1 Scope
This Part of GB 1094 identifies the requirements for power transformers to sustain without damage the effects of overcurrents originated by external short circuits. It describes the calculation procedures used to demonstrate the thermal ability of a power transformer to withstand such overcurrents and both the special test and the theoretical evaluation method used to demonstrate the ability to withstand the relevant dynamic effects.
This Part applies to transformers as defined in the scope of GB 1094.1.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this Part of GB 1094. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative documents referred to applies.
GB 1094.1-1996 Power Transformers — Part 1: General (eqv IEC 60076-1:1993)
GB 1094.3-2003 Power Transformers — Part 3: Insulation Levels, Dielectric Tests and External Clearances in Air (IEC 60076-3:2000, MOD)
GB 1094.11-2007 Power Transformers — Part 11:Dry-type Transformers (IEC 60076-11:2004, MOD)
GB/T 13499-2002 Application Guide for Power Transformers (idt IEC 60076-8:1997)
Foreword II
1 Scope
2 Normative References
3 Requirements with Regard to Ability to Withstand Short Circuit
3.1 General
3.2 Overcurrent conditions
4 Demonstration of Ability to Withstand Short Circuit
4.1 Thermal ability to withstand short circuit
4.2 Ability to withstand the dynamic effects of short circuit
Appendix A (Informative) Theoretical Evaluation of the Ability to Withstand the Dynamic Effects of Short Circuit
A.1 Scope
A.2 General
A.3 Guidelines for conducting the design review
Appendix B (Informative) Short-circuit Apparent Power of the System Specified in IEC 60076-5:2006
Appendix C (Informative) Definition of Similar Transformer
