GB/T 25438-2026Technical parameters and requirements for three-phase oil-immersed transformers with tridimensional wound cores (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

This document supersedes GB/T 25438-2010 "Technical Parameters and Requirements for Three-Phase Oil-Immersed Three-Dimensional Winded Core Distribution Transformers" and is consistent with... Compared with GB/T 25438-2010, apart from structural adjustments and editorial changes, the main technical changes are as follows.

---The "Scope" content has been changed, expanding the applicable voltage levels to include 20kV and 35kV, and broadening the core material range to include electrical components.

Steel and amorphous alloys (see Chapter 1, Chapter 1 of the 2010 edition);

---Performance parameters have been modified for non-excitation voltage regulating distribution transformers with voltage levels of 6kV and 10kV and core material of electrical steel.

The maximum rated capacity of the transformer has been increased from 1600kVA to 4000kVA, and the loss parameters have been adjusted (see Table 1).

1 Scope

This document specifies the performance parameters, technical requirements, inspection rules, marking, lifting, and packaging of three-phase oil-immersed three-dimensional wound core power transformers.

Requirements for loading, transportation, and storage are specified, along with corresponding inspection methods.

This document applies to components with a rated frequency of 50Hz, a rated capacity of 30kVA and above, and a core material of electrical steel and amorphous alloy.

Three-phase oil-immersed three-dimensional wound core power transformers with voltage ratings of 6kV, 10kV, 20kV and 35kV, including off-load and on-load tap-changing types. The manufacture of.

Note: Unless otherwise noted, the term "three-phase oil-immersed three-dimensional wound core power transformer" in this document is abbreviated as "transformer".

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies to this document.

GB/T 1094.2 Power Transformers - Part 2: Temperature Rise of Liquid-Immersed Transformers

GB/T 1094.3 Power Transformers - Part 3: Insulation Levels, Insulation Tests and Air Gap in External Insulation

GB/T 1094.5 Power Transformers - Part 5: Short Circuit Withstand Capacity

GB/T 1094.7 Power Transformers - Part 7: Load Guidelines for Oil-Immersed Power Transformers

GB/T 1094.10 Power Transformers - Part 10: Sound Level Measurement

GB/T 2900.95 Electrical Engineering Terminology. Transformers, Voltage Regulators and Reactors

GB/T 25446 Technical parameters and requirements for oil-immersed amorphous alloy core distribution transformers

JB/T 501 Test Guidelines for Power Transformers

3 Terms and Definitions

The terms and definitions defined in GB/T 1094.1, GB/T 2900.95 and GB/T 25446, as well as the following terms and definitions, apply to this document.

3.2 A power transformer with a three-dimensional wound iron core as its magnetic circuit. 4.6kV and 10kV voltage levels