CN1377108A - Spark gap device of bearing lightning current - Google Patents

Abstract

In order to create an arcing section capable of carrying lightning current with several arcing sections connected in series, the arcing section consisting of n arcing part-sections (FS), whose arc drop voltage is brought to a level of n times the arc drop voltage of one arcing part-section by the series connection of the arcing part-sections (FS), and the arcing part-sections (FS), with the exception of the first arcing section (FS1) to operate in the event of a lightning strike, being wired with capacitances, so that the arcing part-sections (FS) break down successively, the second and every other arcing section (FS2 - FSN) being connected directly to a common reference potential via the capacitances, in such a way that it only fires in the event of an overvoltage due to lightning, it is proposed that the sizing of the control capacitors is carried out in accordance with the following formula: (n-1) x CE = k x CL x uhat/us.

Description

The spark gap device of bearing lightning current

Technical field

The present invention relates to the spark gap device of bearing lightning current, it has the spark gap device of a plurality of series connection, wherein spark gap device comprises n sparkle-distributing inter space device, its arc ignition voltage is owing to the n that the series connection of sparkle-distributing inter space device reaches the arc ignition voltage of sparkle-distributing inter space device doubly is worth, and except the spark gap device of first action under the situation of lightning current takes place by impedance, capacity arrangement sparkle-distributing inter space device particularly, so little by little connect the sparkle-distributing inter space device, wherein second and all other spark gap devices directly place public reference potential by impedance, earth potential particularly, and use the identical impedance of measuring respectively.

Background technology

For example by DE 197 42 302 A1 and the known so spark gap device of DE 197 55 082 A1.

Known, a spark gap device or multistage spark gap device can be used for the potential balance of transient state, have wherein also eliminated the network afterflow of back.So the function of spark gap device can be divided into four kinds of basic functions:

1. striking spark gap device under the situation of lightning overvoltage.

2. bypass or the lightning current of guiding between ground and conductor, and guarantee to fall along the low-voltage of electric arc.

3. guiding and the afterflow of elimination network.

4. spark gap device consolidates and bears locational backswing voltage at spark gap device.

The improvement that is described below only relates at striking spark gap device under the situation of transient overvoltage and under the situation at the lightning overvoltage of main thunder and lightning, and relating to the particularly striking of spark gap device under the situation of lightning overvoltage like this, this lightning overvoltage occurs and has with main lightning like this comparing the steepness that increases under the situation of continuous lightning.

With regard to first subproblem explanation, in technical solution before all, if superpotential height surpasses the striking voltage of the spark gap device of discharger, then because the overvoltage of each transient state, such as on wide significance because the burst when disconnecting inductive load, because the separation of safety device and owing to switching abnormal voltage, realize the striking of the spark gap device of lightning arrester.This means every next lightning arrester action under superpotential situation like this.Constantly may obtain the network afterflow to this by striking, by the structure of lightning arrester by this lightning arrester or to interrupt this network by the safety device that connects in front continuous.Only striking lightning arrester under the situation of lightning overvoltage is proposed in fact according to task.This is useful, if can avoid because other superpotential striking, protects lightning arrester thus and removes the unnecessary voltage fluctuation of network or avoid fuse to disconnect.

Summary of the invention

Therefore task of the present invention is, so constructs spark gap device, i.e. this spark gap device of striking under the situation of lightning overvoltage only.

With regard to the explanation of second subproblem, known, the lightning of 90% major part is disadvantageous cloud-ground thunder discharge.Also have about 50% part disadvantageous continuous discharge to occur under the situation of disadvantageous cloud-ground thunder discharge, its steepness is significantly greater than the first main thunder and lightning.About the lightning overvoltage check spark gap device of its action with the first main thunder and lightning.Under disadvantageous continuous lightning situation, do not check operating characteristics according to present standard.Though, must optimize the operating characteristics of spark gap device about this load because stop the spark gap device of this load.

Therefore target is, on request since disadvantageous continuous lightning enlarge the safety level of spark gap device, only provide safety level so far and this reached same safety level for the lightning impulse voltage of 1.2/50 μ s.

Reach this target according to the present invention thus, realize that according to following formula the parameter of equalizing capacitor is selected: $(n-1)\×\mathrm{CE}=k\×\mathrm{CL}\×\hat{u}/u_s,$

Wherein n is the number of capacitor, and CE is each equalizing capacitor, k is 〉=and 1 coefficient of safety, CL is a line capacitance of being the circuit of voltage source from spark gap device, Be superpotential peak value, u _sIt is the safety level of spark gap device.

Therefore so adjust the operating characteristics of multistage spark gap device, if superpotential signal energy is sufficiently high, because the transient overvoltage of switch operation does not trigger multistage spark gap device, always lightning overvoltage triggers multistage spark gap device, so that striking sparkle-distributing inter space device.If for example because the signal energy of the lightning overvoltage that thunderbolt very far away causes is not enough to the whole multistage spark gap device of striking, then voltage still is limited in the value that is under the safety level.

After eliminating the network afterflow, increased the weight of the backfire of lightning arrester, because equalizing capacitor exhausts the backswing voltage of transient state.

Other purpose of the present invention is, as requested because disadvantageous continuous thunderbolt enlarges the safety level of spark gap device, this safety level that only provides for the lightning impulse voltage of 1.2/50 μ s so far and this is reached same safety level.

All spark gap devices have been pointed out the inert nature that more or less clearlys show based on process gas discharge, this inert nature since discharge delay cause by gas based on the statistics of initial electronics.So discharge delay only has for all, and the lightning arrester of a spark gap device is disadvantageous.This effect also appears in multistage spark gap device.Therefore the sparkle-distributing inter space device of the last striking of multistage spark gap device determines operation voltage.Each spark gap device has been pointed out this characteristic in the pulse characteristic curve, this pulse characteristic curve is given in puncture voltage and the contact between breakdown time.Along with the increase of the steepness of surge voltage so the operation voltage of spark gap device also increase.This may cause under extremely steep superpotential situation, surpasses the safety level that draws from operating characteristics under the lightning impulse voltage of 1.2/50. μ s.One so surpass so, be possible under the superpotential situation that from disadvantageous continuous thunderbolt, produces.

Be suitable for so condition in order to revise spark gap device, suggestion, with the sparkle-distributing inter space device of piezo-resistance layout except the first sparkle-distributing inter space device, these piezo-resistances are parallel to the sparkle-distributing inter space device respectively, wherein carry out the parameter selection of piezo-resistance according to following relational expression:

(n-1)U _r+U _AK＜U _S

Wherein n is the number of spark gap device, U _rBe the residual voltage of piezo-resistance, U _AKBe on the first spark gap device FS1 voltage, provide this voltage, U by anode and cathode fall _SIt is the safety level of multistage spark gap device.

Arrange by circuit under the situation of the very large steepness be implemented in surge voltage valuably and still guarantee safety level with piezo-resistance.

Accompanying drawing is described

Embodiments of the invention and this embodiment of following detailed description have been described in diagram in the drawings.

Fig. 1 pointed out to comprise equivalent circuit diagram according to first circuit arrangement of the present invention;

Fig. 2 has pointed out to comprise the formation of modification of the spark gap device of equivalent circuit diagram.

Preferred implementing form

Fig. 1 has pointed out the layout of a multistage spark gap device.The first sparkle-distributing inter space device FS1 that overvoltage u (t) is on the whole multistage spark gap device and at first only striking has natural capacity C12.After the striking first sparkle-distributing inter space device, on sparkle-distributing inter space device FS2, there is voltage $U_{\mathrm{FS}2}\left(t\right)=U\left(t\right)\frac{C_{25}}{C_{23}+C_{25}}\&ap;U\left(t\right)\mathrm{da}{C}_{23}<<C_{25}.$

Therefore also striking sparkle-distributing inter space device FS2.All other sparkle-distributing inter space devices of striking gradually correspondingly.

Along with equalizing capacitor C1E is inferred in the striking of each sparkle-distributing inter space device from the signal energy of pulse voltage u (t) ... the energy share of the charging of CNE.If signal energy be limited, such as all because the transient overvoltage that causes of switch operation is so decided the equalizing capacitor C1E of parameter in respective value ... exhaust signal energy fully under the situation of C (N-1) E.

Can carry out the parameter selection of equalizing capacitor according to following criterion.

Linear Control.All CE are identical numerical value.Can be according to the numerical value of the following following definite equalizing capacitor of consideration:

Have line capacitance CL on a side of spark gap device, it is because the overvoltage of transient state is charged to U.Electric charge on this conductor then.Striking equalizing capacitor owing to multistage spark gap device when having multistage spark gap device has consumed these electric charges.Therefore electric charge only is distributed on n-1 the sparkle-distributing inter space device.At the voltage that on multistage spark gap device, also has the safety level height after the charge distributing.On equalizing capacitor, there is the * C of charge Q=(n-1) _E* U _SEquate Q=Q by electric charge _LWith consider coefficient of safety and can determine the numerical value of equalizing capacitance.

(n-1)*CE＝k*CL*/U _S

=superpotential peak value

U _SThe safety level of=spark gap device

K=coefficient of safety 〉=1

Wherein CL is a line capacitance of being the circuit of voltage source from spark gap device.

Produce actual infinitely-great signal energy under the situation of thunderbolt, this signal energy makes all sparkle-distributing inter space device actions in all cases.

Therefore so adjust multistage spark gap device operating characteristics valuably, promptly

Because the transient overvoltage of switch operation does not trigger multistage spark gap device.

If superpotential signal energy is enough big, then always lightning overvoltage triggers, so that all sparkle-distributing inter space devices of striking.If the signal energy of lightning overvoltage (for example because long distance very far away thunderbolt cause) is not enough to the whole multistage spark gap device of striking, then voltage still is limited in the value that is under the safe voltage.

After eliminating the network afterflow, increase the weight of the backfire of lightning arrester, because equalizing capacitor exhausts the backswing voltage of transient state.

Fig. 2 has pointed out to have the supplementary circuitry of piezo-resistance.

Avoid because the rising of the voltage of the discharge delay of sparkle-distributing inter space device by circuit layout with piezo-resistance.Piezo-resistance is parallel to sparkle-distributing inter space device FS2 ... FSN, and for almost maintaining consistently by the predetermined level of the characteristic curve of piezo-resistance up to the voltage of time domain on this sparkle-distributing inter space device that postpones striking sparkle-distributing inter space device.Because air spark gap device piezo-resistance is caused delay hardly, draw the pulse characteristic curve of the steepness that depends on voltage hardly.By the natural gas discharge striking first sparkle-distributing inter space device FS1 only.In multistage spark gap device, can transfer to value to the striking voltage of the first sparkle-distributing inter space device FS1 far below safety level.

Carry out the parameter of piezo-resistance selects according to following relational expression:

(n-1)U _r+U _AK＜U _S

N: the number of spark gap device

U _r: the residual voltage on the piezo-resistance

U _AK: draw by anode and cathode fall, the voltage on uppermost sparkle-distributing inter space device FS1.

U _S: the safety level of multistage spark gap device

Arrange realization valuably by circuit, under the situation of the very large steepness of surge voltage, still guarantee safety level with piezo-resistance.

The present invention is not limited to embodiment, and changes in the scope of disclosure variedly.

All are new, describe and/or figure in disclosed single and assemblage characteristic regard as according to feature of the present invention.

Claims (2)

1. the spark gap device that has the bearing lightning current of a plurality of series gap devices, wherein this spark gap device comprises n sparkle-distributing inter space device (FS), its arc ignition voltage is owing to the n that the series connection of sparkle-distributing inter space device (FS) reaches the arc ignition voltage of sparkle-distributing inter space device doubly is worth, and except the spark gap device (FS1) of first action under the situation of lightning current takes place by impedance, capacity arrangement sparkle-distributing inter space device (FS) particularly, so little by little connect sparkle-distributing inter space device (FS), wherein second and all other spark gap devices (FS2-FSN) directly place public reference potential by impedance, earth potential particularly, and use the identical impedance of measuring respectively, it is characterized in that carrying out the parameter selection of equalizing capacitor according to following formula: $(n-1)\&times;\mathrm{CE}=k\&times;\mathrm{CL}\&times;\hat{u}/u_s,$

Wherein n is the number of capacitor, and CE is each equalizing capacitor, k is 〉=and 1 coefficient of safety, CL is a line capacitance of being the circuit of voltage source from spark gap device,

Be superpotential peak value, u.It is the safety level of spark gap device.

2. according to the spark gap device of claim 1, it is characterized in that, except the first sparkle-distributing inter space device FS1, arrange the sparkle-distributing inter space device with piezo-resistance, piezo-resistance is parallel to sparkle-distributing inter space device (FS2-FSN) respectively, wherein carries out the parameter selection of piezo-resistance according to following relational expression:

(n-1)U _r+U _AK＜U _S

Wherein n is the number of spark gap device, U _rBe the residual voltage of piezo-resistance, U _AKBe on the first spark gap device FS1 voltage, provide this voltage, U by anode and cathode fall _SIt is the safety level of multistage spark gap device.

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