CN103956714B - A kind of high sensitivity multi-functional CT open-circuit protecting device - Google Patents
A kind of high sensitivity multi-functional CT open-circuit protecting device Download PDFInfo
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Abstract
A kind of high sensitivity multi-functional CT open-circuit protecting device, relates to the protection device such as power circuit, equipment field, it is characterised in that: containing signal sampling part, perform protection part, single-chip microcomputer and liquid-crystal display section and failure reset part；CT protection device of the present invention is in addition to basic fault display function and total failare number of times writing function; show and writing function with fault moment magnitude of voltage and voltage waveform; whether the device being connected with Current Transformer Secondary side for staff's investigation can cause expendable damage to provide foundation because of secondary side open-circuit voltage; facilitate the malfunction elimination of the complete equipment being equipped with current transformer, save repair time and human cost.
Description
Technical field:
The present invention relates to the protection device such as power circuit, equipment field, specifically a kind of many merits of high sensitivity
Can CT open-circuit protecting device.
Background technology:
The safe operation of power circuit, construction and the safety of personnel with national economy are closely bound up.Electric current is mutual
Sensor is a kind of facility providing for instrumentation and control facility and can reflecting the corresponding current parameters of system,
The safe operation of power system is particularly significant, and operation rule specifies: in operation, Current Transmit secondary
Side loop can not be opened a way.Current Transformer Secondary winding and loop thereof are once in operation open circuit, it will product
The overvoltage of raw thousands of volts volt the most up to ten thousand.This works the mischief not only to the insulation of electrical secondary system, also can make
Transformer is too drastic and scaling loss, even jeopardizes the life security of operations staff.
For these problems, many technical work personnel work it out many contributions, such as: application number
89216913.3, notification number CN2074493U, denomination of invention: Installation of Open-circuit Protection for Current Transformers；Shen
Please number 00229882.1, notification number CN2602931Y, denomination of invention: electric power current transformer controllable silicon is opened
Road protector；Application number 200420010869.6, notification number CN2715407Y, denomination of invention: highly sensitive
Degree CT open-circuit protecting device etc., although obtain certain effect after some protection devices come into operation at present, but
Protection device yet suffers from problem:
The fault detection part of existing Installation of Open-circuit Protection for Current Transformers uses pure hardware detecting circuit,
Select optocoupler as breakdown judge device, be input to single-chip microcomputer or other protection act triggering circuit is
Low and high level signal, it is impossible to record fault moment voltage and false voltage waveform when current transformer is opened a way,
Thus failure judgement whether the device relevant to transformer cannot may be caused expendable damage, no
It is beneficial to the malfunction elimination equipped with current transformer complete equipment.
Summary of the invention:
In order to overcome above-mentioned the deficiencies in the prior art, the present invention designs a kind of multi-functional CT of high sensitivity and opens
Line protection device.This programme aims to solve the problem that prior art cannot be monitored transformer open-circuit voltage and preserve fault
The problem of moment waveform.
Solve the technical problem that used following technical scheme:
A kind of high sensitivity multi-functional CT open-circuit protecting device, it is characterised in that: containing signal sampling part,
Perform protection part, single-chip microcomputer and liquid-crystal display section and failure reset part；
Described signal sampling part is: input voltage is through two divider resistances, with Order RC wave filter phase
Even；One TVS pipe of a parallel connection in divider resistance；Order RC wave filter is connected with signal input amplifier,
Raise voltage by what signal amplifier circuit accessed, sampled input voltage is raised, it is achieved to exchange
The sampling of signal；The output of signal input amplifier is through the AD sampling pin of protective circuit of diode with single-chip microcomputer
It is connected；
Described execution protection portion is divided into: drive power supply through the input anode of the first resistance Yu optical coupling isolator
Connect；Single-chip microcomputer delivery outlet connects the input negative terminal of optical coupling isolator；Optical coupling isolator output one end
Two resistance connect the gate leve of bidirectional triode thyristor, and another terminates bidirectional triode thyristor；Beyond the gate leve of bidirectional triode thyristor
Two pins connect input and common port respectively；
Described liquid-crystal display section: the AD sampling functions of single-chip microcomputer and the programming realization of single-chip microcomputer, aobvious
Show that part selects LCD liquid crystal display screen, have in display: fault phase, fault moment magnitude of voltage, fault
20ms voltage waveform and total failare number of times before moment.
Described failure reset part is: one group of power supply includes VCC, GND, second group of power supply include VCC1,
GNDA, VCC, GND with VCC1, two groups of power supplys of GNDA are directly connected by common mode inductance, VCC1 and electricity
Holding positive pole to connect, GNDA is connected with electric capacity negative pole；Capacitance cathode is through the bipod of the 3rd resistance Yu reset key
And one interface of external reset connects；The another bipod of reset key and another interface of external reset and optocoupler
The positive pole of input connects；The negative pole of electric capacity is connected with the negative pole of optocoupler input；Optocoupler output current collection
Pole connects the input port of single-chip microcomputer, meets power supply VCC through pull-up resistor simultaneously；Optocoupler output emitter stage meets GND
End.
Described signal input signal amplifier circuit includes amplifier, is connected to the electricity on amplifier negative pole
Resistance R6, is connected to the resistance R7 of amplifier negative pole and amplifier out, and is just connected to amplifier
The resistance R8 extremely gone up, the negative pole of described amplifier is connected with the resistance output of Order RC wave filter, institute
The resistance R8 stated is connected with the other end of amplifier and the electric capacity output of Order RC wave filter.
The invention has the beneficial effects as follows:
(1) present invention input port of sampling uses a big resistance and small resistor to connect the principle of dividing potential drop,
Resistance value is very big, effectively reduces the shunting of CT secondary side；
(2) protection device voltage sample of the present invention is accurate, highly sensitive；
(3) protection device antijamming capability of the present invention is strong, and system power supply part uses integrated AC-DC mould
Block power supply, system is more stable；
(4) CT open-circuit protecting device of the present invention is adaptable for multiloop protection device, can be according to CT
Secondary Winding quantity arbitrary extension；
(5) present invention has 485 communication functions, has installed signal transmission interface additional, can realize with comprehensive from
Dynamic control equipment networking, considerably increases automaticity；
(6) CT protection device of the present invention is in addition to basic fault display function and total failare number of times writing function,
Show and writing function with fault moment magnitude of voltage and voltage waveform, mutual with electric current for staff's investigation
Whether the device that sensor secondary side is connected can cause expendable damage to provide because of secondary side open-circuit voltage
Foundation, facilitates the malfunction elimination of the complete equipment being equipped with current transformer, saves repair time and manpower
Cost.
Accompanying drawing illustrates:
Fig. 1 is present configuration schematic diagram.
Detailed description of the invention:
For the technological means making the present invention realize, creation characteristic, reach purpose and effect and be readily apparent from
Solve, below in conjunction with being specifically illustrating, the present invention is expanded on further.
As it is shown in figure 1,
A kind of high sensitivity multi-functional CT open-circuit protecting device, containing signal sampling part, performs protection portion
Point, single-chip microcomputer and liquid-crystal display section and failure reset part；
Signal sampling part is: input voltage is through two divider resistance R1 and R2, and input voltage is through dividing potential drop electricity
Resistance R1 and R2, is connected with Order RC wave filter；A TVS pipe in parallel on divider resistance R2, protection is adopted
Sample circuit；Order RC wave filter is connected with signal amplifier circuit, by accessing in signal amplifier circuit
Raise voltage VRef, sampled input voltage is raised, it is achieved the sampling to AC signal；Signal inputs
Signal amplifier circuit output is connected with Chip Microcomputer A/D sampling pin through protective circuit of diode.
Vice-side winding input voltage is after R1 Yu R2 dividing potential drop, and the voltage on R2 enters through Order RC filter circuit
Row filtering, then through signal amplifier circuit voltage by integral raising, raising voltage magnitude is VRef, signal
Amplifier circuit exports after diode clamp protection circuit, is input to Chip Microcomputer A/D thief hatch, by list
Sheet machine program calculation goes out the input voltage value that vice-side winding is actual.The principle and the method that calculate are as follows: protection
The input voltage of the input of device is VIN, the alternating voltage of input is raised to more than zero volt by VRef, it is ensured that
At VINStill AD conversion work can be normally carried out for single-chip microcomputer during negative value.It is input to single-chip microcomputer
The magnitude of voltage of AD thief hatch isThus derive Current Transformer Secondary side
Virtual voltage with the relation of the voltage of Chip Microcomputer A/D mouth is
Execution protection portion is divided into: drive power supply VCC through the input anode of the first resistance 1R Yu optical coupling isolator
Connect；Single-chip microcomputer delivery outlet connects the input negative terminal of optical coupling isolator；Optical coupling isolator output one end
Two resistance 2R connect the gate leve of bidirectional triode thyristor BT136, and another terminates bidirectional triode thyristor BT136；Two-way can
Two pins beyond the gate leve of control silicon BT136 connect input and common port respectively.
When CT normally works, vice-side winding input voltage is relatively low, and single-chip microcomputer sampling is calculated vice-side winding
Input voltage value be less than initiation value, the single-chip microcomputer delivery outlet in drive circuit is output as high level, optocoupler every
Triode ac switch in device cannot turn on, and the bidirectional triode thyristor gate leve of CT short circuit effect is without driving letter
Number, do not carry out protection act.When CT opens a way, vice-side winding input voltage is very big, and single-chip microcomputer sampling calculates
Obtaining vice-side winding input voltage value and be more than initiation value, the single-chip microcomputer delivery outlet in drive circuit is output as low
Level, the triode ac switch conducting in optical coupling isolator, drive the bidirectional triode thyristor of CT short circuit effect
Gate leve signal, bidirectional triode thyristor carries out protection act.
Liquid-crystal display section: the AD sampling functions of single-chip microcomputer and the programming realization of single-chip microcomputer, shows part
Select LCD liquid crystal display screen, have in display: before fault phase, fault moment magnitude of voltage, fault moment
20ms voltage waveform (including fault moment) and total failare number of times.
Failure reset part is: one group of power supply includes VCC, GND, and second group of power supply includes VCC1, GNDA,
In Fig. 1, two groups of power supplys of VCC, GND and VCC1, GNDA are directly connected by common mode inductance.VCC1 and electricity
Holding positive pole to connect, GNDA is connected with electric capacity negative pole；Capacitance cathode is through resistance SW_R1 and reset key SW's
1,5 pin of 3 pin and external reset interface connect；The 2 of reset key SW, 4 pin and external reset interface
6 pin be connected with the positive pole of optocoupler input；The negative pole of electric capacity is connected with the negative pole of optocoupler input；Light
Coupling output colelctor electrode connects the input port of single-chip microcomputer, meets power supply VCC through pull-up resistor SW_R2 simultaneously；Optocoupler
Output emitter stage connects GND end.
When external reset interface is off and reset key does not presses, optocoupler input anode
Unsettled, optocoupler does not works, and its output is equivalent to off state, single-chip microcomputer input port input high level；
When external reset interface is in short circuit state or reset key presses, optocoupler works, output phase
When in path, single-chip microcomputer input port input low level.Single-chip microcomputer judges that this pin is become low electricity from high level
Flat, then the state of the internal each quantity of state that resets is eliminated to init state, indicating fault etc..
Signal input signal amplifier circuit includes amplifier, the resistance R6 being connected on amplifier negative pole,
It is connected to the resistance R7 of amplifier negative pole and amplifier out, and is connected on amplifier anode
Resistance R8, the negative pole of amplifier is connected with the resistance output of Order RC wave filter, resistance R8 and amplification
The other end of device and the electric capacity output of Order RC wave filter connect.
The general principle of the present invention and principal character and advantages of the present invention have more than been shown and described.One's own profession
Skilled person will appreciate that of industry, the present invention is not restricted to the described embodiments, above-described embodiment and explanation
The principle that the present invention is simply described described in book, without departing from the spirit and scope of the present invention,
The present invention also has various changes and modifications, and these changes and improvements both fall within claimed invention model
In enclosing.Claimed scope is defined by appending claims and equivalent thereof.
Claims (3)
1. a high sensitivity multi-functional CT open-circuit protecting device, it is characterised in that: containing signal sampling
Partly, protection part, single-chip microcomputer and liquid-crystal display section and failure reset part are performed；
Described signal sampling part: input voltage, through two divider resistances, is connected with Order RC wave filter；
One TVS pipe of a parallel connection in divider resistance；Order RC wave filter and signal input signal amplifier circuit
It is connected, raises voltage by what signal amplifier circuit accessed, sampled input voltage is raised, it is achieved
Sampling to AC signal；Signal amplifier circuit output is adopted through the AD of protective circuit of diode with single-chip microcomputer
Sample pin is connected；
Described execution protection portion is divided into: drive power supply to connect through the input anode of the first resistance with optical coupling isolator
Connect；Single-chip microcomputer delivery outlet connects the input negative terminal of optical coupling isolator；Optical coupling isolator output one end second
Resistance connects the gate leve of bidirectional triode thyristor, and another terminates bidirectional triode thyristor；Beyond the gate leve of bidirectional triode thyristor
Two pins connect input and common port respectively；
Described liquid-crystal display section: the AD sampling functions of single-chip microcomputer and the programming realization of single-chip microcomputer, display
Part selects LCD liquid crystal display screen, has: when fault phase, fault moment magnitude of voltage, fault in display
20ms voltage waveform and total failare number of times before carving.
A kind of high sensitivity multi-functional CT open-circuit protecting device the most according to claim 1, it is special
Levy and be: described failure reset part is: one group of power supply includes VCC, GND, and second group of power supply includes
VCC1, GNDA, two groups of power supplys of VCC, GND and VCC1, GNDA are directly connected by common mode inductance, VCC1
Being connected with capacitance cathode, GNDA is connected with electric capacity negative pole；Capacitance cathode is through the 3rd resistance and reset key
Bipod and one interface of external reset connect；The another bipod of reset key and another interface of external reset with
The positive pole of optocoupler input connects；The negative pole of electric capacity is connected with the negative pole of optocoupler input；Optocoupler output
Colelctor electrode connects the input port of single-chip microcomputer, meets power supply VCC through pull-up resistor simultaneously；Optocoupler output emitter stage connects
GND end.
A kind of high sensitivity multi-functional CT open-circuit protecting device the most according to claim 1, it is special
Levy and be: described signal input signal amplifier circuit includes amplifier, is connected on amplifier negative pole
Resistance R6, be connected to the resistance R7 of amplifier negative pole and amplifier out, and be connected to amplify
Resistance R8 on device positive pole, the negative pole of described amplifier is connected with the resistance output of Order RC wave filter,
Described resistance R8 is connected with the other end of amplifier and the electric capacity output of Order RC wave filter.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201410168046.4A CN103956714B (en) | 2014-04-24 | 2014-04-24 | A kind of high sensitivity multi-functional CT open-circuit protecting device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201410168046.4A CN103956714B (en) | 2014-04-24 | 2014-04-24 | A kind of high sensitivity multi-functional CT open-circuit protecting device |
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| CN103956714B true CN103956714B (en) | 2016-09-07 |
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Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105449655B (en) * | 2014-09-03 | 2018-05-22 | 国网河南省电力公司平顶山供电公司 | A kind of Current Transformer Secondary open-circuit-protection method and device |
| CN106532640B (en) * | 2016-10-26 | 2018-11-27 | 国网重庆市电力公司电力科学研究院 | Secondary side open circuit protecting equipment of current mutual inductor |
| CN108418433A (en) * | 2018-03-29 | 2018-08-17 | 深圳驿普乐氏科技有限公司 | A kind of LLC resonant converter and its control circuit, resonance current sample circuit |
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| CN1055261A (en) * | 1991-04-05 | 1991-10-09 | 刘运中 | Open-circuit protector for secondary loop of mutual inductor |
| CN201142567Y (en) * | 2007-12-13 | 2008-10-29 | 广州霍斯通电气有限公司 | Secondary side open circuit protecting equipment of current mutual inductor |
| CN201184891Y (en) * | 2008-01-11 | 2009-01-21 | 俞盛荣 | Detection module for short/open circuit of current mutual inductor secondary circuit |
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| CN103399253A (en) * | 2013-08-20 | 2013-11-20 | 国家电网公司 | Device for detecting circuit opening of secondary circuit of current transformer |
| CN203352155U (en) * | 2013-05-06 | 2013-12-18 | 安徽辉达电力科技有限公司 | Microcomputer monitoring protecting device for current transformer |
| CN203522139U (en) * | 2013-09-30 | 2014-04-02 | 合肥南南电力保护设备有限公司 | Current transformer secondary open-circuit rapid protection circuit |
| CN203911464U (en) * | 2014-04-24 | 2014-10-29 | 合肥沃华电气技术有限公司 | High-sensitivity multifunctional CT circuit opening protecting device |
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Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1055261A (en) * | 1991-04-05 | 1991-10-09 | 刘运中 | Open-circuit protector for secondary loop of mutual inductor |
| CN201142567Y (en) * | 2007-12-13 | 2008-10-29 | 广州霍斯通电气有限公司 | Secondary side open circuit protecting equipment of current mutual inductor |
| CN201184891Y (en) * | 2008-01-11 | 2009-01-21 | 俞盛荣 | Detection module for short/open circuit of current mutual inductor secondary circuit |
| CN201637770U (en) * | 2009-10-15 | 2010-11-17 | 黑龙江龙电电气有限公司 | Three-phase electronic type carrier multi-rate valve-controlled electric energy meter |
| CN203352155U (en) * | 2013-05-06 | 2013-12-18 | 安徽辉达电力科技有限公司 | Microcomputer monitoring protecting device for current transformer |
| CN103399253A (en) * | 2013-08-20 | 2013-11-20 | 国家电网公司 | Device for detecting circuit opening of secondary circuit of current transformer |
| CN203522139U (en) * | 2013-09-30 | 2014-04-02 | 合肥南南电力保护设备有限公司 | Current transformer secondary open-circuit rapid protection circuit |
| CN203911464U (en) * | 2014-04-24 | 2014-10-29 | 合肥沃华电气技术有限公司 | High-sensitivity multifunctional CT circuit opening protecting device |
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| CN103956714A (en) | 2014-07-30 |
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Effective date of registration: 20170524 Address after: 201, room 3, building 16, 230000 Ning Xi Road, Hefei hi tech Zone, Anhui Patentee after: Anhui wohua Electric Equipment Co., Ltd. Address before: 230031, No. 21 Hangzhou Road, Hefei hi tech Zone, Anhui Patentee before: HEFEI VOVA ELECTRICAL TECHNOLOGY CO., LTD. |
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