DE1800205A1 - Circuit breaker for high DC voltages - Google Patents

Description

Dr. Horst pupil 1800205

Patent attorney -

6 Frankfurt / Main 1!
Niddastr. 52:

Sep 30 1968

; '887-HD-3088

General Electric Company, 1 River Road, Schenectady N.Y., USA Circuit breaker for high DC voltages

The invention relates to circuit breakers for high DC voltages and in particular on breakers, where a commutation capacitor is used to generate a current zero crossing is discharged by a switch.

In the case of the current interruption arrangement that is of interest here is a circuit breaker with a DC voltage carrying high voltage network in series that a consumer through powered through the breaker. A normally open commutation circuit is located parallel to the interrupter with a charged capacitor. When the DC circuit should be opened, this capacitor is through the breaker and discharge through the commutation circuit, whereby

ORfQINAt INSPECTED

909820/0813

the current through the breaker can be made zero. The introduction of this current zero passage gives the breaker the opportunity to restore its dielectric strength win and complete the power interruption.

Whether the breaker at this point already has the current completely depends on whether he can withstand the tension that arises immediately after the Current zero crossing builds up. This is after the current zero crossing The voltage that builds up depends to a large extent on the capacitances, inductances and resistances that then present in a circuit that is derived from the direct current * source via the direct current lines, the commutation capacitor and passes through any loads left in the circuit. This circuit is a resonant circuit in which the inductances of the system and the commutation capacitor are in series. In the moment in which the current in the interrupter is interrupted, a continuous exchange of energy between these inductances begins and the commutation capacitor, which is noticeable through oscillations, and these oscillations represent an essential component of the voltage that is directly related builds up after a zero strobe at the breaker.

BATH ORIGINAL. 909820/0813

The object to be achieved with the invention is in that. Reduce the maximum value of that voltage, caused by these vibrations, so that the likelihood that the breaker can withstand this voltage without breakdown.

One way to do this is to use the commutation capacitor to enlarge. However, there are limits to this possibility for economic reasons, since this capacitor be as small as possible for economic reasons should.·

Another object of the invention is therefore the. The peak value of the voltage, which is caused by these oscillations, can be reduced without the commutation capacitor needs to be made bigger.

These objects are achieved in an embodiment of the invention 'a circuit breaker in that before the input of the circuit breaker and the S'tron return line a device for suppressing voltage peaks is arranged. This device for the suppression of ■ Voltage peaks has a spark gap switch, which is ignited shortly before the zero crossing, i.e. before the point in time at which the counter voltage at the breaker has reached a noteworthy value. After igniting the-

ORfQINAl INSPHCTED

- «09120/0913

This spark gap switch, a current flows through the device for suppressing the voltage peaks - so that the energy contained in the oscillations is destroyed. To complete the current interruption, this current must be terminated in the spark gap switch when the energy of the vibrations has been destroyed. This current is interrupted characterized in that a commutation -weiteren qin zero current in the spark gap switch is erztirungen using.

Another object of the invention is to reduce the grain mutation flow for the device for suppressing voltage spikes and for the main breaker from the derive the same capacitor. If you only use a single capacitor for these additional functions one can save an additional expensive capacitor. . ,

Another object of the invention is to reduce the current in the arrangement for suppressing voltage peaks in such a way interrupt so that there is no overvoltage against which the Network must be additionally protected.

Finally, another object of the invention is to use a circuit arrangement according to the invention for un-

90982070813

Interruption of direct currents leads to a direct voltage To protect the high voltage network against inclusions.

In the following, the invention will be based on an exemplary embodiment will be described in detail in conjunction with the drawings. .

Figure 1 shows a schematic of the inventive arrangement for Power interruption. This arrangement is shown in the normally closed condition.

FIG. 2 shows schematically the arrangement according to FIG. 1 during a power interruption. !

I.
i

Figure 3 is a graphical representation and represents the time

lent course of the current; represents that during a power interruption flows in the arrangement of Figure 1 or Figure 2.

FIG. 4 shows schematically a section from the arrangement according to Figures 1 and 2.!

In the figure 1, a direct voltage leading high voltage network with a direct voltage source 12, a load Ik and a line Ϊ6 is shown schematically, through which the

^/ ORIGINAL INSPECTED

909820/0813

Load direct current is supplied. Assume that the normal current flows in the direction of arrows 17 and over a return line 19 returns to the DC voltage source. The 'DC voltage source 12 is shown schematically as a transformer 20 and a rectifier 21 which is in series with the secondary winding of the transformer.

- i

Nen to the current for the load 14 on and off to kön- ^ is a Stromunterbreöher 25 between the load l ^l \ and the DC power source inserted into the conduit 16 12th The inductance of the entire network on the input side has been designated as nit 18.

In the illustrated preferred embodiment of the invention the breaker 25 is a vacuum breaker. This Vacuum interrupter v / eist a highly evacuated, partly made of insulating material housing 26 in which two contacts 27 and 28 which can be moved relative to one another are arranged. 'The fixed contact is the left contact 27, while the right contact 28 is the movable contact that protrudes from the housing 26 on the right. The right contact 28 and that Housings 26 are connected to one another in a vacuum-tight manner by means of a spring bellows 29, so that the right contact 28 is horizontal can be pushed back and forth without the vacuum in the housing 26 is affected.

L INSPECTED

909820 / Ö ^ f3

The right contact 28 is in the closed position according to FIG held in place by a pawl 30 and biased to the right into the open position by a spring 32. If the Pawl 30 is released, the spring 32 pulls the movable contact 28 to the right, so that between the contacts Gap 33 is created, which is shown in FIG. With this separation of the contacts, an arc is created in the gap 33 3 * 1, which goes out quickly and does not ignite again, so that the circuit is interrupted. The way in which this is done will be explained in more detail. To the lie tall fumes, which are generated by the arc, to be able to condense, and to isolate the housing 26 from these metallic vapors To protect, a shielding cylinder 31 made of metal has been provided within the housing.

The vacuum interrupter 25 can be of conventional design and is therefore only shown schematically. Embodiments of vacuum interrupter in an arrangement according to the invention have been described in U.S. Patents 2,9 ^ 9,520 and 3,089,936.

Interrupting direct current is much more difficult than interrupting alternating current, since alternating current is natural Has Hull passages. With alternating currents, the liulldurehganges after every half-wave, and around alternating current

0098 20/0813

to interrupt, it is only necessary to reignite the Avoid arcing after a zero crossing. However, when interrupting direct current it is necessary first to push the current down to zero and then

to ensure that no

Re-ignitions occur more.

One way of making the current in a breaker to zero is to send an auxiliary current through the breaker which is set up opposite the main current r i. This possibility is used in the illustrated embodiment, namely the auxiliary current is derived from the commutation capacitor 35. As will be explained in more detail, the capacitor 35 is charged with the polarity shown in the figure. The capacitor 35 is arranged in a commutation circuit or quenching circuit 36 which bridges the contacts 27, 28 of the interrupter 25. The _v arc quenching circuit 36 is normally open, as in it in series with the commutating capacitor 35, a normally open switch 38 lies. When the switch 38 is closed, the capacitor 35 discharges through a loop in which the breaker contacts 27 and 28 and the arc extinguishing circuit 36 are in series. ¹ At the beginning the discharge current D flows in the loop on ¹ contacts 27 and 28 and the Bögeη-

INSPJICTE0

9 8 2 ¹ O / 0 81 3

ι extinguishing circle 36 in the direction of arrows 39.

This loop represents an oscillating circuit. The capacity

this resonant circuit consists mainly of the capacitor 35, while its inductance can be represented as inductance 50. This discharge current is a current with a relatively high frequency / that of the current Ij. on the line 16 is superimposed. This connection is in the Figure 3 shows the total current through the breaker is shown as curve I ". When the capacitor begins to discharge at time 52, the discharge current builds up Ι »very quickly to a positive peak value and then decreases to a negative peak. This

ι
negative peak work of the discharge current flows through the interrupter 25 in a direction which is opposite to the direction of the current I, so that the total current · Im at the moment 53 in FIG. 3 becomes zero.

In a preferred exemplary embodiment of the invention, the current interruption is achieved by separating the contacts 27 and 28

I.
initiated so that an arc between the contacts

arises as shown in FIG. After a predetermined period of time, the switch 38 is then closed to the Doge extinguishing circle 36 to complete. This is also shown in FIG. As a result, the high-frequency ent-

ι ORIGfNAL INSPECTED

909820/0813

charging current I _D through the arc extinguishing circuit 36 and the interrupter 25, so that the total current is zero, as shown in FIG. 3 and has just been described. if

i "■

the total current becomes zero> the arc extinguishes between the contacts. i

The power interruption is complete when the gap 33 * fc which is then present between the contacts 27 and 28, "the Can withstand counter-voltage that builds up very quickly at the gap after the current has passed zero. The one shown Interrupter is a vacuum interrupter in which the Dielectric strength sets again extremely quickly after the arc has been extinguished when the current passes zero, and this supports the suppression of re-ignition through the counter voltage. Another means, the probability for re-ignition is to trim the peak value that this counter voltage can reach. This

will be explained in detail later.

The normally open one. Switch 30 is preferably on controllable spark gap switch as described, for example, in US Pat. No. 3,087,092. The gap of this switch is formed by two main electrodes Ί0 and Ί2, which are in a highly evacuated housing M.

; ' ^: \ ·. ■ -.; -. _ ■ ',; . ■ . - ..- I ORIGINAL IMSPECTED

ia0982; Ö70813

are arranged at a certain distance from each other.

This gap is denoted by 45. Near the one Main electrode 42 is arranged an ignition electrode 46, the from a hydrogen-impregnated titanium layer on top of a ceramic rod 48 is formed. This ceramic rod 48 is arranged coaxially to the main electrode 42 and on the outside against it the main electrode 42 is sealed. Part of the ceramic rod 48 is not coated with titanium. This part limits you Ignition gap 51 and isolates the under normal conditions Ignition electrode 46 from the main electrode 42. An electrical line 49 passes through the ceramic rod 48 and is at the top ends at the ignition electrode 46.

When an electrical pulse is applied between the ignition electrode 46 and the main electrode 42, it takes place in the ignition gap a breakthrough takes place, and the resulting spark sets a small one from the hydrogen-impregnated ignition electrode 46 Amount of hydrogen free. This hydrogen is rapidly ionized and enters the main gap 45. This will the dielectric strength of the main gap is reduced and the breakthrough initiated in the main gap. The arc that occurs after the breakdown of the main gap 45 between

the electrodes 40 and 42 is shown in FIG. 2 at. If the main gap 45 is punched through, can

^; ''. ORIGINAL INSPECTED

909820/0813

the commutation capacitor 35 moves via the arc 47

through the arc extinguishing circle

36 discharged as it has already been

■ V \.

was written so that the current in the main breaker 25 becomes zero.

When the current in the arc cancellation circuit 36 finally Hull what is still to be explained, arises the dielectric strength of the main gap 45 in the switch 30 of

yourself again, so that

the point distance switch 38

is back to its normal open state.

The pulses for igniting the ignition gap are from somebody usual pulse generator derived. Such a pulse generator has been shown at 56. He's About Impulse Lines 49 j 5i with the ignition electrode and the main electrode tied together. The pulse generator 56 is of the movable Contact 28 of the breaker "25 is activated when the movable Contact 28 has reached a certain point on its opening stroke. At this point a Nooke 7 * 1 catches up a normally open switch to the movable contact 20 ' 75, so that a switch-on circuit 73 for the pulse generator 56 is closed. As a result, an ignition pulse is applied to the ignition gap 51, which closes the spark gap switch 38 will. The figure; 2 shows which position the various Take individual parts after the switch 75

INSPECTED

909Ö20 / 0913

is closed to provide an ignition pulse from the

Ignition of the spark gap switch 38 to cause generator 56.

One way to charge the commutation capacitor 35, which also ends in the exemplary embodiment according to the invention

has already been proposed. According to this proposal, the capacitor 35 is without; Using an additional Auxiliary source charged directly from the power lines 16 and 19. The Konimutierungskondcnsator 35 is direct for this connected to the input of the breaker 25, and between the connection between the capacitor 35 and the switch 3ß a charging branch 5 ^ goes to the return line 19. The condensate

gate 35 is therefore always connected to the DC voltage network, i.e. even when switch 38 is open.

The charging branch 5 ^ has a fairly high resistance 55 on. Regardless of whether the breaker 25 is open or closed, the commutation capacitor 35 and the Resistor 55 in series therewith connected to the connections of the DC voltage source 12. Independent of the interrupter 25 is open or closed, the capacitor 35 can from the voltage source 12 to the full Mains voltage can be charged (provided that switch 38 is open

is). . ■ i

ORIGINAL INSPECTED

909820/0813

■ Since the KoiranutierunEskondensator then on the full Uetz. voltage is charged when the breaker 25 is open; j it is possible to close the breaker 25 and thereby ' to have the ability to return the .interrupter immediately afterwards. to be able to open if this is due to an error, for example

appears necessary in the network. ' ,!

The resistor 55 should have a relatively high value '<have, so that the capacitor 35 is not too fast corresponds loads W \ if an error between the lines 16 and 10 occurs at a location which is close to the breaker 25th Such a fault has been designated by F in FIG. If such an error occurs at the output of the interrupter, the resistor 55 would be connected in parallel to the capacitor 35 as a result of this error, see above

that the capacitor is through the resistor 55 through begins to discharge. However, if the capacitor 35 before the closing of the switch 33 already has a significant part has lost his cargo, he can make the necessary

¹ ι

No longer supply the control current if the switch 38 is closed will. The resistor 55 should therefore be so large that such a too rapid discharge of the capacitor not possible.

To prevent the entire circuit breaker assembly from opening

INSPECTEO

8 ^ 0/0813

solve, a conventional control circuit 59 is provided, which simplifies and is shown schematically. This control circuit 59 has a line 60, the two dom positive and

!
I.

negative connection of a control voltage source runs. This line leads to normally open contacts 62a of an overcurrent relay 62 and to the coil of a trip magnet

; 6k _t with which the pawl 30 is controlled. When the current in the line 16 exceeds a predetermined fourth, the relay 62 picks up, so that the ^ contacts 62a are closed. This creates the circuit for the release magnet 6Ί

j closed. The release magnet then releases the pawl 30

ι off, whereupon the breaker 25 is opened.

j j; :

ι _t

; You can see the whole arrangement; also open by hand, vrenn nan ! a switch 80 closes which is connected in parallel to the normally open contacts of the overcurrent relay 62.

! As a result, the trip circuit 59 is closed, so that the opening of the entire arrangement is triggered as it prepares

; has been described. ^:

■ 1

I (

As a breaker 25 is in by arrangement to interrupt of direct current, preferably a vacuum breaker

i
turns. But you can also use other types of switching devices

use, for example, controllable silicon rectifiers.

ORIGINAL INSPECTED

V "«

90982Ό / 0813

Ea has already been pointed out that there is an aecenspannunc at the gap 33; builds up when the current of the Lichtbo cens 3 ^ in the interrupter 25 by the discharge current of the commutation capacitor 35 has been made to zero. An essential component of this countervoltage comes from the energy which is stored in the inductance I18 and with which the capacitor 35 is charged as soon as the current in the breaker 25 becomes zero. In many practical cases the amount of this energy can be extremely high, so that the capacitor 35 can be charged to an extraordinarily high voltage without the inventive method

a circuit. 99 delimited spark gap switches

icts the one normally of-100 and a non-linear one

Has resistor 102, di ^ e jin series between the line-side connection of the interrupter 25 and the return line 19 are switched. This spark gap switch is ignited in the area of the current zero crossing, and awar preferably immediately after this zero crossing, but even before the point in time at which the counter-voltage has risen to the original value at the contacts the re-ignition can occur in the gap between the contacts of the interrupter 25 J The ignition of the spark gap switch 100 conducts electricity through circuit 99 via the non-

■ _x ^ '■■.: ■, - ORiGlNAL INSPECTED

909020/0813

linear resistance 102 from, έο that the energy of the vibrations

in which non-linear resistance is annihilated.

. ^! The spark gap switch 100 is preferably a controllable

Ibar vacuum switch of the same type as that used for the spark ! Section switch 38 is used. The individual parts of the Funiken distance switch 100, the corresponding individual parts dos

y y

; Spark gap switch '3O are similar, are therefore with

j!

-The same deciphering digits have been used, only before a 1 is set for each reference number. The spark gap switch 100 is activated by a pulse from a pulse generator I101 triggered when a switch I03 in input circuit 104 of the Pulse generator ^ is closed; is.

I.
I.

The non-linear resistor 102 is preferably made of one Material produced with a negative resistance-current characteristic, as sold, for example, by the General Electric Company under the trademark "Thyrite". If the current in this resistor 102 immediately after the Ignition of the spark gap switch 100 is high, the value of the resistor 102 is low, so that "high currents through the Resistance can flow through without the voltage drop across resistor 102 becoming too great. When the energy of the Voltage surge is almost completely destroyed, the value becomes

j
of resistor 102 increases rapidly, so that the current flows through

ORIGINAi INSPECTED 90 9 82Ö / 0813

circle 99 is limited to a much lower value

becomes, for example a

Tenth of the original Stro

mes in the power line. The non-linear Resistor 102 is chosen so that it could limit the follow current as much as possible without it during the initial discharge of the overvoltage energy, an excessive voltage drop builds up across this resistor.

^ The spark gap switch IpO, which is a vacuum switch, cannot interrupt the current in circuit 99 until the current has been pushed down to Hull. To achieve this, the spark gap switch 100 is supplied with a commutation current derived from the same capacitor 35

that is already used to reverse the current in the main breaker

j'I

25 is used. The condenser is at this point charged because it was charged by the surge voltage,

as already described.

ί ■ '

'; To trigger this commutation current, there is a third one

¹ controllable spark gap switch 200 is provided, which is also a vacuum switch and is connected in series with the capacitor 35 via the second spark gap switch 100

is. This spark gap switch 200 is normally

. It can, however, be opened by a pulse from a pulse generator 201 are ignited, which at the ignition gap 251

: ■■ ^; ■ ·! · ;. ORIGINAL INSPECTED

909820/0813

is placed. The pulse generator 201 gives the ignition pulse

i-

if there is a suitable switch in its input circuit 2O'l 203 is closed. How to close switch 203

^ is controlled, is not the subject of the invention and is therefore not shown. In one embodiment,

a simple delay circuit (not shown) use, which closes the switch 203 about 10 msec after the spark gap switch 100 is ignited. When the third

; Point gap switch 200 is ignited, the commutation capacitor can discharge itself via lines 105 and 106 through it. The inductance of this discharge path is shown at 108. This discharge current is an oscillating current which is similar to the current I _D from FIG

is lich. He therefore brings the

all current in the spark gap

switch 100 in the same, way to zero.

'When the current has become zero, it forms on the spark gap switch 100 a counter-voltage, but the maximum value of this particular counter-voltage is proportionate low, so that it does not lead to re-ignition in the spark gap switch 100. Ikr reason for the fact that the maximum four of these Counter-voltage is relatively low, consists in

that the current from the radio operator 100 is interrupted is due to the current-limiting effect of the non-linear resistor 102 immediately before the commutation

INSPECTED

■ 9 0 9 8.2 0 / 0-8 1-3

in the spark gap switch iod is also low. Since the

• ■ I

in the inductance 18 stored energy dem.quadrat this Current is directly proportional, only need lower

i - '■

Amounts of energy to be destroyed, and this can be carried out by the commutation capacitor 35 without j too high a voltage must be developed.

'i

In order to keep the subsequent voltage transitions as low as possible to hold is in the commutation circuit 105, 106 a cons,

107 was provided, but this does not affect the desired power interruption by the spark gap switch 100. This resistance ^! 107 ensures that the fommu-

tion current in commutation circuit 105, 106 is not too high

will. Since in the spark gap class: lower current than in sub-circuit ¹

also be the commutation current ν I _D.

older than 100 a significantly lower 25 is interrupted it is considerably smaller than the current.

From the description so far it can be seen that only a single commutation capacitor 35 is used to divert the current in the main breaker 25 and in the circuit 99 to

to bring the suppression of overvoltages to zero. The use of one and the same capacitor to carry out this Both functions represent a considerable economic advantage, since in this way one of the two would otherwise be required expensive capacitors are saved »

_: ORIGINAL INSPECTED-

40982 ^ 1/0813

The circuit 99 for suppressing overvoltages is working

; ί

regardless of whether the Circuit breaker is opened due to a fault or on request. If the breaker due to an error is opened, he will be much more stressed because

ι
the higher currents that occur with such a fault lead to the storage of significantly higher amounts of energy in the inductance 18, which must be destroyed in the circuit 99.

So far it has only been discussed how the energy is dissipated that is stored on the network side. But it can also Energy stored on the load side of the interrupter, which is dissipated immediately after a power interruption got to. The load-side inductance, which is shown schematically at löa, overdischarges the energy stored in it the fault current path F and pushes the voltage to the Output terminals of the breaker in the negative direction. In order to be able to dissipate this energy, a load-side is required Circuit 399 is provided for suppressing overvoltages, the one controllable spark gap switch 300 and one to it non-linear resistor 302 connected in series. This circuit 399 is between the power line 16 on the load side

and the return line 19 laid

'. ORISiNAL INSPECTED

t ·

Austria 0 9 8 2 d / 0 8 13

422-

i 1

The controllable spark extinguisher switch 300 is exactly like that the spark gap switch $ 3 built so the same Dezug 'digits have been used. Before the reference number for However, the individual parts of the spark plug switch 300 are

Sometimes a 3 was placed.

The non-linear resistance .302

corresponds to the resistance IO4 »Its resistance value increases increasing current.

Shortly after a zero crossing in the main breaker, and if

the voltage at the spark gap switch 3 © 0 reaches a certain fourth, the spark gap switch 300 is of a. Pulse generator 30I fired to complete circuit 399. As a result, the energy that is stored on the load side in the inductance 10a, irji a closed loop I j

'that flow from the fault current path F, part of the

Return line 19, the circle 399 and part of the Hetzleitung 16 consists. The spark gap switch 300 does not need to) | to be able to interrupt a current, as lastjseitig no power source is available, the current ongoing

flow through circle 399

would let. The load-side

Rather, the current drops to zero in a time that corresponds to the

constant L / R of the circle given above.

Here, L is the inductance and R is the resistance of this circuit. Through the non-linear resistor 302 is the The value for R is relatively high, so that the fall time of the

^ 'ORIGINAL INSPECTED-

90982Ö / 0813

Stromes is greatly shortened. When the current is in circuit 399 Has reached zero, it sets the dielectric strength of the spark gap switch 300 again, so that it has its original, original, resumes non-conductive state.

> ■!

The voltage applied to the separate contacts of the main breaker occurs immediately after a current zero crossing is equal to the difference between the mains voltage (between

ι
lines 16 and 19) on the network side of the breaker

and the voltage (between lines 16 and 19) on the Load side of the breaker. These two tensions are directed in opposite directions. This tension is thereby applied to one A relatively low fourth limits that the spark gap switches 100 and 300 | are ignited when the voltages at these spark gap switches are relatively low, and in that the voltage drop across the non-linear resistors iO2 and 302 is kept small by a suitable choice of these resistors. In one embodiment of the invention, the non-linear resistors are like this It means that the maximum voltage drop across the resistor 100 1.6 per unit and the maximum voltage drop across resistor 302 is -0.8 per unit. As mentioned earlier, corresponds the maximum voltage on the contacts the difference between these two tensions, so in this case 2.4 per unit.

ORIGINAL INSPECTED

90 9 8 2 0/0813

In a preferred embodiment, the network-side is used

Circle 99 to suppress ν of the main breaker to be

in overvoltage not only to

during the power interruption the voltage at the contacts

borders, but also at the same time

as surge protection during normal operation. This circuit 99 for suppression of surges can alo lightning

protection to be used because

3r below the usual pole current

can break that flows after the initial breakdown, caused by lightning. This follow current will

interrupted by the fact that the commutation capacitor 35 is triggered by the spark gap switch 200 in the auxiliary commutation circuit 105, 106 is discharged. This allows the

i ι

Commutation capacitor 35 by the spark gap switch 100 discharged, and currently via the auxiliary commutation circuit 1Ö5,

200, 106 so that the current i

η spark gap switch 100

is pushed down to zero and the spark gap switch 100 can regain its dielectric strength.

■ The circuit 399 on the load side for suppressing overvoltages cannot serve as lightning protection, since the current cannot be extinguished in it by itself. It is therefore

important that in the circle 39p no flashover by lightning is caused. Around; To exclude the possibility, lies the breakdown voltage of the load-side arranged

ORIGINAL SNSPECTlB

90982Ö / Ö813

Spark gap switch 300 Noticeably above the Durch3Chlagn-I voltage of the spark gap switch located on the line side ί 100. Therefore, if a voltage caused by lightning

j i

¹ pushes the line 16 along, the network-side spark gap switch 100 and not the load-side > spark gap switch 300 is ignited. Ntfr during a current interruption ¹ itself, the breakdown voltage in the ^1-side load Kreils 399 is reduced voltages for the suppression of iiber- 'as vmrde already explained.

; Through the use of controllable spark gap switchgear, . which are designed as vacuum switches, in circles 99

■ - i

and 399 to suppress overvoltage is the whole Etrom-

I.
ι Interrupter arrangement extremely flexible. The conditions,

under which a breakdown is caused can through ■ a simple setting of the pulse generators for the respective Spark gap switches can be changed quickly and accurately. For example, the spark gap switch hits 100 under normal conditions when a predetermined high voltage is applied to it. This allows this Funkon route counter 100 serve as lightning protection, as already described. However, if the main breaker 25 is operated, speak devices T ^, 75a, the schematic are shown in Figure Ί on and cause the The effective ignition circuit for each of the spark gap switches

ORIGINAL INSPECTED

9 0 9 82070813

Reduce breakdown voltage so that the voltage drop

at the main breaker 25 6 proceeds as it has already been done

a given value has not been overwritten. In the scheme

Table illustration according to Figure H is a pulse source 101

shown, which emits pulses to the ignition electrode 151 when

it is turned on. These

Impulse source is stopped,

if their input circuit 112 by a quick switch is closed, which is shown schematically as thyratron 11'I ^ i represents is. The thyratron 11 * 1 does not normally conduct.

P I

If, however, it is activated at the grid 115, it becomes conductive and thereby switches the pulse source 101 on. The control signal for the thyratron there is a usual voltage sensor

ι-

loaned pulse generator 117 supplied with a capacitor 113 of two capacitors 118, 119 connected in series

is connected, which are placed in parallel with the spark gap switch 100. Under normal conditions, the voltage-sensitive pulse generator 117 then controls the thyratron 11'l when the voltage drop across the capacitor 118 reaches a predetermined V / ert. If, on the other hand, the main breaker 25 is opened, the voltage-sensitive pulse generator 117 is switched over (for example, by turning on a resistor with the aid of the switch 75 _{3 of} the movable contact 28 of the main breaker 25), so that the pulse generator.

ί
117 already at a much lower voltage on the

Capacitor 118 emits a pulse ".

- ORIGINAL. INSPECTED

§09820 / 0813

Claims (8)

—'27'— "* * Claims' sBsssssssssssssssaasassBSSSss) 1. Arrangement for the interruption of currents at high DC voltages, with a circuit breaker, its normally closed contacts are connected in series with a load, furthermore with a commutation circuit with a commutation capacitor which is in series with; a normally open switch is connected in parallel with the circuit breaker contacts, and with means for opening the normally closed circuit breaker contacts, whereby an arc is created between the circuit breaker contacts, characterized in that ^: da ß a branch to limit the Gegerispannunp; is provided at the Strominterruption Konjtakten that develops Will when the arcing strbm between the open circuit breaker contacts is pushed down to zero by the commutation current, which is a normally non-conductive spark gap switch and has a resistor, and mains-side, in front of the current interruption contacts and the current return conductor, that this normally non-conductive spark gap switch at the level of the zero crossing of the arc current between the Strominterbrecherko .takten is ignited, so that electricity is directly off the network through the spark gap switch and the resistor flows', and that to commutate the current through the spark gap switch Means (200, 107) are provided through which the commutation capacitor (35) can be switched in parallel with the spark gap switch (100). ORIGINAL INSPECTED 9Ö9820 / 0813 2. Arrangement according to claim 1, characterized draws that the normally non-conductive Spark gap switch in the | current branch to limit the i - Counter voltage immediately after the arc current crosses zero is ignited between the circuit breaker contacts .. 3. Arrangement according to claim Ii, characterized in that the resistance in the current branch for limiting the counter voltage is a non-linear resistor with a negative resistance-current characteristic. 4. Arrangement according to one of claims 1 to 3, d a d u r c h g e k e η; η ζ e i c h η e t, d a ß the normally non-conductive Spark gap holder a controllable vacuum spark : ■ - ,.: ■■ "■ - ■■ - '[■■ - .. / ■ - ■". ■ "-." ■ Stretching it is. j; ; 5. Arrangement according to claim 1, characterized in that that the means by which the commutation. the condenser capacitor can be connected in parallel to the spark gap switch, have a further controllable spark gap switch between the connection point between the capacitor and the circuit breaker and the connection point between the first spark gap switch j and the resistor. 6. Arrangement according to claim lj, characterized g e k e η η - draws that ukr resistance in the current branch to Limitation of the counter voltage! A resistor with a non-linear one Resistance-current curve, the value of which is chosen so that the one evoked by the highest occurring currents Voltage drop is less than 2.5 times the mains voltage. ί ^/ 7. Arrangement according to one or more of claims 1 to G ₃ marked zje rejects that a second branch is provided to limit the overvoltage at the current interruption contacts, which is arranged on the load side and has a further spark gap switch and a non-linear resistor that this second Spark gap switch is ignited immediately after the zero crossing of the arc current between the circuit breaker contacts, and that the non-linear resistance in the second branch is selected so that the highest voltage drop occurring across it is lower than the mains voltage. 8. Arrangement according to claim 7 * characterized in that that the breakdown voltage of the spark gap switch in the first siromzweig to limit the counter voltage with closed contacts of the circuit breaker lower than the breakdown voltage of the second, on the load side arranged branch to limit the counter voltage lying spark gap switch. ORfGiNAl. (NSPECTED 909820/0813