EP 0078985 A1 19830518 - Internal voltage grading and transient voltage protection for power transformer windings.

Title (en)

Internal voltage grading and transient voltage protection for power transformer windings.

Title (de)

Spannungsverteilung über der Wicklung und Schutz von Leistungstransformatorwicklung gegen transiente Spannungen.

Title (fr)

Répartition de la tension à travers l'enroulement et protection des enroulements de transformateurs de puissance contre des tensions transitoires.

Publication

EP 0078985 A1 19830518 (EN)

Application

EP 82109918 A 19821027

Priority

US 31916881 A 19811109

Abstract (en)

A series string (17, 18) of plural zinc oxide varistor elements (17A-17N 18A-18N) is electrically connected across each winding (11, 12) of a power transformer. with interior winding tops (20, 22) being electrically connected to the junctions between varistor elements. Each varistor string, disposed within the transformer casing, protects its associated winding from voltage surges in the same manner as externally mounted lightning arresters, provides highly effective voltage grading, and suppresses harmful transient voltage oscillations between the winding taps.

IPC 1-7

H01F 27/34

IPC 8 full level

H02H 9/04 (2006.01); H01F 27/34 (2006.01); H02H 7/04 (2006.01)

CPC (source: EP)

H01F 27/343 (2013.01)

Citation (search report)

[Y] FR 2386175 A1 19781027 - ALSTHOM CGEE [FR]
[Y] FR 2389987 A1 19781201 - REINHAUSEN KG MASCHF [DE]
[A] DE 2609548 A1 19761216 - NAT IND AS
[A] DE 2421728 A1 19751113 - TRANSFORMATOREN UNION AG
[A] DE 1763599 A1 19720105 - LICENTIA GMBH
[Y] PATENTS ABSTRACTS OF JAPAN, vol. 5, no. 7, 17th January 1981, page 679 E41; & JP - A - 55 138 214 (TOKYO SHIBAURA DENKI K.K.) (28-10-1980)
[A] PATENTS ABSTRACTS OF JAPAN, vol. 5, no. 145, 12th September 1981, page 817 E74; & JP - A - 56 80 109 (TOKYO SHIBAURA K.K.) (01-07-1981)

Designated contracting state (EPC)

DE FR GB IT SE

DOCDB simple family (publication)

EP 0078985 A1 19830518; ES 516519 A1 19830801; JP S5895932 A 19830607

DOCDB simple family (application)

EP 82109918 A 19821027; ES 516519 A 19821015; JP 18764782 A 19821027