GB/T 20838-2007 in English

《GB/T 20838-2007高压直流输电用油浸式换流变压器技术参数和要求》由604-2（中国电器工业协会）归口，TC44（全国变压器标准化技术委员会）执行，主管部门为中国电器工业协会。
本标准规定了 500kV级及以下直流输电用油浸式换流变压器的性能参数、技术要求、测试项目、标志、包装、运输和贮存，并在附录A中给出了一些具体产品的有关性能参数实例。本标准适用于 500kV级及以下直流输电用单相油浸式换流变压器。

1 Scope

This standard specifies the performance parameters, technical requirements, test items, marking, packing, transport and storage of ±500 kV or below oil-immersed convertor transformers for DC applications (hereinafter referred to as transformers) and performance parameters examples for some specific products are provided in Appendix A.
This standard is applicable to ±500 kV or below single-phase oil-immersed convertor transformers for DC applications.

2 Normative References

The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated references, subsequent amendments (excluding any correction of) to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest editions of the normative documents referred to apply.
GB 1094.1 "Power Transformers--Part 1: General" (GB 1094.1-1996, eqv IEC 60076-1: 1993)
GB 1094.2 "Power Transformers--Part 2: Temperature Rise" (GB 1094.2-1996, eqv IEC 60076-2: 1993)
GB 1094.3 "Power Transformers--Part 3: Insulation Levels, Dielectric Tests and External Clearances in Air" (GB 1094.3-2003, IEC 60076-3: 2000, MOD)
GB 1094.5 "Power Transformers--Part 5: Ability to Withstand Short Circuit" (GB 1094.5-2003, IEC 60076-5: 2000, MOD)
GB/T 18494.2-2007 "Convertor Transformers--Part 2: Transformers for HVDC Applications" (IEC 61378-2: 2001, MOD)
IEC 60296: 2003 "Fluids for electrotechnical Applications--Unused Mineral Insulating Oils for Transformers and Switchgear"

Contents
Foreword I
Introduction II
1 Scope
2 Normative References
3 Schematic Diagram for Wiring Principle of Transformers for 12-pulse Conversion System
4 Performance Parameters
5 Insulation Level
6 Technical Requirements
7 Test Items
8 Marking, Packing, Transport and Storage
Appendix A (Informative) Examples on Relevant Performance Parameters of the Transformer
Appendix B (Informative) Examples of Calculating External Direct Voltage, Polarity Reversal Voltage and External Alternating Voltage of the Valve-side Winding
B.1 Basic Parameters of the Transformer
B.2 External Direct Voltage
Appendix C (Normative) Tests Negotiated between the User Department and the Manufacturing Organization
C.1 Long-time No Load Test
C.2 Oil Flow Electrified Test
C.3 Partial Discharge Measurement During Rotating the Oil Pump