US3590319A - Apparatus for attenuating voltage surges - Google Patents

Apparatus for attenuating voltage surges Download PDF

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US3590319A
US3590319A US843059A US3590319DA US3590319A US 3590319 A US3590319 A US 3590319A US 843059 A US843059 A US 843059A US 3590319D A US3590319D A US 3590319DA US 3590319 A US3590319 A US 3590319A
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line
power switch
attenuating
switch
resistance
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US843059A
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Paul Baltensperger
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BBC Brown Boveri AG Germany
BBC Brown Boveri France SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/59—Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the ac cycle
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/005—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection avoiding undesired transient conditions

Definitions

  • an attenuating resistance assembly which is structurally separate from the power switch itself is connected into the line on the line side of the power switch.
  • This attenuating assembly includes a resistance component in series with the line and having connected in parallel with it a bypass switch and an overvoltage protective device which may be in the form of a spark gap.
  • the bypass switch is opened prior to opening of the power switch, and the overvoltage protective device establishes a limit to the voltage which can be impressed across the attenuating resistance component.
  • a compensating choke coil can also be connected to the line at either side of the attenuating resistance component. In a circuit closing operation, the power switch closes first followed by closing of the bypass switch after a brief time delay.
  • the present invention relates to apparatus to be connected in series with a power switch on'the line side at one end of a high-voltage line and which functions to attenuate voltage surges occurring on the high-voltage line during closing as well as opening of the power switch.
  • apparatus intended to be connected in series with a power switch but structurally separate therefrom at one end of a high-voltage line and intended to attenuate voltage surges occurring on the high-voltage line during closing and opening of the power switch, the apparatus comprising a resistance inserted in the line and there being connected in parallel therewith a bypass switch as well as an overvoltage protector.
  • Apparatus in accordance with this invention being structurally separate from the power switch, is relatively simple to construct, with the additional advantage of a relatively small voltage load on the line inserted resistance.
  • the ohmic value of the resistance should be about equal to the characteristic impedance of the line, i.e. several hundreds of ohms.
  • An advantage of this apparatus is, that the power switch at the end or at the origin of the high-voltage line may be of simple construction because its damping resistance can be dispensed with, while the resistance and the bypass switch of the apparatus in-accordance with this invention can be more favorably dimensioned to a substantial extent.
  • FIG. 1 is a schematic circuit diagram illustrating one embodiment of the invention wherein the attenuating resistance together with its parallel connected bypass switch and overvoltage protector are applied to a single-phase high-voltage line, the attenuating apparatus being connected in on the line side of a power switch located at one end of the line such as at a sub-station where power is fed into the line:
  • FIG. 2 is a schematic circuit diagram similar to Fig. l illustrating a modification wherein a compensating choke coil is incorporated to improve the desired attenuation effect during a switching out, i.e. an opening of the contacts of the power switch;
  • FIG. 3 is also a schematic circuit diagram similar to Fig. 2 but illustrating an alternative mode for connecting in the compensating choke coil;
  • FlGS. 4a and 4b are side elevations of two different forms of apparatus, each of which incorporates the circuit structure as shown in the Fig. l schematic;
  • FIG. 5 is a side elevation of a form of apparatus incorporating the circuit structure shown in the Fig. 2 schematic;
  • FIG. 6 is a side elevation of a form of apparatus incorporating the circuit structure shown in the Fig. 3 schematic, and
  • FIG. 7 is a schematic diagram illustrating one suitable arf rangement for effecting sequential operation of the power switch and bypass switch.
  • a high-voltage line 1 can be connected and disconnected at its station-side end by means of a power switch 2.
  • Reference numeral 3 designates a feeding voltage source to the line, e.g. one or more power stations.
  • the power switch 2 contrary to practice prior to the present improved arrangement, has no damping resistance structurally associated with it however, between the switch 2 and the line 1 i.e. on the line side of the switch, there is connected an attenuating assembly 4 structurally separate from the power switch 2 in accordance with the invention which consists of a resistance 4a connected into the line, a bypass switch 4b connected in parallel with the resistance 4a, and an overvoltage protector 4c connected in parallel with the resistance 4a and also with the switch 4b.
  • the overvoltage protector in its simplestform, may, as illustrated, be constructed as a protective spark gap.
  • the power switch 2 and the bypass switch 4b may be known types and are actuated in a sequence such that the resistance 40 becomes effective during the switching process over a predeterminable optimum period, e.g. 10 ms.
  • the disconnection'sequence may, for example, be that the bypass switch 4b opens first and then, after a small lag, the switch 2 opens; the connection sequence may be that the switch 2 closes first and the bypass switch 4b then closes.
  • the attenuating assembly 4 shown in Fig. l is primarily intended to attenuate voltage surges during connection, but, depending on the ohmic value of the resistance 4a, also has a certain effect during disconnection.
  • the protective spark gap 40 ensures that only a limited voltage will act on the resistance 4a. In the absence of the spark gap 40, the resistance 4a would have to be able to deal with the entire pole voltage, e.g. in the case of short'circuit or phaseopposition during connection.
  • the bypass switch 4b may be constructed as a rapid-break switch having a certain power-switching capacity on connection and disconnection. Thus, for example, when connecting on short circuit it must be able to commutate, i.e.
  • the high-voltage line 1 is equipped with compensating chokes, the latter may be expediently connected either as shown in Fig. 2 or as shown in Fig. 3.
  • the compensating choke 5 is connected as shown in Fig. 2, an especially advantageous attenuating effect will also be obtained during disconnection owing to the resistance 4a, because the resistance 4a, is included in the oscillatory circuit formed by the choke 5 and the line capacity.
  • FIGS. 4a and 4b both of which correspond to Fig. 1 show the main power switch 2 as a multiple type circuit-breaker in which a plurality. of individual power switch units are connected in series.
  • Fig. 4a the bypass switch 4b of the attenuating assembly 4 that is structurally separate from the power switch 2 is shown as having a single vertically disposed contact chamber, whereas in Fig. 4b the contacts of the bypass switch 4b are accommodated in a horizontally disposed double contact chamber.
  • Fig. 5 corresponds to Fig. 2
  • Fig. 6 corresponds to Fig. 3. in all the Figures the same parts are denoted the same reference numerals.
  • Fig. 7 illustrates in a schematic manner one suitable arrangement for actuating the power switch 2 and the bypass switch 4b in their proper sequence.
  • 2a designates a relay contact or a control contact for initiating a closing operation of the power switch.
  • 2b represents the closing coil for the power switch 2 and the appertaining trigger mechanism.
  • This mechanism provides over a mechanical link 2c a mechanical impulse to the control mechanism 2e which, for example, may be constituted by a pneumatic piston. From this latter mechanism, the closing movement is transmitted to the contacts of the power switch 2 by one or a plurality of insulated rods 2f.
  • the closing coil and its trigger mechanism for the bypass switch 4b are designated by 4e and the contact closing mechanism by 4d.
  • the desired time-delay in closing switch 4b following closure of switch 2 is obtained by controlling its closing coil 4e by means of an auxiliary contact 2d in the energizing circuit for this coil, the contact 2d being controlled by link 20 in the control for switch 2.
  • Contact 2d closes a few milliseconds after closing of the contact 2a that serves to energize coil 2b. Regulation of this time-delay may be obtained in different manners, for example, by adding a mechanical timedelay device between and 2d. 7
  • the mechanism depicted operates according to the same principle but in reverse so that the bypass switch opens first followed by opening of the power switch 2 after a brief time-delay.
  • the drawings illustrate the apparatus 4 only for single phase and on only at one end of the high-voltage line. It is obvious that the apparatus 4 may be constructed for multiphase operation, and may be provided at both ends of the high-voltage line.
  • An arrangement for switching longhigh-voltage alternating current transmission lines comprising a power switch located at one end of the transmission line, and an attenuating assembly for attenuating voltage surges which occur as a result of actuating said power switch, said attenuating assembly being structurally separate from said power switch and including an attenuating resistance connected in series with said transmission line on the line side of said power switch, a bypass switch connected in parallel with said attenuating resistance, and an overvoltage protective device also connected in parallel with said attenuating resistance.

Abstract

In order to attenuate voltage surges which may occur on a highvoltage line upon closing or opening of a power switch located at an end of the line which serves to connect the line to a supply source, an attenuating resistance assembly which is structurally separate from the power switch itself is connected into the line on the line side of the power switch. This attenuating assembly includes a resistance component in series with the line and having connected in parallel with it a bypass switch and an overvoltage protective device which may be in the form of a spark gap. The bypass switch is opened prior to opening of the power switch, and the overvoltage protective device establishes a limit to the voltage which can be impressed across the attenuating resistance component. A compensating choke coil can also be connected to the line at either side of the attenuating resistance component. In a circuit closing operation, the power switch closes first followed by closing of the bypass switch after a brief time delay.

Description

United States Patent 1,357,257 11/1920 Slepian APPARATUS FOR ATTENUATING VOLTAGE SURGES 4 Claims, 8 Drawing Figs.
U.S.Cl 317/11C, 200/144, 307/93, 317/16, 317/20 Int. Cl .l. H02h 7/22 Field of Search 307/93; 317/] l, 16, 20; 200/144 AP References Cited UNITED STATES PATENTS 2,802,149 8/1957 Germer et a1 317/11 FOREIGN PATENTS 999,802 2/1952 France 200/144 Primary Examiner lames D. Trammell Attorney- Pierce, Shceffler & Parker ABSTRACT: In order to attenuate voltage surges which may occur on a high-voltage line upon closing or opening of a power switch located at an end of the line which serves to connect the line to a supply source, an attenuating resistance assembly which is structurally separate from the power switch itself is connected into the line on the line side of the power switch. This attenuating assembly includes a resistance component in series with the line and having connected in parallel with it a bypass switch and an overvoltage protective device which may be in the form of a spark gap. The bypass switch is opened prior to opening of the power switch, and the overvoltage protective device establishes a limit to the voltage which can be impressed across the attenuating resistance component. A compensating choke coil can also be connected to the line at either side of the attenuating resistance component. In a circuit closing operation, the power switch closes first followed by closing of the bypass switch after a brief time delay.
PATENTEU JUN2 9 Ian SHEET 1 OF 3 Fig.2
Swan/Mom QUL BfLtlQngper j W2VPWAU APPARATUS FOR ATTENUATING VOLTAGE SURGES The present invention relates to apparatus to be connected in series with a power switch on'the line side at one end of a high-voltage line and which functions to attenuate voltage surges occurring on the high-voltage line during closing as well as opening of the power switch.
For the purpose of diminishing the voltage surges which occur during switching, it is known to provide power switches at the terminal point of the line with damping resistances connected in series with and, also in parallel with, the main power switch. This known arrangement involves the use of corresponding auxiliary switches for switching the damping resistances in and out. The resulting switch construction is complicated, which increases not only the cost but also the failure rate. In particular, the resistances must be dimensioned for the full switch pole voltage for switching in case of short circuit and of phase opposition. The same applies to the associated auxiliary switches. v
it is an object of this invention to provide a relative simple apparatus intended to be connected in series with a power switch on the line side at one end of a high-voltage line and intended to attenuate voltage surges occurring on the high-voltage line during closing and opening of the power switch.
According to the invention there is provided apparatus intended to be connected in series with a power switch but structurally separate therefrom at one end of a high-voltage line and intended to attenuate voltage surges occurring on the high-voltage line during closing and opening of the power switch, the apparatus comprising a resistance inserted in the line and there being connected in parallel therewith a bypass switch as well as an overvoltage protector.
Apparatus in accordance with this invention, being structurally separate from the power switch, is relatively simple to construct, with the additional advantage of a relatively small voltage load on the line inserted resistance. As is known, the ohmic value of the resistance should be about equal to the characteristic impedance of the line, i.e. several hundreds of ohms. An advantage of this apparatus is, that the power switch at the end or at the origin of the high-voltage line may be of simple construction because its damping resistance can be dispensed with, while the resistance and the bypass switch of the apparatus in-accordance with this invention can be more favorably dimensioned to a substantial extent.
Embodiments of the invention will now be described, by
way of example only, with reference to the accompanying schematic drawings wherein:
FIG. 1 is a schematic circuit diagram illustrating one embodiment of the invention wherein the attenuating resistance together with its parallel connected bypass switch and overvoltage protector are applied to a single-phase high-voltage line, the attenuating apparatus being connected in on the line side of a power switch located at one end of the line such as at a sub-station where power is fed into the line:
FIG. 2 is a schematic circuit diagram similar to Fig. l illustrating a modification wherein a compensating choke coil is incorporated to improve the desired attenuation effect during a switching out, i.e. an opening of the contacts of the power switch;
FIG. 3 is also a schematic circuit diagram similar to Fig. 2 but illustrating an alternative mode for connecting in the compensating choke coil;
FlGS. 4a and 4b are side elevations of two different forms of apparatus, each of which incorporates the circuit structure as shown in the Fig. l schematic;
FIG. 5 is a side elevation of a form of apparatus incorporating the circuit structure shown in the Fig. 2 schematic;
FIG. 6 is a side elevation of a form of apparatus incorporating the circuit structure shown in the Fig. 3 schematic, and
FIG. 7 is a schematic diagram illustrating one suitable arf rangement for effecting sequential operation of the power switch and bypass switch.
Referring first to Fig. l, a high-voltage line 1 can be connected and disconnected at its station-side end by means of a power switch 2. Reference numeral 3 designates a feeding voltage source to the line, e.g. one or more power stations. The power switch 2, contrary to practice prior to the present improved arrangement, has no damping resistance structurally associated with it however, between the switch 2 and the line 1 i.e. on the line side of the switch, there is connected an attenuating assembly 4 structurally separate from the power switch 2 in accordance with the invention which consists of a resistance 4a connected into the line, a bypass switch 4b connected in parallel with the resistance 4a, and an overvoltage protector 4c connected in parallel with the resistance 4a and also with the switch 4b. The overvoltage protector, in its simplestform, may, as illustrated, be constructed as a protective spark gap. The power switch 2 and the bypass switch 4b may be known types and are actuated in a sequence such that the resistance 40 becomes effective during the switching process over a predeterminable optimum period, e.g. 10 ms. The disconnection'sequence may, for example, be that the bypass switch 4b opens first and then, after a small lag, the switch 2 opens; the connection sequence may be that the switch 2 closes first and the bypass switch 4b then closes.
The attenuating assembly 4 shown in Fig. l is primarily intended to attenuate voltage surges during connection, but, depending on the ohmic value of the resistance 4a, also has a certain effect during disconnection. The protective spark gap 40 ensures that only a limited voltage will act on the resistance 4a. In the absence of the spark gap 40, the resistance 4a would have to be able to deal with the entire pole voltage, e.g. in the case of short'circuit or phaseopposition during connection. The bypass switch 4b may be constructed as a rapid-break switch having a certain power-switching capacity on connection and disconnection. Thus, for example, when connecting on short circuit it must be able to commutate, i.e. to take over and carry-the current of the spark gap 4c. if the high-voltage line 1 is equipped with compensating chokes, the latter may be expediently connected either as shown in Fig. 2 or as shown in Fig. 3. When the compensating choke 5 is connected as shown in Fig. 2, an especially advantageous attenuating effect will also be obtained during disconnection owing to the resistance 4a, because the resistance 4a, is included in the oscillatory circuit formed by the choke 5 and the line capacity.
FIGS. 4a and 4b both of which correspond to Fig. 1 show the main power switch 2 as a multiple type circuit-breaker in which a plurality. of individual power switch units are connected in series. in Fig. 4a the bypass switch 4b of the attenuating assembly 4 that is structurally separate from the power switch 2 is shown as having a single vertically disposed contact chamber, whereas in Fig. 4b the contacts of the bypass switch 4b are accommodated in a horizontally disposed double contact chamber. As already stated, Fig. 5 corresponds to Fig. 2, and Fig. 6 corresponds to Fig. 3. in all the Figures the same parts are denoted the same reference numerals.
Fig. 7 illustrates in a schematic manner one suitable arrangement for actuating the power switch 2 and the bypass switch 4b in their proper sequence. in this figure, 2a designates a relay contact or a control contact for initiating a closing operation of the power switch. 2b represents the closing coil for the power switch 2 and the appertaining trigger mechanism. This mechanism provides over a mechanical link 2c a mechanical impulse to the control mechanism 2e which, for example, may be constituted by a pneumatic piston. From this latter mechanism, the closing movement is transmitted to the contacts of the power switch 2 by one or a plurality of insulated rods 2f.
The closing coil and its trigger mechanism for the bypass switch 4b are designated by 4e and the contact closing mechanism by 4d. The desired time-delay in closing switch 4b following closure of switch 2 is obtained by controlling its closing coil 4e by means of an auxiliary contact 2d in the energizing circuit for this coil, the contact 2d being controlled by link 20 in the control for switch 2. Contact 2d closes a few milliseconds after closing of the contact 2a that serves to energize coil 2b. Regulation of this time-delay may be obtained in different manners, for example, by adding a mechanical timedelay device between and 2d. 7
To initiate an opening operation of the switches, the mechanism depicted operates according to the same principle but in reverse so that the bypass switch opens first followed by opening of the power switch 2 after a brief time-delay.
The drawings illustrate the apparatus 4 only for single phase and on only at one end of the high-voltage line. It is obvious that the apparatus 4 may be constructed for multiphase operation, and may be provided at both ends of the high-voltage line.
I claim:
1. An arrangement for switching longhigh-voltage alternating current transmission lines comprising a power switch located at one end of the transmission line, and an attenuating assembly for attenuating voltage surges which occur as a result of actuating said power switch, said attenuating assembly being structurally separate from said power switch and including an attenuating resistance connected in series with said transmission line on the line side of said power switch, a bypass switch connected in parallel with said attenuating resistance, and an overvoltage protective device also connected in parallel with said attenuating resistance.
2. Apparatus as defined in claim 1 wherein said overvoltage protective device is constituted by a spark gap.
3. Apparatus as defined in claim 1 and which further includes a compensating choke connected between said line and ground at a point on said line intermediate said power switch and said resistance component.
4. Apparatus as defined in claim 1 and which further includes a compensating choke connected between said line and ground at the line side of said resistance component.

Claims (4)

1. An arrangement for switching long high-voltage alternating current transmission lines comprising a power switch located at one end of the transmission line, and an attenuating assembly for attenuating voltage surges which occur as a result of actuating said power switch, said attenuating assembly being structurally separate from said power switch and including an attenuating resistance connected in series with said transmission line on the line side of said power switch, a bypass switch connected in parallel with said attenuating resistance, and an overvoltage protective device also connected in parallel with said attenuating resistance.
2. Apparatus as defined in claim 1 wherein said overvoltage protective device is constituted by a spark gap.
3. Apparatus as defined in claim 1 and which further includes a compensating choke connected between said line and ground at a point on said line intermediate said power switch and said resistance component.
4. Apparatus as defined in claiM 1 and which further includes a compensating choke connected between said line and ground at the line side of said resistance component.
US843059A 1968-07-24 1969-07-18 Apparatus for attenuating voltage surges Expired - Lifetime US3590319A (en)

Applications Claiming Priority (1)

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CH1111168A CH485344A (en) 1968-07-24 1968-07-24 Arrangement for damping overvoltages on a high-voltage line

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AT (1) AT286419B (en)
BE (1) BE736358A (en)
CH (1) CH485344A (en)
DE (1) DE1920261A1 (en)
ES (1) ES369744A1 (en)
FR (1) FR2013592A1 (en)
GB (1) GB1240024A (en)
NL (1) NL6911130A (en)
NO (1) NO130380B (en)
SE (1) SE347397B (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3957329A (en) * 1974-11-01 1976-05-18 I-T-E Imperial Corporation Fault-current limiter for high power electrical transmission systems
US4042963A (en) * 1975-01-25 1977-08-16 Licentia Patent-Verwaltungs-Gmbh Reduction of mechanical stresses on turbosets upon occurrence of three-pole mains short circuits near generators
US4093968A (en) * 1976-11-22 1978-06-06 Emerson Electric Co. Resistors with heat sink
US4172269A (en) * 1977-12-19 1979-10-23 North American Philips Corporation Circuit for overshoot supression in X-ray generators
US4628268A (en) * 1982-11-18 1986-12-09 Mitsubishi Denki Kabushiki Kaisha Test device for testing an actuator circuit
US5815387A (en) * 1995-12-13 1998-09-29 Mitsubishi Denki Kabushiki Kaisha Transformer protective apparatus having semiconductor and mechanical bypass means
US20090274051A1 (en) * 2008-04-30 2009-11-05 Agilent Technologies, Inc. Dynamic Switch Contact Protection
US8593777B1 (en) * 2012-05-11 2013-11-26 Apple Inc. User-actuated button ESD protection circuit with spark gap

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH598691A5 (en) * 1976-06-21 1978-05-12 Bbc Brown Boveri & Cie
JPS55105921A (en) * 1979-02-08 1980-08-14 Tokyo Shibaura Electric Co Method of closing breaker
CH665053A5 (en) * 1984-11-12 1988-04-15 Bbc Brown Boveri & Cie SWITCH ARRANGEMENT FOR SWITCHING OFF A REACTANCE.

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1357257A (en) * 1918-09-16 1920-11-02 Westinghouse Electric & Mfg Co Switching device
FR999802A (en) * 1946-01-08 1952-02-05 Merlin Gerin Improvements to resistance switches
US2802149A (en) * 1953-12-30 1957-08-06 Bell Telephone Labor Inc Contact protection circuits

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1357257A (en) * 1918-09-16 1920-11-02 Westinghouse Electric & Mfg Co Switching device
FR999802A (en) * 1946-01-08 1952-02-05 Merlin Gerin Improvements to resistance switches
US2802149A (en) * 1953-12-30 1957-08-06 Bell Telephone Labor Inc Contact protection circuits

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3957329A (en) * 1974-11-01 1976-05-18 I-T-E Imperial Corporation Fault-current limiter for high power electrical transmission systems
US4042963A (en) * 1975-01-25 1977-08-16 Licentia Patent-Verwaltungs-Gmbh Reduction of mechanical stresses on turbosets upon occurrence of three-pole mains short circuits near generators
US4093968A (en) * 1976-11-22 1978-06-06 Emerson Electric Co. Resistors with heat sink
US4172269A (en) * 1977-12-19 1979-10-23 North American Philips Corporation Circuit for overshoot supression in X-ray generators
US4628268A (en) * 1982-11-18 1986-12-09 Mitsubishi Denki Kabushiki Kaisha Test device for testing an actuator circuit
US5815387A (en) * 1995-12-13 1998-09-29 Mitsubishi Denki Kabushiki Kaisha Transformer protective apparatus having semiconductor and mechanical bypass means
US20090274051A1 (en) * 2008-04-30 2009-11-05 Agilent Technologies, Inc. Dynamic Switch Contact Protection
US8922957B2 (en) * 2008-04-30 2014-12-30 Keysight Technologies, Inc. Dynamic switch contact protection
US8593777B1 (en) * 2012-05-11 2013-11-26 Apple Inc. User-actuated button ESD protection circuit with spark gap

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CH485344A (en) 1970-01-31
DE1920261A1 (en) 1970-05-27
BE736358A (en) 1969-12-31
SE347397B (en) 1972-07-31
AT286419B (en) 1970-12-10
NL6911130A (en) 1970-01-27
GB1240024A (en) 1971-07-21
NO130380B (en) 1974-08-19
ES369744A1 (en) 1971-04-01
FR2013592A1 (en) 1970-04-03

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