CN108667129B - Low-voltage failure protection circuit - Google Patents
Low-voltage failure protection circuit Download PDFInfo
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- CN108667129B CN108667129B CN201810475056.0A CN201810475056A CN108667129B CN 108667129 B CN108667129 B CN 108667129B CN 201810475056 A CN201810475056 A CN 201810475056A CN 108667129 B CN108667129 B CN 108667129B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
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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
- H02H3/087—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 for dc applications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
-
- 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
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Abstract
The invention discloses a low-voltage failure protection circuit which is applied to power supply protection of a low-voltage side of a motor controller, wherein the low-voltage side of the motor controller is supplied with power through a low-voltage power supply battery, and an emergency circuit is adopted to output emergency voltage to the low-voltage side of the motor controller when the low-voltage output by the low-voltage power supply battery is undervoltage; a comparison circuit is adopted to process and analyze the control voltage to obtain a control signal; and controlling the output state of the emergency voltage by adopting the emergency power supply according to the control signal. By adopting the technical scheme of the invention, the low-voltage side part of the motor controller is powered from the bus through the emergency circuit to drive the motor controller when the low-voltage battery is undervoltage, so that the whole motor controller is in a controllable state, and the emergency circuit is disconnected after the voltage of the low-voltage battery is recovered, thereby realizing the effect of low-voltage failure protection on the motor controller, and the circuit cost is lower.
Description
Technical Field
The invention relates to the field of motor control of pure electric vehicles, in particular to a low-voltage failure protection circuit.
Background
With the development of new energy vehicles, especially the continuous progress of the technology in the field of pure electric vehicles, the protection of a motor controller in the pure electric vehicle is an important technology research and development direction.
In the existing motor controller, the power supply of the low-voltage side (control part) of the controller is realized by the high-voltage side through a flyback power supply mode. When an ignition key signal of an automobile is powered off, the high-voltage side is temporarily in a state of not powering down, and at the moment, the low-voltage side is powered on under the action of the flyback circuit, so that the motor controller is kept in a controllable state for a period of time. By the scheme, low-voltage failure protection is performed when the low-voltage side is powered off temporarily. However, in order to realize the existing scheme, the communication component, the ignition component and the sensor of the motor controller and the vehicle control unit need to be isolated, the equipment system is complex to assemble, the production cost of the equipment is high, and the large-scale popularization is not facilitated.
Disclosure of Invention
In view of the above problems in the prior art, a low voltage failure protection circuit is now provided.
The specific technical scheme is as follows:
a low voltage failure protection circuit for use in power protection of a low voltage side of a motor controller, the low voltage side of the motor controller being connected to an output of a low voltage power supply battery, the low voltage failure protection circuit comprising:
the emergency circuit is respectively connected with the output end of the low-voltage power supply battery and the output end of an emergency power supply and is used for outputting emergency voltage to the low-voltage side of the motor controller when the low-voltage output by the low-voltage power supply battery is undervoltage;
the input end of the comparison circuit is respectively connected with the output end of the low-voltage power supply battery and the output end of the emergency power supply and is used for processing and analyzing the control voltage to obtain a control signal;
the input end of the emergency power supply is connected with the high-voltage power supply, and the control end of the emergency power supply is connected with the output end of the comparison circuit and used for controlling the output state of the emergency voltage according to the control signal.
Preferably, the emergency circuit comprises:
the anode of the first secondary tube is connected with the output end of the low-voltage power supply battery, and the cathode of the first secondary tube is connected with a first node;
a first capacitor, two ends of which are respectively connected with the first node and the second node;
the two ends of the second capacitor are respectively connected with the second node and the output end of the emergency power supply;
the first node is connected with the output end of the emergency power supply, and the second node is grounded.
Preferably, the comparison circuit comprises a comparator and an auxiliary circuit;
the auxiliary circuit includes:
the two ends of the first resistor are respectively connected with the output end of the low-voltage power supply battery and a third node;
the two ends of the second resistor are respectively connected with the third node and the fifteenth node;
a third capacitor, two ends of which are respectively connected with the third node and the fifteenth node;
a fourth resistor, two ends of which are respectively connected with the third node and the second output end of the comparator;
the third node is respectively connected with the first positive input end and the second positive input end of the comparator, and the fifteenth node is connected with a ground terminal;
the first output end of the comparator is connected with a fifth node, and the fifth node is also connected with a pull-up circuit and the output end of the comparison circuit.
Preferably, the auxiliary circuit further comprises:
the two ends of the third resistor are respectively connected with the output end of the emergency power supply and a fourth node;
the negative electrode of the controlled rectifier is connected with the fourth node, the positive electrode of the controlled rectifier is connected with the sixteenth node, and the control electrode of the controlled rectifier is connected with the fourth node;
a fourth capacitor, two ends of which are respectively connected with the fourth node and the sixteenth node;
the fourth node is connected to the first negative input end and the second negative input end of the comparator, respectively, and the sixteenth node is connected to the ground terminal.
Preferably, the auxiliary circuit further comprises:
and two ends of the fifth capacitor are respectively connected with the positive power supply input end and the negative power supply input end of the comparator, the positive power supply input end of the comparator is also connected with the output end of the emergency power supply, and the negative power supply input end of the comparator is grounded.
Preferably, the pull-up circuit includes:
a fifth resistor, two ends of which are respectively connected with the fifth node and the sixth node;
a sixth capacitor, two ends of which are connected to the sixth node and the ground terminal, respectively;
and the sixth node is connected with the output end of the emergency power supply.
Preferably, the emergency power supply includes:
the signal input end of the signal control circuit is connected with the output end of the comparison circuit and is used for acquiring the control voltage and controlling the output state of the emergency power supply through the control voltage;
the input end of the power supply input circuit is connected with the high-voltage power supply, and the output end of the power supply input circuit is connected with the power supply input end of the signal control circuit and is used for performing voltage-stabilizing rectification processing on the high-voltage power supply;
and the input end of the load control circuit is connected with the signal control circuit, and the output end of the load control circuit is connected with the output end of the emergency power supply and is used for controlling the output load and carrying out short-circuit protection.
Preferably, the signal control circuit includes:
the two ends of the sixth resistor are respectively connected with the seventh node and the grid electrode of the first N-channel MOS tube;
a seventh capacitor, two ends of which are connected with the seventh node and the eighth node respectively;
the source electrode of the first N-channel MOS tube is connected with the anode of the series diode;
the two ends of the seventh resistor are respectively connected with the drain electrode of the first N-channel MOS tube and the ninth node;
the negative electrode of the series diode is connected with the eighth node;
an eighth capacitor, two ends of which are connected to the eighth node and the ninth node, respectively;
an eighth resistor, two ends of which are respectively connected with the ninth node and the tenth node;
a step recovery diode, the anode of which is connected with the eighth node and the cathode of which is connected with the tenth node;
the emitter of the first triode is connected with the tenth node, and the collector of the first triode is connected with the ninth node;
a ninth resistor, two ends of which are respectively connected with the base electrode of the first triode and the eleventh node;
a source electrode of the second N-channel MOS tube is connected with the eleventh node, a drain electrode of the second N-channel MOS tube is connected with the output end of the power input circuit, and a grid electrode of the second N-channel MOS tube is connected with the ninth node;
the seventh node is further connected to the output end of the comparison circuit, the eighth node is further connected to a ground terminal and the load control circuit, and the eleventh node is connected to the load control circuit.
Preferably, the power input circuit includes:
a tenth resistor, two ends of which are respectively connected with the high-voltage power supply and the twelfth node;
a ninth capacitor, two ends of which are respectively connected with the twelfth node and the ground terminal;
an eleventh resistor, two ends of which are connected to the twelfth node and the ninth node, respectively;
the twelfth node is also connected with the drain electrode of the second N-channel MOS tube.
Preferably, the load control circuit includes:
the drain electrode of the third N-channel MOS tube is connected with the eighth node, and the grid electrode of the third N-channel MOS tube is connected with the thirteenth node;
a collector of the second triode is connected with the fourteenth node;
a twelfth resistor, two ends of which are respectively connected with the eleventh node and the emitter of the second triode, wherein the twelfth resistor is an adjustable resistor;
a thirteenth resistor, two ends of which are respectively connected with the source electrode of the third N-channel MOS transistor and the base electrode of the second triode;
a fourteenth resistor, two ends of which are respectively connected to the thirteenth node and the fourteenth node;
a fifteenth resistor, two ends of which are connected to the thirteenth node and the eighth node respectively;
and the fourteenth node is connected with the output end of the emergency power supply.
The technical scheme has the following advantages or beneficial effects:
the electric framework of the motor controller is optimized, the low-voltage side part of the motor controller is powered by the low-voltage battery, electricity is taken from the bus through the emergency circuit to drive the motor controller when the low-voltage battery is undervoltage, the whole motor controller is in a controllable state, the emergency circuit is disconnected after the voltage of the low-voltage battery recovers, the effect of low-voltage failure protection of the motor controller is achieved, and the circuit cost is low.
Drawings
Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings. The drawings are, however, to be regarded as illustrative and explanatory only and are not restrictive of the scope of the invention.
FIG. 1 is a schematic diagram of a circuit configuration of an emergency circuit in an embodiment of a low voltage failure protection circuit of the present invention;
FIG. 2 is a schematic diagram of a circuit structure of a comparison circuit in an embodiment of a low voltage fail-safe circuit according to the present invention;
fig. 3 is a schematic circuit diagram of an emergency power supply in an embodiment of the low-voltage failure protection circuit of the invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.
The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.
In a preferred embodiment of the present invention, a low voltage failure protection circuit is applied to power protection of a low voltage side of a motor controller, the low voltage side of the motor controller is connected to an output terminal of a low voltage power supply battery, and the low voltage failure protection circuit includes:
the emergency circuit is respectively connected with the output end of the low-voltage power supply battery and the output end of an emergency power supply and is used for outputting emergency voltage to the low-voltage side of the motor controller when the low-voltage output by the low-voltage power supply battery is undervoltage;
the input end of the comparison circuit is respectively connected with the output end of the low-voltage power supply battery and the output end of the emergency power supply and used for acquiring a control signal according to the processing and analysis of the control voltage;
and the input end of the emergency power supply is connected with the high-voltage power supply, and the control end of the emergency power supply is connected with the output end of the comparison circuit and used for controlling the output state of the emergency voltage according to the control signal.
Specifically, in this embodiment, the emergency circuit connects the low-voltage power supply battery and the emergency power supply output end, and the voltage of the low-voltage power supply battery and the voltage output by the emergency power supply can be output to the low-voltage side of the motor controller through the emergency circuit.
The output voltage of the low-voltage power supply battery is subjected to signal analysis processing based on a circuit by adopting a comparison circuit, a control signal is obtained, and whether the emergency power supply outputs voltage is further controlled by the control signal, so that the motor controller converts the high-voltage power supply into the emergency voltage under the condition of abnormal power failure, and the effect of low-voltage failure protection is realized.
According to the scheme, when the comparison circuit detects the low-voltage abnormal power failure, the motor controller is in a controllable state, and when the low-voltage side power supply is recovered to be normal, the emergency power supply is controlled to be automatically closed, energy is not consumed, and the efficiency is improved. Meanwhile, the motor controller and the whole vehicle controller need to be isolated, and cost is greatly reduced.
In a preferred embodiment of the invention, when the low-voltage side power supply voltage is powered down to 10.3V, the low-voltage failure protection circuit outputs an emergency voltage to control the motor controller to be in a controllable state. When the power supply of the low-voltage side is recovered to 12.9V, the emergency power supply is automatically turned off, and the energy of the high-voltage power supply is not consumed any more.
In a preferred embodiment of the present invention, as shown in fig. 1, the emergency circuit comprises:
the positive electrode of the first secondary tube D1 is connected with the output end Vgd of the low-voltage power supply battery, and the negative electrode of the first secondary tube D1 is connected with the first node N1;
a first capacitor C1, both ends of which are connected to a first node N1 and a second node N2 respectively;
a second capacitor C2, two ends of which are respectively connected with the second node N2 and the output end VDD of the emergency power supply;
the first node N1 is connected to the output terminal VDD of the emergency power supply, and the second node N2 is grounded.
In a preferred embodiment of the present invention, as shown in FIG. 2, the comparison circuit comprises a comparator and an auxiliary circuit;
the auxiliary circuit includes:
the two ends of the first resistor R1 are respectively connected with the output end Vgd of the low-voltage power supply battery and the third node N3;
a second resistor R2, both ends of which are respectively connected with a third node N3 and a fifteenth node N15;
a third capacitor C3, two ends of which are respectively connected to a third node N3 and a fifteenth node N15;
a fourth resistor R4, two ends of which are respectively connected to the third node N3 and the second output terminal OUT2 of the comparator;
the third node N3 is respectively connected to the first positive input terminal IN1+ and the second positive input terminal IN2+ of the comparator, and the fifteenth node N15 is connected to a ground terminal GND;
the first output terminal OUT1 of the comparator is connected to the fifth node N5, and the fifth node N5 is further connected to the output terminal S1 of a pull-up circuit and a comparison circuit.
Specifically, in this embodiment, the auxiliary circuit performs voltage stabilization on the voltage output by the output terminal Vgd of the low-voltage power supply battery, and then introduces the voltage into the comparator for judgment, and outputs a control signal through the first output terminal OUT1 of the comparator to control the output state of the emergency power supply.
Hysteresis is achieved by connecting the second output OUT2 of the comparator to the first and second positive inputs IN1+ and IN2+ of the comparator. Specifically, the voltages inputted to the first positive input terminal IN1+ and the second positive input terminal IN2+ are lower than the reference voltages inputted to the first negative input terminal IN 1-and the second negative input terminal IN2-, and the output of the second output terminal OUT2 is low, the voltages of the first positive input terminal IN1+ and the second positive input terminal IN2+ are further pulled low, so as to stabilize the control signal outputted by the comparing circuit.
In a preferred embodiment of the present invention, as shown in fig. 2, the auxiliary circuit further includes:
two ends of the third resistor R3 are respectively connected with the output end VDD of the emergency power supply and the fourth node N4;
the controlled rectifier D2 has a negative electrode connected with the fourth node N4, a positive electrode connected with the sixteenth node N16 and a control electrode connected with the fourth node N4;
a fourth capacitor C4, two ends of which are connected to the fourth node N4 and the sixteenth node N16, respectively;
the fourth node N4 is connected to the first negative input IN 1-and the second negative input IN 2-of the comparator, respectively, and the sixteenth node N16 is connected to the ground GND.
Specifically, IN this embodiment, the auxiliary circuit is configured to input a stable reference voltage to the first negative input terminal IN 1-and the second negative input terminal IN 2-of the comparator, and further compare and determine the reference voltage and the output voltage of the low-voltage power supply battery, so that the comparator can analyze the output control signal.
In a preferred embodiment of the present invention, as shown in fig. 2, the auxiliary circuit further includes: and two ends of a fifth capacitor C5 are respectively connected with the positive power supply input end and the negative power supply input end of the comparator, the positive power supply input end of the comparator is also connected with the output end VDD of the emergency power supply, and the negative power supply input end of the comparator is grounded.
Specifically, in the present embodiment, the auxiliary circuit is used to supply power to the comparator.
In a preferred embodiment of the present invention, as shown in fig. 2, the pull-up circuit comprises:
a fifth resistor R5, both ends of which are respectively connected with a fifth node N5 and a sixth node N6;
a sixth capacitor C6, two ends of which are respectively connected to the sixth node N6 and the ground GND;
the sixth node N6 is connected to the output terminal VDD of the emergency power supply.
Specifically, in this embodiment, the pull-up circuit is used to amplify the control signal.
In a preferred embodiment of the present invention, the emergency power supply comprises:
the signal input end of the signal control circuit is connected with the output end S1 of the comparison circuit and is used for acquiring control voltage and controlling the output state of the emergency power supply through the control voltage;
the input end of the power supply input circuit is connected with a high-voltage power supply VDC, and the output end of the power supply input circuit is connected with the power supply input end of the signal control circuit and is used for performing voltage-stabilizing rectification processing on the high-voltage power supply VDC;
and the input end of the load control circuit is connected with the signal control circuit, and the output end of the load control circuit is connected with the output end VDD of the emergency power supply, and is used for controlling the output load and carrying out short-circuit protection.
Specifically, in this embodiment, the control circuit is used for controlling the on/off of the internal device according to the control signal to control the output state of the emergency power supply, and the power supply input circuit is used for voltage stabilization and constant current processing, so that the output emergency voltage is more stable, and the load control circuit is used for load capacity adjustment and short circuit protection.
In a preferred embodiment of the present invention, as shown in fig. 3, the signal control circuit comprises:
a sixth resistor R6, both ends of which are respectively connected to the seventh node N7 and the gate of the first N-channel MOS transistor T1;
a seventh capacitor C7, two ends of which are connected to the seventh node N7 and the eighth node N8, respectively;
a source electrode of the first N-channel MOS transistor T1 is connected with the anode of a series diode D3;
a seventh resistor R7, two ends of which are respectively connected with the drain electrode of the first N-channel MOS transistor T1 and a ninth node N9;
the negative electrode of the series diode D3 is connected with the eighth node N8;
an eighth capacitor C8, both ends of which are connected to an eighth node N8 and a ninth node N9, respectively;
an eighth resistor R8, both ends of which are connected with a ninth node N9 and a tenth node N10 respectively;
a step recovery diode D4, the anode of which is connected with the eighth node N8 and the cathode of which is connected with the tenth node N10;
the emitter of the first triode T2 is connected with the tenth node N10, and the collector of the first triode T2 is connected with the ninth node N9;
a ninth resistor R9, both ends of which are respectively connected to the base of the first triode T2 and the eleventh node N11;
a second N-channel MOS transistor T3, the source is connected with an eleventh node N11, the drain is connected with the output end of the power input circuit, and the gate is connected with a ninth node N9;
the seventh node N7 is further connected to the output terminal S1 of the comparison circuit, the eighth node N8 is further connected to the ground GND and the load control circuit, and the eleventh node N11 is connected to the load control circuit.
Specifically, in this embodiment, when the comparator determines that the output voltage of the low-voltage power supply battery is under-voltage, the comparator outputs a low-level control signal, the second N-channel MOS transistor T3 is turned on, the voltage of the output terminal VDD of the emergency power supply is higher than the voltage of the output terminal Vgd of the low-voltage power supply battery, and then the output voltage of the emergency power supply replaces the low-voltage power supply battery for power supply through the emergency circuit. When the comparator judges that the output voltage of the low-voltage power supply battery is normal, the output control signal enables the second N-channel MOS transistor T3 to be in a turn-off state, and the emergency voltage does not supply power.
In a preferred embodiment of the present invention, as shown in fig. 3, the power input circuit includes:
a tenth resistor R10, both ends of which are respectively connected with the high-voltage power supply VDC and a twelfth node N12;
a ninth capacitor C9, both ends of which are connected to the twelfth node N12 and the ground GND, respectively;
an eleventh resistor R11, both ends of which are connected to the twelfth node N12 and the ninth node N9 respectively;
the twelfth node N12 is further connected to the drain of the second N-channel MOS transistor T3.
Specifically, in this embodiment, the power input circuit performs preprocessing on the high-voltage power VDC, so as to ensure the stability of the circuit.
In a preferred embodiment of the present invention, as shown in fig. 3, the load control circuit comprises:
a third N-channel MOS transistor T4, the drain is connected with an eighth node N8, and the gate is connected with a thirteenth node N13;
a collector of the second triode T5 is connected with a fourteenth node N14;
two ends of the twelfth resistor R12 are respectively connected with the eleventh node N11 and the emitter of the second triode T5, and the twelfth resistor R12 is an adjustable resistor;
a thirteenth resistor R13, two ends of which are respectively connected with the source electrode of the third N-channel MOS transistor T4 and the base electrode of the second triode T5;
a fourteenth resistor R14, both ends of which are connected to a thirteenth node N13 and a fourteenth node N14 respectively;
a fifteenth resistor R15, both ends of which are connected to a thirteenth node N13 and an eighth node N8 respectively;
the fourteenth node N14 is connected to the output terminal VDD of the emergency power supply.
Specifically, in this embodiment, the load capacity is controlled by adjusting the resistance of the twelfth resistor R12. The resistance value of the twelfth resistor R12 is increased, the voltage drop of the same load current on the increase of the twelfth resistor R12 is increased, the output voltage of the output end VDD of the emergency power supply is reduced, and the load carrying capacity is reduced; conversely, the resistance of the twelfth resistor R12 is reduced, and the load carrying capacity is improved.
When the load control circuit finds a short circuit of the load, the emergency power supply can be automatically turned off, the emergency circuit is protected from being burnt, and the motor controller is prevented from being damaged. Specifically, when the load is short-circuited, the voltage of the output terminal VDD of the emergency power supply drops instantaneously, which causes the third N-channel MOS transistor T4 to turn off due to the gate voltage being too low, and further, the second transistor T5 does not work due to the base being disconnected, thereby cutting off the whole loop and achieving the above-mentioned short-circuit protection effect.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Claims (9)
1. A low-voltage failure protection circuit is characterized by being applied to power supply protection of a low-voltage side of a motor controller, wherein the low-voltage side of the motor controller is connected with an output end of a low-voltage power supply battery, and the low-voltage failure protection circuit comprises:
the emergency circuit is respectively connected with the output end of the low-voltage power supply battery and the output end of an emergency power supply and is used for outputting emergency voltage to the low-voltage side of the motor controller when the low-voltage output by the low-voltage power supply battery is undervoltage;
the input end of the comparison circuit is respectively connected with the output end of the low-voltage power supply battery and the output end of the emergency power supply, and the comparison circuit is used for analyzing and processing the voltage output by the low-voltage power supply battery based on a circuit to obtain a control signal;
the input end of the emergency power supply is connected with the high-voltage power supply, and the control end of the emergency power supply is connected with the output end of the comparison circuit and used for controlling the output state of the emergency voltage according to the control signal;
the comparison circuit comprises a comparator and an auxiliary circuit;
the auxiliary circuit includes:
the two ends of the first resistor are respectively connected with the output end of the low-voltage power supply battery and a third node;
the two ends of the second resistor are respectively connected with the third node and the fifteenth node;
a third capacitor, two ends of which are respectively connected with the third node and the fifteenth node;
a fourth resistor, two ends of which are respectively connected with the third node and the second output end of the comparator;
the third node is respectively connected with the first positive input end and the second positive input end of the comparator, and the fifteenth node is connected with a ground terminal;
the first output end of the comparator is connected with a fifth node, and the fifth node is also connected with a pull-up circuit and the output end of the comparison circuit.
2. The low voltage failure protection circuit of claim 1, wherein the emergency circuit comprises:
the anode of the first secondary tube is connected with the output end of the low-voltage power supply battery, and the cathode of the first secondary tube is connected with a first node;
a first capacitor, two ends of which are respectively connected with the first node and the second node;
the two ends of the second capacitor are respectively connected with the second node and the output end of the emergency power supply;
the first node is connected with the output end of the emergency power supply, and the second node is grounded.
3. The low voltage failure protection circuit of claim 1, wherein the auxiliary circuit further comprises:
the two ends of the third resistor are respectively connected with the output end of the emergency power supply and a fourth node;
the negative electrode of the controlled rectifier is connected with the fourth node, the positive electrode of the controlled rectifier is connected with the sixteenth node, and the control electrode of the controlled rectifier is connected with the fourth node;
a fourth capacitor, two ends of which are respectively connected with the fourth node and the sixteenth node;
the fourth node is connected to the first negative input end and the second negative input end of the comparator, respectively, and the sixteenth node is connected to the ground terminal.
4. The low voltage failure protection circuit of claim 1, wherein the auxiliary circuit further comprises:
and two ends of the fifth capacitor are respectively connected with the positive power supply input end and the negative power supply input end of the comparator, the positive power supply input end of the comparator is also connected with the output end of the emergency power supply, and the negative power supply input end of the comparator is grounded.
5. The low voltage failure protection circuit of claim 1, wherein the pull-up circuit comprises:
a fifth resistor, two ends of which are respectively connected with the fifth node and the sixth node;
a sixth capacitor, two ends of which are connected to the sixth node and the ground terminal, respectively;
and the sixth node is connected with the output end of the emergency power supply.
6. The low voltage failure protection circuit of claim 1, wherein the emergency power supply comprises:
the signal input end of the signal control circuit is connected with the output end of the comparison circuit and is used for acquiring the control voltage and controlling the output state of the emergency power supply through the control voltage;
the input end of the power supply input circuit is connected with the high-voltage power supply, and the output end of the power supply input circuit is connected with the power supply input end of the signal control circuit and is used for performing voltage-stabilizing rectification processing on the high-voltage power supply;
and the input end of the load control circuit is connected with the signal control circuit, and the output end of the load control circuit is connected with the output end of the emergency power supply and is used for controlling the output load and carrying out short-circuit protection.
7. The low voltage failure protection circuit of claim 6, wherein the signal control circuit comprises:
the two ends of the sixth resistor are respectively connected with the seventh node and the grid electrode of the first N-channel MOS tube;
a seventh capacitor, two ends of which are connected with the seventh node and the eighth node respectively;
the source electrode of the first N-channel MOS tube is connected with the anode of the series diode;
the two ends of the seventh resistor are respectively connected with the drain electrode of the first N-channel MOS tube and the ninth node;
the negative electrode of the series diode is connected with the eighth node;
an eighth capacitor, two ends of which are connected to the eighth node and the ninth node, respectively;
an eighth resistor, two ends of which are respectively connected with the ninth node and the tenth node;
a step recovery diode, the anode of which is connected with the eighth node and the cathode of which is connected with the tenth node;
the emitter of the first triode is connected with the tenth node, and the collector of the first triode is connected with the ninth node;
a ninth resistor, two ends of which are respectively connected with the base electrode of the first triode and the eleventh node;
a source electrode of the second N-channel MOS tube is connected with the eleventh node, a drain electrode of the second N-channel MOS tube is connected with the output end of the power input circuit, and a grid electrode of the second N-channel MOS tube is connected with the ninth node;
the seventh node is further connected to the output end of the comparison circuit, the eighth node is further connected to a ground terminal and the load control circuit, and the eleventh node is connected to the load control circuit.
8. The low voltage failure protection circuit of claim 7, wherein the power input circuit comprises:
a tenth resistor, two ends of which are respectively connected with the high-voltage power supply and the twelfth node;
a ninth capacitor, two ends of which are respectively connected with the twelfth node and the ground terminal;
an eleventh resistor, two ends of which are connected to the twelfth node and the ninth node, respectively;
the twelfth node is also connected with the drain electrode of the second N-channel MOS tube.
9. The low voltage failure protection circuit of claim 7, wherein the load control circuit comprises:
the drain electrode of the third N-channel MOS tube is connected with the eighth node, and the grid electrode of the third N-channel MOS tube is connected with the thirteenth node;
a collector of the second triode is connected with the fourteenth node;
a twelfth resistor, two ends of which are respectively connected with the eleventh node and the emitter of the second triode, wherein the twelfth resistor is an adjustable resistor;
a thirteenth resistor, two ends of which are respectively connected with the source electrode of the third N-channel MOS transistor and the base electrode of the second triode;
a fourteenth resistor, two ends of which are respectively connected to the thirteenth node and the fourteenth node;
a fifteenth resistor, two ends of which are connected to the thirteenth node and the eighth node respectively;
and the fourteenth node is connected with the output end of the emergency power supply.
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| CN201810475056.0A CN108667129B (en) | 2018-05-17 | 2018-05-17 | Low-voltage failure protection circuit |
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| CN201810475056.0A CN108667129B (en) | 2018-05-17 | 2018-05-17 | Low-voltage failure protection circuit |
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| CN108667129B true CN108667129B (en) | 2021-07-30 |
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| CN203289317U (en) * | 2013-04-27 | 2013-11-13 | 上海采埃孚转向系统有限公司 | Gateway power circuit used for electric power steering system |
| CN103269118B (en) * | 2013-05-27 | 2016-05-25 | 浙江南峰电气有限公司 | A kind of back-up source power-supplying circuit |
| CN206628889U (en) * | 2017-04-13 | 2017-11-10 | 株洲中车时代电气股份有限公司 | The controller power source emergency circuit of low-floor AuCT |
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