CN204068210U - Short-circuit protection circuit - Google Patents

Short-circuit protection circuit Download PDF

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Publication number
CN204068210U
CN204068210U CN201420509436.9U CN201420509436U CN204068210U CN 204068210 U CN204068210 U CN 204068210U CN 201420509436 U CN201420509436 U CN 201420509436U CN 204068210 U CN204068210 U CN 204068210U
Authority
CN
China
Prior art keywords
resistance
electric capacity
circuit
operational amplifier
diode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN201420509436.9U
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Chinese (zh)
Inventor
郭宗伟
江小晚
甘利红
丁争
刘帆
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
State Grid Corp of China SGCC
Xianning Power Supply Co of State Grid Hubei Electric Power Co Ltd
Original Assignee
State Grid Corp of China SGCC
Xianning Power Supply Co of State Grid Hubei Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by State Grid Corp of China SGCC, Xianning Power Supply Co of State Grid Hubei Electric Power Co Ltd filed Critical State Grid Corp of China SGCC
Priority to CN201420509436.9U priority Critical patent/CN204068210U/en
Application granted granted Critical
Publication of CN204068210U publication Critical patent/CN204068210U/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

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Abstract

The utility model provides a kind of short-circuit protection circuit, comprising: the first diode, a charge-discharge circuit, an operational amplifier, and three is sequentially connected in series, and described charge-discharge circuit comprises the first resistance and the first electric capacity; Also comprise one the 3rd resistance and one the 4th resistance, a feedback triode, also comprises one the 5th resistance, the 6th resistance, the 7th resistance, the second diode, the second electric capacity, field-effect transistor.The utility model provides a kind of simple, energy-conservation, cost is low, efficiency is high high voltage direct current transmission device short-circuit protection circuit, and when being short-circuited, it can protect converter not to be damaged quickly and efficiently.

Description

Short-circuit protection circuit
Technical field
The application relates to a kind of short-circuit protection circuit.
Background technology
The design relation of converter unit protection circuit is to the safe and stable operation of electric power system.Therefore, to the conceptual design of converter protective circuit and very urgent to the research of its fault recovery.The fault of converter is divided into major loop and control system fault.Fault type comprises converter AC or each terminals short of direct current (as valve short circuit), pair of connecting wires ground short circuit (as AC single-line to ground fault), triggering system set out pulse missing etc.Dissimilar fault can cause overvoltage in varying degrees and overcurrent; converter is as rectification important in high voltage direct current transmission, inverter circuit; except power electronic device Selecting parameter is suitable, drive circuit designs well, suitable overvoltage and overcurrent protection is adopted also to be very necessary.
At present, being generally that various protective circuit is set in converter both sides, by detecting the generation of various abnormal conditions, protecting by controlling the mode such as electric current, voltage.Such as short-circuit protection, first detect short circuit and occur, then control assembly limits electric current, and output current is limited in certain limit, to reach the object of system protection.But, when circuit system is in this state for a long time, system may occurrence temperature too high or consume certain energy, thus cause system failure or waste energy.Another problem is, this protection is complicated, and required parts are many, and cost is high.
Utility model content
The object of the application is to overcome the deficiencies in the prior art and provides a kind of simple, energy-conservation, cost is low, efficiency is high high voltage direct current transmission device short-circuit protection circuit; when being short-circuited, it can protect converter and whole system not to be damaged quickly and efficiently.
The application solves the technical scheme that its technical problem takes: a kind of short-circuit protection circuit, comprising: the first diode, a charge-discharge circuit, an operational amplifier, and three is sequentially connected in series, and described charge-discharge circuit comprises the first resistance and the first electric capacity; Also comprise one the 3rd resistance and one the 4th resistance, a feedback triode, also comprises one the 5th resistance, the 6th resistance, the 7th resistance, the second diode, the second electric capacity, field-effect transistor.
A kind of short-circuit protection circuit, comprise: the first diode, a charge-discharge circuit, an operational amplifier, three is sequentially connected in series, described charge-discharge circuit comprises the first resistance and the first electric capacity, described first resistance is connected with the first Capacitance parallel connection, first resistance is connected the output of the first diode with first electric capacity one end, other end ground connection; The positive input of operational amplifier is connected with the output of the first diode; Also comprise one the 3rd resistance and one the 4th resistance, the negative input of the 3rd resistance one end concatenation operation amplifier, other end ground connection, electromotive force on the negative input of this operational amplifier is reference voltage, this reference voltage produced a constant pressure source dividing potential drop by described 3rd resistance and the 4th resistance, 4th resistance one end is connected with constant pressure source, and the other end is connected on the circuit that the 3rd resistance is connected with operational amplifier negative input; Also comprise a feedback triode, its emitting stage is connected to the output of this operational amplifier, collector electrode is connected to the second resistance, and the other end of the second resistance is connected on the connection line of the output of the first diode and the positive input of operational amplifier, and ground level is connected to one end of the 5th resistance; Also comprise one the 6th resistance, the 7th resistance, the second diode, the second electric capacity, field-effect transistor, wherein the 6th resistance, the 7th resistance, the second electric capacity, field-effect transistor parallel connection, 6th resistance, the 7th resistance, the second electric capacity, field-effect transistor one end are connected to the other end of the 5th resistance, 6th resistance, the second electric capacity, field-effect transistor other end ground connection, be connected to the output of operational amplifier and feed back on the connection line of transistor emitter after the 7th resistance other end and the second Diode series.
The short-circuit protection method of the application's also claimed a kind of short-circuit protection circuit described above, wherein, when the voltage signal inputted is greater than this reference voltage, the electromotive force of the comparative voltage that the output of operational amplifier exports presents high state, the comparative voltage being in high state can make emitter and the collector electrode conducting of feeding back triode, feedback triode after conducting can provide the first feedback current, by the second resistance to the first capacitor charging, also provide the second feedback current simultaneously, on the one hand, by the 5th resistance and the 6th resistance, dividing potential drop is carried out to the voltage that this second feedback current produces, if when voltage, i.e. control signal that the 6th resistance is shared are greater than the critical voltage of grid and the source conduction making field-effect transistor, meeting conducting between the drain electrode of field-effect transistor and source electrode, thus, quick off voltage exports, and implements short-circuit protection, on the other hand, while feedback transistor emitter and base stage conducting, second feedback current via the 5th resistance to this second capacitor charging, feedback triode is made to enter linear work district from operate in saturation district, and then the first feedback current flowing through the second resistance is reduced gradually, to last, the input voltage signal of operational amplifier positive input can lower than the reference voltage of negative input, operational amplifier is no longer exported, namely output is no-voltage, second electric capacity is discharged to earth terminal by the second diode and the 7th resistance, when the capacitance voltage of the second electric capacity is discharged to the critical voltage lower than field-effect transistor conducting, field-effect transistor ends, power supply exports and recovers normal work, when the current signal inputted exceeds again protection point, restart short-circuit protection.
The beneficial effect of the application is:
(1) utilize the 5th resistance and the second electric capacity to control the cycle of operation of short-circuit protection circuit.
(2) comparative voltage utilizing operational amplifier to export is to control the whether action of this short-circuit protection circuit.
(3) short-circuit protection circuit can be made to have quick Disconnected mode and automatic recovery mode simultaneously.
(4) structure is simple, energy-conservation, cost is low, efficiency is high.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of short-circuit protection circuit.
Embodiment
As shown in Figure 1, for the structural representation of short-circuit protection circuit, 1. a short-circuit protection circuit, it is characterized in that, comprising: the first diode 14, charge-discharge circuit, an operational amplifier 11, three is sequentially connected in series, described charge-discharge circuit comprises the first resistance 15 and the first electric capacity 16, described first resistance 15 and the first electric capacity 16 are connected in parallel, and the first resistance 15 is connected the output of the first diode with first electric capacity 16 one end, other end ground connection, the positive input of operational amplifier 11 is connected with the output of the first diode 14, also comprise the negative input of one the 3rd resistance 18 and one the 4th resistance the 19, three resistance 18 one end concatenation operation amplifier 11, other end ground connection, the electromotive force on the negative input of this operational amplifier is reference voltage V rEF, this reference voltage V rEFbeing produced a constant pressure source VDD dividing potential drop by described 3rd resistance and the 4th resistance, the 4th resistance one end is connected with constant pressure source, and the other end is connected on the circuit that the 3rd resistance 18 is connected with operational amplifier 11 negative input, also comprise a feedback triode 12, its emitting stage is connected to the output of this operational amplifier, collector electrode is connected to the second resistance 17, the other end of the second resistance 17 is connected on the connection line of the output of the first diode and the positive input of operational amplifier 11, and ground level is connected to one end of the 5th resistance 20, also comprise one the 6th resistance 22, 7th resistance 23, second diode 24, second electric capacity 21, field-effect transistor 13, wherein the 6th resistance 22, 7th resistance 23, second electric capacity 21, field-effect transistor 13 is in parallel, 6th resistance 22, 7th resistance 23, second electric capacity 21, field-effect transistor 13 one end is connected to the other end of the 5th resistance 20, 6th resistance 22, second electric capacity 21, field-effect transistor 13 other end ground connection, 7th resistance 23 other end is connected to the output of operational amplifier 11 and feeds back on the connection line of transistor emitter after connecting with the second diode 24.
Introduce the course of work of technical scheme below in detail.
First, the current signal that the first diode 14 can import to converter input becomes I via current transformer i, the first electric capacity 16 is charged, produces input voltage signal V i, i.e. the electromotive force of the positive input of operational amplifier 11.The negative input of operational amplifier 11, by the 3rd resistance 18 and the 4th resistance 19, by constant pressure source VDD dividing potential drop, obtains a reference voltage V rEF.
When the voltage signal inputted is greater than this reference voltage, the electromotive force of the comparative voltage that the output of operational amplifier exports presents high state, the comparative voltage being in high state can make emitter and the collector electrode conducting of feeding back triode, feedback triode after conducting can provide the first feedback current I1, by the second resistance to the first capacitor charging, also provide the second feedback current I2 simultaneously, on the one hand, by the 5th resistance and the 6th resistance, dividing potential drop is carried out to the voltage that this second feedback current produces, if when voltage, i.e. control signal that the 6th resistance is shared are greater than the critical voltage of grid and the source conduction making field-effect transistor, meeting conducting between the drain electrode of field-effect transistor and source electrode, thus, quick off voltage exports V0, implements short-circuit protection, on the other hand, while feedback transistor emitter and base stage conducting, second feedback current via the 5th resistance to this second capacitor charging, feedback triode is made to enter linear work district from operate in saturation district, and then the first feedback current flowing through the second resistance is reduced gradually, to last, the input voltage signal of operational amplifier positive input can lower than the reference voltage of negative input, operational amplifier is no longer exported, namely output is no-voltage, second electric capacity is discharged to earth terminal by the second diode and the 7th resistance, when the capacitance voltage of the second electric capacity is discharged to the critical voltage lower than field-effect transistor conducting, field-effect transistor ends, power supply exports and recovers normal work, when the current signal inputted exceeds again protection point, restart short-circuit protection.
This application provides a kind of simple, energy-conservation, cost is low, efficiency is high high voltage direct current transmission device short-circuit protection circuit thus, when being short-circuited, it can protect converter not to be damaged quickly and efficiently.And after short-circuit bar removes, automatically can start converter and run, reenter guard mode.

Claims (1)

1. a short-circuit protection circuit, it is characterized in that, comprise: the first diode (14), a charge-discharge circuit, an operational amplifier (11), three is sequentially connected in series, described charge-discharge circuit comprises the first resistance (15) and the first electric capacity (16), described first resistance (15) and the first electric capacity (16) are connected in parallel, first resistance (15) is connected the output of the first diode with the first electric capacity (16) one end, other end ground connection, the positive input of operational amplifier (11) is connected with the output of the first diode (14), also comprise one the 3rd resistance (18) and one the 4th resistance (19), the negative input of the 3rd resistance (18) one end concatenation operation amplifier (11), other end ground connection, electromotive force on the negative input of this operational amplifier is reference voltage, this reference voltage produced a constant pressure source dividing potential drop by described 3rd resistance and the 4th resistance, 4th resistance one end is connected with constant pressure source, and the other end is connected on the circuit that the 3rd resistance (18) is connected with operational amplifier (11) negative input, also comprise a feedback triode (12), its emitting stage is connected to the output of this operational amplifier, collector electrode is connected to the second resistance (17), the other end of the second resistance (17) is connected on the connection line of the output of the first diode and the positive input of operational amplifier (11), and ground level is connected to one end of the 5th resistance (20), also comprise one the 6th resistance (22), 7th resistance (23), second diode (24), second electric capacity (21), field-effect transistor (13), wherein the 6th resistance (22), 7th resistance (23), second electric capacity (21), field-effect transistor (13) is in parallel, 6th resistance (22), 7th resistance (23), second electric capacity (21), field-effect transistor (13) one end is connected to the other end of the 5th resistance (20), 6th resistance (22), second electric capacity (21), field-effect transistor (13) other end ground connection, 7th resistance (23) other end is connected to the output of operational amplifier (11) and feeds back on the connection line of transistor emitter after connecting with the second diode (24).
CN201420509436.9U 2014-09-04 2014-09-04 Short-circuit protection circuit Expired - Fee Related CN204068210U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201420509436.9U CN204068210U (en) 2014-09-04 2014-09-04 Short-circuit protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201420509436.9U CN204068210U (en) 2014-09-04 2014-09-04 Short-circuit protection circuit

Publications (1)

Publication Number Publication Date
CN204068210U true CN204068210U (en) 2014-12-31

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Application Number Title Priority Date Filing Date
CN201420509436.9U Expired - Fee Related CN204068210U (en) 2014-09-04 2014-09-04 Short-circuit protection circuit

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104218531A (en) * 2014-09-04 2014-12-17 国家电网公司 Short circuit protecting circuit and method
CN107105785A (en) * 2015-01-21 2017-08-29 惠州市吉瑞科技有限公司 Change the switching circuit and method and electronic cigarette of atomizer heating wire equivalent resistance

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104218531A (en) * 2014-09-04 2014-12-17 国家电网公司 Short circuit protecting circuit and method
CN107105785A (en) * 2015-01-21 2017-08-29 惠州市吉瑞科技有限公司 Change the switching circuit and method and electronic cigarette of atomizer heating wire equivalent resistance

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C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20141231

Termination date: 20170904