CN1126676A - Magnetic blast insulator - Google Patents

Abstract

The said insulator for contact net of electric railway has four conductive guide bars in its casing beam, arc-striking electrodes, horse shoe arc-extinguishing magnet in the beam, three shunt resistors mounted on the rear panel of the casing, fixed arc-extinguishing hood fixed through insulator string onto the holder and movable arc striker below the arc-extinguishing hood. The said insulator can cut electric arc at the initial forming stage through magnetic blow into several sections so as to allow locomotive to pass through phase separating area without cutting off power.

Description

Magnetic blast insulator

The present invention relates to a kind of phase breaking insulator of contact nets in electrified railways.

Because electric railway is a single-phase load, in order to keep the balance of three-phase load as far as possible, the phase sequence of contact system generally adopts the method for compartment commutation.For making electric locomotive incessantly completely, require electric upward insulation between each section of contact system, and mechanically keep in touch by contact system.Because electric locomotive is an inductive load, the stray capacitance that is connected in parallel on the load is very little, and the time constant that also is electric locomotive is very little.So pantograph is outage in a single day, the current potential on it is zero very soon.Switching surge this moment (being generally about two times of rated voltages) just acts between power supply and the pantograph.Be that in opposite directions the phase breaking insulator or the section insulator of homophase all produces probably by developing into creeping discharge along air interface initial stage flashover.The arc length of creeping discharge is commonly called as creep distance.Along with the creep distance that advances of electric locomotive is also just more and more longer, so-called arcing phenomenon that Here it is.Under extremely disadvantageous situation, the arcing creep distance can reach tens of rice, and (cause electric locomotive o-volt protection action, power supply is cut off.) that yes is unallowed for this.

At present widely used is to make (phase) section insulator with simple insulation rod, and this shackle does not allow the electric locomotive on-load to pass through.So require electric locomotive before the line circuit breaker of locomotive to be disconnected by (phase) section insulator at present, train relies on inertia to pass through.Again the line circuit breaker of locomotive is closed afterwards by (phase) section insulator.This process is that the driver carries out according to road sign (range estimation signal).Once took place to disconnect the accident (upward slope) that locomotive can not be started once more too early owing to the line circuit breaker of locomotive.The line circuit breaker of locomotive is crossed the operation against rules that late disconnection has just constituted " charged rushing (phase) section insulator ".Operation (phase) section insulator after a while almost neither one not by flash burn.In addition, this shackle can not satisfy the requirement of high speed train.

Someone has designed " extinguishing arc (phase) section insulator " that the simple insulation rod of a kind of usefulness adds nature blow-out gap, and (as Fig. 7) its design is that attempt is guided electric arc into gap (S), back to the natural breaking arc of air-flow when utilizing train operation.And the condition of gap S generation electric arc is: do not produce electric arc between (1) AB, (2) punching voltage of AB is greater than the punching voltage of gap S, consideration condition 1, because the time that electric arc forms is very short (the microsecond order of magnitude), and the time constant of electric locomotive is Millisecond at most only.So,, must just occur very nearby from the A point if produce electric arc.Secondly, 2, one new " extinguishing arc phase section insulators " of consideration condition, the disruptie strength of AB can be transferred to greater than gap S disruptie strength.But the long-time running meeting makes dirty, and metal powder, carbon powder etc. are adsorbed on the AB, and the disruptie strength of AB is descended.And the length of gap S strengthens because of discharging to burn for a long time, and its disruptie strength will increase along with the time.Must make the punching voltage of the punching voltage of AB for a long time in spacious day less than gap S.At this moment, gap S is just ineffective." the extinguishing arc effect of extinguishing arc shackle is identical substantially with zero-lash simple phase section insulator so be somebody's turn to do.

In Japan, the someone adopts another kind of way head it off, promptly utilizes if switch " neutral zone " in turn in vacuum breaker, and this method can reach about 1/10th seconds order of magnitude of power-off time.Its shortcoming is: (1) is too harsh to the requirement of vac switch; (2) cost an arm and a leg; (3) require the maintenance levels height, work capacity is big; (4) the contact system wiring is comparatively complicated.

The objective of the invention is to overcome the existing existing defective of shackle, providing a kind of forms the stage at first at electric arc and just utilizes magnetic blow-out to be divided into plurality of sections, can not produce stable electric arc, allow the locomotive green phase disjunction zone that do not cut off the power supply, carry out in the supercharging of access power supply time stage, and be convenient to make the magnetic blast insulator of installing and keeping in repair.

Technical solution of the present invention is: this magnetic blast insulator comprises the shell crossbeam, plate behind the shell, support, movable striking device, insulator chain, contact wire electric pole and tension disk, in the shell crossbeam, evenly be provided with four guiding conducting rods side by side, the top of guiding conducting rod is provided with the line nose, the lower end that is positioned at the guiding conducting rod of both sides is provided with annular arc electrode, the lower end of middle two guiding conducting rods is connected with the middle part arc electrode, three pairs of staggered shape of a hoof blowout magnets of polarity are fixed on the shell crossbeam by insulating screw, be fixed with three divert shunt resistors behind the shell on the plate, resistor is provided with the line nose, resistor is connected with conducting rod line nose with the braiding soft copper wire by the line nose, fixedly the extinguishing arc cover is by three insulator chains [Z direction two strings, the Y direction is a string] be fixed on the support, support is fixed on the electric pole, the below of extinguishing arc cover is provided with movable striking device, movable striking device is connected with contact wire by the tension disk at two ends, and the pantograph that can join with contact wire is equipped with at the locomotive top.

In the present invention, blowout magnet encases with insulating material, the shape of a hoof permanent magnet made from high permeability materials; Divert shunt resistor is to place the insulating cylinder internal fixation on plate behind the shell resistance, but resistance linear resistance (as water resistance), also can be non-linear be resistance (as metal oxide resistor).

The effect of annular arc electrode is the line nose that makes movable striking device become the part of contact wire and the high pressure on the contact system is introduced shunt resistance.

The effect of guiding conducting rod has two: the relative section of the first and fixing extinguishing arc cover keeps getting in touch on electric; Its two be the guiding with the location.

Middle part arc electrode, guiding conducting rod and annular arc electrode cast in high insulation, in the material of high mechanical properties (as epoxy resin fiberglass, glass-felt plastic etc.).

In the present invention, though insulator chain is equipped with in the outside of this device, but shell still must be made non-conductive.

Principle of work of the present invention is as follows:

Occur in the category that electric arc between pantograph and the shackle belongs to the solid creeping discharge.Its discharge mechanism generally is divided into two stages: begin to develop into tree-shaped scopiform spark discharge for shelf depreciation (discharge of high electric field region); And then develop into creeping discharge (electric arc).

When the unregulated power locomotive passes through, its equivalent circuit such as Fig. 5.Because the insulation resistance of shunt resistance and movable striking device is very big, so its leakage current very little (should guarantee during design that its size is a microampere order).When electric locomotive passes through.Pantograph is with striking device jack-up, near the lower edge of blowout magnet.If tree-shaped brush discharge takes place this moment, these charged particles are under the effect (do not have and lag behind) that is in the associating of magnetic field and electric field.Be that power suffered on it is electric field force and magnetic field force sum: $\stackrel{\→}{f}=\stackrel{\→}{f_C}+\stackrel{\→}{f_M}=q\stackrel{\→}{E}+q\stackrel{\→}{v}\×\stackrel{\→}{B}$ In the formula

It is electric field force;

It is magnetic field force;

Q is the quantity of electric charge of charged particle

It is the electric field intensity between pantograph and the power supply;

It is the kinematic velocity of charged particle;

Be the magnetic induction density this moment between pantograph and the power supply, the equation of motion of charged particle will be determined by following formula: $m\frac{d\stackrel{\→}{v}}{\mathrm{dt}}=q(E+v\×B)$

Because the direction of extra electric field is that the direction (x) of contact wire is identical, promptly

E _x=E, E _y=E _x=0 so extra electric field can only make charged particle seesaw along the direction of contact wire.Since electric locomotive by the time contact wire viewpoint is pressed close to the lower edge of blowout magnet, have only y to component, promptly so can suppose magnetic field

B _y＝B，B _x＝B _x＝0

So we can suppose approx that the kinematic velocity of charged particle has only horizontal component V _xWith normal component Y _Z, should be pointed out that since the Z in magnetic field to component B _ZExist, so V _yAlso just non-vanishing, it will make the direction motion of charged particle at vertical paper.This is favourable for blow-out.But, this effect may be very not remarkable.So the motion of charged particle can be determined by following two scalar equation formulas:

$m\frac{d{v}_x}{\mathrm{dt}}=\mathrm{qE}=q\frac{\mathrm{UmSin}(\mathrm{\&omega;t}+\mathrm{\&psi;})}{V_{t}t}$ $m\frac{d{v}_z}{\mathrm{dt}}=q{V}_{z}B$ $V=\sqrt{V_k^2+{\mathrm{<figure-callout\; id="2"\; label="V\; z"\; filenames="A9410160400101.png,A9410160400102.png"\; state="\{\{state\}\}">V</figure-callout>}}_z^{}}$ $\tan \mathrm{\&theta;}=\frac{\mathrm{Vz}}{\mathrm{Vx}}$ In the formula

U _mSin (wt+ ψ) represents power source voltage;

V _tThe speed of expression electric locomotive

θ represents the angle of moving charged particle and level.

This shows that charged particle will oblique movement.Sometimes to the motion of declivity side, promptly away from the shackle lower edge, this is favourable for extinguish arcs; Sometimes the shackle lower edge promptly is close in upward side's motion, and this is disadvantageous for extinguish arcs.For this reason, we an insulating Design two opposite polarity magnet, (if generation) moves to declivity side to guarantee that one section electric arc is always arranged.Two sizes are identical, and it is zero that the power that direction is opposite almost acts on one section electric arc with regard to the speed that makes electric Arc Motion simultaneously.This just finishes the task of blow-out.Why this present invention just is called the reason of " magnetic blast insulator ".

In case electric arc is extinguished, shunt resistance just is serially connected in the loop of electric locomotive, voltage between pantograph and the shackle has just reduced, particularly adopt the metallic oxide shunt resistance with voltage regulation result, the voltage of the insulating segment (as the ab section) of the striking device that this moment is movable just is clamped at certain scope.These shunt resistances are very necessary.Suppose to be provided with these shunt resistances, then after the magnetic blow-out arc extinction, will produce considerable over voltage on the arc gap.This over voltage is enough to make arc gap secondary breakdown (restriking).In theory, restrike can occur unlimited.Analyzing and putting into practice all proves: restriking repeatedly will make over voltage more and more high, cause the non-conductive destructive break-down probably.This shows, " magnetic blast insulator " of no shunt resistance may be not only unhelpful and harmful it.

In sum, magnetic blast insulator of the present invention forms the stage at first at electric arc and just utilizes magnetic blow-out to be divided into plurality of sections, can not produce stable electric arc, allows the locomotive green phase disjunction zone that do not cut off the power supply, and carries out inserting the supercharging of power supply time stage.The present invention also has is convenient to make the advantage of installing and keeping in repair.

Concrete structure of the present invention is provided by drawings and Examples.

Fig. 1 is a structural representation of the present invention, also is the view in I-AB-I cross section among Fig. 3;

Fig. 2 is the view in P among the figure-Q cross section;

Fig. 3 is the view in II-CD-II cross section among Fig. 1;

Fig. 4 is an operating conditions scheme drawing of the present invention;

Fig. 5 is the left view of Fig. 4;

Fig. 6 is principle analysis figure of the present invention;

Fig. 7 adds the principle schematic of " extinguishing arc (phase) section insulator " in nature blow-out gap for simple insulation rod.

Below in conjunction with drawings and Examples the present invention is described in more detail.

Embodiment:

With reference to Fig. 1, Fig. 2, Fig. 3, Fig. 4, this magnetic blast insulator comprises shell crossbeam 4, plate 16 behind the shell, support 11, movable striking device 9, insulator chain 17, evenly be provided with four guiding conducting rods 3 in contact wire 14 and the tension disk 13 shell crossbeams 4 side by side, line nose 7 is equipped with on the top of guiding conducting rod 3, the lower end that is positioned at the guiding conducting rod 3 of both sides is welded with annular arc electrode 8, the lower end of middle two guiding conducting rods 3 is welded with middle part arc electrode 1, three pairs of staggered shape of a hoof blowout magnets 2 of polarity are fixed on the shell crossbeam 4 by insulating screw, be fixed with three divert shunt resistors 5 behind the shell on the plate 16, resistor 5 is provided with line nose 6, resistor 5 is connected with line nose 7 by the copper cash of line nose 6 and tape insulation layer, fixedly extinguishing arc cover 10 is by three insulator chain 17[Z directions, two strings, the Y direction is a string] be fixed on the support 11, support 11 is fixed on the electric pole 12, the below of extinguishing arc cover 10 is provided with movable striking device 9, movable striking device 9 is connected with contact wire 14 by the tension disk 13 at two ends, and the pantograph 15 that can join with contact wire 14 is equipped with at the locomotive top.

Claims (1)

1, a kind of magnetic blast insulator that is used for the electric traction contact system, comprise shell crossbeam (4), plate behind the shell (16), support (11), movable striking device (9), insulator chain (17), contact wire (14), electric pole (12) and tension disk (13), it is characterized in that: evenly be provided with four guiding conducting rods (3) in the shell crossbeam (4) side by side, guiding conducting rod (3) is provided with line nose (7), the lower end that is positioned at the guiding conducting rod (3) of both sides is provided with annular arc electrode (8), the lower end of middle two guiding conducting rods (3) is connected with middle part arc electrode (1), three pairs of staggered shape of a hoof blowout magnets (2) of polarity are fixed on the shell crossbeam (4) by insulating screw, be fixed with three divert shunt resistors (5) on the plate behind the shell (16), resistor (5) is provided with line nose (6), resistor (5) is connected with line nose (7) with insulation braiding soft copper wire by line nose (6), fixedly extinguishing arc cover (10) is by three insulator chains (17) [Z direction two strings, the Y direction is a string] be fixed on the support (11), support (11) is fixed on the electric pole (12), the below of extinguishing arc cover (10) is provided with movable striking device (9), and movable striking device (9) is connected with contact wire (14) by the tension disk (13) at two ends.

Images