CN101013143A - Highly anti-interference alternating-current/magnetic field sensor - Google Patents
Highly anti-interference alternating-current/magnetic field sensor Download PDFInfo
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- CN101013143A CN101013143A CN 200610125545 CN200610125545A CN101013143A CN 101013143 A CN101013143 A CN 101013143A CN 200610125545 CN200610125545 CN 200610125545 CN 200610125545 A CN200610125545 A CN 200610125545A CN 101013143 A CN101013143 A CN 101013143A
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Abstract
The invention relates to a high anti-interfere performance AC current/magnetic field sensor, comprising the open core Rogowski coil and the integral circuit, and the two outputs of the coil connect to the two inputs of the compensation differential amplifier circuit with the wire, and the open core Rogowski coil opens a gap, symmetrically distributed; the secondary windings are uniform dispersed and symmetrical layout at the two sides of the gap, the integral circuit for the compensation differential integral amplifier circuit, and the compensation differential integral amplifier circuit comprises the differential integral circuit U1 and amplification conditioning circuit U2, and the differential integral circuit U1 using symmetric differential input mode analogy to the operational integrator to from the differential integral circuit, and the differential integral circuit U1 combined parallel connected resistor of integral capacitor of operational integrator to introduce of the compensation slip road. The invention removes the measured wire shape changes or relative position changes and external magnetic field interference, and other factors, effective decreasing the leakage current of integration capacitor through parallel resistor, and low frequency characteristic improved.
Description
Technical field
The invention belongs to a kind of sensor of measuring AC magnetic field or alternating current, specifically, relate to a kind of alternating-current/magnetic field sensor of high anti-jamming capacity.
Background technology
The Rogowski coil can be used to measure the variation in magnetic field, therefore can extrapolate the size of tested electric current by measuring the variation of tested electric current surrounding magnetic field intensity.With Rogowski coil Secondary Winding equably on the skeleton of an annular.The lead that is loaded with tested electric current passes from the center of ring skeleton.The induced potential of Rogowski coil Secondary Winding is directly proportional with the differential that passes the tested electric current at center, so the induced potential of Rogowski coil can be obtained being proportional to the voltage signal of tested electric current through Integral Processing.Therefore just can form current sensor by Rogowski coil and two parts of integrating circuit.
In many cases, also can constitute current sensor by the Rogowski coil separately, it is free-standing Rogowski coil current sensor, at this moment the output of this current sensor is the output of Rogowski coil, be directly proportional with the differential signal of tested electric current, allowing the occasion of fixed phase drift, this Rogowski coil can independently use.After also can this signal being become digital signal, constitute digital integrator, reduce tested current signal with software with the follow-up signal treatment circuit.
The skeleton of Rogowski coil can be to constitute as sensing unit by nonferromagnetic material structure (being hollow coil) or by the Rogowski coil based on open core.
The present invention be directed to Rogowski coil based on open core.
Generally speaking, measure the industry spot of irregular electric current, such as the measurement to the secondary output current of frequency converter, Hall current sensor consumption maximum at needs.And the Rogowski coil is used seldom, and main cause is, is subject to disturb based on the Rogowski coil of open core:
1. the factors such as external magnetic field interference variations that tested wire shape changes or changes and close on the relative position of iron core, these factors are to the influence of measuring accuracy even can reach 10%.
Open core is used widely in fields such as transformer, electric welding machine, reactors, and its relative permeability generally is designed to 10～200 between closed loop iron core and nonferromagnetic material.Under the influence of magnetic field that tested electric current produces, open core can not resemble the iron core of closed loop saturated easily, and the magnetic field intensity that produces in the air gap can not resemble so little in the nonferromagnetic material yet, generally speaking, the specified induced potential of Secondary Winding based on the Rogowski coil of open core of design is about hundreds of millivolts.But all at present Rogowski coils are all perplexed by same problem: the coefficient of mutual inductance of coil is subjected to the influence of the relative position between current carrying conductor and the coil, in some cases, this influence can reach more than 10%, make that the application of Rogowski coil is limited greatly, sometimes, the change of current carrying conductor shape even all can influence the accuracy of measurement.And the existence of adjacent phase current also can cause the influence of can not ignore to measurement.
2.Rogowski the induced potential of coil and the differential of tested electric current are directly proportional, and need the process Integral Processing can obtain being proportional to the voltage signal of tested electric current.But that designs on integrating circuit principle and the structure is unreasonable, makes to measure to be subjected to the influence of extraneous space electromagnetic interference (EMI) very big, almost can not use at the general industry scene.
At present the integrating circuit of general structure is as shown in Figure 1:
Among Fig. 1, R1 is an input resistance, and R2 is a balance resistance, and C1 is an integrating capacitor, and R3 and integrating capacitor C1 are in parallel, and can avoid integrating circuit progressively saturated under the bias voltage influence of amplifier U.This employing integrating circuit structure the most widely is very simple, but have two critical defects can not be ignored: the one, and the introducing of R3 makes the low frequency characteristic variation of integrator; The 2nd, the antijamming capability of this integrator is relatively poor, and through test of many times, this integrator at all can't steady operation in industry spot.
Rogowski coil and integrating circuit be combined to be very suitable for measuring fast-changing electric current, this simple in structure and cheap current sensor, be applied in such as the accurate measurement of industry spot such as frequency converter realization the alternating current more than the frequency 0.5Hz, great application prospect is arranged, but, the accuracy of measurement of Rogowski coil is subjected to the influence of factors such as above-mentioned current carrying conductor and the variation of Rogowski coil relative position, in addition, traditional poor, poor anti jamming capability of integrating circuit low frequency characteristic, industry spot at all can't be stable work.The solution of these two core technology problems is condition precedents that this cheap high reliability current sensor is achieved and promotes.It also is the key technical problem of the technological means solution that the present invention taked.
Summary of the invention
The object of the present invention is to provide a kind of based on open core the Rogowski coil and the alternating-current/magnetic field sensor of the high anti-jamming capacity formed of integrator, to solve the problems referred to above that exist on the existing Rogowski coil pickoff performance, improve its antijamming capability, be applied in industry spot.
A kind of current sensor provided by the invention is made up of Rogowski coil and high reliability integrator based on open core, two output terminals of coil are connected to two input ends of compensation differential integrating amplification circuit with lead, be the input of the output of coil as integrating amplification circuit, but in the design of these two parts and make and all take the special technique means, to guarantee its performance.In addition, allowing the occasion of fixed phase drift, this Rogowski coil also can not need integrating circuit independently to use, and the output of this current sensor at this moment is the output of Rogowski coil, is directly proportional with the differential signal of tested electric current.
Coiling does not have specific (special) requirements to Rogowski coil in the past to Secondary Winding, so that its interference free performance is relatively poor.One of technological means of the present invention is: the present invention has taked the technical measures of special Secondary Winding coiling, to improve its performance.Rogowski coil based on open core of the present invention is characterised in that: open core has one or more air gap, if an above air gap generally is defined as even number, and is symmetrically distributed; The secondary coiling must be distributed in the two ends of all air gaps symmetrically and evenly, the most important thing is, as close as possible air gap is wanted in the position of coiling.
The Rogowski coil that adopts above-mentioned coiling technological means to handle reduces greatly to the sensitivity of current carrying conductor and Rogowski coil relative position.Through repeatedly test, any variation of current carrying conductor position in the Rogowski coil window and cause that the variable quantity of coil coefficient of mutual inductance generally is no more than 0.2%, and to the non-inductive output of electric current beyond the window of Rogowski coils loop center, thereby the Rogowski coil that this performance greatly promotes can be used in industry spot widely.
There are two big critical defects in the integrating circuit of general type: the one, and low frequency characteristic is poor; The 2nd, the antijamming capability deficiency can't steady operation in the strong jamming occasion.Two of technological means of the present invention is, the present invention has designed a kind of compensation differential integrating amplification circuit, its schematic diagram as shown in Figure 2, among Fig. 2, U1 is differential integrating circuit, U2 amplifies modulate circuit.Different with traditional integrating circuit is:
A. adopt differential input mode, strengthened the antijamming capability of integrator; The differential input mode of symmetry usually is used in the amplifying circuit of feeble signal, and the present invention in integrator, has constituted differential integrating circuit with the input mode analogy of this instrument amplifier.Among Fig. 2, R11, R12 equate that with the R1 of Fig. 1 among Fig. 2, C11, C12 equate that with the C1 of Fig. 1 through repeatedly test, the antijamming capability of this differential integrating circuit is extremely strong.
B. introduce the compensation branch road on the parallel resistance of integrating capacitor, improved the low frequency characteristic of integrator.
Among Fig. 2, R21, R22, R23, R24 equate with the R2 of Fig. 1, and be symmetrically distributed, and form equalizing network by R3, C2 in the centre, from the loop of output terminal, compensated the leakage current of integrating capacitor, like this under the situation that does not change the influence of amplifier dc offset voltage among the U1 through parallel resistance through R22, R3, C2 and R24 formation, leakage current on the integrating capacitor reduces greatly, and the low frequency characteristic of integrator can be greatly improved.
Three of technological means of the present invention is to utilize the Rogowski coil of described open core and the printed circuit board (PCB) of integrating circuit to constitute an earth potential shield, all electronic devices and components all place among this shield, can effectively protect the influence of high frequency interference magnetic field to sensor.See described in the specific implementation for details.
The employing that the present invention adopts special coiling based on the Rogowski coil of open core as sensing element, compensation differential integrating amplification circuit changes tested current signal into the current/magnetic field sensor with high anti-jamming capacity of low voltage signal output as modulate circuit.Adopt air-gap iron core structure Rogowski coil, induced potential is big many than hollow coil, antijamming capability strengthens, particularly adopting is uniformly dispersed secondary coiling is arranged in the air gap both sides symmetrically, secondary coiling is to greatest extent near air gap, eliminated basically that tested wire shape changes or change with the relative position of iron core and the factors such as external magnetic field interference of closing on to the influence of Rogowski coil accuracy of measurement.Allowing the occasion of fixed phase drift based on the employing of the special coiling of this technological means based on the Rogowski coil of open core, this Rogowski coil also can not need integrating circuit independently to use, at this moment the output of this current sensor is the output of Rogowski coil, is directly proportional with the differential signal of tested electric current.
The present invention has designed compensation differential integrating amplification circuit, compares with general integrating amplification circuit, and its antijamming capability greatly strengthens.In addition, integrating amplification circuit has increased symmetrical compensation formula loop, has effectively reduced the leakage current of integrating capacitor through parallel resistance, and the low frequency characteristic of integrating amplification circuit has obtained effective improvement.Adopt a kind of shielding mode flexibly and cleverly, the positive of printed circuit board (PCB) of open core and integrating circuit all is connected with the ground wire of power supply, constituting a shield thus shields all electronic devices and components, further strengthened the stability of current sensor, with sensor to external world the sensitivity of interfere with electromagnetic field drop to minimum.The above-mentioned technological means that the present invention takes has improved the interference free performance of existing Rogowski coil greatly, has solved based on the current sensor of the Rogowski coil key technical problem in industry spot practicability.
Description of drawings
Fig. 1 is the integrating circuit figure of existing structure sensor.
Fig. 2 is compensation differential integrating amplification circuit figure of the present invention.
Fig. 3 a is a coil Secondary Winding coiling synoptic diagram of the present invention.
Fig. 3 b is a Rogowski coil Secondary Winding coiling partial schematic diagram of the present invention.
Fig. 4 is that the Rogowski coil of open core of the present invention and the printed circuit board (PCB) of integrating circuit constitute an earth potential shield synoptic diagram.
Embodiment
The invention will be further described in conjunction with the accompanying drawings.
It at first is the design of the Rogowski coil of open core.The core configuration of open core and size, air gap quantity, openings of sizes can design according to the factors such as size of tested electric current.Generally speaking, tested electric current is big more, and core dimensions is big more, and air gap quantity is many more, and opening size is big more.If when selecting to open on the iron core more than one air gap, generally be defined as even number, and be symmetrically distributed, the equivalent relative permeability of open core generally is designed to 30～100 and is advisable.
The coiling of Rogowski coil: at first be the number of turn of determining the Secondary Winding coiling, the Secondary Winding output induced potential during with rated current calculates the secondary number of turns that the Rogowski coil needs.Then the secondary coiling of this quantity is distributed in symmetrically the both sides of all air gaps, all secondary coilings must be as much as possible near the most contiguous with it air gap, shown in Fig. 3 a Rogowski coil Secondary Winding coiling synoptic diagram and Fig. 3 b Rogowski coil Secondary Winding coiling partial schematic diagram.1 is iron core among the figure, and 2 is air gap, and the Secondary Winding 3 of disperseing symmetry joins end to end between the segmentation to greatest extent near air gap 2, and 9 for constituting the coiling of Secondary Winding 3, finally draws through terminal 4.
The design of integrating amplification circuit.The circuit ultimate principle is followed the associated description in the summary of the invention, and in order to guarantee the low frequency characteristic of integrator, the selection of interlock circuit major parameter also will be followed following criterion:
C2, C3 should be enough big, for example desirable 10uF;
2
JI* 2R2 (R1+R2) * C1/R1＞＞1/f
L, f
LLower-cut-off frequency for tested electric current;
2
JI* R4*C3＞＞1/f
L, f
LLower-cut-off frequency for tested electric current.
Shielding measure, the present invention utilizes the Rogowski coil of open core and the printed circuit board (PCB) of integrating circuit to constitute an earth potential shield, all electronic devices and components all place among this shield, can effectively protect the influence of high frequency interference magnetic field to sensor.Printed circuit board (PCB) 5 and on components and parts, as shown in Figure 4 based on the relative position of the Rogowski coil 1 of open core, the front 6 of printed circuit board (PCB) is the stratum, the back side 7 of printed circuit board (PCB) is element layer, coil secondary coiling 3 is connected with the printed circuit board (PCB) back side 7, realize by being connected the connection of lead 8 realizations on electric on open core and stratum, through this technological means, the shield of the present invention's design has further improved the jamproof performance of integrating amplification circuit.
Claims (3)
1, a kind of alternating-current/magnetic field sensor of high anti-interfering performance, form by Rogowski coil and integrating circuit based on open core, two output terminals of coil are connected to two input ends of compensation differential integrating amplification circuit with lead, it is characterized in that: the Rogowski coil of open core adopts the Rogowski coil of air-gap iron core structure, open core has the air gap of one or more even numbers, and is symmetrically distributed; And secondary coiling is uniformly dispersed symmetry arrangement in the air gap both sides, Rao Xian position will as close as possible air gap simultaneously; Integrating circuit is compensation differential integrating amplification circuit, compensation differential integrating amplification circuit is made of differential integrating circuit U1 and amplification modulate circuit U2, differential integrating circuit U1 adopts the differential input mode analogy of symmetry to constitute differential integrating circuit in the amplifier integrator, and differential integrating circuit U1 has also introduced the compensation branch road on the parallel resistance of the integrating capacitor of amplifier integrator.
2, the alternating-current/magnetic field sensor of high anti-interfering performance according to claim 1 is characterized in that: the positive of printed circuit board (PCB) of open core and integrating circuit all is connected with the ground wire of power supply, constitutes a shield thus.
3, the alternating-current/magnetic field sensor of high anti-interfering performance according to claim 2, it is characterized in that: the Rogowski coil of open core and the printed circuit board (PCB) of integrating circuit are positive to be the stratum, the back side of printed circuit board (PCB) is element layer, the Rogowski coil secondary coiling of open core is connected with the printed circuit board (PCB) back side, the Rogowski coil of open core and stratum realize connection on electric constituting an earth potential shield by being connected lead.
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| CNB2006101255450A CN100501415C (en) | 2006-12-21 | 2006-12-21 | Highly anti-interference alternating-current/magnetic field sensor |
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| CNB2006101255450A CN100501415C (en) | 2006-12-21 | 2006-12-21 | Highly anti-interference alternating-current/magnetic field sensor |
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| CN100501415C CN100501415C (en) | 2009-06-17 |
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| CN102878917A (en) * | 2012-09-17 | 2013-01-16 | 华中科技大学 | Signal operation device based on Rogowski coil measurement |
| CN102998522A (en) * | 2012-12-17 | 2013-03-27 | 韦兆碧 | Current measurement device and method |
| CN103245816A (en) * | 2012-02-02 | 2013-08-14 | 台达电子工业股份有限公司 | Integrated current sensing device |
| CN103616549A (en) * | 2013-11-29 | 2014-03-05 | 国家电网公司 | Broadband low-current measurement device based on isolated PCB-type Rogowski coil |
| CN104345196A (en) * | 2014-10-30 | 2015-02-11 | 南京信息工程大学 | Active weak power frequency current induction coil |
| CN104406671A (en) * | 2014-11-27 | 2015-03-11 | 北京万集科技股份有限公司 | Dynamic weighing method based on leakage current model, and dynamic weighing system based on leakage current model |
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| CN111381084A (en) * | 2020-01-16 | 2020-07-07 | 华中科技大学 | Stray parameter becomes more meticulous adjustable high frequency current sensor |
| CN111505539A (en) * | 2020-05-08 | 2020-08-07 | 麦克斯(郑州)医疗科技有限公司 | Transient magnetic field measurement system |
| RU2761319C1 (en) * | 2021-04-26 | 2021-12-07 | Федеральное государственное бюджетное научное учреждение "Федеральный исследовательский центр "Красноярский научный центр Сибирского отделения Российской академии наук" | Broadband highly sensitive variable magnetic field sensor |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19505812C2 (en) * | 1995-02-09 | 1997-02-06 | Siemens Ag | Current detection coil for a current transformer |
| DE19640981A1 (en) * | 1996-10-04 | 1998-04-16 | Asea Brown Boveri | Rogowski coil |
| CN1243247C (en) * | 2003-11-29 | 2006-02-22 | 华中科技大学 | Current sensor |
| FR2870040B1 (en) * | 2004-05-10 | 2006-06-09 | Areva T & D Sa | ROGOWSKI TYPE WINDING CURRENT TRANSFORMER HAVING PARTIAL CIRCUITS ASSOCIATED IN FORMING A COMPLETE CIRCUIT |
| FR2870350B1 (en) * | 2004-05-13 | 2006-07-14 | Schneider Electric Ind Sas | DEVICE FOR MEASURING AN ELECTRICAL CURRENT, CURRENT SENSOR, ELECTRICAL SENSOR AND CUTTING DEVICE COMPRISING SUCH A MEASURING DEVICE |
| GB0412129D0 (en) * | 2004-05-29 | 2004-06-30 | Lem Heme Ltd | Improvements in and relating to current measuring apparatus |
| CN100492025C (en) * | 2006-05-12 | 2009-05-27 | 中国科学院上海微系统与信息技术研究所 | Optical current sensor based on microelectronic mechanical system, making and detecting method thereof |
| CN200986573Y (en) * | 2006-12-21 | 2007-12-05 | 武汉天任光电互感器有限公司 | High anti-interference AC/magnetic field sensor |
-
2006
- 2006-12-21 CN CNB2006101255450A patent/CN100501415C/en not_active Expired - Fee Related
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| CN103245816A (en) * | 2012-02-02 | 2013-08-14 | 台达电子工业股份有限公司 | Integrated current sensing device |
| CN103245816B (en) * | 2012-02-02 | 2015-08-12 | 台达电子工业股份有限公司 | Integrated current sensor device |
| CN102878917B (en) * | 2012-09-17 | 2014-11-12 | 华中科技大学 | Signal operation device based on Rogowski coil measurement |
| CN102878917A (en) * | 2012-09-17 | 2013-01-16 | 华中科技大学 | Signal operation device based on Rogowski coil measurement |
| CN102998522A (en) * | 2012-12-17 | 2013-03-27 | 韦兆碧 | Current measurement device and method |
| CN103616549A (en) * | 2013-11-29 | 2014-03-05 | 国家电网公司 | Broadband low-current measurement device based on isolated PCB-type Rogowski coil |
| CN104345196A (en) * | 2014-10-30 | 2015-02-11 | 南京信息工程大学 | Active weak power frequency current induction coil |
| CN104406671A (en) * | 2014-11-27 | 2015-03-11 | 北京万集科技股份有限公司 | Dynamic weighing method based on leakage current model, and dynamic weighing system based on leakage current model |
| CN104406671B (en) * | 2014-11-27 | 2017-01-25 | 北京万集科技股份有限公司 | Dynamic weighing method based on leakage current model, and dynamic weighing system based on leakage current model |
| CN104796114B (en) * | 2015-05-15 | 2017-07-28 | 哈尔滨工业大学 | A kind of analogue integrator of low leakage errors |
| CN104796114A (en) * | 2015-05-15 | 2015-07-22 | 哈尔滨工业大学 | Low-leakage error analogue integrator |
| CN106291032A (en) * | 2016-08-04 | 2017-01-04 | 中国电子科技集团公司第四十研究所 | A kind of current detecting unit leakage current eliminates circuit and removing method |
| CN106291032B (en) * | 2016-08-04 | 2019-03-26 | 中国电子科技集团公司第四十一研究所 | A kind of current detecting unit leakage current eliminates circuit and removing method |
| CN110542830A (en) * | 2019-08-15 | 2019-12-06 | 杭州柯林电气股份有限公司 | Self-zero-adjusting integrating circuit, measuring circuit and method for measuring traveling wave of power transmission line |
| CN111381084A (en) * | 2020-01-16 | 2020-07-07 | 华中科技大学 | Stray parameter becomes more meticulous adjustable high frequency current sensor |
| CN111505539A (en) * | 2020-05-08 | 2020-08-07 | 麦克斯(郑州)医疗科技有限公司 | Transient magnetic field measurement system |
| RU2761319C1 (en) * | 2021-04-26 | 2021-12-07 | Федеральное государственное бюджетное научное учреждение "Федеральный исследовательский центр "Красноярский научный центр Сибирского отделения Российской академии наук" | Broadband highly sensitive variable magnetic field sensor |
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