IEC 60076-15 pdf download

IEC 60076-15 pdf download Power transformers – Part 15: Gas-filled power transformers
1scope
This standard applies to gas-filled power transformers (including auto-transformers). Thestandard applies to all construction technologies.
This standard does not apply to
single-phase transformers with rated power less than 1 kVA and three-phasetransformers less than 5 kVA;
dry-type transformers (see lEC 60076-11);instrument transformers (see lEC 60044);
starting transformers;
testing transformers;
traction transformers mounted on rolling stock;welding transformers.
Where lEC standards do not exist for the transformers mentioned above or for other specialtransformers, this standard may be applicable as a whole or in parts.
NOTEThis standard can be applicable to the gas parts of a transformer in which an insulating gas is used with aninsulating liquid.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60050,International Electrotechnical Vocabulary
IEC 60076-1:1993,Power transformers – Part 1: General
IEC 60076-2:1993,Power transformers – Part 2: Temperature rise
IEC 60076-3:2000，Power transformers – Part 3: Insulation levels,dielectric tests and externalclearances in air
IEC 60076-5, Power transformers – Part 5: Ability to withstand short circuitIEC 60076-10,Power transformers – Part 10: Determination of sound levelsIEC 60085,Electrical insulation – Thermal classification and designation
IEC 60376，Specification of technical grade sulfur hexafluoride SF6 for use in electricaleauibment
IEC 62271 -1 , High-voltage switchgear and controlgear – Part 1: Common specifications
ISO 9001 :2000, Quality management systems – Requirements
3 Definitions
For the purpose of this document, the following definitions apply. Other terms used have the meanings ascribed to them in IEC 60076-1 , or IEC 60050.
3.1
gas-filled transformer
a transformer of which the magnetic circuit and windings are placed in an enclosure filled with an insulating gas. Generally sulfur hexafluoride (SF 6 ) gas is used, and sometimes this transformer is called a gas-insulated transformer.
3.2
rated gas pressure
gas pressure (gauge pressure) at 20 °C designed for use in a gas-filled transformer
3.3
guaranteed minimum gas pressure
the minimum gas pressure (gauge pressure) at 20 °C, which is able to guarantee the insulation of a gas-filled transformer
NOTE A transformer of which the magnetic circuit and windings are placed in an enclosure or a vessel filled with an insulating liquid such as perfluorocarbon, natural ester, synthetic ester, silicon oil and vegetable oil should be considered a liquid immersed type transformer.
3.4
design pressure of tanks
relative pressure used to determine the design of the tanks
NOTE It is at least equal to the maximum pressure in the tank at the highest temperature that the gas can reach under specified maximum service condition.
3.5 Definitions, symbols and units relating to gas and vacuum tightness
3.5.1
absolute leakage rate
F
the amount of gas escaped by time unit at rated filling pressure (or density), expressed in Pa m 3 /s
3.5.2
permissible leakage rate
F p
the maximum permissible absolute leakage rate of gas at rated filling pressure (or density) specified by the manufacturer, expressed in Pa m 3 /s
3.5.3
relative leakage rate
F rel
the absolute leakage rate related to the total amount of gas in the transformer at rated filling pressure (or density). It is expressed in percentage per year or per day.