CN203218098U - Electronic current-voltage combined transformer for GIS (Geographic Information System) - Google Patents

Abstract

The utility model relates to an electronic current-voltage combined transformer for a GIS (Geographic Information System). The electronic current-voltage combined transformer comprises an external pressure container housing, and a suspended electric potential cylinder arranged to penetrate through a primary conductor, wherein a Rogowski coil current transformer and a coaxial capacitive voltage divider are mounted on the suspended electric potential cylinder; the coaxial capacitive voltage divider comprises a high voltage capacitor and low voltage capacitors; the coaxial capacitive voltage divider is provided with at least two low voltage capacitors; and each low voltage capacitor forms a branch of output. A plurality of low voltage capacitors, like two, can be provided for the electronic current-voltage combined transformer, so that the functions of dual voltage transformer sensing heads, dual output and dual protection can be realized; and the electronic current-voltage combined transformer has the advantages of small size, high interference resistance, high precision, high reliability, low cost and the like.

Description

GIS electronic type current/voltage combination transformer

Technical field

The utility model relates to a kind of GIS electronic type current/voltage combination transformer.

Background technology

Electronic type voltage transformer adopts the capacitance partial pressure structure more at present, as CN202384167U, and the disclosed structure of patent documentations such as CN202384166U.Use the coaxial configuration of primary shielding cover and suspension cylindrical shell as high-voltage capacitance; with the coaxial metal layer structure of dielectric as low-voltage capacitance; the low-voltage capacitance side and go up resistance introduce collector, after integration, amplification, double A/D conversion, be converted into light signal by photoelectric conversion device and insert merge cells through optical fiber and handle the back synchronously to measurement protection equipment.

Along with electric power system to big capacity, superhigh pressure and ultra high voltage direction develop, to the power equipment miniaturization, intellectuality, the requirement of high reliability is also more and more higher.The above power station of the 110KV level measuring system that intelligent grid is proposed at national grid adopts two principles of protecting, and voltage transformer need adopt the double-sensing head.

The utility model content

The purpose of this utility model provides a GIS that the double-sensing head can be provided with electronic type current/voltage combination transformer, has only the univoltage sensor head in the prior art in order to solve, and does not have the problem of two voltage sensor head electronic mutual inductors.

For achieving the above object, scheme of the present utility model is:

A kind of GIS electronic type current/voltage combination transformer, comprise outside vessel shell, be used for being located in floating potential tube (7) on the Primary Conductor, be equiped with Luo-coil current transformer and coaxial capacitance voltage divider on the floating potential tube, the coaxial capacitance voltage divider comprises high-voltage capacitance and low-voltage capacitance, described coaxial capacitance voltage divider is provided with at least two low-voltage capacitances, and each low-voltage capacitance forms the output of No. one voltage transformer.

Described low-voltage capacitance is by the floating potential tube outside intermediate capacitance of coaxial laying screen and low-voltage capacitance screen successively from inside to outside, and the dielectric formation between intermediate capacitance screen and the low-voltage capacitance screen; The intermediate capacitance screen comprises at least two along same circle distribution, watt shape, mutual nonconducting second metal level (62), and the low-voltage capacitance screen is the 3rd metal level (63) of tubular.

Be provided with dielectric between described floating potential tube and second metal level, the floating potential tube is the high-voltage capacitance screen.

The first metal layer (61) also closely has been sticked outside the floating potential tube.

Described each second metal-layer structure, size are all identical.

Each second metal level and the 3rd metal level all form a sensing head interface, connect collecting unit by holding wire.

The utility model is the intermediate capacitance screen of a plurality of electrical isolation parts by increasing separable, is used to form a plurality of low-voltage capacitances.Like this, the utility model low-voltage capacitance is with regard to more than one, can increase to a plurality ofly, as two, can realize two voltage transformer sensing heads, dual output, and the function of two protections possesses miniaturization, and is high anti-interference, high accuracy, advantages such as high reliability, low cost.

Description of drawings

Fig. 1 (a) is GIS electronic type current/voltage combination transformer, and Fig. 1 (b) is partial view;

Fig. 2 is the coaxial configuration schematic diagram;

Fig. 3 is capacitance-resistance dividing potential drop electrical schematic diagram.

Embodiment

The utility model is described in more detail below in conjunction with accompanying drawing.

As shown in Figure 1, for single-phase GIS electronic type current/voltage combination transformer, its structure is based on traditional SF6 gas-insulated GIS current/voltage combination transformer structure, the outside is vessel shell 4, Luo-coil 10 is fixed in the solenoid housing 9, and Luo-coil housing 9 is fixed in the vessel shell 4.Primary Conductor 3 and punching Luo-coil are formed current sensing head, and the signal that current sensing head is collected causes collecting unit.Primary Conductor 3 is passed floating potential cylindrical shell 7, needs insulation processing between floating potential cylindrical shell 7 and the vessel shell 4.The corresponding coaxial ganged condenser that is located on the Primary Conductor, its high-voltage capacitance are by Primary Conductor, floating potential tube 7, and the insulating gas between them constitutes., the floating potential tube is the high-voltage capacitance screen.The high-voltage capacitance screen outside is coaxial successively from inside to outside to arrange the intermediate capacitance screen and low-voltage capacitance shields.Low-voltage capacitance is by intermediate capacitance screen and low-voltage capacitance screen, and the dielectric between intermediate capacitance screen and the low-voltage capacitance screen constitutes; The intermediate capacitance screen comprises at least two along same circle distribution, watt shape, mutual nonconducting second metal level, and the low-voltage capacitance screen is the 3rd metal level of tubular.Be provided with dielectric between floating potential tube and second metal level.High-voltage capacitance screen and intermediate capacitance screen form intermediate capacitance with the dielectric between them.Each second metal level and the 3rd metal level all form a sensing head interface, and build-out resistor in parallel constitutes the capacitance-resistance bleeder circuit, and whole formation multihead can be distinguished the sampled voltage signal circuit.Connect collecting unit 1 by holding wire.Collecting unit is installed on the vessel shell 4, and the output digital optical signal is exported through optical fiber.The electronics collecting unit requires to be installed in the housing of good electromagnetic shielding, has improved the operational environment of electronic loop, reduces electromagnetic interference, and power supply is the collecting unit power supply on the spot, overcomes the problem that active instrument transformer exists, and power supply is stable.At the big resistance of low-voltage capacitance output two ends parallel connection, form high voltage and suppress circuit, at voltage acquisition device input small resistor in parallel, guarantee voltage signal progress of disease precision.

Second metal level, the 3rd metal level can adopt metal forming, and the dielectric between second metal level and the 3rd metal level, between floating potential tube and second metal level can adopt engineering plastics.As a kind of execution mode, intermediate capacitance screen and low-voltage capacitance screen can adopt whole three-layer metal paper tinsel 6 to constitute, infilling work plastics between the three-layer metal paper tinsel, ground floor metal forming 61 closely is sticked in the floating potential tube outside, with floating potential tube conduction short circuit, ground floor metal forming and floating potential tube form the high-voltage capacitance screen, second metal forming 62 is the intermediate capacitance screen, the 3rd metal forming 63 is the low-voltage capacitance screen, Primary Conductor and high-voltage capacitance screen and the insulating gas between them form high-voltage capacitance, high-voltage capacitance screen and intermediate capacitance screen and the dielectric between them form intermediate capacitance, and intermediate capacitance screen and low-voltage capacitance screen and the dielectric between them form low-voltage capacitance.In the present embodiment, second metal level is watt shape of two symmetries.Two second metal-layer structures, size are all identical, and high-voltage capacitance screen and intermediate capacitance screen constitute two low-voltage capacitances like this.Overall structure has just constituted a high-voltage capacitance, two intermediate capacitance, two low-voltage capacitances like this, from two intermediate capacitance numbers of winning the confidence respectively, press down the value bleeder resistance at two low-voltage capacitance sides difference parallel high voltages, just constituted double-sensing head sampled voltage signal respectively.Circuit such as Fig. 2, shown in Figure 3.Constitute coaxial capacitance C1 with SF6 gas between Primary Conductor and the floating potential tube 7,

$c_1=\frac{{2\mathrm{\π\ϵ}}_o{\mathrm{\ϵ}}_{r}l}{\ln \frac{b}{a}}---\left(1\right)$

In the formula: ε ₀The dielectric constant of relative vacuum; ε _RDielectric constant; L capacitance plate length; A suspends and manages radius; B high-tension shielding radius.High-voltage capacitance screen (ground floor metal forming and suspension positioning pipe) and second layer metal shield between how much symmetrical mutual two clad with metal foil and constitute centre fan-shaped (cross section is fan-shaped) coaxial capacitance C2, C2 ' respectively with engineering plastics.The second layer becomes how much symmetries, and two clad with metal foil of electrically conductings and the 3rd layer do not cover between the paper tinsel of metal and constitute the fan-shaped coaxial capacitance C3 of low pressure, C3 ' respectively with engineering plastics, the 3rd layer of clad with metal foil earthing potential mutually.Because intermediate capacitance screen and low-voltage capacitance screen are fan-shaped coaxial capacitances, thus C2, C2 ', C3, C3 ' capacitance can ask, again because how much of second layer clad with metal foil are symmetrical, so, C2=C2 ', C3=C3 '.

According to electrical principle as shown in Figure 3, no-load voltage ratio K1, K2, for:

$k1=k2=\frac{\mathrm{Ui}}{\mathrm{Uo}}=\left|\frac{\mathrm{\α}(1+j{Z}_0\mathrm{\ωC}1)}{j{Z}_0\mathrm{\ωC}1}\right|---\left(2\right)$

In the formula

$\mathrm{\α}=\sqrt{\frac{{\mathrm{\ω}}^2{(C_2+C_3)}^2{R}^2+1}{\mathrm{\ω}{C}_{2}R}}$

$Z_0=\frac{\mathrm{j\ωR}(C2+C3)+1}{2(\mathrm{j\ωC}2-{\mathrm{\ω}}^{2}C2C3R)}$

Because C1, C2, C2 ', C3, C3 ' all can obtain according to physical dimension, output valve U0=Uo ', build-out resistor R=R ' can ask.

Claims (6)

1. a GIS is with electronic type current/voltage combination transformer, comprise outside vessel shell, be used for being located in floating potential tube (7) on the Primary Conductor, be equiped with Luo-coil current transformer and coaxial capacitance voltage divider on the floating potential tube, the coaxial capacitance voltage divider comprises high-voltage capacitance and low-voltage capacitance, it is characterized in that described coaxial capacitance voltage divider is provided with at least two low-voltage capacitances, each low-voltage capacitance forms the output of No. one voltage transformer.

2. a kind of GIS according to claim 1 is with electronic type current/voltage combination transformer, it is characterized in that, described low-voltage capacitance is by the floating potential tube outside intermediate capacitance of coaxial laying screen and low-voltage capacitance screen successively from inside to outside, and the dielectric formation between intermediate capacitance screen and the low-voltage capacitance screen; The intermediate capacitance screen comprises at least two along same circle distribution, watt shape, mutual nonconducting second metal level (62), and the low-voltage capacitance screen is the 3rd metal level (63) of tubular.

3. a kind of GIS according to claim 2 is characterized in that with electronic type current/voltage combination transformer, is provided with dielectric between described floating potential tube and second metal level, and the floating potential tube is the high-voltage capacitance screen.

4. a kind of GIS according to claim 3 is characterized in that with electronic type current/voltage combination transformer, and the first metal layer (61) also closely has been sticked outside the floating potential tube.

According to claim 3 or 4 described a kind of GIS with electronic type current/voltage combination transformers, it is characterized in that described each second metal-layer structure, size are all identical.

6. a kind of GIS according to claim 5 is characterized in that with electronic type current/voltage combination transformer each second metal level and the 3rd metal level all form a sensing head interface, connects collecting unit by holding wire.

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