CN204347186U - A kind of polarity testing device of current transformer - Google Patents
A kind of polarity testing device of current transformer Download PDFInfo
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- CN204347186U CN204347186U CN201520032242.9U CN201520032242U CN204347186U CN 204347186 U CN204347186 U CN 204347186U CN 201520032242 U CN201520032242 U CN 201520032242U CN 204347186 U CN204347186 U CN 204347186U
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- current transformer
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- 238000012360 testing method Methods 0.000 title claims abstract description 46
- 230000000087 stabilizing effect Effects 0.000 claims description 14
- 230000003321 amplification Effects 0.000 claims description 7
- 239000003990 capacitor Substances 0.000 claims description 7
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 7
- 238000000034 method Methods 0.000 description 10
- 238000010586 diagram Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 4
- 238000010998 test method Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
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Abstract
The utility model discloses a kind of polarity testing device of current transformer, comprise housing, current transformer polarity testing circuit is provided with in housing, described current transformer polarity testing circuit is by power supply unit, and the polarity test unit of some groups is formed, described polarity test unit is by current polarity mirror menu unit, the output signal that anti-interference and comparing unit and polarity display unit compose in series current transformer inputs to current polarity mirror menu unit and carries out polarity judgement, polar signal after judgement carries out except making an uproar and amplifying through anti-interference and comparing unit, finally in polarity display unit, demonstrate polarity judged result, power supply unit is current polarity mirror menu unit, anti-interference and comparing unit and polarity display unit provide power supply respectively.
Description
Technical field
The utility model relates to a kind of polarity testing device of current transformer.
Background technology
Current transformer (CT) is the important electrical equipment of electric system, and big current is converted to small area analysis by it, is supplied to secondary device, and carries the vital task of being carried out by a secondary side equipment isolating.The normal work of correctness on the equipment such as protection, measurement, metering of system of its wiring has extremely important impact.When new installation CT puts into operation or changes CT secondary cable, utilizing polarity test method to check the correctness of CT wiring, has been the requisite working routine of relay protection staff.
Existing CT polarity test can method mainly contain two kinds: CT comprehensive tester method of testing and DC-method.Below two kinds of methods are compared:
(1) CT comprehensive tester method of testing utilizes the CT comprehensive tester of finished product to carry out polarity test.This method integration degree is high, and test result accurately and reliably; But comprehensive tester comprises the various functions such as the test of CT no-load voltage ratio, volt-ampere characteristic test, and these functions carry out separately we of polarity test for hope, are redundancy feature; This is also the main cause causing its cost high, bulky; In real work, this kind of method is generally not used in test CT polarity separately.
(2) DC-method uses dry cell to carry out " drooping " experiment at primary side, at the external indicator type current meter of secondary side, judges current transformer polarity by its yawing moment; The equipment prices of this method is cheap, is easy to carry, uses comparatively extensive; But this kind of method has two shortcomings: one is that when measuring no-load voltage ratio larger mutual inductor, ammeter pointer deflection amplitude is little, is sometimes difficult to distinguish; Two is can only measure one group of tap the same time, inefficiency.
Utility model content
In order to solve the shortcoming of prior art, the utility model proposes a kind of polarity testing device of current transformer.
The utility model is by the following technical solutions:
A kind of polarity testing device of current transformer, comprise housing, current transformer polarity testing circuit is provided with in housing, described current transformer polarity testing circuit is by power supply unit, and the polarity test unit of some groups is formed, described polarity test unit is composed in series by reflect first, the anti-interference and comparing unit of menu and polarity display unit of current polarity; The output signal of current transformer inputs to current polarity mirror menu unit and carries out polarity judgement, polar signal after judgement carries out except making an uproar and amplifying through anti-interference and comparing unit, finally in polarity display unit, demonstrate polarity judged result, power supply unit provides power supply respectively for current polarity first, the anti-interference and comparing unit of mirror menu and polarity display unit.
Described power supply unit, comprises the first Voltage stabilizing module and the second Voltage stabilizing module, and the input end of described first Voltage stabilizing module and the second Voltage stabilizing module all accesses d. c. voltage signal Ui; The output terminal of described first Voltage stabilizing module connects a polarity of voltage converting unit; Input end and the output terminal of described first Voltage stabilizing module are all connected with some filter capacitors; Input end and the output terminal of described second Voltage stabilizing module are all connected with some filter capacitors.
Described current polarity mirror menu unit, by diode D1, diode D2, electric capacity C1, electric capacity C2, stabilivolt D
z1, stabilivolt D
z2, resistance R1, resistance R2, resistance R3 and resistance R4 form, and the negative electrode of described diode D1 is connected with the secondary tap of current transformer, and the anode of diode D1 is connected with the negative pole of electric capacity C1, the plus earth of electric capacity C1; The anode of described diode D2 is connected with the secondary tap of current transformer, and the negative electrode of diode D2 is connected with the positive pole of electric capacity C2, the minus earth of electric capacity C2; Described stabilivolt D
zthe plus earth of 1, stabilivolt D
zthe two ends of electric capacity C1 are connected in parallel to after the anode series resistance R1 of 1; Described stabilivolt D
zthe plus earth of 2, stabilivolt D
zthe two ends of electric capacity C2 are connected in parallel to after the negative electrode series resistor R2 of 2; The two ends of described electric capacity C1 are also parallel with resistance R3; The two ends of described electric capacity C2 are also parallel with resistance R4; The output terminal of described current polarity mirror menu unit is the anode of diode D1 and the negative electrode of diode D2.
Described anti-interference and comparing unit, comprises the first comparer and the second comparer, and the positive polarity input end of described first comparer is connected to the negative electrode of diode D1, and the negative polarity input end of the first comparer connects one except filter amplification circuit of making an uproar; The negative polarity input end of described second comparer is connected to the anode of diode D2, and the positive polarity input end of the second comparer also connects one except filter amplification circuit of making an uproar.
Described except filter amplification circuit of making an uproar, comprise amplifier A0, its positive polarity input end is connected with resistance R5, and the other end of resistance R5 is connected with power supply; The described resistance R5 contact that is connected with amplifier A0 positive polarity input end is also connected with electric capacity C5 respectively with resistance R6, the equal ground connection of the other end of resistance R6 and electric capacity C5; The negative polarity input end of described amplifier A0 is connected with its output terminal.
The polarity indicating module that described polarity display unit is LED display module or is made up of triode and light emitting diode.
The beneficial effects of the utility model are:
(1), in described current transformer polarity testing circuit, be integrated with some roads polarity test unit, can test some groups of taps simultaneously, substantially increase testing efficiency;
(2) use light emitting diode to indicate current transformer polarity, compare indicator type current meter more directly perceived, there will not be the too small situation being beyond recognition polarity of throw of the pointer;
(3) stabilivolt in the utility model, for stablizing the input terminal voltage of the first comparer and the second comparer, is convenient to rear class and is carried out processing and be unlikely to burn device and cause danger;
(4) comparer one end of the present utility model connects except dry filter amplification circuit, produces drift, the reliability and stability of assurance device for suppressing the voltage reference of the input end of comparer;
(5) the utility model is all incorporated to a resistance at electric capacity C1 and electric capacity C2 both sides, is capacitor discharge after transformer current disappears, thus extinguishes diode, is convenient to carry out next one experiment and need not artificially discharge;
(6) the utility model is integrated with power supply unit, charger for mobile phone can be used to input as external direct current, provide the burning voltage of positive and negative 5V; On the one hand as the working power of each chip, can be used as benchmark voltage that is anti-interference and comparing unit on the one hand, eliminate outside connected switch power supply, reduce machine volume, lay the first stone for board normally works.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model;
Fig. 2 is current polarity of the present utility model mirror menu unit;
Fig. 3 is a) for comprising the anti-interference of the first comparer and comparing unit schematic diagram;
Fig. 3 b) for comprising the anti-interference of the second comparer and comparing unit schematic diagram;
Fig. 4 is a) the current polarity indicating member schematic diagram of same polarity;
Fig. 4 b) be the current polarity indicating member schematic diagram of reversed polarity;
Fig. 5 is power supply unit schematic diagram of the present utility model;
Fig. 6 is housing of the present utility model.
Embodiment
The utility model is further illustrated below in conjunction with Figure of description:
As shown in Figure 1, a kind of polarity testing device of current transformer, comprise housing, current transformer polarity testing circuit is provided with in housing, described current transformer polarity testing circuit is by power supply unit, and three groups of polarity test unit are formed, described polarity test unit is composed in series by reflect first, the anti-interference and comparing unit of menu and polarity display unit of current polarity; As shown in Figure 6, connection terminal L1, N1 on the utility model housing, L2, N2, and L3, N3, be respectively the input of three groups of polarity test unit; L often in group connects Current Transformer Secondary side tap anode, and N connects common port; Housing is also provided with 6 holes, the LED 0 of three groups of polarity display units, LED1, LED2, LED3, LED4, LED5 is respectively equipped with in 6 holes, wherein LED0, LED2 and LED4 represent this group polarity test result is respectively same polarity, and LED1, LED3 and LED5 then represent reversed polarity; The upper POWER hole of housing connects power supply unit.
Wherein, the principle of polarity mirror choosing is: the characteristic utilizing diode unilateral conduction, ensures that CT electric current is under opposed polarity, charges to different electric capacity.When being acquired a certain degree by the capacitance voltage charged, will exceed the reference value of setting, two comparers of corresponding positive reversed polarity will export+5V high level.
As shown in Figure 2, when selecting polarity mirror to select diode, maximum current, maximum reverse pressure drop and response speed is considered.Consider that the secondary current utilizing dry cell to induce is all in mA rank, reverse voltage can not exceed the limit value of storage capacitor, and the requirement of response speed also can not be high especially.Therefore select the most frequently used 1n4007 commutation diode, its electric current permissible value at 1A, reverse voltage maximal value 1000V, response speed the slowest also at 10uS, adapt to the needs of the design completely.Electric capacity C1 in the present embodiment and electric capacity C2 is all adjusted to 300pf, can solve the electric current drooping experiment generation too small, cause and charging capacitor two ends can not be charged to predetermined voltage, thus cannot light the problem of diode.
As Fig. 3 a) and Fig. 3 b) shown in, operational amplifier selects OP-07 and LM258 operational amplifier.OP-07 is connected into voltage follower form, is used for carrying out except filtering process of making an uproar to the voltage reference produced; LM258 is connected into comparer form.
As Fig. 4 a) and Fig. 4 b) shown in, the polarity indicating module be made up of triode and light emitting diode selected by the present embodiment Semi-polarity display unit, the principle of this polarity indicating module is: when polarity discrimination is for just or inverse time, corresponding comparer exports high level, is lighted by LED by a typical LED driving circuit.The core of described driving circuit is NPN type triode.When selecting NPN type triode, it is envisaged that its power consumption and frequency, NPN type triode selects 8050 type triodes, and power consumption only has 625mW, and frequency reaches 150kHZ, adapts to Power Supplies Condition completely.
As shown in Figure 5, power supply unit provides power supply respectively for current polarity first, the anti-interference and comparing unit of mirror menu and polarity display unit.Direction of current mirror selects in circuit, and all comparer original papers all need+5V and-5V two-way power supply, and therefore power module reliably must export these two kinds of level.When selecting linear voltage regulation chip, group member considers precision, power and working temperature: in the design, wish the line regulation of voltage below 0.5%, carrying load ability is not less than 3W.Working-yard circumstance complication, therefore wishes that device normally can work in the environment of 0 DEG C-70 DEG C.
Select LM1117-5 as linear voltage regulation chip, the voltage of+5V can be obtained.Its parameter is as shown in table 1:
Table 1LM1117-5 parameter
| Index | Output voltage | Output current | Line regulation | Load regulation rate | Working temperature |
| +5V | 800mA | 0.2% (maximum) | 0.4% (maximum) | 0℃—125℃ |
No matter from output voltage grade, precision, demanded power output, or to the tolerance of working environment, this chip all meets the requirements.Consider and only have+5V voltage to be inadequate, alternative is with 7660 as level transferring chip, and+5V the voltage transitions that one of them LM1117-5 can be produced is-5V voltage.
In order to the reliability of intensifier circuit, the present embodiment have also been devised the three external connection terminals in tunnel in addition, when power module damages, directly can power by Switching Power Supply.
The use procedure of polarity testing device of current transformer of the present utility model is:
(1) primary connection is carried out to surveyed current transformer, and prepare dry cell;
(2) respectively from the measurement of this phase current mutual inductor secondary side, metering and protection three groups of coils draw one group of tap, amount to three groups of taps, be connected to L1, N1 of the utility model housing, on L2, N2 and L3, N3 terminal, as shown in Figure 6; L often in group connects the anode of current transformer terminal, and N connects common port.Be that device powers on by POWER hole charger;
(3) carry out drooping experiment at primary side;
(4) by observing housing LED0-LED5, judge the polarity often organizing tap, wherein LED0, LED2 and LED4 represent same polarity, and LED1, LED3 and LED5 represent reversed polarity;
(5) each tap of each mutually each coil is measured in circulation, and makes a record;
(6) test is terminated: dismounting wire and device, restoring scene.
By reference to the accompanying drawings embodiment of the present utility model is described although above-mentioned; but the restriction not to the utility model protection domain; one of ordinary skill in the art should be understood that; on the basis of the technical solution of the utility model, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection domain of the present utility model.
Claims (8)
1. a polarity testing device of current transformer, it is characterized in that, comprise housing, current transformer polarity testing circuit is provided with in housing, described current transformer polarity testing circuit is by power supply unit, and the polarity test unit of some groups is formed, described polarity test unit is composed in series by reflect first, the anti-interference and comparing unit of menu and polarity display unit of current polarity; The output signal of current transformer inputs to current polarity mirror menu unit and carries out polarity judgement, polar signal after judgement carries out except making an uproar and amplifying through anti-interference and comparing unit, finally in polarity display unit, demonstrate polarity judged result, power supply unit provides power supply respectively for current polarity first, the anti-interference and comparing unit of mirror menu and polarity display unit.
2. a kind of polarity testing device of current transformer as claimed in claim 1, it is characterized in that, described power supply unit, comprises the first Voltage stabilizing module and the second Voltage stabilizing module, and the input end of described first Voltage stabilizing module and the second Voltage stabilizing module all accesses d. c. voltage signal Ui; The output terminal of described first Voltage stabilizing module connects a polarity of voltage converting unit.
3. a kind of polarity testing device of current transformer as claimed in claim 2, is characterized in that, input end and the output terminal of described first Voltage stabilizing module are all connected with some filter capacitors; Input end and the output terminal of described second Voltage stabilizing module are all connected with some filter capacitors.
4. a kind of polarity testing device of current transformer as claimed in claim 2, is characterized in that, described power supply unit is also circumscribed with three road terminals, and described three road terminals are connected with Switching Power Supply.
5. a kind of polarity testing device of current transformer as claimed in claim 1, is characterized in that, described current polarity mirror menu unit, by diode D1, diode D2, electric capacity C1, electric capacity C2, stabilivolt D
z1, stabilivolt D
z2, resistance R1, resistance R2, resistance R3 and resistance R4 form, and the negative electrode of described diode D1 is connected with the secondary tap of current transformer, and the anode of diode D1 is connected with the negative pole of electric capacity C1, the plus earth of electric capacity C1; The anode of described diode D2 is connected with the secondary tap of current transformer, and the negative electrode of diode D2 is connected with the positive pole of electric capacity C2, the minus earth of electric capacity C2; Described stabilivolt D
zthe plus earth of 1, stabilivolt D
zthe two ends of electric capacity C1 are connected in parallel to after the anode series resistance R1 of 1; Described stabilivolt D
zthe plus earth of 2, stabilivolt D
zthe two ends of electric capacity C2 are connected in parallel to after the negative electrode series resistor R2 of 2; The two ends of described electric capacity C1 are also parallel with resistance R3; The two ends of described electric capacity C2 are also parallel with resistance R4; The output terminal of described current polarity mirror menu unit is the anode of diode D1 and the negative electrode of diode D2.
6. a kind of polarity testing device of current transformer as claimed in claim 1, it is characterized in that, described anti-interference and comparing unit, comprise the first comparer and the second comparer, the positive polarity input end of described first comparer is connected to the negative electrode of diode D2, and the negative polarity input end of the first comparer connects one except filter amplification circuit of making an uproar; The negative polarity input end of described second comparer is connected to the anode of diode D1, and the positive polarity input end of the second comparer also connects one except filter amplification circuit of making an uproar.
7. a kind of polarity testing device of current transformer as claimed in claim 6, is characterized in that, described except filter amplification circuit of making an uproar, and comprises amplifier A0, and its positive polarity input end is connected with resistance R5, and the other end of resistance R5 is connected with power supply; The described resistance R5 contact that is connected with amplifier A0 positive polarity input end is also connected with electric capacity C5 respectively with resistance R6, the equal ground connection of the other end of resistance R6 and electric capacity C5; The negative polarity input end of described amplifier A0 is connected with its output terminal.
8. a kind of polarity testing device of current transformer as claimed in claim 1, is characterized in that, the polarity indicating module that described polarity display unit is LED display module or is made up of triode and light emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520032242.9U CN204347186U (en) | 2015-01-16 | 2015-01-16 | A kind of polarity testing device of current transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520032242.9U CN204347186U (en) | 2015-01-16 | 2015-01-16 | A kind of polarity testing device of current transformer |
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| Publication Number | Publication Date |
|---|---|
| CN204347186U true CN204347186U (en) | 2015-05-20 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201520032242.9U Expired - Fee Related CN204347186U (en) | 2015-01-16 | 2015-01-16 | A kind of polarity testing device of current transformer |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107643505A (en) * | 2017-10-11 | 2018-01-30 | 国网宁夏电力公司吴忠供电公司 | 110kV current transformer integrated form polarity test devices |
| CN108089091A (en) * | 2017-12-20 | 2018-05-29 | 国家电网公司 | A kind of secondary wiring of current mutual inductor polarity measurement device and measuring instrument |
| CN108181545A (en) * | 2017-12-29 | 2018-06-19 | 国家电网公司 | A kind of polarity test circuit for current transformer |
-
2015
- 2015-01-16 CN CN201520032242.9U patent/CN204347186U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107643505A (en) * | 2017-10-11 | 2018-01-30 | 国网宁夏电力公司吴忠供电公司 | 110kV current transformer integrated form polarity test devices |
| CN108089091A (en) * | 2017-12-20 | 2018-05-29 | 国家电网公司 | A kind of secondary wiring of current mutual inductor polarity measurement device and measuring instrument |
| CN108089091B (en) * | 2017-12-20 | 2020-07-28 | 国家电网公司 | Current transformer secondary wiring polarity measuring device and measuring instrument |
| CN108181545A (en) * | 2017-12-29 | 2018-06-19 | 国家电网公司 | A kind of polarity test circuit for current transformer |
| CN108181545B (en) * | 2017-12-29 | 2020-10-27 | 国家电网公司 | Polarity test circuit for current transformer |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150520 Termination date: 20160116 |
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| EXPY | Termination of patent right or utility model |