DE1588607A1 - Spark gap and discharge control arrangement - Google Patents

Description

Patent attorneys

Dipl.-Chem. i. SCHULZE D i ρ I. -1 η g. E. GUTSCHER

HEiDELBERQ

Gaisbergstrasse 3 telephone 23269

Γ ". Paragraph Dipl.-Chem. 1. Schulze, Dipl.-Ing, E. Gutscher, Patent Attorneys ~ 1 6900 Heidelberg, Gaisbergstrasse

OUR MARK: 164-2 G7 YOUR SIGN:

Applicant: The Ohio Brass Company, 380 North Main Street, Mansfield, Ohio, V, St. A.

Spark gap and discharge control arrangement

The invention relates to a spark gap with a pre-ionization and control device for surge arresters, discharge systems and the like.

009825/0377

It is known, for example, in tfcer voltage arresters the main spark gap by means of an ion source To ignite auxiliary or pre-ionization spark gaps, to make the atmosphere in the main spark gap more conductive make · The auxiliary streoke is designed in such a way that it can be used with relatively small current densities ignites, so that the electrode spacing during the life of the surge arrester must be kept within tight tolerances. Such an arrangement is useful because the auxiliary line is not in the Main discharge path of the surge arrester is and therefore executed very precisely and economically within narrow tolerances and can be produced. This result could not be achieved for the main route without great effort will.

But difficulties arise here because it is flawless Work of the spark gap device is required, the auxiliary streoke by the overvoltages in the Circuit to which the lightning rod is connected to Bringing response and working the main radio link to ensure after the ignition of the auxiliary spark gap.,

00.9828 / 0 * 77-

The invention is based on the object of providing spark gaps that work reliably when overvoltages occur constant resistance voltages for lightning rods and surge systems To create and the like, which have a preionization device in which the breakdown voltage over a long service life in the predetermined range remains and the effects of the changes in the dimensions of the link path parts and the distances between electrons due to breakthroughs are kept as small as possible.

The present invention relates to a spark gap with a discharge control and a Vorionisierungseinrich- ' device, in which a novel arrangement of auxiliary switching spark gaps and voltage dividing systems are combined with the main spark gap of the surge arrester. The main and auxiliary spark gaps as well as the voltage dividers are arranged in several cascade stages, in which first one main spark gap and then the other main spark gaps are ignited be, where dl · order by overturning the Voltage division between the individual stages, which is caused by the ignition of the main spark stretches that switch through By the inventive. Structure can include the main and

009825/0377

Auxiliary spark gaps and the voltage divider in one compact The unit of the surge arrester can be assembled.

The invention is explained in more detail with reference to the drawings, in which some exemplary embodiments are shown.

Fig. 1 is a side view of a spark gap arrangement according to the invention;

Fig. 2 is a circuit diagram of an overvoltage discharge circuit; that is a spark gap and discharge control according to the invention with a preionization arrangement is based on;

Fig. 3 is a sectional plan view of a spark gap plate taken along line 3'-3 in Fig. 1 showing the Arrangement of the electrodes and the voltage divider resistors on the spark gap plates illustrated;

FIG. 4 is a section of the spark gap plate of FIG. 3 along line 4-4; ·

Fig. 5 is a circuit diagram of a spark gap with a different one Execution of discharge control.

009825/0377

Fig. 1 shows the structure of the spark gap 10, in which several Spark gap plates 11, 12, 13 and 14 with associated middle plates 15 and 16 work together to stretch the spark, associated arc chambers and the control and discharge circuits of the spark gap control stages S1, S2, S3 and S4 according to FIG. 2 are delimited. Plates 11-14 are coming with the associated center plates 16 and 15 along a Increase and a recess on the circumference for engagement and are embedded in the end face of the plate part 17. This rope -17 points in the middle to the four spark gap plates a solenoid 18. This assembly is in the form of a Stack, the elements of which are attached one behind the other to two'.z of metal existing end plates 19 and 20 are attached, which each If necessary, the spark gap arrangement with the housing of the Connect the surge arrester, the spam feed line or the valve resistor.

According to FIG. 2, the spark gap arrangement 10 has four inches Main spark gaps 21, 22, 23, 24 lying in series, which determine are assigned parallel spark gaps, resistors and capacitors. Be that way four switching control stages S1, S2, S3 and S4 formed, which

009825/0377

lie in series with a coil 25 assigned to the spark gaps 21 to 24. The arrangement 10, a non-linear valve resistor 27, a voltage line 28 and ground 29 form a series circuit 26 which forms a protective circuit or surge arrester represents for the voltage line 28.

A magnetic field is generated by the coil 25, which the Arcs in the individual spark gaps 21 to 24 apart pulls. Two fixed spark gaps 30 and 31 are used for Shunting the coil 25 and working during the initial phase of the discharge from the network 28 to earth 29 via the spark gaps 21 to 24. After a long enough time, the flow of current is extinguished through the coil 25 the arcs in the spark gaps 30 and 31 »so that the magnetic field generated by the coil 25 increases, whereby the arcs in the spark gaps 21 to 24 get moving. The spark gaps 30 and 31 can can also be replaced by arrangements of non-linear resistors such as those shown in U.S. Patents 2,825,008 and 3.109 * 367 are described. There are also arrangements for this suitable with arc-lengthening electrodes

00-982S / 0377

In the arrangement 10, the spark gap is your stage Traffic jams of a spark gap 21, a switching spark gap 32, which is in series with Sohaltwideristors 33 and 34, and a Voltage divider resistor 35 «The spark gap control stage S2 consists of the spark gap 22, a switching spark gap 36 with series resistors 37 and 38 and a voltage divider resistor 39 · The spark gap control stage S3 consists of the spark gap 23, a capacitor 40 and a voltage divider resistor 41. The spark gap S4 consists of a switching spark gap 42 with series resistors 43 and 44 and a voltage divider resistor 45 * The described! The individual stages are made up of each other and are parallel to each other.

The stages S1, S2 and S4 have voltage divider resistors 35 » 39 and 4-5 with the same value, while the voltage divider resistor 4-1 of level S3 small compared to resistors 35 » 39 and 45 is. The switching spark gaps 32, 36 and 42 are like this designed to ignite at the same voltage, but that is smaller than the breakdown voltage of the main spark gap, while the associated series resistances, d. h, the resistors 33 and 34 of the line 32, the resistors 37 and

009825/0377

the line 36 and the resistors 43 and 44 of the line 42, are increasingly smaller for the successive stages, so that after ignition of the switching spark gaps as a result Due to the unequal voltage division at the main spark gaps 21, 22 and 24 different voltages are present.

The switching spark gaps 32, 36 and 42 have precisely defined small electrode gaps, the electrodes directly next to the main spark paths 21, 22 and 24 arranged are. The switching spark gaps work both as Yorionizers for the main spark gaps and as switches for the individual switching stages and are for discharges in a narrow voltage range with precisely defined tolerances designed. During manufacture, one of the spark gaps 32, 36 and 42 is calculated for ignition at approximately the calculated Voltage selected. Affect minor changes during manufacture of the remaining switching spark gaps From the material point of view, this is no longer general work when the line 32 determines the firing order of the stages, because the Resistance is greater.

00 982 5/0 37 7

always

The mode of operation of the arrangement 10 depends on the type of overvoltage on the conductor 28. She. Working method at Mains overvoltages with slowly rising wave flanks, in the case of sehaltwellen, the following is:

"The residual voltages are between the individual main spark gaps 21 to 24- in the ratio of the individual voltage divider resistors 35, 59 »^ and 45 to the total value of the divided by four voltage divider resistors. Accordingly, yor the ignition of the switching spark gap 32, the Mains voltage in the same voltages above the levels SI, S2 and S4 and a much smaller voltage shared across S3 »

If an overvoltage occurs on the Hetz conductor 28 ignite the spark gaps 52, 36 and 42 and place the switching resistors 33 and 34- parallel to the voltage divider resistor 35, the ^ switching resistors 37 and 38 in parallel with the resistor 45. The resistors 33 and 34- are larger than the resistors 37 and 38 »which in turn are greater than the resistances 43 and 44. The voltage distribution changes accordingly between the stages S1, S2 and S4 after the ignition of the spark gaps 32, 56 and 42 so that respectively

009825/0371

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a larger part of the Netzispänntäig falls over the I-gap gaps 21, 22 and 24 in this sequence, corresponding to the ratio of the parallel resistances of the steps S1, S2 and S4. As a result, line 21 ignites first and then lines 22 and 24, whereupon the entire line voltage is applied to _: _. Line 23 is present »which ignites last. The ignition sequence ends and the discharge sequence begins, while the energy is discharged from the mains conductor 28 via the valve resistor 27 to earth 29. During the discharge, the coil 25 pulls the Jiichtbogen in the haptic stretches 21 to 24 apart, whereby the discharge is terminated, as it is described in the patents mentioned "

The resistor 41 is smaller than the resistance of the parallel connection of voltage divider resistors and switching resistors with ignited switching spark gaps in stages S1, S2 and S4, so that the main spark gap 23 is only ignited when the main spark gaps 21, 22 and 24 have ignited. Resistor 41 is small in relation to the voltage divider resistors 35 »39 and 45, so that the switching spark gaps 32, 36 and 42 are definitely ahead of the main spark gap 23 ignite.

00 9825/0377

The operation of the discharge control device in the event of overvoltages, which have a steeply rising wave flank, i.e. with pulse voltages, is the following:

The pulse voltages are between the individual main spark gaps in the ratio of the impedance of the relevant Stage, namely the impedance of the capacitor 40 or the Impedance of the capacitor 40 along with the voltage divider resistor 41 for level S3 or, for levels S1, S2 and S4, the resistors 35 »39 and 45, to the series impedance all levels divided together. The capacitor 40 has a capacity that is large in relation to the stray capacities of stages S1, S2 and S4, so that the impedance component this level is small for impulse voltages with a sufficiently steep rising edge and the impressed spahing is mainly divided between the main spark gaps 21, 22 and 24 «The main spark gaps ignite accordingly 21, 22 and 24, but not necessarily in this order, after which the impressed voltage is applied directly to stage S3, so that the main spark gap 23 is ignited.

009825/0377

The firing order just described is mainly not determined by the switching spark gaps, rather this is primarily dependent on the voltage that is between the individual stages as a result of the steep edge of the pulse voltage through the capacitor 40 builds up. Me firing order of Main spark gaps 21, 22 and 24 · is undetermined and will not initiated with certainty by the ignition of the switching spark gap 32 with the main spark gap 21.

In these two application cases of the invention, the voltage at which the ignition sequence control of the main spark gaps no longer takes place by the switching spark gaps is mainly determined by the edge steepness of the ¹ pulse voltage. The control function can be maintained for steep pulses by adjusting the time constants of the individual stages to one another.

The structure of the stage S4 of the arrangement 10 is shown in FIG. 3 and FIG. 4 illustrates the structure of the spark gap plate 14. The spark gap plate 14 has a circular shape Shape and consists of arc-resistant, ceramic material. There is a hip 50 on the outer circumference

009825/0377

Inner surface 51 delimits an arc chamber 52. The electrodes 53 and 54, which form the main spark gap 24, are attached to the plate 14 and the plate 16 by means of a binding agent, such as epoxy resin, and rivets 55 v ^ 56. Two ceramic webs 57 ^liIld 58, which form a unit with the plate 14, delimit the arc chamber 52. In this, the arc is generated under the action of the magnetic field of the coil 18 from the closely spaced end faces of the electrodes 53 and 5 along them diverging surfaces pulled apart to the radial outer parts of the arc chamber.

A special (Cell 60 made of ceramic material is part of the The end face of the plate 14 is fastened between the webs 57 and 58. The part of the switching spark gap 42

forming electrodes 61 and 62 made of resistance material exist and so form the switching resistors 43 and 44. The electrodes 61 and 62 have a cylindrical shape and are in circular openings in protruding sections of the Part 60 held. Their free ends are close together with a precisely defined distance and form the spark gap 42. A resistor 63 is located between the radial one

009825/0377

External part of the part 60 and the peripheral rib 50 of the plate 14 and forms the voltage divider resistor 45 according to FIG. 1. The lead wires of the resistor 63 are to the electrodes 61 and 62 and connected to electrodes 53 and 54, whereby the parallel connection is established in stage S4 will*

The spark gap plates 11, 12 and 13 in stages S1, S2 and S3 can be constructed in the same way as stage S4 be. In step S3, the resistor 41 can be connected to the The two electrodes 61 and 62 and the capacitor 40 take the place of the resistor 63, or vice versa, resistor 41 can replace resistor 63 and capacitor 40 can replace electrodes 61 and 62.

In the embodiment according to FIG. 2, the electrode spacing is iii "" "" "* the main spark gaps only critical at line 21. the remaining routes 22 and 23 and, 24 can be adjusted with regard to the setting of the electrode spacing relatively wide! Subject to tolerances o

The spark gap device according to FIG. 5 consists of an arrangement of main spark gaps, a discharge control

0 0 9 0 257 037 7

lind a torionization circuit in four stages S5, S6, S7 and SS, which in structure and mode of operation are essentially the spark gap and discharge control according to Tig. 1 and 2 equals ο However, facility 65 has one symmetrical arrangement of the stages S6 and S7 with respect to the Steps S5 and S8, so that the structure of the panels 11, 15, 12 is identical to the structure of the plates 15 »1-6, 14.

Like I ¹ Xg. 5 shows, the main spark gaps 66, 67, 68 and 69 are parallel to the associated voltage divider resistors 70, 71, 72 and 73 and to the switching spark gap 74, to the capacitor 75, to the capacitor 76 and to the switching spark gap 77, respectively, whereby the stages S5, S6, S7 and S8 are formed. The individual stages are in series with a magnetic coil 78, to which spark gaps 79 and 80 are parallel, as in the arrangement according to FIG. 1.

The voltage divider resistors 70 and 73 and the voltage divider resistors 71 and 72 are the same, with the resistances 70 and 73 are considerably larger than the resistors 71 and 72. Correspondingly, those resting against the arrangement 65 will be Mains and overvoltages between the main spark gaps

009825/0377

66 and 69 on the one hand and the main spark gaps 67 and 68 on the other hand are unequally divided. The resistances that are in series with the switching spark gaps 74- and 77 are different, the resistances of the spark gap 74- being greater than the resistances of the spark gap 77) so that an overvoltage that occurs triggers the two switching spark gaps 74- and 77 , which in turn cause the ignition of the main spark gap 66 and then the main spark gap 69. After the spark gaps 66 and 69 have become conductive, the entire mains voltage is impressed on the main spark gaps 67 and 68, which then ignite. The spark gaps 67 and 68 ignite at the same time, provided that the resistors 71 and 72 are the same. If the resistors 71 and 72 are different - favorable values are 1 megohm for the resistor 71 and 2 megohms for the resistor 72 - the spark gaps 76 and 75 ignite in this order. In general, unequal values for the resistors 71 and 72 bring about an equalization of the time constants of the two stages S6 and S7.

The mode of operation of the arrangement 65 in the event of overvoltages steeply rising edge is the following:

0098 25/0 3 77

158BED7

The capacitors 75 and ψβ shape the main spark gaps 66 and 69 and the associated switching spark gaps 7 ² J and 7? 'On a large rope of the mains voltage. Accordingly, these spark gaps ignite, whereupon the mains voltage is applied to the main spark gaps 67 and 68, so that they ignite and thus initiate the ignition sequence. The capacitances of the capacitors 75 and 76 can expediently be about twenty times as large as the stray capacitances of the structure of a stage, so that more than 90% of the mains voltage drops in stages S5 and S8. The embodiment according to FIG. 5 thus ensures reliable ignition both in the case of pulse voltages and in the case of switching waves.

The capacitors 75 and 76 and / or also the voltage divider resistors 71 and 72 can be unequal to indicate an increase the voltage in one of the stages S6 and S7 and thus a specific firing order of these stages.

In a surge arrester with a circuit arrangement according to FIG. 2 as a spark gap control, the from the American patents 2,825,008 and 3,019 36? known The individual components have characteristics that are used the following values prove advantageous *

0 0 98: 2 5 / 0.3: 7

Voltage divider resistors: R35j H39 »R4-5 - 15 mohm

R41 - 500 kohm

Switching resistors including FJ2, EJ3, R34 - 10 mohm switching path at
ignited switching spark gap: "# 36, RJ7, R38 - 6 molm

Capacitor: 0 40 - 100 mmf

A detailed structure of the arrangement including limping legs and solenoid is shown in Pig »1. The nominal voltage is 4.5 kilovolts. Tests have shown that such a spark gap structure for switching shafts and pulse voltages can work for a very long time remain.

The arrangement in the described embodiments, in which is the resistance value of the series connection consisting of the switching spark gap and two switching resistors when the switching spark gap is ignited is less than the associated voltage divider resistor, is preferred to arrangements in which the

Resistance value of the switching spark gap and the switching resistors is greater than the associated voltage divider resistance.

An advantage of the ITuiiken route arrangements described here, in particular of the exemplary embodiment according to FIG. 3. 5, is that Voltage divider resistors with very high values for the initial Voltage distribution can be used so that it does not affect the ignition sequence of the main spark gap remain and therefore do not have to be taken into account. Therefore, in one embodiment according to I? Ig. 5 the Resistors 70 and 73 can be completely neglected. the other components can have the following values:

Voltage divider resistors: R71 - 500 kohm

Έ.72 - 1.0 mohm

Switching resistors including J74 - 8.5 mohm switching spark gap at
Ignited switching gap: Έ77 - 4.5 mohm

Capacitors; 075 - 200 mmf

076 - 100 mmf

Tests have the stability of the ignition data with switching shafts and pulse voltages are shown. In another example According to Fig. 5, the voltage divider resistors E70 and E73 are 15 mohm, while the other components are the have the same values.

009825/0377

Another advantage of the new spark gap arrangement is that the electrode spacings for a given breakdown voltage can be greatly enlarged with consistent ignition data. An increase in the distance between the electrodes means a reduction in the effect of changes in electrode dimensions.

The term "time spectrum" is used for the scale of the Rise or delay times of the applied surge wave.

00 9 825/0377

Claims (10)

.J left-hand link and load control arrangement, characterized in that several Limping distance electrodes (53> 54) with several in parallel lying elements (42, 43, 44, 45) connected in series Steps (Si, S2, S3, S4) form, each step (S1, S2, S4) from two electrodes forming the main spark gap (24) (53> 54), a resistor (45) for voltage division between the stages (S1 .. «, S4) and one with switching resistors (43, 44) in strainer and to the main spark gap (24) parallel switching spark gap (42) exists that furthermore the electrodes (53 »54) of the switching spark gap (42) are arranged directly next to the associated main spark gaps (24) and together with these form a preionization arrangement, and that the series resistors (43, 44) and Switching spark gaps (32, 36, 42) of the individual ^ stages (S1, S2, S4) are designed differently and a second voltage subdivision form in such a way that the main spark stray (21) a stage (S1) before the main spark gaps (22, 23, 24) of the other stages (82, S3, S4) can be ignited. 009825/0 3 77 2.] and discharge control arrangement according to claim. 1, characterized in that the resistance value of the series connection of switching resistors (33j 34) and switching spark gap (32) of the first stage (S1) larger as the resistance values of the series connections made up of switching resistors (37, 38, 43, 44) and switching spark gaps (36, 42) of the second and fourth stages (S2, S4) and smaller than the voltage divider resistor (35) of the first stage (S1) is such that the ignition of the main spark gap (21) as the first of the main spark gaps (21, 22, 23, 24) regardless of the firing order of the switching spark gaps (32, 36, 42) is. 3. Spark gap and discharge control arrangement according to the claims 1 and 2, characterized in that the electrical distance of the main spark gap (21) of the first stage (S1) is designed precisely for a certain breakdown voltage and the remaining main spark gaps (22, 23, 24) are subject to large tolerances with regard to their electrode spacing. 009825/0377 4. Funk-enstrecken- Lind discharge control arrangement according to the claims 1 to 3 »characterized in that the spark gap order (TO) by capacitive switching means (40), which in at least one of the stages parallel to the main spark gap are shaded, is designed for overvoltages with steep wave flanks in a wide time spectrum. 5 »Spark gap and discharge control arrangement according to claim 4, characterized in that four connected in series Stages (S1 - S4) are provided, of which three stages (S1, S2, S4) have switching spark gap electrodes which are connected in parallel to the main spark gap electrodes, and that in the remaining stage (S3) a capacitor (40) is parallel to the main spark gap (23) " 6. SHinkenverbindungs- and Ent charge control arrangement according to claim 4, characterized in that in two of the four stages (S6,, S?) Capacitors (75 »76) parallel to the main spark paths (67, 68) lie. 009825/0377 7. Spark gap and discharge control arrangement according to claims 4- and 6, characterized in that the spark gap arrangement (10) by adjusted time constants in the two stages (S5, S6), in which a switching spark gap (74, 77) parallel to the main spark gap ( 66, 69) is designed for overvoltages with steep wave flanks. 8. Spark gap and discharge st your arrangement according to the claims 1 to 7j characterized in that the spark gap arrangement (10) constructed from spark gap plates (11, 12, 15-14) and a magnetic coil (18) in stack form is, wherein the voltage dividing switching means (61, 62, 63) • are mounted on the plates (11 ... 14), and that the Main spark gap electrodes (53 »54) in the magnetic field of the Coil (18) have divergent surfaces, the breakdown voltage of the main spark gap being greater is than that of the switching spark gaps. 9. spark gap and discharge control arrangement according to claim 8, characterized in that the switching radio long-range electrodes of cylindrical parts (61, 62) made of resistance 009825/0377 material that form the switching resistors (43, 44) exist and are held next to, but at a distance from, the main spark gap electrodes (53 »54). 10. Funke ns drying and discharge control arrangement according to the claims 8 and 9, characterized in that the main spark gap electrodes (53j 54) and the holder of the Switching spark gap electrodes (61, 62) on a spark gap plate (14) are arranged. 009825/0377