CN106786366B - Current Transformer Secondary side open-circuit-protection early warning system - Google Patents
Current Transformer Secondary side open-circuit-protection early warning system Download PDFInfo
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- CN106786366B CN106786366B CN201611169564.3A CN201611169564A CN106786366B CN 106786366 B CN106786366 B CN 106786366B CN 201611169564 A CN201611169564 A CN 201611169564A CN 106786366 B CN106786366 B CN 106786366B
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- 238000001514 detection method Methods 0.000 claims abstract description 28
- 230000001052 transient effect Effects 0.000 claims description 17
- 239000004065 semiconductor Substances 0.000 claims description 16
- 101100365087 Arabidopsis thaliana SCRA gene Proteins 0.000 claims description 14
- 101150105073 SCR1 gene Proteins 0.000 claims description 14
- 101100134054 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) NTG1 gene Proteins 0.000 claims description 14
- 239000003990 capacitor Substances 0.000 claims description 9
- 230000002441 reversible effect Effects 0.000 claims description 3
- 230000005611 electricity Effects 0.000 claims description 2
- 238000000034 method Methods 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000001939 inductive effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
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- 238000007689 inspection Methods 0.000 description 1
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Classifications
-
- 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
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
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- Emergency Protection Circuit Devices (AREA)
Abstract
A kind of Current Transformer Secondary side open-circuit-protection early warning system provided by the invention, including the detection unit for detecting Current Transformer Secondary side open-circuit condition, the protection indicating unit for executing protection under open-circuit condition to Current Transformer Secondary side and control alarm unit；The output end of the detection unit is connect with the input terminal of control alarm unit, and the control alarm unit control protection indicating unit circuit closed forms parallel-connection structure with disconnecting and executing open-circuit-protection, the protection indicating unit and load RL；In view of this; the object of the present invention is to provide a kind of Current Transformer Secondary side open-circuit-protection early warning systems; the open-circuit condition of Current Transformer Secondary side can accurately be detected; and the secondary side protection of current transformer is executed while detection; and the secondary side open circuit early warning of current transformer can be made in time; counter-measure is made conducive to accurate, it is ensured that the operational safety of power grid.
Description
Technical field
The present invention relates to a kind of power protection system more particularly to a kind of Current Transformer Secondary side open-circuit-protection early warning systems
System.
Background technique
Current transformer is equipment particularly important in power grid, for acquiring middle current information, the isolation electricity of electric system
Power equipment etc., therefore, the stable operation of current transformer are related to the operational safety of power grid, however, current transformer is being run
It is easy to appear open circuit phenomenon in the process, and current transformer open circuit will lead to serious accident of power supply, this is because when electric current is mutual
After sensor open circuit, high pressure is induced in the secondary side of current transformer, it will to current transformer itself and secondary side apparatus
Cause badly damaged, to threaten the power supply safety of electric system, however there is presently no effective method or apparatuss pair
The open-circuit condition of the secondary side of current transformer carries out accurate detection and open-circuit-protection.
It is, therefore, desirable to provide a kind of new Current Transformer Secondary side open-circuit-protection system, it is mutual can accurately to detect electric current
The open-circuit condition of sensor secondary side, and the secondary side of execution current transformer is protected while detection, and can be timely
The secondary side open circuit early warning for making current transformer, conducive to counter-measure is accurately made, it is ensured that the operational safety of power grid.
Summary of the invention
In view of this, the object of the present invention is to provide a kind of Current Transformer Secondary side open-circuit-protection early warning system, it can
The open-circuit condition of accurate detection Current Transformer Secondary side, and the secondary side of execution current transformer is protected while detection
Shield, and the secondary side open circuit early warning of current transformer can be made in time, conducive to counter-measure is accurately made, it is ensured that power grid
Operational safety.
A kind of Current Transformer Secondary side open-circuit-protection early warning system provided by the invention, including for detecting Current Mutual Inductance
The detection unit of device secondary side open-circuit condition refers to for executing the protection of protection under open-circuit condition to Current Transformer Secondary side
Show unit and control alarm unit；
The output end of the detection unit is connect with the input terminal of control alarm unit, and the control alarm unit control is protected
Finger shield shows that element loop closure forms parallel-connection structure with disconnecting and executing open-circuit-protection, the protection indicating unit and load RL.
Further, the detection unit include two-way transient diode TVS1, two-way transient diode TVS2, resistance R1,
Detect Current Transmit 1 and rectification circuit ZL；
One end of the secondary coil of one end and current transformer of the two-way transient diode TVS1 connects, and the other end is logical
It crosses resistance R1 to connect with the one end for the primary coil for detecting Current Transmit 1, detects the another of the primary coil of current transformer
One end ground connection, the both ends of secondary coil and the positive input terminal of rectification circuit ZL and negative input end for detecting Current Transmit 1 connect
It connects, output end of the output end of rectification circuit ZL as detection unit, the both ends of two-way transient diode TVS2 are connected to
Detect the both ends of the secondary coil of Current Transmit 1.
Further, the control alarm unit includes signal input module and control module and alarm module；
The input terminal of the input module is connect with the output end of rectification circuit ZL, the output end and control mould of input module
The input terminal of block connects, the control module control protection indicating unit circuit closed and disconnection, the alarm module and control
Module connection.
Further, the input module includes capacitor C1, resistance R3, adjustable resistance R4, resistance R5, resistance R6 and amplifier
U1；
One end of capacitor C1 is connect with the output end of rectification circuit ZL, and other end ground connection, capacitor C1 and rectification circuit ZL are defeated
The points of common connection of outlet is public between resistance R3 and adjustable resistance R4 by being grounded after resistance R3 and adjustable resistance R4 series connection
Tie point is connect by resistance R5 with the in-phase end of amplifier U1, and the reverse side of amplifier U1 is grounded by resistance R6, and amplifier U1's is defeated
Output end of the outlet as input module.
Further, the control module includes optocoupler G1, processing circuit IC1, resistance R7, resistance R8, metal-oxide-semiconductor Q1, brilliant lock
Pipe SCR1 and relay J1；
The anode of the light emitting diode of the optocoupler G1 is connect with the output end of amplifier U1, the light emitting diode of optocoupler G1
Cathode ground connection, the collector of the phototriode of optocoupler U1 connect power supply VCC, the hair of the phototriode of optocoupler U1 by resistance R7
Emitter-base bandgap grading is grounded by resistance R8, and the collector of the phototriode of optocoupler U1 is also connect with the control electrode of thyristor SCR1, brilliant lock
The anode of pipe SCR1 is connect with the source electrode of metal-oxide-semiconductor Q1, and the drain electrode of metal-oxide-semiconductor connects power supply VCC, the grid and processing circuit IC1 of metal-oxide-semiconductor
Control terminal connection, the cathode of thyristor SCR1 is grounded by the coil of relay J1, the input terminal and amplifier of processing circuit IC1
The output end of U1 connects.
Further, the alarm module is GPRS circuit, and the processing circuit IC1 is logical by GPRS circuit and control centre
Letter connection.
Further, the protection indicating unit includes the control switch J1-K1 and indicator light of resistance R2, relay J1
LED1, it is commonly connected between one end of the resistance R1 and two-way transient diode TVS1 and the secondary coil of current transformer
The other end of point connection, resistance R1 is connect by the anode of the control switch J1-K1 and indicator light LED1 of relay J1, indicator light
The cathode polar region of LED1.
Beneficial effects of the present invention: by means of the invention it is possible to the open-circuit condition of Current Transformer Secondary side is accurately detected, and
And the secondary side protection of current transformer is executed while detection, and the secondary side that can make current transformer in time is opened
Road early warning, conducive to counter-measure is accurately made, it is ensured that the operational safety of power grid.
Detailed description of the invention
The invention will be further described with reference to the accompanying drawings and examples:
Fig. 1 is circuit diagram of the invention.
Specific embodiment
Fig. 1 is circuit diagram of the invention, as shown, a kind of Current Transformer Secondary side open circuit provided by the invention
Protect early warning system, including for detecting Current Transformer Secondary side open-circuit condition detection unit, for current transformer
Secondary side executes the protection indicating unit and control alarm unit of protection under open-circuit condition；
The output end of the detection unit is connect with the input terminal of control alarm unit, and the control alarm unit control is protected
Finger shield shows that element loop closure forms parallel-connection structure with disconnecting and executing open-circuit-protection, the protection indicating unit and load RL,
By means of the invention it is possible to accurately detect the open-circuit condition of Current Transformer Secondary side, and execution electric current is mutual while detection
The secondary side of sensor is protected, and can make the secondary side open circuit early warning of current transformer in time, conducive to reply is accurately made
Measure, it is ensured that the operational safety of power grid.
In the present embodiment, the detection unit includes two-way transient diode TVS1, two-way transient diode TVS2, resistance
R1, detection Current Transmit 1 and rectification circuit ZL；
One end of the secondary coil of one end and current transformer of the two-way transient diode TVS1 connects, and the other end is logical
It crosses resistance R1 to connect with the one end for the primary coil for detecting Current Transmit 1, detects the another of the primary coil of current transformer
One end ground connection, the both ends of secondary coil and the positive input terminal of rectification circuit ZL and negative input end for detecting Current Transmit 1 connect
It connects, output end of the output end of rectification circuit ZL as detection unit, the both ends of two-way transient diode TVS2 are connected to
The both ends for detecting the secondary coil of Current Transmit 1, by this structure, when the secondary side of current transformer is opened a way
When, it is induced instant high-voltage and high current in the secondary side of current transformer, two-way transient diode is breakdown, and passes through
The primary coil of resistance R1 and detection current transformer imports the earth, so that the secondary load equipment to current transformer has
The protection of effect, and at the same time detection current transformer exports inductive signal and exported by rectification circuit, due to resistance R1 and inspection
The collective effect for surveying current transformer primary coil, the inductive signal for detecting the secondary side output of current transformer is not too large,
To be impacted to the subsequent conditioning circuit of detection current transformer, wherein rectification circuit ZL is whole using full-bridge type diode
Current circuit.
In the present embodiment, the control alarm unit includes signal input module and control module and alarm module；
The input terminal of the input module is connect with the output end of rectification circuit ZL, the output end and control mould of input module
The input terminal of block connects, the control module control protection indicating unit circuit closed and disconnection, the alarm module and control
Module connection.
Input module described in the present embodiment include capacitor C1, resistance R3, adjustable resistance R4, resistance R5, resistance R6 and
Amplifier U1；
One end of capacitor C1 is connect with the output end of rectification circuit ZL, and other end ground connection, capacitor C1 and rectification circuit ZL are defeated
The points of common connection of outlet is public between resistance R3 and adjustable resistance R4 by being grounded after resistance R3 and adjustable resistance R4 series connection
Tie point is connect by resistance R5 with the in-phase end of amplifier U1, and the reverse side of amplifier U1 is grounded by resistance R6, and amplifier U1's is defeated
Output end of the outlet as input module；When being operated normally by protective current mutual inductor, due to detecting current transformer no signal
Output, amplifier U1 exports low level at this time, after rectification circuit ZL exports detection signal, passes through resistance R3's and adjustable resistance R4
The in-phase end of amplifier U1 is input to after partial pressure, at this point, amplifier U1 exports high level, the high level one side input processing circuit
In IC1, on the other hand, the conducting of optocoupler G1 is controlled, this system stable operation, and amplifier U1 can be conducive to by above structure
Certain buffer action can also be played.
In the present embodiment, the control module include optocoupler G1, processing circuit IC1, resistance R7, resistance R8, metal-oxide-semiconductor Q1,
Thyristor SCR1 and relay J1；
The anode of the light emitting diode of the optocoupler G1 is connect with the output end of amplifier U1, the light emitting diode of optocoupler G1
Cathode ground connection, the collector of the phototriode of optocoupler U1 connect power supply VCC, the hair of the phototriode of optocoupler U1 by resistance R7
Emitter-base bandgap grading is grounded by resistance R8, and the collector of the phototriode of optocoupler U1 is also connect with the control electrode of thyristor SCR1, brilliant lock
The anode of pipe SCR1 is connect with the source electrode of metal-oxide-semiconductor Q1, and the drain electrode of metal-oxide-semiconductor connects power supply VCC, the grid and processing circuit IC1 of metal-oxide-semiconductor
Control terminal connection, the cathode of thyristor SCR1 is grounded by the coil of relay J1, the input terminal and amplifier of processing circuit IC1
The output end of U1 connects, and after amplifier U1 exports high level, IC1 controls metal-oxide-semiconductor Q1 conducting, and optocoupler G1 conducting is so that thyristor
SCR1 conducting, relay J1 obtain it is electric, at this time relay J1 open type control switch J1-K1 closure, to protect indicating unit
Protection is executed, and guard mode instruction is carried out by indicator light LED1 and is indicated by the open-circuit condition of protective current mutual inductor；
When protecting indicating unit to execute protection, due to the decline of voltage, two-way transient diode TVS1 is restored to cut-off, detects electric current
Mutual inductor CT1 exports low level without output, amplifier U1, and optocoupler G1 ends at this time, but still persistently output high level is IC1
Metal-oxide-semiconductor Q1 conducting, due to the trigger characteristic of thyristor SCR1, relay J1 still works, and protection indicating unit continuously carries out guarantor
Shield, after IC1 receives protection END instruction, metal-oxide-semiconductor Q1 cut-off, relay J1 power loss, the control switch J1-K1 of relay J1
It is restored to normally open, wherein processing circuit IC1 uses existing processing chip, such as the embedded chip of STM32 series.
In the present embodiment, the alarm module is GPRS circuit, and the processing circuit IC1 passes through in GPRS circuit and control
Heart communication connection, by this structure, timely feedbacks warning message conducive to processing circuit IC1 in order to which conjunction is made by control centre
Reason, timely and effectively treatment measures, and it is conducive to input control instruction into processing IC circuit 1, control metal-oxide-semiconductor Q1 is disconnected.
In the present embodiment, the protection indicating unit includes resistance R2, the control switch J1-K1 of relay J1 and instruction
Lamp LED1, the public company between one end of the resistance R1 and two-way transient diode TVS1 and the secondary coil of current transformer
The other end of contact connection, resistance R1 is connect by the anode of the control switch J1-K1 and indicator light LED1 of relay J1, is indicated
The cathode polar region of lamp LED1 can be formed well by this structure to by the secondary side load equipment of protective current mutual inductor
Protection.
Finally, it is stated that the above examples are only used to illustrate the technical scheme of the present invention and are not limiting, although referring to compared with
Good embodiment describes the invention in detail, those skilled in the art should understand that, it can be to skill of the invention
Art scheme is modified or replaced equivalently, and without departing from the objective and range of technical solution of the present invention, should all be covered at this
In the scope of the claims of invention.
Claims (3)
1. a kind of Current Transformer Secondary side open-circuit-protection early warning system, it is characterised in that: including for detecting current transformer
The detection unit of secondary side open-circuit condition, the protection for executing protection under open-circuit condition to Current Transformer Secondary side indicate
Unit and control alarm unit；
The output end of the detection unit is connect with the input terminal of control alarm unit, and the control alarm unit control protection refers to
Show that element loop closure forms parallel-connection structure with disconnecting and executing open-circuit-protection, the protection indicating unit and load RL；
The detection unit includes two-way transient diode TVS1, two-way transient diode TVS2, resistance R1, detection Current Mutual Inductance
Device CT1 and rectification circuit ZL；
One end of the secondary coil of one end and current transformer of the two-way transient diode TVS1 connects, and the other end passes through electricity
Resistance R1 is connect with the one end for the primary coil for detecting Current Transmit 1, detects the another of the primary coil of Current Transmit 1
End ground connection, the both ends for detecting the secondary coil of Current Transmit 1 are connect with the positive input terminal of rectification circuit ZL and negative input end,
The both ends of output end of the output end of rectification circuit ZL as detection unit, two-way transient diode TVS2 are connected to detection
The both ends of the secondary coil of Current Transmit 1；
The control alarm unit includes signal input module and control module and alarm module；
The input terminal of the input module is connect with the output end of rectification circuit ZL, the output end of input module and control module
Input terminal connection, the control module control protection indicating unit circuit closed and disconnection, the alarm module and control module
Connection；
The input module includes capacitor C1, resistance R3, adjustable resistance R4, resistance R5, resistance R6 and amplifier U1；
One end of capacitor C1 is connect with the output end of rectification circuit ZL, other end ground connection, capacitor C1 and rectification circuit ZL output end
Points of common connection by resistance R3 and adjustable resistance R4 series connection after be grounded, it is commonly connected between resistance R3 and adjustable resistance R4
Point is connect by resistance R5 with the in-phase end of amplifier U1, and the reverse side of amplifier U1 is grounded by resistance R6, the output end of amplifier U1
Output end as input module；
The control module include optocoupler G1, processing circuit IC1, resistance R7, resistance R8, metal-oxide-semiconductor Q1, thyristor SCR1 and after
Electric appliance J1；
The anode of the light emitting diode of the optocoupler G1 is connect with the output end of amplifier U1, the cathode of the light emitting diode of optocoupler G1
Ground connection, the collector of the phototriode of optocoupler U1 connect power supply VCC, the emitter of the phototriode of optocoupler U1 by resistance R7
It is grounded by resistance R8, the collector of the phototriode of optocoupler U1 is also connect with the control electrode of thyristor SCR1, thyristor
The anode of SCR1 is connect with the source electrode of metal-oxide-semiconductor Q1, and the drain electrode of metal-oxide-semiconductor Q1 connects power supply VCC, the grid and processing circuit of metal-oxide-semiconductor Q1
The control terminal of IC1 connects, and the cathode of thyristor SCR1 is grounded by the coil of relay J1, the input terminal of processing circuit IC1 with
The output end of amplifier U1 connects.
2. Current Transformer Secondary side open-circuit-protection early warning system according to claim 1, it is characterised in that: the alarm mould
Block is GPRS circuit, and the processing circuit IC1 is communicated to connect by GPRS circuit and control centre.
3. Current Transformer Secondary side open-circuit-protection early warning system according to claim 1, it is characterised in that: the protection refers to
Show that unit includes resistance R2, the control switch J1-K1 of relay J1 and indicator light LED1, one end of the resistance R2 with it is two-way
Points of common connection connection between transient diode TVS1 and the secondary coil of current transformer, the other end of resistance R2 by after
The anode of the control switch J1-K1 and indicator light LED1 of electric appliance J1 are connect, the cathode ground connection of indicator light LED1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611169564.3A CN106786366B (en) | 2016-12-16 | 2016-12-16 | Current Transformer Secondary side open-circuit-protection early warning system |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201611169564.3A CN106786366B (en) | 2016-12-16 | 2016-12-16 | Current Transformer Secondary side open-circuit-protection early warning system |
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| CN106786366A CN106786366A (en) | 2017-05-31 |
| CN106786366B true CN106786366B (en) | 2019-04-30 |
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Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107785869A (en) * | 2017-11-08 | 2018-03-09 | 河南森源电气股份有限公司 | A kind of current transformer and its secondary side protective arrangement for limiting output voltage |
| CN107785870B (en) * | 2017-11-11 | 2023-11-24 | 河南森源电气股份有限公司 | Current transformer and secondary side open circuit protection device thereof |
| CN107979071A (en) * | 2017-12-06 | 2018-05-01 | 国家电网公司 | Remote monitoring of power transmission line system |
| CN109687596B (en) * | 2018-12-31 | 2021-09-07 | 国家电网有限公司 | Power supply for power transmission line monitoring equipment |
| CN110223582B (en) * | 2019-07-09 | 2024-03-26 | 郑州万特电气股份有限公司 | Combined transformer explosion burning demonstration system and demonstration method |
| CN110988575B (en) * | 2019-12-30 | 2022-08-16 | 国家电网有限公司 | Electric power terminal electric quantity acquisition warning system |
| CN111060864A (en) * | 2020-01-14 | 2020-04-24 | 杭州海兴电力科技股份有限公司 | Secondary side state detection circuit of current transformer, fire alarm device and electric energy meter |
| CN113093062B (en) * | 2021-04-29 | 2023-06-27 | 北京送变电有限公司 | Terminal strip open circuit monitoring system |
| CN117117805A (en) * | 2023-08-23 | 2023-11-24 | 广东开放大学（广东理工职业学院） | Open-circuit protection method for current transformer |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202206118U (en) * | 2011-07-28 | 2012-04-25 | 安徽三和电力技术有限公司 | Current mutual induction secondary over-voltage protection device |
| CN205304634U (en) * | 2015-12-29 | 2016-06-08 | 山东电力工程咨询院有限公司 | A output voltage regulator circuit for high tension transmission line is last and response energy taking device thereof |
| CN205484496U (en) * | 2016-04-01 | 2016-08-17 | 重庆水利电力职业技术学院 | Voltage transformer with output protection |
| CN206442105U (en) * | 2016-12-16 | 2017-08-25 | 国家电网公司 | Current transformer monitoring and protecting system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6286936B2 (en) * | 2013-08-22 | 2018-03-07 | 富士電機株式会社 | POWER CIRCUIT DEVICE, CURRENT MEASUREMENT DEVICE, POWER MONITORING SYSTEM, AND POWER CIRCUIT DEVICE PROTECTION METHOD |
-
2016
- 2016-12-16 CN CN201611169564.3A patent/CN106786366B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202206118U (en) * | 2011-07-28 | 2012-04-25 | 安徽三和电力技术有限公司 | Current mutual induction secondary over-voltage protection device |
| CN205304634U (en) * | 2015-12-29 | 2016-06-08 | 山东电力工程咨询院有限公司 | A output voltage regulator circuit for high tension transmission line is last and response energy taking device thereof |
| CN205484496U (en) * | 2016-04-01 | 2016-08-17 | 重庆水利电力职业技术学院 | Voltage transformer with output protection |
| CN206442105U (en) * | 2016-12-16 | 2017-08-25 | 国家电网公司 | Current transformer monitoring and protecting system |
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