit is connected with the first branch circuit and the second branch circuit.
5. The overcurrent protection apparatus of claim 4, wherein the mirrored current source circuit further comprises:
the first resistor is arranged on the first branch and is connected with the first switch piece;
the second resistor is arranged on the second branch and is connected with the second switch piece;
the resistance value of the first resistor is the same as that of the second resistor.
6. The overcurrent protection apparatus of claim 5, wherein the mirrored current source circuit further comprises:
the third resistor is arranged on the first branch and is connected with the positive electrode of the power supply and the first switch piece;
the fourth resistor is arranged on the second branch and is connected with the sampling resistor and the second switch piece;
the resistance value of the third resistor is the same as that of the fourth resistor, and the resistance value of the third resistor is smaller than that of the first resistor; and/or the resistance value of the fourth resistor is smaller than the resistance value of the second resistor.
7. The overcurrent protection device of claim 4, wherein the detection circuit comprises:
a third switching element connected to the first branch and the second branch;
the detection module is connected with the third switch piece;
and when the third switch piece is conducted, the detection module sends a conduction signal to the control circuit, so that the control circuit sends an overcurrent early warning signal according to the conduction signal.
8. The overcurrent protection device of claim 7, wherein,
the first switch piece is a PNP triode; and/or
The second switch piece is a PNP triode; and/or
The third switch piece is a PNP triode.
9. A drive control circuit, characterized by comprising:
the overcurrent protection device according to any one of claims 1 to 8;
a power supply;
and the overcurrent protection device is connected with the positive electrode of the power supply and the driving circuit.
10. An electric motor assembly, comprising:
the drive control circuit according to claim 9;
a motor, the drive control circuit being configured to control operation of the motor.
CN202310002144.XA 2023-01-03 2023-01-03 Overcurrent protection device, drive control circuit and motor assembly Pending CN116093880A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310002144.XA CN116093880A (en) 2023-01-03 2023-01-03 Overcurrent protection device, drive control circuit and motor assembly

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310002144.XA CN116093880A (en) 2023-01-03 2023-01-03 Overcurrent protection device, drive control circuit and motor assembly

Publications (1)

Publication Number Publication Date
CN116093880A true CN116093880A (en) 2023-05-09

Family

ID=86207695

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310002144.XA Pending CN116093880A (en) 2023-01-03 2023-01-03 Overcurrent protection device, drive control circuit and motor assembly

Country Status (1)

Country Link
CN (1) CN116093880A (en)

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