Edition 2.02018-09
INTERNATIONAL STANDARD
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Edition 2.02018-09
INTERNATIONAL STANDARD
INTERNATIONALELECTROTECHNICALCOMMISSION
CONTENTS
FOREWORD. 41 Scope .62 Normative references ..62.1 2.2 IEEE references. IEC references.. ..6 .62.3 ISO references.. .73 2.4 Terms and definitions. CENELEC references ..7 .74 Use of normative references. ..85 Rating.. .86 Service conditions ..86.1 6.1.1 Normal service conditions. General .. .86.1.2 Temperature of external cooling medium . ..86.2 Particular service conditions for transformers installed in a tower or nacelle. ..96.2.1 6.2.2 Temperature rise correction.. General .. .96.3 Content of harmonic currents in the transformer. -106.4 Over-excitation Harmonic distortion of voltage.. ..116.5 6.6 Transient voltages ...11 ..116.7 Humidity and salinity. .116.8 6.9 Corrosion protection Level of vibration .12 .126.10 Consideration for hermetically sealed transformers. ..126.11 Flammability issues with transformers mounted in the tower or nacelle .126.12 Electrical characteristics Thermal cycling of transformer.. 12 .127.1 Highest voltage for equipmen... ..127.2 Tappings (tap-changer). .127.3 7.4 Connection group.. Dimensioning of neutral connection 13 137.5 Short-circuit impedance . ..137.6 Overload capability - Insulation levels for high and low voltage windings ..137.7 7.8 Inrush current .13 .147.9 Frequency of energization... .147.10 7.11 Operation with forced cooling.. Ability to withstand short circuit.... ...14 147.12 Over-temperature protection. .148 Rating plate. ..149 Tests. ...159.1 9.2 Additional tests for wind turbine transformers. List and classification of tests (routine type and special tests). 15 15
IEC/IEEE 60076-16:2018 3 IEC/IEEE 20189.2.1 9.2.2 General Lightning impulse type tests.. .15 .159.2.3 Lightning impulse routine sample tests 159.2.4 Partial discharge test for liquid-immersed transformers. 15Annex A (informative) Effects of voltage harmonics . 9.2.5 Climatic and environmental tests for dry-type transformers. ..16 15A.1 Design and specification considerations... .16A.2 Effects of voltage harmonics . .16Bibliography..
Table 1 - Remended minimum values of short-circuit impedance for transformerswith two separate windings 13Table A.1 - Example of voltage harmonic order. 17
