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High-voltage switchgear

January 01, 1970

High-voltage switchgear is any switchgear used to connect or disconnect a part of a high-voltage power system. This equipment is essential for the protection and safe operation, without interruption, of a high voltage power system, and is important because it is directly linked to the quality of the electricity supply.

800 kV high-voltage switchgear

The term "high voltage" covers the former medium voltage (MV) and the former high voltage (HV), so refers to equipment with a rated voltage of over 1000 V in the case of alternating current, and over 1500 V in the case of direct current. The industrial applications of high voltage circuit breakers are for the moment limited to alternating current because they are more economical, there are however high voltage disconnectors for direct current connections.

High-voltage switchgear was invented at the end of the 19th century for operating motors and others electric machines.[1] The technology has been improved over time and can be used with voltages up to 1,100 kV.[2]

Classification edit

Functional classification edit

Disconnectors and earthing switches edit

Disconnectors and earthing switches are safety devices used to open or to close a circuit when there is no current through them. They are used to isolate a part of a circuit, a machine, a part of an overhead line or an underground line so that maintenance can be safely conducted.

The opening of the line isolator or busbar section isolator is necessary for safety, but not sufficient. Grounding must be conducted at both the upstream and downstream sections of the device under maintenance. This is accomplished by earthing switches.

In principle, disconnecting switches do not have to interrupt currents, as they are designed for use on de-energized circuits. In practice, some are capable of interrupting currents (as much as 1,600 ampere under 300 V but only if current is drawn via a same circuit half breaker bypass system), and some earthing switches must interrupt induced currents which are generated in a non-current-carrying line by inductive and capacitive coupling with nearby lines (up to 160 A under 20 kV).[3]

High-current switching mechanism edit

High-current switching mechanisms are used for energized circuits carrying a normal load. Some can be used as a disconnecting switch. But if they can create a short-circuit current, they can not interrupt it.[4][5]

Contactor edit

Contactors are similar in function to high-current switching mechanisms, but can be used at higher rates. They have a high electrical endurance and a high mechanical endurance.[6]

Fuses edit

A fuse can automatically interrupt a circuit with an overcurrent flowing in it for a fixed time. This is accomplished by the fusion of an electrical conductor which is graded.

Fuses are mainly used to protect against short circuits. They limit the peak value of the fault current.

In three-phase electric power, they only eliminate the phases where the fault current is flowing, which can pose a risk for both the malfunctioning devices and the people. To alleviate this problem, fuses can be used in conjunction with high-current switches or contactors.

Like contactors, high-voltage fuses are used only in the band 30 kV to 100 kV.[citation needed]

Circuit breaker edit

A high voltage circuit breaker is capable of connecting, carrying and disconnecting currents under the rated voltage (the maximal voltage of the power system which it is protecting).

Under normal operational conditions, circuit breakers can be used to (dis)connect a line. Circuit breakers can also be used to interrupt current when anomalies are detected, such as a short-circuit.

Circuit breakers are essential elements of high-voltage power systems because they are the only means to safely interrupt a short circuit current. The international standard IEC 62271-100 defines the demands linked to the characteristics of a high voltage circuit breaker.[7]

The circuit breaker can be equipped with electronic devices to know at any moment their states, such as wear or gas pressure, and to detect faults from characteristic derivatives. It can also permit planned maintenance operations and to avoid failures.[8][9]

To operate on long lines, circuit breakers are equipped with a closing resistor to limit overvoltages.[10][11]

They can be equipped with devices to synchronize closing and/or opening, to limit the overvoltages and the inrush currents from the lines, the unloaded transformers, the shunt reactances and the capacitor banks.[12][13]

Some devices are designed to have the characteristics of the circuit breaker and the disconnector,[14] but their use is not widespread.

References edit

  1. ^ British Pattern GB 20069 Improvements in Apparatus for Controlling the Application or Use of Electric Currents of High Tension and Great Quantity in 1893, on espacenet.com
  2. ^ Lin Jiming et al., Transient characteristics of 1100 kV circuit-breakers, International Symposium on International Standards for Ultra High Voltage, Beijing, Juillet 2007.
  3. ^ IEC 62271-102 for A.C. disconnectors and earthing switches
  4. ^ Norme CEI 60265-1 Interrupteurs pour tension assignée supérieure à 1 kV et inférieure à 52 kV
  5. ^ Norme CEI 60265-2 Interrupteurs pour tension assignée supérieure à 52 kV
  6. ^ Norme CEI 60470 Contacteurs pour courant alternatif haute tension et démarreurs de moteurs à contacteurs
  7. ^ Norme CEI 62271-100 Disjoncteurs à haute tension
  8. ^ E.Thuries, G.Ebersohl, J.P.Dupraz, O.Chetay, J.P.Montcorgé, Introduction de l'électronique numérique dans les auxiliaires de l'appareillage et amélioration de la fiabilité, 1994, CIGRE session 1994, rapport 23/13-09
  9. ^ Denis Dufournet, Disjoncteurs SF6 – Évolution de 1959 à 1994, 1994, Revue générale de l'électricité n° 5
  10. ^ D.E. Heldman, I.B. Johnson, C.H. Titus, D.D. Wilson, Switching of Extra-High-Voltage Circuits, Surge reduction with circuit-breaker resistors, 1964, IEEE Transactions on Power Apparatus and Systems, Vol. 83 (1964–12)
  11. ^ Eugène Maury, Problèmes apparaissant aux tensions les plus élevées lors de la manœuvre des disjoncteurs, 1964, CIGRE session 1964
  12. ^ Eugène Maury, La fermeture synchronisée des disjoncteurs 525 kV et 765 kV, moyen de réduire les surtensions de manœuvre sur lignes à vide, 1966, CIGRE session 1966.
  13. ^ Groupe de travail CIGRE 13.07, Controlled switching of HV AC circuit breakers, 1999, Electra N° 183
  14. ^ Norme CEI 62271-108 Disjoncteur-sectionneurs

External links edit

  • IEEE Switchgear Committee, on ewh.ieee.org

January 01, 1970
high, voltage, switchgear, help, expand, this, article, with, text, translated, from, corresponding, article, french, march, 2022, click, show, important, translation, instructions, view, machine, translated, version, french, article, machine, translation, lik. You can help expand this article with text translated from the corresponding article in French March 2022 Click show for important translation instructions View a machine translated version of the French article Machine translation like DeepL or Google Translate is a useful starting point for translations but translators must revise errors as necessary and confirm that the translation is accurate rather than simply copy pasting machine translated text into the English Wikipedia Do not translate text that appears unreliable or low quality If possible verify the text with references provided in the foreign language article You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation A model attribution edit summary is Content in this edit is translated from the existing French Wikipedia article at fr Appareillage electrique a haute tension see its history for attribution You may also add the template Translated fr Appareillage electrique a haute tension to the talk page For more guidance see Wikipedia Translation High voltage switchgear is any switchgear used to connect or disconnect a part of a high voltage power system This equipment is essential for the protection and safe operation without interruption of a high voltage power system and is important because it is directly linked to the quality of the electricity supply 800 kV high voltage switchgear The term high voltage covers the former medium voltage MV and the former high voltage HV so refers to equipment with a rated voltage of over 1000 V in the case of alternating current and over 1500 V in the case of direct current The industrial applications of high voltage circuit breakers are for the moment limited to alternating current because they are more economical there are however high voltage disconnectors for direct current connections High voltage switchgear was invented at the end of the 19th century for operating motors and others electric machines 1 The technology has been improved over time and can be used with voltages up to 1 100 kV 2 Contents 1 Classification 1 1 Functional classification 1 1 1 Disconnectors and earthing switches 1 1 2 High current switching mechanism 1 1 3 Contactor 1 1 4 Fuses 1 1 5 Circuit breaker 2 References 3 External linksClassification editFunctional classification edit Disconnectors and earthing switches edit Disconnectors and earthing switches are safety devices used to open or to close a circuit when there is no current through them They are used to isolate a part of a circuit a machine a part of an overhead line or an underground line so that maintenance can be safely conducted The opening of the line isolator or busbar section isolator is necessary for safety but not sufficient Grounding must be conducted at both the upstream and downstream sections of the device under maintenance This is accomplished by earthing switches In principle disconnecting switches do not have to interrupt currents as they are designed for use on de energized circuits In practice some are capable of interrupting currents as much as 1 600 ampere under 300 V but only if current is drawn via a same circuit half breaker bypass system and some earthing switches must interrupt induced currents which are generated in a non current carrying line by inductive and capacitive coupling with nearby lines up to 160 A under 20 kV 3 High current switching mechanism edit High current switching mechanisms are used for energized circuits carrying a normal load Some can be used as a disconnecting switch But if they can create a short circuit current they can not interrupt it 4 5 Contactor edit Contactors are similar in function to high current switching mechanisms but can be used at higher rates They have a high electrical endurance and a high mechanical endurance 6 Fuses edit A fuse can automatically interrupt a circuit with an overcurrent flowing in it for a fixed time This is accomplished by the fusion of an electrical conductor which is graded Fuses are mainly used to protect against short circuits They limit the peak value of the fault current In three phase electric power they only eliminate the phases where the fault current is flowing which can pose a risk for both the malfunctioning devices and the people To alleviate this problem fuses can be used in conjunction with high current switches or contactors Like contactors high voltage fuses are used only in the band 30 kV to 100 kV citation needed Circuit breaker edit A high voltage circuit breaker is capable of connecting carrying and disconnecting currents under the rated voltage the maximal voltage of the power system which it is protecting Under normal operational conditions circuit breakers can be used to dis connect a line Circuit breakers can also be used to interrupt current when anomalies are detected such as a short circuit Circuit breakers are essential elements of high voltage power systems because they are the only means to safely interrupt a short circuit current The international standard IEC 62271 100 defines the demands linked to the characteristics of a high voltage circuit breaker 7 The circuit breaker can be equipped with electronic devices to know at any moment their states such as wear or gas pressure and to detect faults from characteristic derivatives It can also permit planned maintenance operations and to avoid failures 8 9 To operate on long lines circuit breakers are equipped with a closing resistor to limit overvoltages 10 11 They can be equipped with devices to synchronize closing and or opening to limit the overvoltages and the inrush currents from the lines the unloaded transformers the shunt reactances and the capacitor banks 12 13 Some devices are designed to have the characteristics of the circuit breaker and the disconnector 14 but their use is not widespread References edit British Pattern GB 20069 Improvements in Apparatus for Controlling the Application or Use of Electric Currents of High Tension and Great Quantity in 1893 on espacenet com Lin Jiming et al Transient characteristics of 1100 kV circuit breakers International Symposium on International Standards for Ultra High Voltage Beijing Juillet 2007 IEC 62271 102 for A C disconnectors and earthing switches Norme CEI 60265 1 Interrupteurs pour tension assignee superieure a 1 kV et inferieure a 52 kV Norme CEI 60265 2 Interrupteurs pour tension assignee superieure a 52 kV Norme CEI 60470 Contacteurs pour courant alternatif haute tension et demarreurs de moteurs a contacteurs Norme CEI 62271 100 Disjoncteurs a haute tension E Thuries G Ebersohl J P Dupraz O Chetay J P Montcorge Introduction de l electronique numerique dans les auxiliaires de l appareillage et amelioration de la fiabilite 1994 CIGRE session 1994 rapport 23 13 09 Denis Dufournet Disjoncteurs SF6 Evolution de 1959 a 1994 1994 Revue generale de l electricite n 5 D E Heldman I B Johnson C H Titus D D Wilson Switching of Extra High Voltage Circuits Surge reduction with circuit breaker resistors 1964 IEEE Transactions on Power Apparatus and Systems Vol 83 1964 12 Eugene Maury Problemes apparaissant aux tensions les plus elevees lors de la manœuvre des disjoncteurs 1964 CIGRE session 1964 Eugene Maury La fermeture synchronisee des disjoncteurs 525 kV et 765 kV moyen de reduire les surtensions de manœuvre sur lignes a vide 1966 CIGRE session 1966 Groupe de travail CIGRE 13 07 Controlled switching of HV AC circuit breakers 1999 Electra N 183 Norme CEI 62271 108 Disjoncteur sectionneursExternal links editIEEE Switchgear Committee on ewh ieee org Retrieved from https en wikipedia org w index php title High voltage switchgear amp oldid 1222955428, wikipedia, wiki, book, books, library,

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