ДСТУ EN 60076-2:2016 Трансформаторы силовые. Часть 2. Превышение температуры трансформаторов с жидким диэлектриком (EN 60076-2:2011, IDT)

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«Український науково-дослідний і навчальний центр
проблем стандартизації, сертифікації та якості»
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З наданням чинності від 2016-09-01

CONTENTS

1 Scope

2 Normative references

3 Terms and definitions

4 Cooling methods

4.1 Identification symbols

4.2 Transformers with alternative cooling methods

5 Normal cooling conditions

5.1 Air-cooled transformers

5.2 Water-cooled transformers

6 Temperature rise limits

6.1 General

6.2 Temperature rise limits at rated power

6.3 Modified requirements for special cooling conditions

6.3.1 General

6.3.2 Air-cooled transformers

6.3.3 Water-cooled transformers

6.4 Temperature rise during a specified load cycle

7 Temperature rise tests

7.1 General

7.2 Temperature of the cooling media

7.2.1 Ambient temperature

7.2.2 Water temperature

7.3 Test methods for temperature rise determination

7.3.1 General

7.3.2 Test by short-circuit method for two winding transformers

7.3.3 Test modification for particular transformers

7.4 Determination of liquid temperatures

7.4.1 Top-liquid temperature

7.4.2 Bottom and average liquid temperatures

7.5 Determination of top, average and bottom liquid temperature rises

7.6 Determination of average winding temperature

7.7 Determination of winding resistance at the instant of shutdown

7.8 Determination of average winding temperature rise at the instant of shutdown

7.9 Determination of the average winding to liquid temperature gradient

7.10 Determination of the hot-spot winding temperature rise

7.10.1 General

7.10.2 Determination by calculation

7.10.3 Direct measurement during the temperature rise test

7.11 Uncertainties affecting the results of the temperature rise test

7.12 Dissolved gas-in-oil analysis

7.13 Corrections

Annex A (informative) Hot-spot winding temperature rise determination for OFAF and OFWF cooled transformers based on the top-liquid temperature in tank

Annex В (informative) Methods to estimate the hot-spot winding temperature rises

Annex C (informative) Techniques used in temperature rise testing of liquid-immersed transformers

Annex D (informative) Dissolved gases analysis for the detection of local overheating

Annex E (informative) Application of optical fibre sensors for winding hot-spot measuremei

Bibliography

Figure B.1 - Temperature rise distribution model for ON cooling methods

Figure B.2 - Value of factor Q as a function of rated power and strand height (W)

Figure B.3 - Typical liquid flow paths in a disk winding with diverting washers

Figure C.1 - Recommended circuit for transformers with a low resistance winding using two separate direct current sources, one for each winding

Figure C.2 - Alternative recommended circuit using only one direct current source for both windings

Figure C.3 - Average winding temperature variation after shutdown

Figure C.4 - Extrapolation of the cooling down curve, using the fitting curve

Figure E.1 - Optical fibre sensor application for a disk winding of core type transformer

Figure E.2 - Optical fibre sensor application for a transposed cable of core type transformer

Figure E.3 - Modality of optical fibre sensor application in the winding spacer of core type transformer

Figure E.4 - Optical fibre sensor application for high voltage winding of shell type transformer

Table 1 - Temperature rise limits

Table 2 - Recommended values of temperature rise corrections in case of special service conditions

Table 3 - Exponents for the corrections of temperature rise test results

Table A.1 - Hot-spot winding temperature rises for some specific transformers determined from conventional heat run test data combined with calculated hot-spot winding temperature rise, and from direct fibre-optic measurements

Table C.1 - Example of cooling down curve calculation spreadsheet

Table D.1 - Minimum detectable value S_D of gases in oil

Table D.2 - Admissible limits for gas rate increases

Table E.1 - Minimum recommended number of sensors for three-phase transformers

Table E.2 - Minimum recommended number of sensors for single-phase transformers