CN202601407U - High-voltage electronic type voltage transformer - Google Patents

High-voltage electronic type voltage transformer Download PDF

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Publication number
CN202601407U
CN202601407U CN 201220219521 CN201220219521U CN202601407U CN 202601407 U CN202601407 U CN 202601407U CN 201220219521 CN201220219521 CN 201220219521 CN 201220219521 U CN201220219521 U CN 201220219521U CN 202601407 U CN202601407 U CN 202601407U
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CN
China
Prior art keywords
voltage
current
transformer
current transformer
winding
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn - After Issue
Application number
CN 201220219521
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Chinese (zh)
Inventor
关平
王红星
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SHENZHEN STM TECHNOLOGY Co Ltd
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SHENZHEN STM TECHNOLOGY Co Ltd
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Priority to CN 201220219521 priority Critical patent/CN202601407U/en
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Publication of CN202601407U publication Critical patent/CN202601407U/en
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Abstract

The utility model discloses a high-voltage electronic type voltage transformer. The voltage transformer consists of a high-voltage current-limiting resistor, a first current transformer and a zero magnetic flux current signal amplifying unit circuit, wherein a pin of the high-voltage current-limiting resistor is connected with one pole of a voltage signal to be measured; and the other end of the high-voltage current-limiting resistor is connected with a pin of a primary winding of the first current transformer; the other pin of the primary winding of the first current transformer is connected with the other pole of the voltage signal to be measured; and a secondary winding of the first current transformer is connected with an input end of the zero magnetic flux current signal amplifying unit circuit 4. The high-voltage electronic type voltage transformer provides a high-voltage detection product which has the characteristics of high precision, high reliability and safety, low power consumption, low heat dissipation, small size, low cost and wide application range, and of which a primary side and a secondary side are electrically isolated completely.

Description

A kind of high-tension electricity minor voltage transformer
Technical field
The utility model relates to a kind of voltage transformer, especially a kind of high-tension electricity minor voltage transformer.
Background technology
Build medium-term and long-term plans according to the national grid intelligent grid; All power equipments are all in the automation that realizes in various degree; 10kV, 35kV medium voltage distribution network automation development are especially rapid; Meanwhile expose a lot of problems, wherein widely applying voltage transformer (PT) device at distribution line is exactly one of problem, and the used PT of distribution has two kinds of functions usually concurrently at present: power taking and voltage detecting.Yet; In 10kV or 35kV isolated neutral system,, show as PT voltage and raise because the non-linear exciter inductance of voltage transformer and system's direct-to-ground capacitance produce ferro resonance when line voltage distribution has the fluctuation sudden change; The PT magnetic core is tending towards saturated; The primary winding electric current sharply increases, and causes at last that PT is overheated to be burnt even the accident of blasting, so use PT to have very big potential safety hazard.Shortcomings such as PT also exists volume big simultaneously, and installation needs the space, is not easy to be integrated in the intellectual monitoring equipment, and cost is high, and economy is bad.Need to seek a kind of product and substitute existing P T.
Some novel electronic formula voltage transformers (EVT) just occur to voltage detecting in recent years, generally all adopted the principle of electric resistance partial pressure, capacitance-resistance dividing potential drop or capacitance partial pressure.(patent No.: be exactly to adopt the electric resistance partial pressure principle 201110028244.7), two the key point bucking electrodes and the over-pressure safety device (generally using the voltage suppressor spare of similar discharge tube and so on) of this patent implementation method do not show by the patent of invention " current-voltage transformer " of Beijing Shuimuyuanhua Electric Applicance Co., Ltd application.Use the voltage transformer volume of voltage divider principle little, in light weight, simple in structure, transmission frequency bandwidth, good, the no resonance of the linearity, overcome saturated shortcoming unshakable in one's determination, non-loadedly share, allow the short circuit open circuit and have higher reliability, and the requirement that instrument transformer can satisfy measurement simultaneously and protect.But this kind instrument transformer has at least two to lack limit: martingale is altogether adopted in 1, once input, secondary output, does not carry out electrical isolation, has very big potential safety hazard; 2, output voltage signal is faint, receives external interference easily, need do a large amount of anti-interference process, uses in the only suitable digital transformer substation.
Summary of the invention
In order to overcome the problem that the above-mentioned existing high tension voltage detection technique of mentioning exists; The utility model discloses a kind of 10kV, 35kV line voltage distribution detection instrument transformer; So that a kind of mesohigh network voltage detection equipment of safe, reliable, high performance-price ratio to be provided, can be widely used in the mesohigh electrical network and to realize that voltage signal detects.The resonance that the utility model can solve traditional electromagnetic transformer (PT) simultaneously damages the use limitation of problem such as hidden danger, poor reliability and volume is big, cost height and electronic type voltage transformer, is applied to the voltage detecting of all mesohigh circuits with a kind of reliable mode of economy.
Middle and high power matching network circuit uses PT to realize voltage detecting in a large number and to terminal equipment power supply is provided; But there is potential safety hazard and uneconomical; To this solution of proposition being arranged is that handle assembly power taking and voltage signal sampling separate, and device adopts the CT power taking from the circuit power taking, and there is multiple thinking in specific embodiments; Because of power taking does not belong to the utility model content, do not do explanation at this.
The technical scheme that the utility model is taked is:
A kind of voltage signal checkout gear; Form by high-voltage and current-limitation resistance, first current transformer, zero flux current signal amplification unit circuit; Wherein high-voltage and current-limitation resistance pin is received a utmost point of surveying voltage signal; One pin of a winding of another termination first current transformer; Another utmost point of voltage signal is surveyed in another pin reception of a winding of first current transformer, and the secondary winding of first current transformer inserts the input of zero flux current signal amplification unit circuit, a wherein pin ground connection of the secondary winding of first current transformer.
Or; The utility model is by high-voltage and current-limitation resistance, first current transformer, second current transformer; Zero flux current signal amplification unit circuit is formed, and wherein high-voltage and current-limitation resistance pin is received a utmost point of surveying voltage signal, a pin of a winding of another termination first current transformer; Another utmost point of voltage signal is surveyed in another pin reception of a winding of first current transformer; The secondary winding of first current transformer links to each other with a winding of second current transformer, and with the wherein pin ground connection of the secondary winding of first current transformer, the secondary winding of second current transformer inserts the input of zero flux current signal amplification unit circuit.
The line voltage distribution that conventional P T detects voltage system all is added on the coil of primary side and directly detects voltage; This programme is to become electric current to voltage to be measured; Pass to secondary side to current signal through electromagnetic isolation, change into voltage signal to electric current again at secondary side and supply measuring system to use.The utility model becomes mA level through high-voltage and current-limitation resistance with voltage transitions to be measured; The electric current that voltage swing big or small and to be measured is directly proportional; This electric current flows through a winding of first current transformer; First current transformer be one once, the approaching current transformer of the secondary number of turn; Secondary side at first current transformer will produce and the sizable electric current of primary side current, and this electric current flows through a winding of second current transformer, and second current transformer is a current transformer that no-load voltage ratio is 1:1; The electric current of a mA level that is directly proportional with voltage swing to be measured also just appears in its secondary side, and this electric current supplies measuring system to use through the voltage signal that zero flux current signal amplification unit circuit zooms into required amplitude.A wherein pin and the transformer casing of the secondary winding of first current transformer of this instrument transformer must connect the earth in use.
A key of the utility model is to use zero flux current signal amplification technique, and this technology can accurately detect little current signal.
This instrument transformer can be designed to as a whole on physical structure, needs to give zero flux current signal amplification unit circuit to increase a working power like this, and instrument transformer is exactly active like this; Also can make high-voltage and current-limitation resistance and first current transformer as a wholely, second current transformer is formed to be put in the measuring system with zero flux current signal amplification unit circuit and is gone, and instrument transformer is exactly passive like this.Second current transformer all not necessarily in two kinds of structures; Shown in above second kind of technical scheme; When ground and the earth of working power when joining, can remove second current transformer, directly insert zero flux current signal amplification unit circuit to the secondary winding of first current transformer.
Another key of the utility model is the insulation processing of instrument transformer primary side and secondary side and how guarantees the electric clearance and the parasitic capacitance that reduces input two interpolars between on high-tension side two voltage signal input terminals.Mainly take two measures: one is that first current transformer adopts particular structural; The 2nd, voltage transformer is taked the integral layout of " one " font structure, and it is minimum to guarantee to have between two voltage sample incoming lines enough electric clearances and a parasitic capacitance of input two interpolars to drop to, and instrument transformer can also keep smaller volume simultaneously.
The utility model solves the problem that the above-mentioned existing high tension voltage detection technique of mentioning exists; A kind of precision height, primary side and the complete electrical isolation of secondary side, reliability and high tension voltage detection technique and product safe, low in energy consumption, that heating is little, volume is little, cost is low, applied widely are provided, have following beneficial effect:
Because the primary current of first current transformer of the novel high-pressure electronic type voltage transformer that the utility model proposed by the high-voltage and current-limitation resistance limits, size of current is basically by the resistance decision, and electric current is the mA level; Very little; Therefore can as PT, not exist overcurrent, overheated maybe, so do not have the risk of as PT, burning or exploding, reliability of operation and safe; Can reduce electric power accident and take place, for the power supply network provides safety guarantee.
2. realize electrical isolation fully between the electronic measurement system of the primary side of high pressure and back voltage, and the secondary winding one end ground connection of first current transformer, therefore safe, and applied widely.
3. adopt the magnetic core and the rational technique for coiling of zero flux current Sampling techniques and high magnetic permeability, certainty of measurement is high, in the full operating ambient temperature range of regulation, can guarantee to satisfy 0.5 grade requirement.
4. low in energy consumption, the heating little; Volume is little, cost is low, economizes on resources significantly: be example only with 10 ~ 35kV distribution automation outdoor switch, and annual 500000 meters of switch of producing; Every switch is joined two PT at least; Every amounts to 20KG at least with silicon steel material and copper cash, epoxide resin material 10KG, and every year, only outdoor switch amounted to consumption 50*103*2*20=2000 ton (copper material and iron material) and 50*103*2*10/1000=1000 ton (epoxy resin).And the novel high-pressure electronic type voltage transformer that this patent provides since first current transformer once, the electric current of secondary coil all is the mA level, and is very little, therefore can use thin enamelled wire coiling once, secondary coil, and low in energy consumption, heating is little; On high-tension side voltage basically all falls on current-limiting resistance, and the primary winding voltage of first current transformer is zero basically, and turn-to-turn insulation is easy to handle.Adopt zero flux current Sampling techniques in addition; Once, secondary coil can adopt the low number of turn, adopt little magnetic core; Novel voltage mutual inductor material usage copper < 0.1KG, magnetic core < 1KG, an epoxy resin < 5KG; < < < 5KG has reduced small product size, has reduced manufacturing cost a power taking CT consumption copper greatly, significantly reduces the raw material that consumed for 2KG, epoxy resin for 1.5KG, magnetic core.
5. " one " font topology layout of adopting can guarantee that volume is little, can reduce the parasitic capacitance between the input electrode again and increase the creepage distance between input electrode, and small product size is little.
6. because volume is little, power consumption is little, do not exist the dangerous of blast therefore can be integrated in the intellectual monitoring equipment, be beneficial to the installation of equipment.
Description of drawings
Below in conjunction with accompanying drawing and embodiment the utility model is described further:
Fig. 1 is the circuit diagram of the utility model;
Fig. 2 is the cutaway view of first current transformer in the utility model;
Fig. 3 is the structural representation of first current transformer in the utility model;
Fig. 4 is the coiling sketch map of first current transformer among the embodiment of the utility model;
Fig. 5 is the coiling sketch map of first current transformer among another embodiment of the utility model.
Embodiment
For technical problem, technical scheme and advantage that the utility model will be solved is clearer, specify the embodiment of the utility model below in conjunction with Fig. 1, Fig. 2, Fig. 3, Fig. 4 and Fig. 5.
Shown in the circuit theory sketch map among Fig. 1, the voltage transformer that the utility model proposed is made up of with zero four parts such as flux current signal amplification unit circuit 4 grades high-voltage and current-limitation resistance 1, the first current transformer 2, the second current transformers 3.A utmost point (like the A phase bus among Fig. 1) of voltage signal is surveyed in a pin reception of high-voltage and current-limitation resistance 1; One pin of a winding 21 of another termination first current transformer 2; Another utmost point (like the B phase bus among Fig. 1) of voltage signal is surveyed in another pin reception of a winding 21 of first current transformer 2; The secondary winding 22 of first current transformer 2 links to each other with a winding of second current transformer 3; And with the wherein pin ground connection of the secondary winding 22 of first current transformer 2, the secondary winding of second current transformer 3 inserts the input of zero flux current signal amplification unit circuit 4.
The line voltage distribution that conventional P T detects voltage system all is added on the coil of primary side and directly detects voltage; This programme is to become electric current to voltage to be measured; Pass to secondary side to current signal through electromagnetic isolation, change into voltage signal to electric current again at secondary side and supply measuring system to use.Like Fig. 1, through high-voltage and current-limitation resistance 1 voltage transitions to be measured is become the electric current I p=Vg/Rx of a mA level, wherein, Ip is the electric current of a winding of first current transformer 2, and Vg is a high-voltage signal to be measured, and Rx is a high-voltage and current-limitation resistance.This electric current flows through a winding of first current transformer 2; First current transformer 2 be one once, the approaching current transformer of the secondary number of turn; Secondary side at it will produce and the sizable electric current of primary side current; This electric current flows through a winding of second current transformer 3; Second current transformer 3 is the current transformers that no-load voltage ratio is 1:1, and the electric current of a mA level that is directly proportional with voltage swing to be measured also just appears in its secondary side, and this electric current supplies measuring system to use through the voltage signal that zero flux current signal amplification unit circuit 4 zooms into required amplitude.A wherein pin and the transformer casing of the secondary winding 22 of first current transformer 2 of this instrument transformer must connect the earth in use.
Said instrument transformer can be designed to following two kinds on physical structure: structure one; Combine high-voltage and current-limitation resistance 1 and first current transformer 2 and make the instrument transformer body; Second current transformer 3; Zero flux current signal amplification unit circuit 4 is put in the measuring system and goes, and instrument transformer is exactly passive like this; Structure two is high-voltage and current-limitation resistance 1, the first current transformer 2; Second current transformer 3; Zero flux current signal amplification unit circuit 4 is designed to as a whole, needs to give zero flux current signal amplification unit circuit 4 to increase a working power like this, and instrument transformer is exactly active like this.In two kinds of structures; Second current transformer 3 all not necessarily; When the ground of the working power of zero flux current signal amplification unit circuit 4 and the earth join; Can remove second current transformer 3, directly insert zero flux current signal amplification unit circuit 4 to the secondary winding 22 of first current transformer 2.
The utility model has two key processing techniques, and first key is the insulation processing of primary side and secondary side, mainly takes two measures:
One is that first current transformer 2 adopts special technique for coiling.Specific practice is: as shown in Figure 4, transformer core 23 is selected the toroidal core of magnetic material of permalloy or other high magnetic permeability of high magnetic permeability for use, and instrument transformer first and second winding 21,22 is respectively in the upper and lower semi-ring position layering coiling of toroidal core 23.As shown in Figure 3; Earlier at second of toroidal core 23 around system secondary winding 22; Secondary winding 22 is at the cabling in the raised floor of the ring of toroidal core 23, packs the magnetic core 23 after the good secondary winding 22 of coiling in the toroidal shell 24 that insulating material makes into again, to this housing injection ring epoxy resins 25 magnetic core 23 of the good secondary winding 22 of coiling is sealed in the epoxy resin 25; Form a class F insulation and isolate, again the magnetic core after epoxy resin 25 sealings 23 first around winding 21 of system.The number of turn of winding 21 and secondary winding 22 is suitable.The instrument transformer equipment that first current transformer 2 that coiling is good and other part combination sealing form the utility model.First current transformer 2 after handling like this has enough insulation and takies volume little.
First current transformer 2 can also adopt magnetic core 23 coilings of the CD shape of sealing, and is as shown in Figure 5, at the upper and lower side column elder generation coiling insulating barrier 26 of CD magnetic core, and then once, secondary winding 21,22 is respectively on the upper and lower side column of CD shape magnetic core 23.
The 2nd, primary side takes the topology layout of " one " font to control to minimum with parasitic capacitance between the electric clearance that increases the voltage sample incoming line and electrode.Specific practice is: like Fig. 2, shown in 3; One utmost point of voltage signal to be measured is introduced from said instrument transformer left end binding post 11; Get into instrument transformer internal high pressure current-limiting resistance 1 left pin end, high-voltage and current-limitation resistance 1 horizontal direction of pen type arranges that the right leads ends of high-voltage and current-limitation resistance connects leading foot of first siding ring (winding 21) of current transformer 2; The direct-connected instrument transformer right-hand member of another leading foot of coil binding post 12, another utmost point of voltage signal is surveyed in 12 reception of right-hand member binding post.Left and right sides binding post 11,12, high-tension resistive 1, first siding ring 21 are the middle and upper part that in-line is distributed in instrument transformer, in the confined space of instrument transformer, make and form maximum insulation distance between high voltage bus.
Another key of the utility model is zero flux current signal amplification technique.Specific practice is: like Fig. 1, the secondary winding of second current transformer 3 inserts the input of zero flux current signal amplification unit circuit 4, and R1 is a Voltage Feedback resistance, and R2, C are phase compensating network, and D1, D2 are the voltage clamp diode.The output voltage V o=I*R1 of zero flux current signal amplification unit circuit 4 changes output voltage V o through regulating feedback resistance R1.According to the empty short notion of the positive and negative input of amplifier; The output voltage of second current transformer 3 of this mode is 0V, is operated in zero load condition, makes detection signal undistorted; Have high inspection precision, can accurately detect the little current signal that primary winding flows through; Compensating network reaches required compensation precision through adjustment resistance R 2, and for the occasion that does not need compensating phase shift, capacitor C and compensating resistance R2 can not connect; D1, D2 make the positive and negative phase terminal voltage of amplifier clamped in the forward voltage drop of D1, D2, the protective current translation circuit.
The above be the utility model preferred embodiment, it does not constitute the restriction to the utility model protection range, so long as realize that with essentially identical means the purpose of the utility model all should belong to the protection range of the utility model.

Claims (8)

1. high-tension electricity minor voltage transformer; It is characterized in that: comprise high-voltage and current-limitation resistance (1), first current transformer (2) and zero flux current signal amplification unit circuit (4); Wherein a utmost point of voltage signal is surveyed in a pin reception of high-voltage and current-limitation resistance (1); One pin of a winding (21) of another termination first current transformer (2); Another utmost point of voltage signal is surveyed in another pin reception of a winding (21) of first current transformer (2); The secondary winding (22) of first current transformer (2) inserts the input of zero flux current signal amplification unit circuit (4), a wherein pin ground connection of the secondary winding (22) of first current transformer (2).
2. high-tension electricity minor voltage transformer according to claim 1; It is characterized in that: also comprise second current transformer (3); A winding of second current transformer (3) links to each other with the secondary winding (22) of first current transformer (2), and the secondary winding of second current transformer (3) inserts the input of zero flux current signal amplification unit circuit (4).
3. high-tension electricity minor voltage transformer according to claim 1 and 2; It is characterized in that: the transformer core of first current transformer (2) adopts the toroidal core (23) of the magnetic material of high magnetic permeability, and one of which, secondary winding (21,22) are separately positioned on the upper and lower semi-ring position of toroidal core (23).
4. high-tension electricity minor voltage transformer according to claim 1 and 2; It is characterized in that: first current transformer (2) adopts the CD shape magnetic core (23) of sealing; It once, secondary winding (21,22) is separately positioned on the upper and lower side column of magnetic core (23), and it once, also be provided with insulating barrier (26) between secondary winding (21,22) and the magnetic core (23).
5. high-tension electricity minor voltage transformer according to claim 1 and 2; It is characterized in that: high-voltage and current-limitation resistance (1) is the one encapsulating structure with first current transformer (2), and wherein the left and right binding post (11,12) of high-voltage and current-limitation resistance (1), first current transformer (2) and a winding (21) are the in-line distribution.
6. high-tension electricity minor voltage transformer according to claim 2 is characterized in that: second current transformer (3) is operated in zero load condition, and its output voltage is zero.
7. high-tension electricity minor voltage transformer according to claim 2; It is characterized in that: zero flux current signal amplification unit circuit (4) comprises amplifier; Be connected to Voltage Feedback resistance between the input of said amplifier and the output, be connected to the voltage clamp diode between the positive and negative input of amplifier.
8. high-tension electricity minor voltage transformer according to claim 7 is characterized in that: zero flux current signal amplification unit circuit (4) comprises the phase compensating network that is made up of resistance and electric capacity.
CN 201220219521 2012-05-16 2012-05-16 High-voltage electronic type voltage transformer Withdrawn - After Issue CN202601407U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 201220219521 CN202601407U (en) 2012-05-16 2012-05-16 High-voltage electronic type voltage transformer

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Application Number Priority Date Filing Date Title
CN 201220219521 CN202601407U (en) 2012-05-16 2012-05-16 High-voltage electronic type voltage transformer

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CN 201220219521 Withdrawn - After Issue CN202601407U (en) 2012-05-16 2012-05-16 High-voltage electronic type voltage transformer

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102682985A (en) * 2012-05-16 2012-09-19 深圳市深泰明科技有限公司 High-voltage electronic type voltage transformer
CN106908656A (en) * 2015-12-23 2017-06-30 施耐德电气美国股份有限公司 Current transformer with enhanced temperature measurement function

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102682985A (en) * 2012-05-16 2012-09-19 深圳市深泰明科技有限公司 High-voltage electronic type voltage transformer
CN102682985B (en) * 2012-05-16 2015-04-22 深圳市深泰明科技有限公司 High-voltage electronic type voltage transformer
CN106908656A (en) * 2015-12-23 2017-06-30 施耐德电气美国股份有限公司 Current transformer with enhanced temperature measurement function
CN106908656B (en) * 2015-12-23 2021-05-28 施耐德电气美国股份有限公司 Current transformer with enhanced temperature measurement

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GR01 Patent grant
AV01 Patent right actively abandoned

Granted publication date: 20121212

Effective date of abandoning: 20150422