CN109994987B - Over-current protection circuit based on CPLD and over-current protection method thereof - Google Patents
Over-current protection circuit based on CPLD and over-current protection method thereof Download PDFInfo
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- CN109994987B CN109994987B CN201711481987.3A CN201711481987A CN109994987B CN 109994987 B CN109994987 B CN 109994987B CN 201711481987 A CN201711481987 A CN 201711481987A CN 109994987 B CN109994987 B CN 109994987B
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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
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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
- H02H1/0061—Details of emergency protective circuit arrangements concerning transmission of signals
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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
- H02H1/04—Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of DC component by short circuits in AC networks
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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
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Abstract
The invention relates to the technical field of overcurrent protection of electronic devices, and provides an overcurrent protection circuit based on a CPLD and an overcurrent protection method thereof, wherein the overcurrent protection circuit comprises the following steps: the device comprises a current sensor, an overcurrent judgment module, a CPLD, a DSP and a driving module; the current sensor sends a current detection signal to the overcurrent judgment module; when the overcurrent judging module detects that the current detection signal is out of the preset range, an overcurrent signal is sent to the CPLD; the CPLD latches an overcurrent signal, sends a fault signal to the DSP and sends a turn-off control signal to the drive module; the DSP stops sending a driving signal to the driving module through the CPLD according to the fault signal; the invention adopts the CPLD to be connected with the overcurrent judging module, can quickly respond to the system during overcurrent, has high sensitivity, can better protect devices and greatly shortens the response time of overcurrent protection.
Description
Technical Field
The invention relates to the technical field of overcurrent protection of electronic devices, in particular to an overcurrent protection circuit based on a CPLD and an overcurrent protection method thereof.
Background
In the prior art, overcurrent protection is usually performed by a software protection method, which includes two steps of overcurrent judgment and overcurrent protection, because overcurrent judgment is needed in a software mode, the overcurrent protection time is long, and meanwhile, the set overcurrent protection circuit also includes a trigger holding circuit and a reset circuit, and the trigger holding circuit and the reset circuit need to be reset by a main control chip after being held, so that the time response of the overcurrent protection is relatively long.
Disclosure of Invention
The invention provides an overcurrent protection circuit based on a CPLD and an overcurrent protection method thereof, which can perform quick overcurrent protection response during overcurrent.
The method is realized in such a way, and a first aspect of the invention provides an overcurrent protection circuit based on a CPLD, which comprises: the device comprises a current sensor, an overcurrent judgment module, a CPLD, a DSP and a driving module;
the current sensor sends a current detection signal to the overcurrent judging module;
when the overcurrent judging module detects that the current detection signal is out of a preset range, an overcurrent signal is sent to the CPLD;
the CPLD latches the overcurrent signal to send a fault signal to the DSP and sends a turn-off control signal to the drive module;
and the DSP stops sending a driving signal to the driving module through the CPLD according to the fault signal.
The invention provides an overcurrent protection method of an overcurrent protection circuit based on a CPLD, wherein the overcurrent protection circuit comprises: the device comprises a current sensor, an overcurrent judgment module, a CPLD, a DSP and a driving module;
the overcurrent protection method comprises the following steps:
the current sensor sends a current detection signal to the overcurrent judgment module;
when the overcurrent judging module detects that the current detection signal is out of a preset range, an overcurrent signal is sent to the CPLD;
the CPLD latches the overcurrent signal to send a fault signal to the DSP and sends a turn-off control signal to the drive module;
the DSP stops sending a driving signal to the driving module through the CPLD according to the fault signal;
when the overcurrent judging module detects that the current detection signal is in a preset range, an overcurrent-preventing signal is sent to the CPLD;
the CPLD sends a fault clearing signal to the DSP according to the no-overcurrent signal;
and the DSP sends a clearing latch signal to the CPLD according to the fault clearing signal, so that the CPLD stops sending a turn-off control signal to the driving module, and sends a driving signal to the driving module through the CPLD.
The invention provides an overcurrent protection circuit based on CPLD and an overcurrent protection method thereof, which adopt the CPLD to replace a trigger holding circuit connected with the output end of an overcurrent judgment circuit and a reset circuit connected with the trigger holding circuit in the prior art, when receiving an overcurrent trigger signal, a DSP stops outputting a drive signal, and outputs high-level PWM to a drive module to enable the drive module to be in a high-level state.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of an overcurrent protection circuit based on a CPLD according to an embodiment of the present invention;
fig. 2 is a circuit diagram of an overcurrent determination module in an overcurrent protection circuit based on a CPLD according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an overcurrent protection circuit based on a CPLD according to another embodiment of the present invention;
fig. 4 is a circuit diagram of a current filtering module in an overcurrent protection circuit based on a CPLD according to another embodiment of the present invention;
fig. 5 is a schematic structural diagram of an overcurrent protection circuit based on a CPLD according to another embodiment of the present invention;
fig. 6 is a schematic structural diagram of an overcurrent protection circuit based on a CPLD according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
An embodiment of the present invention provides an over-current protection circuit based on a CPLD (Complex Programmable Logic Device), as shown in fig. 1, the over-current protection circuit includes: the current sensor 10, the overcurrent determination module 30, the CPLD40, the DSP (Digital Signal Processing) 50, and the driving module 60.
The current sensor 10 is respectively connected with the overcurrent judging module 30 and the DSP50, and the CPLD40 is respectively connected with the overcurrent judging module 30, the DSP50 and the driving module 60.
The current sensor 10 sends a current detection signal to the overcurrent judging module 30;
when the overcurrent judging module 30 detects that the current detection signal is out of the preset range, an overcurrent signal is sent to the CPLD 40;
the CPLD40 latches an overcurrent signal and sends a fault signal to the DSP50, and simultaneously sends a turn-off control signal to the drive module 60;
the DSP50 stops sending the driving signal to the driving module 60 through the CPLD40 according to the fault signal.
The current sensor 10 is configured to sample a current signal and send a current detection signal to the overcurrent determination module 30, and both the overcurrent determination module 30 and the DSP50 can determine the current detection signal, where the overcurrent determination module 30 determines the current detection signal in a hardware structure, and the DSP50 determines the current detection signal in a software manner, so that the determination speed of the overcurrent determination module 30 on the current detection signal is faster than the determination speed of the DSP 50.
Wherein, the over-current determining module 30 can compare the current signal with the reference voltage after converting the current signal into the voltage signal by setting the comparing circuit, and can compare the voltage signal with the reference voltage by adopting the forward voltage comparison or simultaneously adopting the forward voltage and the reverse voltage comparison, specifically, determine the received current signal, when the current detecting signal is out of the preset range, for example, out of the range of-3A to +2A, send the over-current signal to the CPLD40 to realize the control of the driving module 60 by the CPLD40, the over-current determining module outputs the over-current signal to the CPLD40, the hardware over-current signal is pulled down, the CPLD40 latches the over-current signal after detecting the over-current and outputs high-level PWM (Pulse Width Modulation) to the driving module 60, the CPLD40 takes over the driving signal sent by the DSP50 to the driving module 60 to turn off the driving signal sent by the DSP, the turn-off mode of the CPLD40 can adopt six-phase open circuit or three-phase short circuit, etc., at the moment, the mode is determined by a strategy adopted by a user, the main control chip DSP can detect that the overcurrent latch signal is low, and stops outputting the driving signal to the driving module.
The embodiment of the invention adopts CPLD to replace a trigger holding circuit connected with the output end of an overcurrent judging circuit and a reset circuit connected with the trigger holding circuit in the prior art, when receiving an overcurrent trigger signal, the DSP stops outputting a drive signal and outputs high-level PWM to a drive module to enable the drive module to be in a high-level state, because the response time of the DSP or the MCU (Micro Controller Unit, single-chip microcomputer) needs dozens of to hundreds of us, and the CPLD is hardware established by various logic gates, the response time of the CPLD is below a few us, the CPLD can quickly respond to a system during overcurrent, has high sensitivity and can better protect devices, thereby greatly shortening the response time of overcurrent protection.
Further, in the above-mentioned embodiment, when the CPLD40 is in the latched state, as an implementation manner, the CPLD40 may be unlocked according to the current signal detected by the overcurrent determination module 30, when the overcurrent determination module 30 detects that the current detection signal is within the preset range, the no-overcurrent signal is sent to the CPLD40, the CPLD40 sends the fault clearing signal to the DSP50 according to the no-overcurrent signal, and the DSP50 sends the clearing latch signal to the CPLD40 according to the fault clearing signal, so that the CPLD40 stops sending the shutdown control signal to the driving module 60, and sends the driving signal to the driving module 60 through the CPLD 40.
Specifically, when the overcurrent determination module 30 detects that the current is in the normal range, a high level signal is output, the CPLD40 sends a fault clearing signal to the DSP50 according to the no overcurrent signal, the DSP outputs a clear overcurrent flag signal, that is, the overcurrent flag signal of the CPLD40 is pulled down, the CPLD40 clears the overcurrent latch signal after detecting that the overcurrent flag signal is cleared, the DSP50 can detect that the overcurrent latch signal is high, at this time, the CPLD40 outputs a PWM signal, which is switched to the DSP50 to output a PWM signal through the CPLD40, the CPLD40 does not interfere with the driving signal sent by the DSP50, and is only used for signal transmission.
When the CPLD40 is in the latched state, as another embodiment, the current sensor 10 is connected to the DSP50, the current sensor 10 is configured to sample a current signal and send a current detection signal to the overcurrent determination module 30, both the overcurrent determination module 30 and the DSP50 can determine the current detection signal, the DSP50 determines the current detection signal in a software manner, and when the DSP50 detects that the current detection signal sent by the current sensor 10 returns to normal, the DSP50 sends a latch clearing signal to the CPLD40, so that the CPLD40 stops sending the shutdown control signal to the driving module 60, and sends a driving signal to the driving module 60 through the CPLD 40.
After the DSP50 receives the fault signal, the DSP50 receives the current detection signal sent by the current sensor 10, determines the current detection signal, and clears the fault signal of the CPLD40 when it detects that the current detection signal is recovered to normal, for example, when the current detection signal is in the range of-3A to + 2A.
The invention adopts the DSP to monitor the current signal in time, and when the current signal is recovered to be normal, the fault signal of the CPLD is cleared in time, and the operation of the driving system is recovered.
Further, as shown in fig. 2, the over-current determining module 30 includes a first voltage following module 301, a forward reference voltage providing module 302, a forward reference voltage comparing module 303, a backward reference voltage providing module 304, a backward reference voltage comparing module 305, and an RC filtering module 306.
The input end of the first voltage following module 301 is the input end of the over-current determining module 30, the output end of the first voltage following module 301 is connected to the inverting input end of the forward reference voltage comparing module 302 and the non-inverting input end of the backward reference voltage comparing module 305, the output end of the forward reference voltage providing module 302 is connected to the non-inverting input end of the forward reference voltage comparing module 303, the output end of the backward reference voltage providing module 304 is connected to the inverting input end of the backward reference voltage comparing module 305, the output ends of the forward reference voltage comparing module 302 and the backward reference voltage comparing module 304 are connected to the input end of the RC filtering module 306 in common, and the output end of the RC filtering module is the output end of the over-current determining module 30.
The first voltage following module 301 outputs a voltage signal to the forward reference voltage comparing module 302 and the reverse reference voltage comparing module 305, when the forward reference voltage comparing module 302 and the reverse reference voltage comparing module 305 determine that the voltage value of the voltage signal is between the voltages provided by the forward reference voltage providing module 302 and the reverse reference voltage providing module 304, the forward reference voltage comparing module 302 and the reverse reference voltage comparing module 305 output a high level signal to the RC filtering module 306, and the RC filtering module 306 filters the high level signal and then outputs the high level signal.
Specifically, the first voltage follower module 301 includes: a resistor R09, an operational amplifier IC1A and a capacitor C3; a first end of the resistor R09 is connected with an output end of the current sensor 10, a second end of the resistor R09 is connected with a non-inverting end of the operational amplifier IC1A, a first end of the capacitor C3 is connected with a power supply end of the operational amplifier IC2B, and a second end of the capacitor C3 is grounded; the output end of the operational amplifier IC1A is the output end of the first voltage follower module 301; the module is used for isolating the influence of the post-stage circuit on the output signal.
The reverse reference voltage providing module 304 includes: the circuit comprises a resistor R4, a resistor R5, a resistor R6 and a capacitor C1; a first end of the resistor R4 is connected with a power supply, a second end of the resistor R4, a first end of the resistor R5 and a first end of the capacitor C1 are connected to a second signal input end of the reverse reference voltage comparison module in a common mode, a second end of the resistor R5 is connected with a first end of the resistor R6, and a second end of the resistor R6 and a second end of the capacitor C1 are connected to the ground in a common mode; the reverse reference voltage providing module 304 is configured to adjust the reverse reference voltage value through adjustment of the resistance values of the resistor R4, the resistor R5, and the resistor R6.
The forward reference voltage providing module 302 includes: the resistor R12, the resistor R13, the resistor R14 and the capacitor C6; the output end of the forward reference voltage comparison module 303 is connected to the non-inverting input end of the forward reference voltage comparison module 303, and the connection relationship and the working principle of other components and the backward reference voltage providing module can be analogized, which is not described herein again.
The back reference voltage comparison module 305 includes: a comparator IC2B, a resistor R7, a capacitor C8; the first end of the resistor R07 is connected with the output end of the first voltage following module, the second end of the resistor R07 is connected with the non-inverting input end of the comparator IC2B, the first end of the capacitor C8 is connected with the power supply end of the operational amplifier IC2B, and the second end of the capacitor C8 is grounded; the output end of the comparator IC2B and the output end of the positive reference voltage comparison module are connected to the input end of the filter module in common; this module is used to compare the current sense signal of the current sensor 10 with the inverted reference voltage providing module value by a comparator.
The forward reference voltage comparison module 302 includes: comparator IC2A, resistor R10, capacitor C4; the inverting input end of the comparator IC2A is connected with the output end of the first voltage following module; a first end of the resistor R10 is connected with an output end of the positive reference voltage providing module, a second end of the resistor R10 is connected with a non-inverting input end of the comparator IC2A, a first end of the capacitor C4 is connected with a power supply end of the operational amplifier IC2A, and a second end of the capacitor C4 is grounded; the output end of the comparator IC2A and the output end of the reverse reference voltage comparison module are connected to the input end of the filter module in common; this module is used to compare the current sense signal of the current sensor 10 with the positive reference voltage supply module value via a comparator.
The RC filtering module 306 includes: a resistor R16 and a capacitor C7; a first end of the resistor R16 is connected to the output ends of the backward reference voltage comparison module 305 and the forward reference voltage comparison module 3022, and performs filtering processing on the output signal.
Further, the over-current determining module 30 further includes a pull-up resistor R11, a first end of the resistor R11 is connected to the power supply, and a second end of the resistor R11 is connected to the power supply, and is connected to the output terminal of the reverse reference voltage comparing module 305, the output terminal of the forward reference voltage comparing module 302, and the input terminal of the RC filtering module 306; when the outputs of the forward reference voltage comparison module 305 and the backward reference voltage comparison module 302 are at a high level, the output high level value is increased to ensure that the output value is at a high level.
Further, the forward reference voltage comparison module 302 further comprises a first hysteresis module; the first hysteresis module comprises a resistor R15; the first end of the resistor R15 is connected with the second end of the resistor R7 and the non-inverting input end of the IC 2B; a second terminal of the resistor R15 is connected to an output terminal of the comparator IC 2B. The comparator has simple structure, high sensitivity and poor anti-interference capability; therefore, the interference resistance of the first hysteresis module can be improved.
The backward reference voltage comparison module 305 further comprises a second hysteresis module; the second hysteresis module includes a resistor R8; the first end of the resistor R8 is connected with the second end of the resistor R7 and the non-inverting input end of the IC 2B; a second terminal of the resistor R8 is connected to the output terminal of the comparator IC 2B. The connection relationship and the operation principle of the second hysteresis module can be similar to those of the first hysteresis module, and are not described herein again.
Further, as shown in fig. 3, the overcurrent protection circuit further includes: the input end of the current filtering module 20 is connected with the output end of the current sensor 10, and the output end of the current filtering module 20 is connected with the input end of the overcurrent judging module 30 and the input end of the DSP 50;
the current filtering module 20 filters the spike pulse in the current detection signal to eliminate the problem that the CPLD works due to the current spike when the device is turned on or off and the motor is changed in speed, thereby avoiding the error protection of the CPLD device.
Further, the current filtering module 20 includes a voltage division filtering module 201, a second voltage following module 202 and a secondary filtering module 203, and the voltage division filtering module 201, the second voltage following module 202 and the secondary filtering module 203 are connected in sequence;
the voltage division filtering module 201 filters the current detection signal and then sends the current detection signal to the second voltage follower circuit 202;
the second voltage following module 202 rectifies the filtered current detection signal and outputs the rectified current detection signal to the second-stage filtering module 203;
the secondary filtering module 203 performs secondary filtering on the rectified current detection signal and outputs the filtered current detection signal.
The embodiment adopts the partial pressure filter module, the second voltage following module and the secondary filter module, and the current signals are respectively filtered, isolated and filtered again, so that the influence of the current spike on the judgment result is reduced.
Further, as shown in fig. 4, the voltage division filtering module 201 includes a resistor R01, a resistor R02, and a capacitor C01;
a first end of the resistor R01 is connected with a signal output end of the current sensor 10, and a second end of the resistor R01 is connected with a first end of the resistor R02, a first end of the capacitor C01 and an input end of the second following module; the second terminal of the resistor R02 and the second terminal of the capacitor C01 are connected to ground.
Further, the second voltage following module 202 includes: an operational amplifier IC01A, a capacitor C02;
the non-inverting input end of the operational amplifier IC01A is connected with the output end of the voltage division filtering module, and the inverting input end of the operational amplifier IC01A is connected with the output end of the operational amplifier IC01A and the input end of the secondary filtering module.
Further, the two-stage filtering module 203 includes: a resistor R1 and a capacitor C03;
the first end of the resistor R1 is connected to the output end of the second voltage following module, and the second end of the resistor R1 is connected to the first end of the capacitor C03 and the signal input end of the overcurrent judging module 30.
The invention adopts CPLD to replace the trigger holding circuit connected with the output end of the over-current judging circuit and the reset circuit connected with the trigger holding circuit in the prior art, and combines other hardware circuits through the CPLD, the CPLD is equivalent to hardware established by various logic gates, the response time is below us, the invention can quickly respond to the system when over-current occurs, the sensitivity is high, and the device can be better protected, thereby greatly shortening the response time of over-current protection.
Another embodiment of the present invention provides an overcurrent protection circuit based on a CPLD, as shown in fig. 5, the overcurrent protection circuit includes: the current sensor 10, the CPLD40, the DSP50, and the drive module 60;
the current sensor 10 is respectively connected with the overcurrent judgment module 30 and the DSP50, the CPLD40 is respectively connected with the DSP50 and the drive module 60, and the DSP50 is connected with the drive module 60;
the current sensor 10 sends a current detection signal to the DSP 50;
when the current detection signal detected by the DSP50 is outside the preset range, the DSP50 sends an overcurrent signal to the CPLD40, the CPLD40 latches the overcurrent signal and sends a fault signal to the DSP50, and at the same time sends a shutdown control signal to the drive module 60, and the DSP50 stops sending the drive signal to the drive module 60 through the CPLD 49;
when the DSP50 detects that the current detection signal is within the preset range, the DSP50 sends a clear latch signal to the CPLD40, causes the CPLD40 to stop sending the shutdown control signal to the driver module 60, and sends a driving signal to the driver module 60 through the CPLD 40.
The embodiment of the invention adopts the DSP to monitor the current detection signal of the current sensor in time and judge the current detection signal, controls the CPLD to start sending a turn-off control signal to the driving module when detecting that the current detection signal is out of a preset current range, such as-3A-2A range, and clears the fault signal of the CPLD in time when detecting that the current detection signal is recovered to be normal, thereby recovering the operation of the driving system.
The invention provides an overcurrent protection method of an overcurrent protection circuit based on a CPLD, wherein the overcurrent protection circuit comprises the following steps: the device comprises a current sensor, an overcurrent judgment module, a CPLD, a DSP and a driving module;
the overcurrent protection method comprises the following steps:
the current sensor sends a current detection signal to the overcurrent judging module;
when the overcurrent judging module detects that the current detection signal is out of the preset range, an overcurrent signal is sent to the CPLD;
the CPLD latches an overcurrent signal to send a fault signal to the DSP and sends a turn-off control signal to the drive module;
the DSP stops sending a driving signal to the driving module through the CPLD according to the fault signal;
when the overcurrent judging module detects that the current detection signal is in a preset range, an overcurrent-preventing signal is sent to the CPLD;
the CPLD sends a fault clearing signal to the DSP according to the non-overcurrent signal;
and the DSP sends a clearing latch signal to the CPLD according to the fault clearing signal, so that the CPLD stops sending a turn-off control signal to the driving module, and sends a driving signal to the driving module through the CPLD.
When a current detection signal detected by the DSP is out of a preset range, the DSP sends an overcurrent signal to the CPLD, the CPLD latches the overcurrent signal and sends a fault signal to the DSP, and simultaneously sends a turn-off control signal to the drive module, and the DSP stops sending the drive signal to the drive module through the CPLD;
when the current detection signal detected by the DSP is in the preset range, the DSP sends a latch clearing signal to the CPLD, so that the CPLD stops sending a turn-off control signal to the driving module, and sends a driving signal to the driving module through the CPLD.
According to some embodiments of the present invention, as shown in fig. 6, an overcurrent protection circuit based on a CPLD includes a current sensor 10, an overcurrent determination module 30, a CPLD40, a DSP50, and a driving module 60;
the current sensor 10 is respectively connected with the overcurrent judgment module 30 and the DSP50, the CPLD40 is respectively connected with the overcurrent judgment module 30, the DSP50 and the drive module 60, and the DSP50 is connected with the drive module 60;
the current sensor 10 sends a current detection signal to the overcurrent judging module 30 and the DSP 50;
when the overcurrent judging module 30 and/or the DSP50 detect that the current detection signal is outside the preset range, the overcurrent judging module 30 and/or the DSP50 sends an overcurrent signal to the CPLD 40;
the CPLD40 latches an overcurrent signal to send a fault signal to the DSP50 and sends a turn-off control signal to the drive module 60;
the DSP50 stops sending the driving signal to the driving module 60 through the CPLD40 according to the fault signal.
When the overcurrent judging module 30 and the DSP50 detect that the current detection signal is within the preset range, the overcurrent judging module 30 and/or the DSP50 send an overcurrent-prevention signal to the CPLD;
the CPLD40 sends a fault clearing signal to the DSP50 according to the no-overcurrent signal;
the DSP50 sends a clear latch signal to the CPLD40 based on the fault clear signal, causes the CPLD40 to stop sending the shutdown control signal to the drive module 60, and sends the drive signal to the drive module 60 through the CPLD 40.
The embodiment of the invention can judge the current detection signal of the current sensor by adopting a hardware circuit and a software judging mode, can mutually verify by adopting two judging modes, can quickly and accurately respond to a system when overcurrent occurs, has high sensitivity and can better protect a device.
For the specific working process of the module in the overcurrent protection method, reference may be made to the corresponding process in the foregoing embodiment, which is not described herein again.
The above examples are only intended to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein.
Claims (8)
1. An over-current protection circuit based on a CPLD, which is characterized by comprising: the device comprises a current sensor, a current filtering module, an overcurrent judging module, a CPLD, a DSP and a driving module;
the input end of the current filtering module is connected with the output end of the current sensor, the output end of the current filtering module is connected with the input end of the overcurrent judging module and the input end of the DSP, and the CPLD is respectively connected with the overcurrent judging module, the DSP and the driving module;
the current filtering module sends a current detection signal to the overcurrent judging module and the DSP;
the current filtering module comprises a partial pressure filtering module, a second voltage following module and a secondary filtering module, and the partial pressure filtering module, the second voltage following module and the secondary filtering module are sequentially connected;
the voltage division filtering module filters the current detection signal and then sends the current detection signal to the second voltage following module;
the second voltage following module rectifies the filtered current detection signal and outputs the rectified current detection signal to the second-stage filtering module;
the secondary filtering module is used for carrying out secondary filtering on the rectified current detection signal and then outputting the filtered current detection signal;
when the overcurrent judging module and/or the DSP detects that the current detection signal is out of a preset range, the overcurrent judging module and/or the DSP sends an overcurrent signal to the CPLD;
the over-current judging module converts the current detection signal into a voltage signal in a form of setting a comparison circuit, and then compares the voltage signal with a forward voltage or compares the forward voltage and a reverse voltage with a reference voltage;
the CPLD latches the overcurrent signal and sends a fault signal to the DSP, and simultaneously sends a turn-off control signal to the drive module;
and the DSP stops sending a driving signal to the driving module through the CPLD according to the fault signal.
2. The overcurrent protection circuit of claim 1, wherein: when the overcurrent judging module and the DSP detect that the current detection signal is in a preset range, the overcurrent judging module and/or the DSP send an overcurrent-free signal to the CPLD;
the CPLD sends a fault clearing signal to the DSP according to the no-overcurrent signal;
and the DSP sends a clearing latch signal to the CPLD according to the fault clearing signal, so that the CPLD stops sending a turn-off control signal to the driving module, and sends a driving signal to the driving module through the CPLD.
3. The overcurrent protection circuit of claim 1, wherein: the current sensor sends a current detection signal to the overcurrent judgment module;
and when the DSP detects that the current detection signal sent by the current sensor is in a normal current range, the DSP sends a latch clearing signal to the CPLD, so that the CPLD stops sending a switching-off control signal to the driving module, and sends a driving signal to the driving module through the CPLD.
4. The overcurrent protection circuit of claim 3, wherein: when the current detection signal detected by the DSP is out of the normal current range, sending an overcurrent signal to the CPLD;
the CPLD latches the over-current signal and sends a fault signal to the DSP, and simultaneously sends a turn-off control signal to the drive module;
and the DSP stops sending a driving signal to the driving module through the CPLD.
5. The overcurrent protection circuit of claim 1, wherein: the overcurrent judging module comprises a first voltage following module, a forward reference voltage providing module, a forward reference voltage comparing module, a reverse reference voltage providing module, a reverse reference voltage comparing module and an RC filtering module;
the input end of the first voltage following module is the input end of the overcurrent judging module, the output end of the first voltage following module is connected with the reverse phase input end of the forward reference voltage comparing module and the same phase input end of the reverse reference voltage comparing module, the output end of the forward reference voltage providing module is connected with the same phase input end of the forward reference voltage comparing module, the output end of the reverse reference voltage providing module is connected with the reverse phase input end of the reverse reference voltage comparing module, the output ends of the forward reference voltage comparing module and the reverse reference voltage comparing module are commonly connected with the input end of the RC filtering module, and the output end of the RC filtering module is the output end of the overcurrent judging module;
the first voltage following module outputs a voltage signal to the forward reference voltage comparison module and the reverse reference voltage comparison module, and when the forward reference voltage comparison module and the reverse reference voltage comparison module judge that the voltage value of the voltage signal is between a first voltage value provided by the forward reference voltage providing module and a second voltage value provided by the reverse reference voltage providing module, the first voltage following module outputs a high-level signal to the RC filtering module;
and the RC filtering module filters the high-level signal and then outputs the high-level signal.
6. The overcurrent protection circuit of claim 5, wherein: the forward reference voltage comparison module comprises a first comparator, a resistor R10, a resistor R15 and a capacitor C4, wherein a first end of the resistor R10 is a non-inverting input end of the forward reference voltage comparison module, a second end of the resistor R10 is connected with the non-inverting input end of the first comparator and a first end of the resistor R15, a second end of the resistor R15 is connected with an output end of the first comparator and forms an output end of the forward reference voltage comparison module, a first end of the capacitor C4 is connected with a power input end of the first comparator, a second end of the capacitor C4 is grounded, and an inverting input end of the first comparator is an inverting input end of the forward reference voltage comparison module;
the reverse reference voltage comparison module comprises a second comparator, a resistor R7, a resistor R8 and a capacitor C8, the first end of the resistor R7 is the non-inverting input end of the reverse reference voltage comparison module, the second end of the resistor R7 is connected with the non-inverting input end of the second comparator and the first end of the resistor R8, the second end of the resistor R8 is connected with the output end of the second comparator and constitutes the output end of the reverse reference voltage comparison module, the first end of the capacitor C8 is connected with the power input end of the second comparator, the second end of the capacitor C8 is grounded, and the inverting input end of the second comparator is the inverting input end of the reverse reference voltage comparison module.
7. The overcurrent protection circuit of claim 1, wherein: the voltage division filtering module comprises a resistor R01, a resistor R02 and a capacitor C01;
a first end of the resistor R01 is connected with a signal output end of the current sensor, a second end of the resistor R01 is connected with a first end of the resistor R02, a first end of the capacitor C01 and an input end of the second voltage following module, and a second end of the resistor R02 and a second end of the capacitor C01 are connected to the ground in common;
the second voltage following module includes: an operational amplifier IC01A, a capacitor C02;
the non-inverting input end of the operational amplifier IC01A is connected with the output end of the voltage division filtering module, and the inverting input end of the operational amplifier IC01A and the output end of the operational amplifier IC01A are connected with the input end of the secondary filtering module in common;
the secondary filter module comprises: a resistor R1 and a capacitor C03;
the first end of the resistor R1 is connected with the output end of the second voltage following module, and the second end of the resistor R1 is connected with any end of the capacitor C03 and the signal input end of the over-current judgment module.
8. An overcurrent protection method of an overcurrent protection circuit based on a CPLD is characterized in that the overcurrent protection circuit comprises: the device comprises a current sensor, a current filtering module, an overcurrent judging module, a CPLD, a DSP and a driving module;
the overcurrent protection method comprises the following steps:
the input end of the current filtering module is connected with the output end of the current sensor, the output end of the current filtering module is connected with the input end of the overcurrent judging module and the input end of the DSP, the current filtering module filters spike pulses in current detection signals, and the CPLD is respectively connected with the overcurrent judging module, the DSP and the driving module;
the current filtering module sends a current detection signal to the overcurrent judging module and the DSP;
the current filtering module comprises a partial pressure filtering module, a second voltage following module and a secondary filtering module, and the partial pressure filtering module, the second voltage following module and the secondary filtering module are sequentially connected;
the voltage division filtering module filters the current detection signal and then sends the current detection signal to the second voltage following module;
the second voltage following module rectifies the filtered current detection signal and outputs the rectified current detection signal to the second-stage filtering module;
the secondary filtering module is used for carrying out secondary filtering on the rectified current detection signal and then outputting the current detection signal;
when the overcurrent judging module and/or the DSP detects that the current detection signal is out of a preset range, the overcurrent judging module and/or the DSP sends an overcurrent signal to the CPLD;
the over-current judging module converts the current detection signal into a voltage signal in a form of setting a comparison circuit, and then compares the voltage signal with a forward voltage or compares the forward voltage and a reverse voltage with a reference voltage;
the CPLD latches the over-current signal, sends a fault signal to the DSP and sends a turn-off control signal to the drive module;
the DSP stops sending a driving signal to the driving module through the CPLD according to the fault signal;
when the overcurrent judging module and the DSP detect that the current detection signal is in a preset range, the overcurrent judging module and/or the DSP send an overcurrent-preventing signal to the CPLD;
the CPLD sends a fault clearing signal to the DSP according to the no-overcurrent signal;
and the DSP sends a clearing latch signal to the CPLD according to the fault clearing signal, so that the CPLD stops sending a turn-off control signal to the driving module, and sends a driving signal to the driving module through the CPLD.
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| CN110763910A (en) * | 2019-11-11 | 2020-02-07 | 绵阳市维博电子有限责任公司 | Digital display DC meter and current sampling circuit thereof |
| CN112683115B (en) * | 2020-12-16 | 2024-01-30 | 陕西航天时代导航设备有限公司 | Torpedo steering engine driving system based on CPLD control |
| CN113489317B (en) * | 2021-05-26 | 2023-06-09 | 中国电子科技集团公司第四十一研究所 | Program-controlled output power control circuit |
| CN114123102B (en) * | 2021-11-29 | 2023-03-17 | 珠海格力电器股份有限公司 | Overcurrent delay protection circuit and method and frequency converter |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101667023A (en) * | 2009-09-29 | 2010-03-10 | 河北工业大学 | Device for performing priority processing on fault of electric actuator based on CPLD and realizing method thereof |
| CN102118018A (en) * | 2009-12-31 | 2011-07-06 | 天津市松正电动科技有限公司 | Protection circuit with functions of upper limit and lower limit |
| CN103001189A (en) * | 2012-11-05 | 2013-03-27 | 冶金自动化研究设计院 | Converter overvoltage and overcurrent fault alarming protective circuit |
| CN103499736A (en) * | 2013-10-22 | 2014-01-08 | 重庆长安汽车股份有限公司 | Over-current detection circuit and over-current protection circuit |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI397246B (en) * | 2009-11-06 | 2013-05-21 | Analog Vision Technology Inc | Protection circuit with latch control |
-
2017
- 2017-12-29 CN CN201711481987.3A patent/CN109994987B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101667023A (en) * | 2009-09-29 | 2010-03-10 | 河北工业大学 | Device for performing priority processing on fault of electric actuator based on CPLD and realizing method thereof |
| CN102118018A (en) * | 2009-12-31 | 2011-07-06 | 天津市松正电动科技有限公司 | Protection circuit with functions of upper limit and lower limit |
| CN103001189A (en) * | 2012-11-05 | 2013-03-27 | 冶金自动化研究设计院 | Converter overvoltage and overcurrent fault alarming protective circuit |
| CN103499736A (en) * | 2013-10-22 | 2014-01-08 | 重庆长安汽车股份有限公司 | Over-current detection circuit and over-current protection circuit |
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