CN202650975U - Breaker vacuum degree on-line detection apparatus and potential information capturing sensor - Google Patents

Abstract

The utility model discloses a breaker vacuum degree on-line detection apparatus and a potential information capturing sensor, which establish an inherent relation among a dielectric constant in an arc extinguishing chamber, the potential characteristics of a shielding cover and the vacuum degree inside the arc extinguishing chamber, based on vacuum insulation and the real work conditions of the discharging principle and the vacuum arc extinguishing chamber. The breaker vacuum degree on-line detection apparatus and the potential information capturing sensor can enable the on-line detection of the vacuum degree of a vacuum breaker to be realized, through measuring the potential information of the shielding cover of the vacuum arc extinguishing chamber of the high-voltage vacuum breaker to obtain the vacuum degree inside the vacuum arc extinguishing chamber.

Description

Breaker vacuum degree on-line measuring device and current potential information capture transducer

Technical field

The utility model relates to the online detection field of electric power system high-voltage switch gear state, is specifically related to a kind of breaker vacuum degree on-line measuring device and current potential information capture transducer.

Background technology

Circuit breaker is the security guard in the electric power system, plays the control and protection double action in system.As the leading products of high-voltage switch gear, high-pressure vacuum breaker has represented State Grid's industrial expansion level to a certain extent, and its health status, service behaviour are closely related with economic and social benefits with the safe and stable operation of electric power system.In vacuum circuit-breaker state-evaluation and failure diagnosis research, vacuum degree is one of principal element that determines the vacuum circuit-breaker connecting-disconnecting function, so the indoor vacuum level of the vacuum extinction of vacuum circuit-breaker and detect the focus that all becomes research all the time and pay close attention to.In order to realize normal disjunction and the arc extinguishing of electric current, usually require the indoor pressure of vacuum extinction generally not to be higher than a certain numerical value (10 ^-2Pa).

At present off-line maintenance is generally adopted in maintenance and the detection of Vacuity of Vacuum Circuit Breakers, namely adopts off-line equipment and test method when carrying out periodic inspection, and the vacuum degree of vacuum interrupter is checked.The time between overhauls(TBO) that the off-line method mandatory provision is certain, its principle is " expire required, it is required good to repair ", has suitable blindness and mandatory, practice shows that the work of planned maintenance considerable part does not have practical significance and is unnecessary, and the result has caused " the excessively maintenance " of equipment.If at a time when maintenance runs into the equipment state defective later, but do not come out fully in maintenance process, the timely discovery of failing puts into operation again, equipment " maintenance is not enough " at this moment can occur again.Along with planning and the application development of intelligent grid technology, intellectuality and the repair based on condition of component system of electrical equipment are had higher requirement, therefore how to realize that the online detection of Vacuity of Vacuum Circuit Breakers is one of present problem to be solved.

The utility model content

Technical problem to be solved in the utility model provides a kind of breaker vacuum degree on-line measuring device and current potential information capture transducer, and it can realize the online detection of Vacuity of Vacuum Circuit Breakers.

For addressing the above problem, the utility model is achieved through the following technical solutions:

A kind of breaker vacuum degree of the utility model on-line measuring device mainly is comprised of current potential information capture transducer, signal condition unit, digital filtering unit, AD conversion unit, computation of table lookup unit, memory cell, on-the-spot display and remote communication interface; Wherein the output of current potential information capture transducer links to each other via the input of signal condition unit with the digital filtering unit; The input of digital filtering unit is by the input of AD conversion unit; Computation of table lookup unit and memory cell interconnect; The output of memory cell is connected with remote communication interface with on-the-spot display respectively.Described current potential information capture transducer mainly is comprised of insulation shell, electric screen layer, magnetic masking layer, epoxy resin, current potential capture electrode, capacitive coupling device, signal output; Insulation shell is the hollow cylindrical cavity of front/rear end closure; The hollow tube-shape that connects before and after electric screen layer and magnetic masking layer are; The electric screen layer be attached on the madial wall of insulation shell after magnetic masking layer is mutually nested; The discoid current potential capture electrode that consists of via metal material is arranged in the inner chamber of insulation shell, and the current potential capture electrode is near front end face and the current potential capture electrode and the coaxial setting of insulation shell of insulation shell; One end of current potential capture electrode links to each other with the negative pole of signal output, and the other end of current potential capture electrode links to each other with the positive pole of signal output through the capacitive coupling device; Epoxy resin is built in the inner chamber of insulation shell;

In the said apparatus, described electric screen layer is nested in the inboard of magnetic masking layer.

A kind of current potential information capture of the utility model transducer mainly is comprised of insulation shell, electric screen layer, magnetic masking layer, epoxy resin, current potential capture electrode, capacitive coupling device, signal output; Insulation shell is the hollow cylindrical cavity of front/rear end closure; The hollow tube-shape that connects before and after electric screen layer and magnetic masking layer are; The electric screen layer be attached on the madial wall of insulation shell after magnetic masking layer is mutually nested; The discoid current potential capture electrode that consists of via metal material is arranged in the inner chamber of insulation shell, and the current potential capture electrode is near front end face and the current potential capture electrode and the coaxial setting of insulation shell of insulation shell; One end of current potential capture electrode links to each other with the negative pole of signal output, and the other end of current potential capture electrode links to each other with the positive pole of signal output through the capacitive coupling device; Epoxy resin is built in the inner chamber of insulation shell.

In the sensor, described electric screen layer is nested in the inboard of magnetic masking layer.

Compared with prior art, the utlity model has following features:

1. based on dielectric physics and vacuum insulation and discharge theory, set up the relation of gas pressure intensity and dielectric constant in the high voltage vacuum interrupter, so provide vacuum degree under the arc control device condition of work (P represents with the arc control device internal gas pressure) and dielectric constant contact the mechanism formula; Based on the relation of vacuum degree and dielectric constant, set up the relation of induced potential (alternating current component and DC component) on vacuum degree and the vacuum circuit-breaker suspension radome based on electromagnetic induction principle, current potential can obtain by current potential information capture transducer on the radome;

2. adopt the Ansoft simulation software to set up P (vacuum degree)-ε _r(dielectric constant), ε _r(dielectric constant)-U(radome current potential) analytical model of contact between, obtain vacuum degree P (vacuum degree)-U(radome current potential by Ansoft and Matlab collaborative modeling) between inner link, thereby provide theoretical foundation for in-line detection method for vacuum level in the high-pressure vacuum breaker arc control device.

3. radome current potential acquisition sensor device adopts capacitive coupling and dividing potential drop mode based on electromagnetic induction principle, can catch sensitive, exactly the feature of radome current potential (alternating current component and DC component);

4. breaker vacuum degree on-line measuring device adopts radome current potential acquisition sensor to gather radome current potential information, and by processing center the radome current potential information of catching is tabled look-up and to obtain arc control device vacuum degree P after processing, for the realization of the online detection of vacuum circuit-breaker provides the measuring and application platform.

Description of drawings

Fig. 1 is breaker vacuum degree on-line measuring device schematic diagram.

Fig. 2 is current potential information capture sensor construction schematic diagram.

Fig. 3 is the on-the-spot mounting arrangements structure chart of breaker vacuum degree online test method.

Fig. 4 is the current potential information capture installation of sensors arrangement figure that amplifies among Fig. 3.

Fig. 5 is breaker vacuum degree online test method schematic diagram.

Number in the figure: 1, insulation shell; 2, electric screen layer; 3, magnetic masking layer; 4, epoxy resin; 5, current potential capture electrode; 6, capacitive coupling device; 7, signal output.

Embodiment

A kind of breaker vacuum degree on-line measuring device mainly is comprised of current potential information capture transducer, signal condition unit, digital filtering unit, AD conversion unit, computation of table lookup unit, memory cell, on-the-spot display and remote communication interface as shown in Figure 1.Wherein the output of current potential information capture transducer links to each other via the input of signal condition unit with the digital filtering unit; The input of digital filtering unit is by the input of AD conversion unit; Computation of table lookup unit and memory cell interconnect; The output of memory cell is connected with remote communication interface with on-the-spot display respectively.Send in the AD conversion unit after the current potential information process signal condition unit of the breaker vacuum arc control device radome of current potential information capture transducer collection and the conditioning of digital filtering unit and the filtering, the AD conversion unit analog quantity is converted into digital quantity, this digital quantity is tabled look-up as the input of computation of table lookup unit, checking result is output as vacuum values to be detected, stores this numeric data memory cell and carry out output valve on-the-spot display realization demonstration and remote communication interface realization data transmission communication under the control of checkout gear central processing unit.

It is exactly that known current potential is caught transducer that above-mentioned current potential information capture transducer can adopt existing, but in order to be more suitable for catching the current potential information of circuit breaker radome, in the utility model, described current potential information capture transducer as shown in Figure 2, it mainly is comprised of insulation shell 1, electric screen layer 2, magnetic masking layer 3, epoxy resin 4, current potential capture electrode 5, capacitive coupling device 6, signal output 7.Insulation shell 1 is the hollow cylindrical cavity of front/rear end closure.The hollow tube-shape that connects before and after electric screen layer 2 and magnetic masking layer 3 are.Be attached on the madial wall of insulation shell 1 after electric screen layer 2 and magnetic masking layer 3 are mutually nested.Carrying out when mutually nested, electric screen layer 2 can be nested in inboard or the outside of magnetic masking layer 3.In the utility model, described electric screen layer 2 is nested in the inboard of magnetic masking layer 3.The discoid current potential capture electrode 5 that consists of via metal material is arranged in the inner chamber of insulation shell 1, and current potential capture electrode 5 is near front end face and the current potential capture electrode 5 and insulation shell 1 coaxial setting of insulation shell 1.One end of current potential capture electrode 5 links to each other with the negative pole of signal output 7, and the other end of current potential capture electrode 5 links to each other through the positive pole of capacitive coupling device 6 with signal output 7; Epoxy resin 4 is built in the inner chamber of insulation shell 1.Above-mentioned capacitive coupling device 6 is class capacitor element, the simplyst can be an electric capacity, but the precision of catching in order to improve current potential, this capacitive coupling device 6 can complicated capacitance kind device.

The coupling body that current potential information capture transducer adopts is the capacitance kind device, and its need of work cooperates with front terminal potential capture electrode 5; Whole electrical work unit adopts epoxy resin 4 to be cast in the high-tension insulator of specific dimensions and structure, at the insulator inwall respectively by 2 layers of magnetic cylindraceous and electric screen layer 2, can increase so selectivity and accuracy that every phase current potential information capture sensor signal is picked up, avoid the interference of other phase level signals; There is signal output interface at back at transducer, generally adopts coaxial cable or Shielded Twisted Pair, and the output signal of transducer is drawn, and sends into follow-up monitoring and processing module unit.In addition, coupling body also can adopt coil form or inductance element, and the electromagnetic field around the arc control device that are coupled changes, and can only qualitatively judge arc control device vacuum degree and whether arrive deteriorated critical and maximum conditions based on electromagnetic induction and Ba Shen law this moment.The analytical method that this paper adopts has with it larger difference, be exactly all can be by radome in larger vacuum excursion on vacuum degree situation in the current potential information quantitative response arc control device.

Current potential information capture transducer diameter and height carry out theory according to the type of monitoring vacuum circuit-breaker arc extinguishing chamber and structure according to the electromagnetic field distribution situation and calculate, purpose is to make the current potential information capture transducer radome current potential information that can obviously be coupled, and realizes picking up accurately and reliably getting final product.Determining of current potential information capture transducer concrete structure and electric parameter determined according to vacuum circuit breaker constructions to be monitored and arc control device parameter.

Fig. 3 is the on-the-spot mounting arrangements structure chart of in-line detection method for vacuum level in the high-pressure vacuum breaker arc control device.Fig. 4 is the fitting arrangement of in-line detection method for vacuum level current potential information capture transducer in the high-pressure vacuum breaker arc control device.Each switch cubicle or vacuum circuit-breaker consist of mutually by 3, and each adopts vacuum-ness detecting device of the present utility model (current potential information capture transducer) to extract characteristic signal amount to be detected mutually, according to the analytical method that the utility model proposes, based on P-ε _rThe contact mechanism that-U determines is as long as can grasp the specific features of vacuum interrupter radome current potential U, just can the interior vacuum degree situation of continuous detecting arc control device.Each circuit breaker; be equipped with independently current potential information capture transducer of 3 mutual items; cooperate necessary signal condition and protected location, the ethernet interface that formation has on the spot data analysis processing, data storage, warning indication and adopts the IEC618509-2 communication standard.

A kind of breaker vacuum degree online test method that adopts above-mentioned breaker vacuum degree on-line measuring device and current potential information capture transducer to realize as shown in Figure 5, comprises the steps:

(1) a collection of circuit breaker of customization is as laboratory sample, the structure and material parameter of the vacuum interrupter of above-mentioned each laboratory sample circuit breaker is all consistent with the structure and material parameter of circuit breaker to be measured, and the indoor vacuum degree of the vacuum extinction of each laboratory sample circuit breaker is different;

(2) one by one above-mentioned each laboratory sample circuit breaker is installed on the off-line calibration platform, and makes the front end of current potential information capture transducer relative with the axis of the vacuum interrupter of laboratory sample circuit breaker; Wherein the off-line calibration platform is identical with circuit breaker actual installation arrangement to be measured;

(3) the laboratory sample circuit breaker is pulled open the specified load of opening apart from and applying rated voltage at its two ends; Measure respectively the radome current potential information of each laboratory sample circuit breaker by current potential information capture transducer;

The radome current potential information of (4) vacuum degree and the current potential information capture transducer of known laboratory sample circuit breaker being caught is carried out record, and draws out the corresponding relation curve of vacuum degree and radome current potential;

(5) the corresponding relation curve tabulation with vacuum degree and radome current potential deposits in the memory cell of breaker vacuum degree on-line measuring device;

(6) in the actual testing process, by on the breaker vacuum degree on-line measuring device with current potential information capture transducer catch the radome current potential information of circuit breaker to be measured, and the gained sampled value is sent into breaker vacuum degree on-line measuring device; Breaker vacuum degree on-line measuring device can obtain the practical vacuum degree value of vacuum circuit-breaker to be detected by searching pre-stored vacuum degree and radome current potential form in its memory cell.

Can know that by the screen potential that detects the high-pressure vacuum breaker vacuum interrupter theoretical foundation of its vacuum degree is as follows:

One: vacuum degree P and DIELECTRIC CONSTANT ε _rThe contact Analysis on Mechanism

The vacuum degree analytical method is theoretical based on dielectric physics, vacuum insulation and discharge, high-voltage switch gear in the vacuum circuit-breaker arc extinguishing chamber, at first quote from the dielectric physics gram labor Hughes-Mosso and form (Clausius-Mossotti) equation, under Lorentz effective electric field condition, set up the macroparameter of dielectric polarization and the contact of micro-parameter, embody as formula 1. shown in:

$\frac{{\mathrm{\ϵ}}_r-1}{{\mathrm{\ϵ}}_r+2}=\frac{n_0\·\mathrm{\α}}{3{\mathrm{\ϵ}}_0}$ ①

Formula 1. in: ε _r, ε ₀Be respectively relative dielectric constant and the permittivity of vacuum of gaseous dielectric; α is the air molecule polarizability; n ₀Be the polarized particle number in the dielectric unit volume.Consider the relation of planning particle in molal volume and the unit volume, 1. formula can be converted into the form of formula shown in 2.:

$\left[P\right]=\frac{{\mathrm{\ϵ}}_r-1}{{\mathrm{\ϵ}}_r+2}\·\frac{M}{\mathrm{\ρ}}=\frac{N_0\·\mathrm{\α}}{{3\mathrm{\ϵ}}_0}$ ②

Formula 2. in, M and ρ are respectively dielectric molal weight and density, N ₀Be Avogadro constant number, [P] is the mole polarization.For specific dielectric, 2. the formula right-hand member shows, polarizability α has definite value, and irrelevant with density p, and therefore [P] is for determining constant.2. the formula left end shows, molal weight M fixes (the indoor vacuum electric medium of vacuum extinction and condition of work satisfy this requirement), has again [P] to be constant, therefore can draw

With the proportional relation of density p.2. can be with ρ and ε by formula _rRelation further be converted to the form of formula shown in 3.:

$\mathrm{\ρ}\·\frac{\left[P\right]}{M}=\mathrm{\ρ}\·k_1=\frac{{\mathrm{\ϵ}}_r-1}{{\mathrm{\ϵ}}_r+2}$ ③

Formula 3. in, can find out

Therefore just set up the density of gaseous dielectric and the relation of relative dielectric constant, usually DIELECTRIC CONSTANT ε _rIncrease along with the increase of density of acid ρ, its physical significance is that the polarized particle number increases in the unit volume, so ε along with density of acid ρ increases _rAlso increase with ρ.

In physics and ventilating engineering, do, density of moist air tried to achieve by the equation of gaseous state of formula shown in 4.:

$\mathrm{\ρ}={\mathrm{\ρ}}_0\·\frac{T_0\·P}{P_0\·T}$ ④

ρ, ρ in the formula ₀Be respectively the density of dry air under off-rating and the standard atmospheric conditions, units/kg/m ³P, P ₀Be respectively the pressure of air under off-rating and the standard atmospheric conditions, the kPa of unit; T, T ₀Be respectively the thermodynamic temperature of air under off-rating and the standard atmospheric conditions, unit K.With formula 4. the substitution formula 3. can obtain:

$P=\frac{M}{\left[P\right]}\·\frac{P_0}{{\mathrm{\ρ}}_0{T}_0}T\·\frac{{\mathrm{\ϵ}}_r-1}{{\mathrm{\ϵ}}_r+2}$ ⑤

Under the vacuum interrupter condition of work, the vacuum electric medium temperature T in the arc control device can think constant, so 5. formula can further be written as:

$P=\frac{k_2}{k_1}\·\frac{{\mathrm{\ϵ}}_r-1}{{\mathrm{\ϵ}}_r+2}=k\·\frac{{\mathrm{\ϵ}}_r-1}{{\mathrm{\ϵ}}_r+2}$ ⑥

Formula 6. in,

Under the vacuum extinction room environmental, by the physical significance of k with embody that can to draw k be a constant value, the indoor pressure of vacuum extinction (vacuum degree) and DIELECTRIC CONSTANT ε have so far been obtained fully _rPhysics contact mechanism, namely formula is 6..

Two: set up DIELECTRIC CONSTANT ε _rWith contacting of vacuum interrupter radome induced potential U, and then obtain P-ε _r-U inner link is for the utility model high-pressure vacuum breaker in-line detection method for vacuum level and implementation provide theoretical foundation.

According to full-scale vacuum interrupter concrete structure and material parameter, adopt the Ansoft finite element analysis software to set up vacuum interrupter 3D analytical model.In the Three-dimensional static electric field solver, electric scalar potential Φ as definite condition, adopts formula form 7. to find the solution with correct boundary condition as unknown variable:

$\▿\·({\mathrm{\ϵ}}_r\·{\mathrm{\ϵ}}_0\text{\▿\Φ})=-{\mathrm{\ρ}}_V$ ⑦

Wherein, Φ (x, y, z) is three-dimensional electric scalar potential, ε _r(x, y, z) is three relative dielectric constants on the direction vector, ε ₀Be permittivity of vacuum, ρ _V(x, y, z) is volume charge density.Find the solution and obtain electric scalar potential Φ, further draw electric field strength E and electric displacement vector D by first in the Maxwell equation group, namely formula 8..In addition, current density, J also can be calculated by three-dimensional scalar point position Φ.

$\left\{\begin{array}{c}E=-\▿\mathrm{\Φ}\\ D={\mathrm{\ϵ}}_r\·{\mathrm{\ϵ}}_0\·(-\▿\mathrm{\Φ})\end{array}\right.$ ⑧

If find the solution boundary condition, contact and border are implemented the voltage drive source, for example analyze the vacuum interrupter that rated voltage is 10kV, can apply rated operational voltage is that power frequency 10kV high pressure is sinusoidal, voltage drive is peak value 14.14kV, and the voltage 0V on the outer boundary finds the solution iterations and condition of convergence setting, the operating analysis model can obtain P-ε _r-U analysis result data, and result of calculation figure.

Three: based on the electrostatic induction principle, design vacuum interrupter radome current potential is caught transducer, this transducer adopts the special substance capacity cell, and 3 extract respectively radome current potential information mutually, and vacuum degree detects application system online in the transducer establishment vacuum circuit-breaker arc extinguishing chamber based on catching.

Claims (4)

1. breaker vacuum degree on-line measuring device is characterized in that: mainly be comprised of current potential information capture transducer, signal condition unit, digital filtering unit, AD conversion unit, computation of table lookup unit, memory cell, on-the-spot display and remote communication interface; Wherein the output of current potential information capture transducer links to each other via the input of signal condition unit with the digital filtering unit; The input of digital filtering unit is by the input of AD conversion unit; Computation of table lookup unit and memory cell interconnect; The output of memory cell is connected with remote communication interface with on-the-spot display respectively;

Above-mentioned current potential information capture transducer mainly is comprised of insulation shell (1), electric screen layer (2), magnetic masking layer (3), epoxy resin (4), current potential capture electrode (5), capacitive coupling device (6), signal output (7); Insulation shell (1) is the hollow cylindrical cavity of front/rear end closure; The hollow tube-shape that connects before and after electric screen layer (2) and magnetic masking layer (3) are; Electric screen layer (2) be attached on the madial wall of insulation shell (1) after magnetic masking layer (3) is mutually nested; The discoid current potential capture electrode (5) that consists of via metal material is arranged in the inner chamber of insulation shell (1), and current potential capture electrode (5) is near front end face and the current potential capture electrode (5) and the coaxial setting of insulation shell (1) of insulation shell (1); One end of current potential capture electrode (5) links to each other with the negative pole of signal output (7), and the other end of current potential capture electrode (5) links to each other through the positive pole of capacitive coupling device (6) with signal output (7); Epoxy resin (4) is built in the inner chamber of insulation shell (1).

2. breaker vacuum degree on-line measuring device according to claim 1, it is characterized in that: described electric screen layer (2) is nested in the inboard of magnetic masking layer (3).

3. current potential information capture transducer is characterized in that: mainly be comprised of insulation shell (1), electric screen layer (2), magnetic masking layer (3), epoxy resin (4), current potential capture electrode (5), capacitive coupling device (6), signal output (7); Insulation shell (1) is the hollow cylindrical cavity of front/rear end closure; The hollow tube-shape that connects before and after electric screen layer (2) and magnetic masking layer (3) are; Electric screen layer (2) be attached on the madial wall of insulation shell (1) after magnetic masking layer (3) is mutually nested; The discoid current potential capture electrode (5) that consists of via metal material is arranged in the inner chamber of insulation shell (1), and current potential capture electrode (5) is near front end face and the current potential capture electrode (5) and the coaxial setting of insulation shell (1) of insulation shell (1); One end of current potential capture electrode (5) links to each other with the negative pole of signal output (7), and the other end of current potential capture electrode (5) links to each other through the positive pole of capacitive coupling device (6) with signal output (7); Epoxy resin (4) is built in the inner chamber of insulation shell (1).

4. current potential information capture transducer according to claim 3, it is characterized in that: described electric screen layer (2) is nested in the inboard of magnetic masking layer (3).

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