CN102103156A - Digital current transformer and method for measuring current of AC (Alternating Current) transmission conductor - Google Patents
Digital current transformer and method for measuring current of AC (Alternating Current) transmission conductor Download PDFInfo
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- CN102103156A CN102103156A CN2009102644271A CN200910264427A CN102103156A CN 102103156 A CN102103156 A CN 102103156A CN 2009102644271 A CN2009102644271 A CN 2009102644271A CN 200910264427 A CN200910264427 A CN 200910264427A CN 102103156 A CN102103156 A CN 102103156A
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- 230000005540 biological transmission Effects 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000004020 conductor Substances 0.000 title abstract 5
- 238000005070 sampling Methods 0.000 claims abstract description 6
- 238000001514 detection method Methods 0.000 claims description 9
- 239000003990 capacitor Substances 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 3
- 230000006698 induction Effects 0.000 claims description 3
- 238000005381 potential energy Methods 0.000 abstract 4
- 230000001939 inductive effect Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 229910052802 copper Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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Abstract
The invention provides a digital current transformer and a method for measuring the current of an AC (Alternating Current) transmission conductor, and relates to a current detecting device and method of a power transmission line. The digital current transformer comprises a coil 1 provided with a magnetic skeleton and used for supplying power, a coil 2 provided with a nonmagnetic skeleton and used for sampling, and a current detecting circuit. The method for measuring the current of the AC transmission conductor by using the digital current transformer comprises the following steps of: 1) inducing electrical potential energy formed due to the difference of magnetic field intensities on different circumferences of the AC transmission conductor by using the coil 2, and transmitting the weak electrical potential energy signal to a sampling circuit; 2) sampling energy by using the coil 1; (3) transmitting the electrical potential energy signal amplified by an amplifier to an analog to digital converter, converting the electrical potential energy signal into a digital signal, and transmitting the digital signal to a processor, wherein a conversion program is preset in the processor, the digital signal is solved by using the processor preset with the conversion program, is converted into a current signal through a digital to analog converter, and is transmitted to a current display meter to display the current value in the AC transmission conductor.
Description
Technical field
The present invention relates to the method for a kind of power transmission line current sensing means and detection electric current thereof,
Relate in particular to a kind of current sensing means that is similar to mutual inductor with and detect the method for electric current.
Background technology
The domestic current transformer that adopts all is to adopt the A/A conversion regime at present, that is to say the mode that the primary current dress is changed to 0-5A.This mode has had the history of last 100 years, and the existing problem of this kind current transformer is: 1, power consumption is big; 2, the steel of Hao Yonging, copper material are many; 3, the no-load voltage ratio relation is arranged; 4, can not open-circuit working; 5, overload is fragile.
Especially preceding 2 points, at present, power consumer is more and more, causes the use amount of mutual inductor very big, and what no-load voltage ratio present mutual inductor need, and could take out metering signal, that is to say, at each user side, also needs to reuse two-stage mutual inductor at least.Leads such as used copper material, siliconized plate in each mutual inductor, magnetic material are a lot, and these materials, cost is big on the one hand, on the other hand can consumed power.
Summary of the invention
The present invention is directed to above problem, provide a kind of and guaranteed to realize under the prerequisite of mutual inductor function the method for digital electric current transformer that the metal material utilization is few and measurement ac transmission current in wire.
Technical scheme of the present invention is: comprise housing, be arranged on the coil in the housing, described coil comprises the coil with magnetic skeleton one that is used for energy supply, coil with non magnetic skeleton two and the current detection circuit that is used to take a sample; Described current detection circuit comprises amplifier, analog to digital converter, processor, digital to analog converter and current values indicator gauge; Described coil two connects amplifier, provides the sampling current data to amplifier; Described coil one connects amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter, gives amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter energy supply; Described coil one and coil two are arranged in the housing with one heart.
Described coil one links to each other with analog to digital converter by the same amplifier of an energy supply circuit, processor, digital to analog converter, current values indicator gauge, and described energy supply circuit comprises bridge rectifier circuit, capacitor and stabilivolt, and described capacitor and stabilivolt also connect.
The method of utilizing digital current mutual inductor of the present invention to measure the ac transmission current in wire is:
1), the employing spiral shell is responded to the ac transmission lead energies of position that magnetic field intensity difference forms on different circumference around the coil two on the non-magnetic skeleton, and this faint energy of position signal is transferred to sample circuit;
2), adopt spiral shell to gather the induction current of ac transmission lead around the coil one on the magnetic skeleton, and this electric current offered amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter through rectification, filtering, as the work energy of amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter;
3), the energy of position signal after amplifier amplifies, be transferred to analog to digital converter, be converted to digital signal; Be transferred to processor again, default conversion program in processor, the processor that is preset with the conversion program resolves digital signal, and is converted into current signal by digital to analog converter, is transferred to the electric current indicator gauge, shows the current value in the ac transmission lead.
The present invention has adopted another kind of mode that the electric current in the interchange lead of electric power transfer is detected; Adopt one to use the coil two of non magnetic skeleton coiling to take a sample, utilize the energy of position under different magnetic field intensity poor, be captured in the weak voltage that produces in the lead of sample coil and fall; Utilize a coil one with very little magnetic skeleton to produce bigger electric energy again, be used to offer current detection circuit.The voltage drop signal that the current detection circuit method is faint, and resolve this signal, finally by the conversion program, draw the current value in the tested lead.The conversion program can be good in the budget of when design, also can survey the formula that draws conversion by one or many.The present invention also can not utilize the figure pattern in the technical scheme, and directly adopts by amplifier output analog quantity, draws current value by the conversion to analog quantity.The present invention has following characteristic: 1, mutual inductor does not have no-load voltage ratio, and output both can be analog quantity and also can be digital quantity; 2, current transformer need not to add working power.
Principle of work of the present invention is: when the current transformer primary side passed through electric current, the Current Transformer Secondary side induced ac voltage.Linear relationship rising big or small in direct ratio when magnitude of voltage and primary current.Because coil winding can not produce the magnetic saturation phenomenon on a non-magnetic conduction skeleton, the non-constant width of all these mutual inductor ranges.The mutual inductor secondary voltage is very small to be amplified by electron-amplifier, converts digital signal output to by A/D again.
Description of drawings
Fig. 1 is the stereographic map of Inside coil of the present invention
1 is lead among the figure, the 2nd, and coil one, 21st, the output terminal of coil one, the 3rd, coil two, 31st, the output terminal of coil two;
Fig. 2 is that first kind of Inside coil of the present invention is provided with form
Fig. 3 is that second kind of Inside coil of the present invention is provided with form
Fig. 4 is a synoptic diagram of getting the energy circuit among the present invention
Fig. 5 is the synoptic diagram of sample circuit among the present invention
Fig. 6 be experiment test of the present invention once, the secondary current relation table.
Embodiment
The present invention comprises housing, is arranged on the coil in the housing shown in Fig. 1-5, and described coil comprises the coil with magnetic skeleton 1 that is used for energy supply, coil with non magnetic skeleton 23 and the current detection circuit that is used to take a sample; Described current detection circuit comprises amplifier, analog to digital converter, processor, digital to analog converter and current values indicator gauge; The output terminal 31 of described coil 23 connects amplifier, provides the sampling current data to amplifier; The output terminal of described coil 1 connects amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter by functional circuit, gives amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter energy supply; Described coil 1 and coil 23 are arranged in the housing with one heart.
The same amplifier of the energy supply circuit of described coil 1, processor, digital to analog converter, current values indicator gauge link to each other with analog to digital converter, and described energy supply circuit comprises bridge rectifier circuit, capacitor and stabilivolt, and described capacitor and stabilivolt also connect.
Wherein coil 1, coil 23 are provided with one heart, mutual interior external position relation shown in Fig. 2,3, whichever interior, that outside, all can realize the present invention.
The method of utilizing digital current mutual inductor of the present invention to measure electric current in the ac transmission lead 1 is:
1), the employing spiral shell is responded to the ac transmission lead energies of position that magnetic field intensity difference forms on different circumference around the coil 23 on the non-magnetic skeleton, and this faint energy of position signal is transferred to sample circuit; Be presented as very weak current value.
2), adopt spiral shell to gather the induction current of ac transmission lead around the coil 1 on the magnetic skeleton, and this electric current offered amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter through rectification, filtering, as the work energy of amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter;
3), energy of position signal (very weak current value) after amplifier amplifies, be transferred to analog to digital converter, be converted to digital signal; Be transferred to processor again, default conversion program in processor, the processor that is preset with the conversion program resolves digital signal, and is converted into current signal by digital to analog converter, is transferred to the electric current indicator gauge, shows the current value in the ac transmission lead.
Meaning of the present invention is: 1, save copper material, steel in a large number, copper material only uses 30% of traditional mutual inductor copper material, and steel only use 40% of traditional mutual inductor; 2, physical quantity no distortion digital transmission, the long-distance transmissions of physical quantity.3, for realizing that digital transformer substation provides mutual inductor.
The invention process target is: 1, electric pressure is 10kV and 400V; 2, current measurement signal converts to and gathers behind the voltage and carry out digital transmission; 3, can simulate output or numeral output; 4, good insulation preformance; 5, in light weight, have only about 1/2nd of traditional mutual inductor weight; 6, broad quantum can reach 0-1000A; 7, transmission is undistorted.
The explanation of experiment situation
The 10kV/400V current transformer of designing should be similar with the current transformer of original use on physical dimension, can directly substitute the existing current transformer that uses uses, and power consumption is little, guarantee long-time steady operation, signals collecting should guarantee that precision should be arranged, the signal transmission will guarantee undistorted, and signal output should be adopted the digital quantity output port, and transmission range can adapt to on-the-spot request for utilization.
Performance requirement
1, range 0-1000A
2. precision 1-0.5 level
3, operating voltage 3.3V
4, working temperature-25 ℃～+ 55 ℃
5, power consumption 50mW
6, digital quantity transmission, transmission range 4km
7, relative humidity＜93%
8, the withstand voltage 2000V of 400V mutual inductor
9, the withstand voltage 48kV of 10kV mutual inductor
10, can save copper material 70%, save steel 60%
11, overload capacity 200%
12, operation of current transformers safety is not afraid of open circuit and short circuit.
Experimental result as shown in Figure 6.
Claims (3)
1. a digital electric current transformer comprises housing, is arranged on the coil in the housing, it is characterized in that described coil comprises the coil with magnetic skeleton one that is used for energy supply, coil with non magnetic skeleton two and the current detection circuit that is used to take a sample; Described current detection circuit comprises amplifier, analog to digital converter, processor, digital to analog converter and current values indicator gauge; Described coil two connects amplifier, provides the sampling current data to amplifier; Described coil one connects amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter, gives amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter energy supply; Described coil one and coil two are arranged in the housing with one heart.
2. a kind of digital electric current transformer according to claim 1, it is characterized in that, described coil one links to each other with analog to digital converter by the same amplifier of an energy supply circuit, processor, digital to analog converter, current values indicator gauge, described energy supply circuit comprises bridge rectifier circuit, capacitor and stabilivolt, and described capacitor and stabilivolt also connect.
3. a method of utilizing the described digital current mutual inductor of claim 1 to measure the ac transmission current in wire is characterized in that,
1), the employing spiral shell is responded to the ac transmission lead energies of position that magnetic field intensity difference forms on different circumference around the coil two on the non-magnetic skeleton, and this faint energy of position signal is transferred to sample circuit;
2), adopt spiral shell to gather the induction current of ac transmission lead around the coil one on the magnetic skeleton, and this electric current offered amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter through rectification, filtering, as the work energy of amplifier, processor, digital to analog converter, current values indicator gauge and analog to digital converter;
3), the energy of position signal after amplifier amplifies, be transferred to analog to digital converter, be converted to digital signal; Be transferred to processor again, default conversion program in processor, the processor that is preset with the conversion program resolves digital signal, and is converted into current signal by digital to analog converter, is transferred to the electric current indicator gauge, shows the current value in the ac transmission lead.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910264427.1A CN102103156B (en) | 2009-12-22 | 2009-12-22 | Digital current transformer and method for measuring current of AC (Alternating Current) transmission conductor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910264427.1A CN102103156B (en) | 2009-12-22 | 2009-12-22 | Digital current transformer and method for measuring current of AC (Alternating Current) transmission conductor |
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| CN102103156A true CN102103156A (en) | 2011-06-22 |
| CN102103156B CN102103156B (en) | 2015-01-28 |
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| CN200910264427.1A Active CN102103156B (en) | 2009-12-22 | 2009-12-22 | Digital current transformer and method for measuring current of AC (Alternating Current) transmission conductor |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104101775A (en) * | 2013-04-02 | 2014-10-15 | 优利德科技(中国)有限公司 | Current measuring circuit |
| CN104950155A (en) * | 2014-03-25 | 2015-09-30 | 利思电气（上海）有限公司 | Self-powered high-accuracy active current sensor |
| CN111679115A (en) * | 2020-06-10 | 2020-09-18 | 中国南方电网有限责任公司超高压输电公司大理局 | Detection method for working states of sensors of pincerlike ammeter and valve water cooling equipment |
-
2009
- 2009-12-22 CN CN200910264427.1A patent/CN102103156B/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104101775A (en) * | 2013-04-02 | 2014-10-15 | 优利德科技(中国)有限公司 | Current measuring circuit |
| CN104950155A (en) * | 2014-03-25 | 2015-09-30 | 利思电气（上海）有限公司 | Self-powered high-accuracy active current sensor |
| CN104950155B (en) * | 2014-03-25 | 2019-03-15 | 利思电气（上海）有限公司 | A kind of self-powered type high-precision active electric current sensor |
| CN111679115A (en) * | 2020-06-10 | 2020-09-18 | 中国南方电网有限责任公司超高压输电公司大理局 | Detection method for working states of sensors of pincerlike ammeter and valve water cooling equipment |
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| CN102103156B (en) | 2015-01-28 |
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Owner name: YANGZHOU POWER SUPPLY CO., JIANGSU PROV ELECTRIC P Effective date: 20121109 |
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Effective date of registration: 20121109 Address after: 225801 members of the Baoying province Jiangsu County Road No. 288 Applicant after: Baoying County Power Supply Company of Jiangsu Electric Power Company Applicant after: Yangzhou Power Supply Company of Jiangsu Electric Power Company Applicant after: Jiangsu Electric Power Company Applicant after: State Grid Corporation of China Address before: 225801 members of the Baoying province Jiangsu County Road No. 288 Applicant before: Baoying County Power Supply Company of Jiangsu Electric Power Company |
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