CN114566938A - Overcurrent protection device and method for silicon carbide power MOSFET, electronic equipment and medium - Google Patents

Overcurrent protection device and method for silicon carbide power MOSFET, electronic equipment and medium Download PDF

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Publication number
CN114566938A
CN114566938A CN202210066811.6A CN202210066811A CN114566938A CN 114566938 A CN114566938 A CN 114566938A CN 202210066811 A CN202210066811 A CN 202210066811A CN 114566938 A CN114566938 A CN 114566938A
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current
mosfet
silicon carbide
carbide power
signal
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高大威
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Tsinghua University
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Tsinghua University
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    • 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
    • H02H7/20—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 electronic equipment
    • H02H7/205—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 electronic equipment for controlled semi-conductors which are not included in a specific circuit arrangement
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/687—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The application relates to the technical field of silicon carbide power electronic device application, in particular to an over-current protection device, method and equipment of a silicon carbide power MOSFET, wherein the device comprises: the current detection module is used for detecting the conduction current of the silicon carbide power MOSFET and generating a first overcurrent signal when the conduction current is greater than a preset current; the complex programmable logic device is used for stopping outputting the PWM control signal and sending an external interrupt request to the micro control unit when receiving the first overcurrent signal; and the microcontroller unit is used for stopping sending the PWM control signal to the MOSFET according to the first overcurrent signal and the external interrupt request and stopping the MOSFET. Therefore, the problems that the MOSFET is damaged due to the fact that the time required for the micro control unit to be turned off is too long when overcurrent is detected are solved, and the MOSFET is subjected to overcurrent protection by detecting the saturation voltage drop, the conduction current and the like of the MOSFET, so that the MOSFET is optimally controlled after overcurrent occurs.

Description

Overcurrent protection device and method for silicon carbide power MOSFET, electronic equipment and medium
Technical Field
The present invention relates to the Field of silicon carbide power electronic device application technologies, and in particular, to an over-current protection device, method, electronic device, and medium for a silicon carbide power MOSFET (Metal Oxide Semiconductor Field Effect Transistor).
Background
Generally, power electronic devices generally have a certain overcurrent capability, and when overcurrent occurs, measures should be taken quickly to turn off the devices or reduce the current flowing through the devices to a normal level so as not to damage the devices. Silicon carbide power MOSFETs can withstand very short overcurrent times, typically only a few microseconds, and therefore require a fast overcurrent detection method and protection strategy.
The current overcurrent protection method for the power semiconductor is mainly characterized in that saturation voltage drop at two ends of the power semiconductor or flowing conducting current is detected, if the saturation voltage drop exceeds a normal range, an overcurrent signal is sent to a microcontroller unit through a control circuit, and the overcurrent signal is processed by the microcontroller unit and then returns to a power semiconductor device, so that the device is turned off and protected. The over-current detection and control mode needs to be operated by a microcontroller unit, and the singlechip belongs to a digital chip, so that the operation time is long, the time from detecting an over-current signal to controlling the turn-off of a power device exceeds the maximum over-current time which can be borne by the silicon carbide power MOSFET, and the silicon carbide power MOSFET is damaged.
Disclosure of Invention
The application provides an overcurrent protection device and method for a silicon carbide power MOSFET, electronic equipment and a medium, and aims to solve the problem that the silicon carbide power MOSFET is damaged due to the fact that a micro control unit is analyzed after overcurrent detection and finally the time required for pulling down all driving signals is too long.
An embodiment of a first aspect of the present application provides an overcurrent protection device for a silicon carbide power MOSFET, including the following steps:
the current detection module is used for detecting the conduction current of the silicon carbide power MOSFET and generating a first overcurrent signal when the conduction current is greater than a preset current;
a CPLD (Complex Programmable Logic Device) for stopping outputting a PWM (Pulse Width Modulation) control signal and sending an external interrupt request to the micro control unit when receiving the first overcurrent signal; and
and the microcontroller unit is used for stopping sending the PWM control signal to the MOSFET according to the first overcurrent signal and the external interrupt request and stopping the silicon carbide power MOSFET from working.
According to an embodiment of the present application, the over-current protection device of silicon carbide power MOSFET further comprises:
the silicon carbide power MOSFET driving circuit is used for detecting the saturation voltage drop of the silicon carbide power MOSFET, generating a turn-off driving signal when the saturation voltage drop is larger than the preset threshold value, and controlling the MOSFET to be turned off according to the turn-off driving signal so as to perform overcurrent protection on the MOSFET.
According to an embodiment of the present application, the silicon carbide power MOSFET driver circuit is further configured to:
and generating a second over-current signal when the saturation voltage drop is greater than a preset threshold value, and sending the second over-current signal to the CPLD, so that the CPLD closes the output of the Pulse Width Modulation (PWM) control signal, and sends an external interrupt request to the micro control unit.
According to an embodiment of the present application, the current detection module includes:
the Hall current sensor is used for detecting the conducting current of the MOSFET;
and the current comparator is used for judging whether the conduction current is greater than the preset current or not, and generating and sending a first overcurrent signal to the complex programmable logic device CPLD and the micro control unit when the conduction current is greater than the preset current.
According to an embodiment of the present application, the microcontroller unit is further configured to:
when the first overcurrent signal is not received and/or the silicon carbide power MOSFET driving circuit does not detect that the saturation voltage drop is larger than the preset threshold value, the PWM control signal is continuously sent to the MOSFET, and the MOSFET is controlled to normally work based on the PWM control signal.
According to the overcurrent protection device of the silicon carbide power MOSFET, the on-state current of the silicon carbide power MOSFET is detected through the current detection module, and when the on-state current is larger than the preset current, a first overcurrent signal is generated; when the first overcurrent signal is received through the complex programmable logic device CPLD, the output of the pulse width modulation PWM control signal is stopped, and an external interrupt request is sent to the micro control unit; and stopping sending the PWM control signal to the MOSFET through the microcontroller unit according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working. Therefore, the problems that the silicon carbide power MOSFET is damaged due to the fact that the micro control unit is detected from overcurrent to analyze, and finally the time required for pulling down all driving signals is too long are solved.
An embodiment of a second aspect of the present application provides an overcurrent protection method for a silicon carbide power MOSFET, including:
detecting the on-current of the MOSFET;
when the conduction current is larger than the preset current, generating the first overcurrent signal, and when the CPLD receives the first overcurrent signal, stopping outputting a Pulse Width Modulation (PWM) control signal and sending an external interrupt request to a micro control unit; and
and stopping sending the PWM control signal to the MOSFET according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working.
According to an embodiment of the present application, the method for overcurrent protection of a silicon carbide power MOSFET further includes:
detecting a saturation voltage drop of the MOSFET;
and generating a turn-off driving signal when the saturation voltage drop is greater than a preset threshold value, and controlling the MOSFET to be turned off according to the turn-off driving signal so as to perform overcurrent protection on the MOSFET.
According to an embodiment of the present application, the method for overcurrent protection of a silicon carbide power MOSFET further includes:
if the saturation voltage drop is less than or equal to the preset threshold value and the conduction current is less than or equal to the preset current, the PWM control signal is continuously sent to the MOSFET through the micro control unit, and the MOSFET is controlled to normally work based on the PWM control signal.
According to the overcurrent protection method of the silicon carbide power MOSFET, the conducting current of the silicon carbide power MOSFET is detected through the current detection module, and when the conducting current is larger than the preset current, a first overcurrent signal is generated; when the first overcurrent signal is received through the complex programmable logic device CPLD, the output of the pulse width modulation PWM control signal is stopped, and an external interrupt request is sent to the micro control unit; and stopping sending the PWM control signal to the MOSFET through the microcontroller unit according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working. Therefore, the problems that the silicon carbide power MOSFET is damaged due to the fact that the micro control unit is detected from overcurrent to analyze and finally the time required for pulling down all driving signals is too long are solved, the conducting current and the saturation voltage drop of the silicon carbide power MOSFET are respectively detected through signals fed back by the Hall current sensor and the driving circuit and are subjected to overcurrent protection, optimal control of the silicon carbide power MOSFET after overcurrent occurs is achieved, and the working safety of the silicon carbide power MOSFET is improved.
An embodiment of a third aspect of the present application provides an electronic device, including: the over-current protection method for the silicon carbide power MOSFET comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the over-current protection method for the silicon carbide power MOSFET.
A fourth aspect of the present application provides a computer-readable storage medium, on which a computer program is stored, where the computer program is executed by a processor to implement the method for overcurrent protection of a silicon carbide power MOSFET according to the foregoing embodiment.
Additional aspects and advantages of the present application 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 present application.
Drawings
The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a diagram illustrating an example of a structure of an over-current protection device for a silicon carbide power MOSFET according to an embodiment of the present application;
fig. 2 is a schematic structural diagram illustrating a method for overcurrent protection of a silicon carbide power MOSFET according to an embodiment of the present application;
FIG. 3 is a schematic diagram of the components of an over-current detection module and the connection to a silicon carbide power MOSFET according to an embodiment of the present application;
FIG. 4 is a flow chart of over-current protection by detecting the on-current of a silicon carbide power MOSFET provided in accordance with one embodiment of the present application;
FIG. 5 is a flow chart of over-current protection by detecting saturation voltage drop of a silicon carbide power MOSFET provided in accordance with one embodiment of the present application;
fig. 6 is a flowchart of an over-current protection method for a silicon carbide power MOSFET according to an embodiment of the present application;
fig. 7 is a schematic structural diagram of an electronic device provided according to an embodiment of the present application.
Detailed Description
Reference will now be made in detail to the embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present application and should not be construed as limiting the present application.
The overcurrent protection device, method, electronic device and medium of the silicon carbide power MOSFET according to the embodiments of the present application are described below with reference to the accompanying drawings.
Before introducing the overcurrent protection apparatus, method, electronic device and medium of the silicon carbide power MOSFET according to the embodiments of the present application, a protection circuit in the related art is briefly introduced.
Specifically, the related art discloses an insulated gate bipolar drive protection circuit, which judges whether a power-density module of the circuit is short-circuited by detecting voltages at two ends of a collector and an emitter of a power device. For wide bandgap devices, the over-current time tolerance is low, so that too long blanking time will inevitably cause the wide bandgap device to be damaged during the short circuit process.
However, in the overcurrent protection mode in the related art, the time required for pulling down all the driving signals is long from current detection to analysis by the microcontroller unit, so that effective protection of the silicon carbide power MOSFET is difficult to form, and optimal control of the silicon carbide power MOSFET after overcurrent cannot be realized.
In view of the above problems, the present application provides an over-current protection device for a silicon carbide power MOSFET, in which a current detection module detects a conduction current of the silicon carbide power MOSFET, and generates a first over-current signal when the conduction current is greater than a preset current; when the first overcurrent signal is received through the complex programmable logic device CPLD, the output of the pulse width modulation PWM control signal is stopped, and an external interrupt request is sent to the micro control unit; and stopping sending the PWM control signal to the MOSFET through the microcontroller unit according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working. Therefore, the problems that the silicon carbide power MOSFET is damaged due to the fact that the micro control unit is detected from overcurrent to analyze, and finally the time required for pulling down all driving signals is too long are solved.
Specifically, fig. 1 is a diagram illustrating a structure of an overcurrent protection apparatus for a silicon carbide power MOSFET according to an embodiment of the present application.
As shown in fig. 1, the overcurrent protection device 10 of the silicon carbide power MOSFET includes: the device comprises a current detection module 100, a complex programmable logic device CPLD200 and a microcontroller unit 300.
The current detection module 100 is configured to detect a conduction current of the silicon carbide power MOSFET, and generate a first overcurrent signal when the conduction current is greater than a preset current; the complex programmable logic device CPLD200 is configured to stop outputting the PWM control signal and send an external interrupt request to the micro control unit 300 when receiving the first overcurrent signal; the micro-controller unit 300 is configured to stop sending the PWM control signal to the MOSFET according to the first overcurrent signal and the external interrupt request, and stop the silicon carbide power MOSFET from operating.
In some embodiments, the current detection module 100 includes: a hall current sensor 101 for detecting the on-current of the MOSFET; the current comparator 102 is configured to determine whether the conduction current is greater than a preset current, and generate and send a first overcurrent signal to the complex programmable logic device CPLD200 and the micro control unit 300 when the conduction current is greater than the preset current.
Specifically, as shown in fig. 2 and 3, the current detection module 100 is configured to detect a conduction current of the silicon carbide power MOSFET and perform an overcurrent determination; the current detection module 100 includes a hall current sensor 101, a current comparator 102 and peripheral circuits thereof, and the position and structure of the detection module are shown in fig. 3. Where a is a hall current sensor 101 and B is a current comparator 102. Hall current sensor 101 detects the on-current I of a silicon carbide power MOSFETDSAnd passes the on current signal to current comparator 102 and microcontroller unit 300. The current comparator 102 will conduct the current IDSAnd a reference current IREFA comparison is made. When the on-current is greater than the reference current, the sic power MOSFET is determined to be in an overcurrent state, and the current comparator 102 outputs an overcurrent signal to the CPLD200 and the microcontroller unit 300. The CPLD200 processes the PWM signal generated by the microcontroller unit 300 and outputs the processed PWM signal to the silicon carbide power MOSFET driving circuit 400 for generating a driving signal, and also receives an overcurrent fault signal generated by the current detection module and the driving circuit, and when receiving the fault signal, the CPLD200 immediately turns off the PWM signal output and sends an external interrupt request to the microcontroller unit 300.
The microcontroller unit 300 is the main control chip of the silicon carbide power MOSFET, containing all the control algorithms of the silicon carbide power MOSFET. The microcontroller unit 300 calculates the duty ratio of the power MOSFET according to the reference voltage or current value, and outputs a corresponding PWM signal to the CPLD 200. When the microcontroller unit 300 receives the on-current analog signal from the current detection module 100, comparing the on-current analog signal with a set threshold, if the current value is greater than the set threshold, determining that the current value is over-current, and pulling down all the PWM output signals; when the microcontroller unit 300 receives an external interrupt request from the CPLD200 or an overcurrent signal from the current detection module 100, it determines that the silicon carbide power MOSFET is in an overcurrent state, and pulls down all PWM output signals to complete overcurrent protection on software.
That is, the micro controller unit 300 is further configured to process the PWM signal to generate a driving signal for driving the silicon carbide power MOSFET, and determine that a fault occurs when the silicon carbide power MOSFET performs a protection action, and control the silicon carbide power MOSFET to stop operating.
Further, in some embodiments, the over-current protection device 10 for a silicon carbide power MOSFET further comprises: and the silicon carbide power MOSFET driving circuit 400 is used for detecting the saturation voltage drop of the silicon carbide power MOSFET, generating a turn-off driving signal when the saturation voltage drop is greater than a preset threshold value, and controlling the MOSFET to be turned off according to the turn-off driving signal so as to perform overcurrent protection on the MOSFET.
Further, in some embodiments, the silicon carbide power MOSFET driver circuit 400 is further configured to: and generating a second over-current signal when the saturation voltage drop is greater than a preset threshold value, and sending the second over-current signal to the CPLD200, so that the CPLD200 closes the output of the Pulse Width Modulation (PWM) control signal, and sends an external interrupt request to the micro-control unit.
Further, in some embodiments, the microcontroller unit 300 is further configured to: when the first overcurrent signal is not received and/or the silicon carbide power MOSFET driving circuit does not detect that the saturation voltage drop is larger than the preset threshold value, the PWM control signal is continuously sent to the MOSFET, and the MOSFET is controlled to normally work based on the PWM control signal.
Specifically, as shown in fig. 2, the silicon carbide power MOSFET driving circuit 400 includes a gate driving chip for generating a silicon carbide power MOSFET driving signal and peripheral circuits thereof, where the peripheral circuits mainly include a dc conversion circuit for generating a driving voltage for turning on and off the silicon carbide power MOSFET, a silicon carbide power MOSFET saturation voltage drop detection circuit, and the like; the silicon carbide power MOSFET saturation voltage drop detection circuit is mainly used for detecting the saturation voltage drop of the silicon carbide power MOSFET, the saturation voltage and the saturation voltage are fed into an overcurrent fault detection pin of a grid drive chip after being divided by a divider resistor, when the fed-in voltage is larger than a threshold value limited by the fault detection pin, the silicon carbide power MOSFET is judged to be in an overcurrent state, a turn-off drive signal is generated, the silicon carbide power MOSFET is judged to be in an overcurrent state, and overcurrent signals 1 to CPLD are output.
Meanwhile, when the microcontroller unit 300 generates a PWM signal to drive the silicon carbide power MOSFET, the silicon carbide power MOSFET driving circuit detects the saturation voltage drop of the silicon carbide power MOSFET, and the current detection module 100 detects the on-current of the silicon carbide power MOSFET; when the saturation voltage drop and/or the conduction current meet the overcurrent condition, the CPLD200 closes the output of the PWM signal, turns off the silicon carbide power MOSFET through the driving circuit, and sends an external interrupt signal to the microcontroller unit, so that the silicon carbide power MOSFET is subjected to overcurrent protection, and the signal is controlled to control the MOSFET to normally work; and if the saturated voltage drop and the conducting current do not meet the overcurrent condition, continuously sending a PWM control signal to the MOSFET and controlling the MOSFET to normally work based on the PWM control signal.
That is, the micro controller unit 300 is further configured to receive a fault signal sent by an external device, and control the silicon carbide power MOSFET to stop operating according to the fault signal.
Therefore, the signals fed back by the Hall current sensor and the driving circuit respectively detect the conduction current and the saturation voltage drop of the silicon carbide power MOSFET, the working safety of the silicon carbide power MOSFET is improved, the problem that the silicon carbide power MOSFET is damaged due to overcurrent is solved, the problems that the current detection is performed in the overcurrent protection technology of the silicon carbide power electronic device, the microcontroller unit is used for analyzing, the time required for finally reducing all driving signals is long, and the silicon carbide power MOSFET is difficult to form effective protection are effectively solved. In addition, the control circuit aims at the over-current control of the silicon carbide power MOSFET, and can be widely applied to various circuits, such as a DC/DC direct current converter, a DC/AC motor controller and the like
In order to facilitate those skilled in the art to further understand the over-current protection device of the silicon carbide power MOSFET of the embodiments of the present application, the following description is further provided in conjunction with a protection method corresponding to the over-current protection device of the silicon carbide power MOSFET.
As shown in fig. 4 and 5, fig. 4 is a flowchart of overcurrent protection by detecting the on-current of the silicon carbide power MOSFET, and fig. 5 is a flowchart of overcurrent protection by detecting the saturation voltage drop of the silicon carbide power MOSFET.
Specifically, the method for performing overcurrent protection by detecting the on-current of the silicon carbide power MOSFET comprises the following steps:
s1: the Hall current sensor detects the conduction current of the silicon carbide power MOSFET;
s2: the microcontroller unit judges whether the current is over-current according to the conducting current signal, if so, the step enters S3; if not, the process goes to S5;
s3: the microcontroller unit pulls down all the PWM control signals and stops sending the control signals to the silicon carbide MOSFET;
s4: the driving circuit generates a turn-off driving signal, and the silicon carbide power MOSFET is turned off;
s5: the microcontroller unit sends out PWM control signals to control the normal work of the silicon carbide power MOSFET
S6: the current comparator judges whether the on current is larger than the reference current, if so, the step enters S7; if not, go to S10;
s7: the overcurrent signal is transmitted to the CPLD and the microcontroller unit;
s8: the CPLD immediately closes the PWM signal output and sends an external interrupt request to the microcontroller unit;
s9: the driving circuit generates a turn-off driving signal, and the silicon carbide power MOSFET is turned off;
s10: the microcontroller unit sends out a PWM control signal to control the silicon carbide power MOSFET to work normally;
s11: the microcontroller unit stops sending control signals to the silicon carbide power MOSFET;
s12: the microcontroller unit stops sending control signals to the silicon carbide power MOSFET.
The overcurrent protection is carried out by detecting the saturation voltage drop of the silicon carbide power MOSFET, and the method comprises the following steps:
s13: the driving circuit detects the saturation voltage drop of the power MOSFET;
s14: the driving circuit judges whether the saturation voltage drop is larger than a limited voltage threshold value, if so, the operation goes to S15; if not, go to S17;
s15: the overcurrent signal is transmitted to the CPLD, and the CPLD immediately closes the PWM signal output and sends an external interrupt request to the microcontroller unit;
s16: the driving circuit generates a turn-off driving signal, and the silicon carbide power MOSFET is turned off;
s17: the microcontroller unit sends out a PWM control signal to control the silicon carbide power MOSFET to work normally;
s18: the microcontroller unit stops sending control signals to the silicon carbide power MOSFET.
Therefore, from current detection, analysis is carried out to the microcontroller unit, the time required for finally lowering all driving signals is long, and the problem of forming effective protection on the silicon carbide power MOSFET is difficult to form. Therefore, the problem that effective protection of the silicon carbide power MOSFET is difficult to form due to the fact that the time required for pulling down all driving signals is long and the silicon carbide power MOSFET is difficult to form is solved from current detection to analysis of a microcontroller unit in the silicon carbide power MOSFET overcurrent protection technology.
According to the overcurrent protection device of the silicon carbide power MOSFET, the on-state current of the silicon carbide power MOSFET is detected through the current detection module, and when the on-state current is larger than the preset current, a first overcurrent signal is generated; when the first overcurrent signal is received through the complex programmable logic device CPLD, the output of the pulse width modulation PWM control signal is stopped, and an external interrupt request is sent to the micro control unit; and stopping sending the PWM control signal to the MOSFET through the microcontroller unit according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working. Therefore, the problems that the silicon carbide power MOSFET is damaged due to the fact that the micro control unit is detected from overcurrent to analyze, and finally the time required for pulling down all driving signals is too long are solved.
Next, an overcurrent protection method of a silicon carbide power MOSFET according to an embodiment of the present application is described with reference to the drawings.
Fig. 6 is a flowchart of an overcurrent protection method for a silicon carbide power MOSFET according to an embodiment of the present application.
As shown in fig. 6, the method for overcurrent protection of a silicon carbide power MOSFET in the embodiment of the present application includes the following steps:
in step S601, the on current of the MOSFET is detected;
in step S602, when the on-current is greater than the preset current, a first over-current signal is generated, and when the CPLD receives the first over-current signal, the output of the PWM control signal is stopped, and an external interrupt request is sent to the micro control unit;
in step S603, the PWM control signal is stopped from being transmitted to the MOSFET according to the first overcurrent signal and the external interrupt request, and the silicon carbide power MOSFET is stopped from operating.
Further, in some embodiments, a method of over-current protection for a silicon carbide power MOSFET, further comprises:
detecting the saturation voltage drop of the MOSFET;
and generating a turn-off driving signal when the saturation voltage drop is greater than a preset threshold, and controlling the MOSFET to be turned off according to the turn-off driving signal so as to perform overcurrent protection on the MOSFET.
Further, in some embodiments, a method of over-current protection for a silicon carbide power MOSFET, further comprises:
and if the saturation voltage drop is less than or equal to the preset threshold value and the conduction current is less than or equal to the preset current, continuously sending a PWM control signal to the MOSFET through the micro control unit, and controlling the MOSFET to normally work based on the PWM control signal.
It should be noted that the above explanation of the embodiment of the over-current protection device for silicon carbide power MOSFET is also applicable to over-current protection of the silicon carbide power MOSFET of this embodiment, and will not be described herein again.
According to the overcurrent protection method of the silicon carbide power MOSFET, the conducting current of the silicon carbide power MOSFET is detected through the current detection module, and when the conducting current is larger than the preset current, a first overcurrent signal is generated; when the first overcurrent signal is received through the complex programmable logic device CPLD, the output of the pulse width modulation PWM control signal is stopped, and an external interrupt request is sent to the micro control unit; and stopping sending the PWM control signal to the MOSFET through the microcontroller unit according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working. Therefore, the problems that the silicon carbide power MOSFET is damaged due to the fact that the micro control unit is detected from overcurrent to analyze, and finally the time required for pulling down all driving signals is too long are solved.
Fig. 7 is a schematic structural diagram of an electronic device according to an embodiment of the present application. The electronic device may include:
memory 701, processor 702, and a computer program stored on memory 701 and executable on processor 702.
The processor 702, when executing the program, implements the over-current protection method for the silicon carbide power MOSFET provided in the above-described embodiments.
Further, the electronic device further includes:
a communication interface 703 for communication between the memory 701 and the processor 702.
A memory 701 for storing computer programs operable on the processor 702.
The memory 701 may comprise high-speed RAM memory, and may also include non-volatile memory (non-volatile memory), such as at least one disk memory.
If the memory 701, the processor 702 and the communication interface 703 are implemented independently, the communication interface 703, the memory 701 and the processor 702 may be connected to each other through a bus and perform communication with each other. The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended ISA (EISA) bus, or the like. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 7, but this is not intended to represent only one bus or type of bus.
Optionally, in a specific implementation, if the memory 701, the processor 702, and the communication interface 703 are integrated on a chip, the memory 701, the processor 702, and the communication interface 703 may complete mutual communication through an internal interface.
The processor 702 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), or one or more Integrated circuits configured to implement embodiments of the present Application.
The present embodiment also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method of over-current protection of a silicon carbide power MOSFET as above.
In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means 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 application. In this specification, the schematic representations of the terms used above are not necessarily intended to 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 N embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "N" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more N executable instructions for implementing steps of a custom logic function or process, and alternate implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of implementing the embodiments of the present application.
The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or N wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.
It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware that is related to instructions of a program, and the program may be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.
In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a separate product, may also be stored in a computer readable storage medium.
The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims (10)

1. An over-current protection device for a silicon carbide power MOSFET, comprising:
the current detection module is used for detecting the conduction current of the silicon carbide power MOSFET and generating a first overcurrent signal when the conduction current is greater than a preset current;
the complex programmable logic device CPLD is used for stopping outputting the pulse width modulation PWM control signal and sending an external interrupt request to the micro control unit when receiving the first overcurrent signal; and
and the microcontroller unit is used for stopping sending the PWM control signal to the MOSFET according to the first overcurrent signal and the external interrupt request and stopping the silicon carbide power MOSFET from working.
2. The apparatus of claim 1, further comprising:
the silicon carbide power MOSFET driving circuit is used for detecting the saturation voltage drop of the silicon carbide power MOSFET, generating a turn-off driving signal when the saturation voltage drop is larger than the preset threshold value, and controlling the MOSFET to be turned off according to the turn-off driving signal so as to perform overcurrent protection on the MOSFET.
3. The apparatus of claim 2, wherein the silicon carbide power MOSFET driver circuit is further configured to:
and generating a second over-current signal when the saturation voltage drop is greater than a preset threshold value, and sending the second over-current signal to the CPLD, so that the CPLD closes the output of the Pulse Width Modulation (PWM) control signal, and sends an external interrupt request to the micro control unit.
4. The apparatus of claim 1 or 2, wherein the current detection module comprises:
the Hall current sensor is used for detecting the conducting current of the MOSFET;
and the current comparator is used for judging whether the conduction current is greater than the preset current or not, and generating and sending a first overcurrent signal to the complex programmable logic device CPLD and the micro control unit when the conduction current is greater than the preset current.
5. The apparatus of claim 4, wherein the microcontroller unit is further configured to:
when the first overcurrent signal is not received and/or the silicon carbide power MOSFET driving circuit does not detect that the saturation voltage drop is larger than the preset threshold value, the PWM control signal is continuously sent to the MOSFET, and the MOSFET is controlled to normally work based on the PWM control signal.
6. A method of overcurrent protection for a silicon carbide power MOSFET, using the apparatus of any one of claims 1 to 5, the method comprising the steps of:
detecting the on-current of the MOSFET;
when the conduction current is larger than the preset current, generating the first overcurrent signal, and when the CPLD receives the first overcurrent signal, stopping outputting a Pulse Width Modulation (PWM) control signal and sending an external interrupt request to a micro control unit; and
and stopping sending the PWM control signal to the MOSFET according to the first overcurrent signal and the external interrupt request, and stopping the silicon carbide power MOSFET from working.
7. The method of claim 6, further comprising:
detecting a saturation voltage drop of the MOSFET;
and generating a turn-off driving signal when the saturation voltage drop is greater than a preset threshold, and controlling the MOSFET to be turned off according to the turn-off driving signal so as to perform overcurrent protection on the MOSFET.
8. The method of claim 7, further comprising:
if the saturation voltage drop is less than or equal to the preset threshold value and the conduction current is less than or equal to the preset current, the PWM control signal is continuously sent to the MOSFET through the micro control unit, and the MOSFET is controlled to normally work based on the PWM control signal.
9. An electronic device, comprising: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the method of over-current protection of a silicon carbide power MOSFET of any of claims 6-8.
10. A computer-readable storage medium having stored thereon a computer program, the program being executable by a processor for implementing the method of over-current protection of a silicon carbide power MOSFET according to any of claims 6-8.
CN202210066811.6A 2022-01-20 2022-01-20 Overcurrent protection device and method for silicon carbide power MOSFET, electronic equipment and medium Pending CN114566938A (en)

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Application publication date: 20220531