CN205826736U - A kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing - Google Patents

A kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing Download PDF

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Publication number
CN205826736U
CN205826736U CN201620741378.1U CN201620741378U CN205826736U CN 205826736 U CN205826736 U CN 205826736U CN 201620741378 U CN201620741378 U CN 201620741378U CN 205826736 U CN205826736 U CN 205826736U
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China
Prior art keywords
circuit
coil
electric current
magnet ring
digital conversion
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Expired - Fee Related
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CN201620741378.1U
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Chinese (zh)
Inventor
杨秀增
周思颖
蒙韦清
韦孟娇
陆伟艳
李海生
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Guangxi Normal University for Nationalities
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Guangxi Normal University for Nationalities
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Abstract

This utility model provides a kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing, including active zero-flux current transformer, signal processing circuit and analog digital conversion and single chip machine controlling circuit;Active zero-flux current transformer includes primary coil, secondary coil, detection coil, main magnet ring, auxiliary magnet ring, back-off coil and error compensation circuit;Signal processing circuit includes pre-amplification circuit, active band-pass filter, true effective value converting circuit and the 2nd amplifying circuit;Analog digital conversion and single chip machine controlling circuit include biproduct typing A/D change-over circuit, single-chip microcomputer minimum control system and LCD display module.This utility model current detecting is accurate, precision is high, use the mode of connection of single-turn cored structure, Zero flux current sensor can be directly sleeved on tested cable during measurement, it is convenient to measure, security performance is high, is suitable to the test of the security leak electric current of various household electrical appliance, power supply, cable, binding post, Medical Instruments and strong power system.

Description

A kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing
Technical field
This utility model relates to a kind of current measurement system, especially relates to the single-turn cored structure formula current measurement of a kind of high accuracy System.
Background technology
In engineering practice and scientific experiments, it is often necessary to on-line measurement leakage current size, such as, pass through in transformer station Measure the leakage current of high pressure equipment earth lead, analyze the insulation status of high pressure equipment.These leakage currents are the least, typically exist Between a few μ A to hundreds of mA, common current measuring instrument is difficult to measure, and therefore, research Weak current on-line measurement instrument has Very important realistic meaning.
The universal measurement method of current small DC current has two kinds.One is to directly amplify the most directly to carry out current/voltage Then conversion carries out voltage amplification, and owing to being that direct current amplifies, this method is highly susceptible to imbalance and the drift of electronic device characteristics Move and have influence on the stable and accurate of work.Another kind is chopping modulation, and direct current signal is the most first transformed to alternating voltage, more right Alternating voltage carries out voltage amplification, is transformed to DC voltage the most again.This method overcomes the shortcoming of the method for directly amplifying but electric Road is complicated.
Summary of the invention
For solving the problem of above-mentioned existence, this utility model provides the single-turn cored structure formula electric current on-line testing of a kind of high accuracy System, including, active zero-flux current transformer, signal processing circuit and analog digital conversion and single chip machine controlling circuit;Wherein, institute State active zero-flux current transformer and include primary coil, secondary coil, detection coil, main magnet ring, auxiliary magnet ring, back-off coil And error compensation circuit;Described signal processing circuit includes pre-amplification circuit, active band-pass filter, RMS conversion electricity Road and the 2nd amplifying circuit;Described analog digital conversion and single chip machine controlling circuit include that biproduct typing A/D change-over circuit, single-chip microcomputer are Little control system and LCD display module;When on the cable that described primary coil is enclosed within tested electric current, will be in main magnet ring, auxiliary The magnetic flux of change is produced on magnet ring;The faradic current that described detection coil is produced by the magnetic flux changed for sensing;Described error Compensating circuit and be used for carrying out described faradic current phase shift process, described bucking coil is for receiving the faradism after phase shift processes Stream;Described secondary coil is used for induced voltage, and described pre-amplification circuit and active band lead to small echo device for described faradism Pressure is amplified and Filtering Processing, and described virtual value counting circuit voltage after processing carries out conversion Calculation, calculates The virtual value of induced voltage;Described 2nd amplifying circuit is used for being amplified described voltage effective value, described analog digital conversion and list Sheet machine control circuit voltage effective value after amplifying carries out analog digital conversion, and by described LCD display module measuring Result shows.
Further, described primary coil is single turn.
Further, described error compensation circuit includes preamplifier, phase-shifting circuit, band filter and V/I Change-over circuit.
The beneficial effects of the utility model are: in order to enable the size of accurately on-line measurement Weak current, this utility model profit Use Zero flux current sensing techniques, design high-precision current on-line measurement instrument, use the mode of connection of single-turn cored structure, during measurement Zero flux current sensor can be directly sleeved on tested cable, there is measurement convenient, security performance advantages of higher, adapt to Test in the security leak electric current of various household electrical appliance, power supply, cable, binding post, Medical Instruments and strong power system.
Accompanying drawing explanation
Fig. 1 is current measurement instrument system design frame chart of the present utility model;
Fig. 2 is the Zero flux error compensation circuit figure of current measurement instrument system of the present utility model;
Fig. 3 is electric current on-line measurement instrument signal processing circuit figure of the present utility model;
Fig. 4 is analog to digital conversion circuit and the control circuit figure thereof of current measurement instrument system of the present utility model;
Fig. 5 is the scm software control algolithm flow chart of current measurement instrument system of the present utility model.
Detailed description of the invention
With detailed description of the invention, this utility model is described further below in conjunction with the accompanying drawings.
As it is shown in figure 1, high accuracy single-turn cored structure formula electric current Online Transaction Processing of the present utility model includes, active Zero flux Current transformer, signal processing circuit and analog digital conversion and single chip machine controlling circuit three parts.
Wherein, active zero-flux current transformer include primary coil (single turn), secondary coil, detection coil, main magnet ring, Auxiliary magnet ring, back-off coil and error compensation circuit.
Signal processing circuit includes that pre-amplification circuit, active band-pass filter, true effective value converting circuit and the 2nd are amplified Circuit forms.
Analog digital conversion and single chip machine controlling circuit include biproduct typing A/D change-over circuit, single-chip microcomputer minimum control system and LCD display module.
When the primary coil of single-turn cored structure formula Zero flux current transformer is enclosed within the cable of tested electric current, help main Produce the magnetic flux of change on magnetic, auxiliary magnet ring, detect coil-induced electric current, after error compensation circuit phase shift processes, be added to mutually The bucking coil of sensor, makes the electric current I that the secondary coil of current transformer induces3More accurate.
The voltage that secondary coil induces, after pre-amplification circuit, active band lead to the process of small echo device, is sent to virtual value Counting circuit, calculates the virtual value of induced voltage signal, now carries out voltage magnitude amplification through the 2nd amplifying circuit, just carries out mould Number conversion, finally shows measurement result by LCD display module.
From AC transformer operation principle, during operation of current transformers, meet following magneto electromotive force equilibrium equation:
N1I1+N1I0=N2I2 (1)
Wherein, N1、I1For coil turn and the electric current of armature winding, N2、I2For the secondary winding coil number of turn and electric current, I0For The exciting curent of primary winding coil.From (1) formula, due to N1I0Existence, N1I0It is not equal to N2I2, therefore, reduce N1I0Greatly Little, the certainty of measurement of transformer can be improved.Zero-flux current transformer is made according to this principle, as it is shown in figure 1, Produce induced field current by the detection coil on main magnet ring, after error compensation circuit processes, be added to the compensation of transformer Strengthen exciting curent on coil, force the exciting curent I of primary winding coil0Reduce, improve the certainty of measurement of current transformer.
Fig. 2 is Zero flux error compensation circuit figure, mainly by preamplifier U1, phase-shifting circuit U2, band filter U3With V/I change-over circuit U4Composition.Preamplifier uses chopper-zero-stabilized formula high-operational amplifier ICL7650 to be designed, and has height Gain, high cmrr, imbalance be little and the feature such as low of drifting about.R5、R4、C6、R6It is phase shift with TL1001, changes R4 And C6During value, signal phase can change.R7、C9、C19、R8、R9、R10A band filter, filtering is constituted with TL1001 The mid frequency of device is set to 50HZ, can effective filter out interference signal.CA3080 is the spaning waveguide operational amplifier of a superior performance, can be real Existing V/I conversion, regulates R13Value, thus it is possible to vary the bias current of spaning waveguide operational amplifier.
As it is shown in figure 1, the voltage signal magnitude of secondary winding coil sensing is the least, and it is mixed with interference signal, carries out A/D Before conversion, will be amplified the signal that this is small, filtering etc. processes.
Fig. 3 is the signal processing circuit figure of this measuring instrument, mainly by pre-amplification circuit, active band-pass filter, really have Valid value change-over circuit and the 2nd amplifying circuit composition.ICL7650 chip is high-performance chopper-zero-stabilized formula high-operational amplifier, and it amplifies Multiple is by resistance R2And R3Determine.The signal amplified through pre-amplification circuit is mixed with other interference signal, it is necessary to logical by a band Filter circuit filters it, and the mid frequency of wave filter is set to 50HZ.In order to improve current measurement precision, this tester uses AD637 designs a high-precision true effective value converting circuit, as shown in Figure 3.The amplitude of the voltage signal after converted also than Less, need further amplification just can carry out A/D conversion, U4、R9、R10For direct proportion amplifying circuit, its amplification is by R10、 R9Ratio determine.
In order to improve A/D conversion accuracy, this measurement pilot production double integration A/D change-over circuit with capacity of resisting disturbance, Fig. 4 For A/D change-over circuit and single chip machine controlling circuit figure, mainly include double integration A/D change-over circuit, single-chip microcomputer minimum control system And LCD display module.R3And C6For the anti-mixing low pass filter of A/D converter, analogue signal enters through this wave filter 35th foot of ICL7109 transducer.Single-chip microcomputer reads, by P1 mouth, the digital signal changed, treated after, show with LCD The current value passed through of module display measured conductor.
Fig. 5 is the scm software control algolithm flow chart of this measuring instrument, as seen from the figure, when program is run, and first monolithic Machine performs initialization operation, is then read the voltage of the STATUS pin of ICL7109 by P0.0 mouth, understands A/D converter Duty, if the voltage read is high voltage, shows a period of times such as ICL7109 is in A/D conversion, single-chip microcomputer again Read STATUS pin voltage.If the voltage read is low-voltage, show ICL7109A/D EOC, at this moment, single-chip microcomputer The data changed can be read.When reading data, single-chip microcomputer is set to low-voltage P0.4 mouth, first reads least-significant byte data, then Read the data of most-significant byte again.After data read by single-chip microcomputer, calculate the current value of measured conductor, and shown by LCD module Out.
The foregoing is only preferred embodiment of the present utility model, not in order to limit this utility model, all at this Any amendment, equivalent and the improvement etc. made within the spirit of utility model and principle, should be included in this utility model Protection domain within.

Claims (3)

1. a high accuracy single-turn cored structure formula electric current Online Transaction Processing, it is characterised in that:
Including, active zero-flux current transformer, signal processing circuit and analog digital conversion and single chip machine controlling circuit;
Described active zero-flux current transformer includes primary coil, secondary coil, detection coil, main magnet ring, auxiliary magnet ring, benefit Taste coil and error compensation circuit;
Described signal processing circuit includes that pre-amplification circuit, active band-pass filter, true effective value converting circuit and the 2nd are amplified Circuit;
Described analog digital conversion and single chip machine controlling circuit include biproduct typing A/D change-over circuit, single-chip microcomputer minimum control system and LCD display module;
When on the cable that described primary coil is enclosed within tested electric current, the magnetic flux of change will be produced on main magnet ring, auxiliary magnet ring; The faradic current that described detection coil is produced by the magnetic flux changed for sensing;Described error compensation circuit is for described sensing Electric current carries out phase shift process, and described bucking coil is for receiving the faradic current after phase shift processes;
Described secondary coil is used for induced voltage, and described pre-amplification circuit and active band lead to small echo device for described faradism Pressure is amplified and Filtering Processing, and described virtual value counting circuit voltage after processing carries out conversion Calculation, calculates The virtual value of induced voltage;
Described 2nd amplifying circuit is used for being amplified described voltage effective value, described analog digital conversion and single chip machine controlling circuit Voltage effective value after amplifying carries out analog digital conversion, and by described LCD display module, measurement result is shown.
A kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing the most according to claim 1, it is characterised in that: described Primary coil is single turn.
A kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing the most according to claim 2, it is characterised in that: described Error compensation circuit includes preamplifier, phase-shifting circuit, band filter and V/I change-over circuit.
CN201620741378.1U 2016-07-14 2016-07-14 A kind of high accuracy single-turn cored structure formula electric current Online Transaction Processing Expired - Fee Related CN205826736U (en)

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Application Number Priority Date Filing Date Title
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110907875A (en) * 2019-12-05 2020-03-24 北京东方计量测试研究所 Hall current sensor calibration device and method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110907875A (en) * 2019-12-05 2020-03-24 北京东方计量测试研究所 Hall current sensor calibration device and method
CN110907875B (en) * 2019-12-05 2021-08-17 北京东方计量测试研究所 Hall current sensor calibration device and method

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CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20161221

Termination date: 20170714