CN201514831U

CN201514831U - Rogowski coil

Info

Publication number: CN201514831U
Application number: CN2009200973316U
Authority: CN
Inventors: 刘翠青; 刘佳峰; 方兵; 文涛; 华琴; 范林涛; 崔新友; 刘�文
Original assignee: WUHAN FIBERHOME ELECTRIC CO Ltd
Current assignee: WUHAN FIBERHOME ELECTRIC CO Ltd
Priority date: 2009-06-26
Filing date: 2009-06-26
Publication date: 2010-06-23
Anticipated expiration: 2019-06-26

Abstract

The utility model belongs to the technical field of current measurement, and relates to a Rogowski coil, comprising a frame and a secondary winding, wherein the frame is made of non-magnetic material containing magnetism in two ten thousandths; the secondary winding is directly adhered on the frame and consists of screw coils which are formed by a metal layer covering the surface of the frame and with processed needless parts; and the two ends of the screw coils lead out the terminals of inductive potential. The Rogowski coil is a coil with low expansion coefficient and high precision, can obviously improve the saturation characteristic and linearity when being used for a current transformer, and greatly enhance the measuring accuracy and anti-electromagnetic interference capability.

Description

A kind of Rogowski coil

Technical field

The utility model relates to a kind of coil of measuring the transducer of magnetic field or electric current, relates in particular to a kind of current sensor that is applied to the electric power system current measurement, belongs to power domain.

Background technology

At present, the electric power mutual-inductor that uses in electric power system mainly is an electromagnetic current transducer.In order to satisfy power system development and Automation of Electric Systems, digitized needs, also developed the current transformer that utilizes other principle of induction both at home and abroad.According to the difference of selecting sensing head for use, importantly be divided into two kinds: based on the pure optical current mutual inductor of Faraday magnetooptical effect principle with based on the electronic current mutual inductor of Rogowski (hollow) coil.

Electromagnetic current transducer is made of unshakable in one's determination and first and second winding, and its major defect has: 1, insulation technology requires complicated, inflammable and explosive.2, dynamic range is little, and frequency band is narrow, and error is big.3, with high costs.For the electromagnetic current transducer of superhigh pressure, because the consumption of its insulation mode and material, cause that it is bulky, production cost significantly increases, brought difficulty also for transportation and installation.4, increased strict to secondary side.Mainly containing 1. the secondary side load can not open a way, otherwise can cause high voltage, and equipment or personnel are damaged; 2. to the burden requirement strictness, if the secondary side load is excessive, numerical value and phase error will increase.5, increased intermediate conversion links.The electric current of secondary output is generally the current signal of 1A or 5A, needs to change into little current signal through power pack, is input to microcomputer measurement or protective device again.6, electromagnetic current transducer is subject to shortcomings such as electromagnetic interference, maintenance workload are big, oil leaking pollution environment in addition.These shortcomings of electromagnetic current transducer have seriously restricted Power System Intelligentization, device miniaturization, functional diversities, requirement that the protection reliability is high.

Current transformer based on the Faraday magnetooptical effect principle belongs to pure optical current mutual inductor.Because it is subjected to the influence of factors such as temperature, mechanical oscillation bigger, though domestic had a product linked network trial run, stability, reliability are not high, and cost an arm and a leg, there are many key issues not to be resolved, therefore fail to form product and use in electric power system.

Based on the electronic current mutual inductor of Rogowski (hollow) coil have that volume is little, in light weight, cost is low, no iron core, responding range is big, frequency response is wide advantage, do not have magnetic saturation and ferromagnetic oscillation problem; Also avoided the temperature and the vibration problem that exist in the pure optical sensing head.But, the hollow coil current sensing head of being developed at present that is used for electronic current mutual inductor, all be directly by center with straight conductor with the non magnetic annular skeleton of the secondary coil of lead coiling, or secondary winding is produced on the printed circuit board (PCB) (PCB) of intermediate hollow, straight conductor is by the center of PCB.

Based on Wound-rotor type Rogowski coil, mainly contain following shortcoming: the expansion of whole winding is the summation of the expansion of the expansion of skeleton and lead, wherein the expansion of lead accounts for 80% of whole expansion, particularly is heated when serious when coil, and lead has the constraint that breaks away from skeleton and the trend that protrudes; Be limited to the restriction of coiling machinery and technology, and the deviation brought of coil rack, coiling can not be accomplished real evenly tight.Patent based on wire winding mainly contains 200610019929.4,200620098280.5, US7227441B2.

Based on printed circuit board (PCB) (PCB) formula Rogowsk coil, mainly contain following shortcoming: the existence of each via hole all can bring certain distributed inductance and distributed capacitance, can bring unpredictable influence to final certainty of measurement; The structure of plane has brought no small difficulty for the shielding of coil, if the mode that adopts integral body to apply copper shields and can bring very big eddy current.Patent based on printed circuit board (PCB) (PCB) technology mainly contains 200710053143.9,2007100553143.9, US5414400, US5442280, US5461309, US6313623B1, US007227442B2, US7227442B2.

The utility model content

The purpose of this utility model is to overcome above-mentioned the deficiencies in the prior art, a kind of hollow Rogowski coil of low-expansion coefficient high-precision spiral cast that is applicable to current transformer is provided, this utilizes this kind air core coil as current transformer, and traditional relatively electromagnetic transformer can obviously improve transient characterisitics, the linearity and the anti-electromagnetic interference capability of current transformer; Existing relatively hollow coil current transformer, its linearity is better, anti-electromagnetic interference capability is stronger.

The utility model adopts following technical scheme:

A kind of Rogowski coil, this coil comprises skeleton and secondary winding, it is characterized in that: described skeleton is made with interior nonmagnetic substance by containing magnetic 2/10000ths, described secondary winding directly is attached on the skeleton, fall the helical coil that forms after the unwanted part and constitute by the metal level that covers the skeleton surface is treated, draw the terminal of induced potential at the two ends of described helical coil.

As preferred implementation, Rogowski coil of the present utility model, helical coil uniformity; Described skeleton is annular, oval ring or rectangular loop; Offer hollow channel on described skeleton, described hollow channel is an annular, and its shape is similar to the outer shroud or the interior ring of skeleton, two terminals of the loop line formation coil of drawing through hollow channel from an end of described helical coil one; The direction of described loop line is opposite with the direction of the big wire turn that coil windings forms; Described nonmagnetic substance is pottery or glass fibre; Described metal level is gold, silver or copper.

The utility model rolls into one the advantage of above-mentioned two kinds of methods, has overcome shortcoming separately simultaneously again.At first, also be the most important is the same with printed circuit board (PCB) (PCB) technology, take certain technology directly to be attached on the hypothallus secondary winding, thus the error that expands and bring because of lead that has overcome that wire winding brings; Simultaneously, strict controlled cutting, corrosion or turbid quarter are adopted in the generation of secondary winding, thereby guarantee the uniformity of winding; At last, it is smoothly smooth and easy that the coil that adopts this mode to make has kept traditional Rogowsk winding wire cabling, is easy to realize the advantage that shields.Technique effect is as follows:

1, this air core coil does not have ferromagnetic material, can not have the very high linearity, fast response characteristic because of tested electric current is big and saturated, and bandwidth;

2, the bulk expansion of Rogowski (hollow) coil depends primarily on two factors, be the expansion (accounting for 80%) of the lead of coiling and the expansion of skeleton, in the utility model, lead directly is attached on the non magnetic skeleton of rigidity, and the expansion of coil integral body just equals the expansion of skeleton basically;

3, a hollow channel can be set in this air core coil skeleton, this passage can serve as the backward channel of whole winding loop line, the expansion joint the when existence of this passage can also be served as skeleton and expanded, thus effectively reduce the bulk expansion of skeleton;

4, utilize hollow channel to serve as the backward channel of loop line, can guarantee fully that loop line occupy the solenoid center, it is best that the compensation effect of loop line can reach;

5, thus adopt modes such as cutting, corrosion or turbid quarter to dispose the helical form secondary winding that unwanted metal level forms uniformity, the interference that the secondary winding of height uniformity can be offset stray magnetic field effectively.

In a word, the related Rogowski coil of the utility model is a kind of low-expansion coefficient, high-precision coil, when being used for current transformer, the saturation characteristic and the linearity of current transformer be can obviously improve, certainty of measurement and anti-electromagnetic interference capability improved greatly.

Description of drawings

Fig. 1 is the typical structure outline drawing of the Rogowski coil of a kind of application sensors of the utility model.

Fig. 2 is the enlarged drawing of the coil that cuts out, and the figure empty is the vestige for cutting out partly, and black part is divided into and remains the conductive metal layer that serves as winding wire.

Fig. 3 is the hollow channel position view of skeleton structure.

Fig. 4 is the typical outlet schematic diagram of being connected of coil two ends outlet terminal and loop line and whole winding.

Wherein, 1 is coil windings, and 2 is the loop line in the hollow channel, and 3 is the skeleton hollow channel, and 4 is coil first outlet terminal, and 5 is coil second outlet terminal.

Embodiment

Below in conjunction with the drawings and specific embodiments the utility model is further described.

Referring to Fig. 1, the Rogowski coil of a kind of application sensors that the utility model patent relates to comprises skeleton and secondary winding, and skeleton is made by non magnetic low-expansion materials such as pottery or glass fibres.Fig. 2 is the enlarged drawing of the coil that cuts out, and the figure empty is the vestige for cutting out partly, and black part is divided into and remains the conductive metal layer that serves as winding wire.Secondary winding is made of at the spiral helicine coil that high conductivity metal levels such as one deck silver on skeleton surface or copper form after cutting, corrosion or turbid quarter falling unwanted part technologies such as plating, spraying, plasma spraying, sputter or evaporations, naturally form the leading-out terminal of winding at the two ends of helical coil, wherein an end finally forms second outlet terminal that first outlet terminal of coil, an other end directly serve as coil through loop line.

As shown in Figure 2, the skeleton structure inside of Rogowski coil can be provided with a hollow channel along the coil direction, hollow channel is preferably disposed on the skeleton centre position, this hollow channel can serve as the backward channel of whole winding loop line, when guaranteeing that fully loop line occupy the solenoid center, it is best that the loop line compensation effect can reach.Expansion joint when the existence of this passage can also be served as skeleton and expanded, thus the bulk expansion of skeleton effectively reduced.

As shown in Figure 3, coil windings 1 is cut off naturally by skeleton hollow channel 3, and the terminals of winding are served as at the two ends of the winding that will form thus.The backward channel of whole winding loop line 2 is positioned at hollow channel, and the direction of loop line is opposite with the direction of the big wire turn that the coil winding forms, and can offset the influence of big wire turn.End in the loop line in the hollow channel welds mutually with coil windings, and the other end of loop line welds mutually with first outlet terminal 4 of coil.

Adopt the mode of electroplating cutting more earlier to make secondary winding, make production technology simple, product reliability improves greatly, and the coiling performance increases, and consistency is more secure, and controllability is stronger.Its manufacturing process is specific as follows:

1, the design of skeleton and making: at first according to concrete applied environment, mainly be the profile of a current carrying conductor and profile and the basic size that physical size is determined the Rogowski coil rack, comprise external diameter, internal diameter and the height of skeleton; The cross section of skeleton can be circle or rectangle.Framework material can be selected non magnetic low-expansion coefficient class material, for example: contain magnetic 2/10000ths with interior pottery or glass fibre etc.Its surface of framework material need to guarantee enough fineness, hollow channel if desired, and its position preferred design is at the positive center of skeleton, and its profile and layout can be referring to Fig. 2, Fig. 3.

2, the sticking of conductive matrices: on bright and clean skeleton surface, adopt and electroplate or the whole metal level that covers high conductivities such as one deck silver or copper of spraying coating process.In order to improve the consistency of whole winding, hypothallus requires uniformity, and the hypothallus of different batches requires to keep identical thickness as far as possible.

3, the design of secondary winding: secondary winding is made of spiral helicine coil, and its two outlet terminals lay respectively at the exit of hollow channel at skeleton, and referring to Fig. 4, the whole winding winding requires to accomplish even distribution on skeleton.Simultaneously in order to guarantee the consistency of coil, the strict unanimity of coil turn.

4, the making of secondary winding: can adopt modes such as cutting, corrosion or turbid quarter to dispose unwanted metal level in the concrete operations, thereby form complete spiral helicine coil and outlet terminal.In order to reduce the resistance of winding as far as possible, it is narrow that the metal level of disposing will be tried one's best, and that is to say guaranteeing under the situation of cutting effect, allows wide that winding tries one's best.

5, the making of loop line be connected: specifically referring to Fig. 4

A) one of them terminals of end in the loop line in the hollow channel and winding weld, shown in blue line among the figure; An other end of loop line serves as first outlet terminal 4 of coil.

B) coil windings is cut off naturally by the skeleton hollow channel, and the another one terminals of winding serve as second outlet terminal 5 of coil.

C) direction of loop line will guarantee that the direction of the big wire turn that forms with coil windings is opposite, to offset the influence of big wire turn.

Claims

1. Rogowski coil, this coil comprises skeleton and secondary winding, it is characterized in that: described skeleton is made with interior nonmagnetic substance by containing magnetic 2/10000ths, described secondary winding directly is attached on the skeleton, fall the helical coil that forms after the unwanted part and constitute by the metal level that covers the skeleton surface is treated, draw the terminal of induced potential at the two ends of described helical coil.

2. Rogowski coil according to claim 1 is characterized in that, described helical coil uniformity.

3. Rogowski coil according to claim 1 is characterized in that, described skeleton is annular, oval ring or rectangular loop.

4. Rogowski coil according to claim 3, it is characterized in that, on described skeleton, offer hollow channel, described hollow channel is an annular, its shape is similar to the outer shroud or the interior ring of skeleton, and the loop line of drawing through hollow channel from an end of described helical coil forms two terminals of coil.

5. Rogowski coil according to claim 4 is characterized in that, the direction of described loop line is opposite with the direction of the big wire turn that coil windings forms.

6. according to any described Rogowski coil of claim 1 to 5, it is characterized in that described nonmagnetic substance is pottery or glass fibre.

7. according to any described Rogowski coil of claim 1 to 5, it is characterized in that described metal level is gold, silver or copper.