GB 20052-2024 Minimum allowable values of energy efficiency and the energy efficiency grades for power transformers
1 Scope
This document specifies the minimum allowable values of energy efficiency, energy efficiency grades and test methods for power transformers.
This document is applicable to 10 kV three-phase oil-immersed/dry-type off-circuit-tap-changing distribution transformers with a rated frequency of 50 Hz and rated power of 30 kVA – 2,500 kVA; 35 kV – 500 kV oil-immersed power transformers with a rated frequency of 50 Hz and rated power of 3,150 kVA and above; 6 kV – 35 kV three-phase oil-immersed/dry-type transformers for photovoltaic power projects, wind turbine applications, and energy storage on the new energy power generation sides, with a rated frequency of 50 Hz and rated power of 500 kVA and above; 66 kV three-phase oil-immersed transformers for photovoltaic power projects, wind turbine applications, and energy storage on the new energy power generation sides, with a rated frequency of 50 Hz and rated power of 3,150 kVA – 20,000 kVA.
This document is not applicable to gas-filled power transformers, tower transformers, and nacelle transformers.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1094.1 Power transformers - Part 1: General
GB/T 1094.11 Power transformers - Part 11: Dry-type transformers
GB/T 1094.16 Power transformers - Part 16: Transformers for wind turbine applications
GB/T 2900.95 Electrotechnical terminology - Transformers, voltage regulators and reactors
GB/T 6451 Technical parameters and requirements for oil-immersed power transformers
GB/T 10228 Technical parameters and requirements for dry-type power transformers
GB/T 22072 Specifications and technical requirements for dry-type amorphous alloy core distribution transformers
GB/T 25438 Specification and technical requirements for three-phase oil-immersed tridimensional toroidal-core distribution transformers
GB/T 25446 Specification and technical requirements for oil-immersed amorphous alloy core distribution transformers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 1094.1, GB/T 1094.11, GB/T 1094.16 and GB/T 2900.95 as well as the following apply.
3.1
minimum allowable values of energy efficiency for power transformer
maximum allowable limits of no-load loss and load loss of transformer under specified test conditions
4 Energy efficiency grades
The energy efficiency of power transformers is classified into 3 grades, among which Grade 1 represents the highest energy efficiency, with the lowest loss. The measured no-load loss and load loss of power transformers of all grades under rated power shall not be greater than those specified in Tables 1 to 28.
Under rated power, the measured no-load loss and load loss of transformers of all grades for photovoltaic power projects, wind turbine applications, and energy storage on new energy power generation sides shall not be greater than those specified in Tables 29 to 35. For products having a rated power that are not listed in the table, the no-load loss and load loss shall be determined with the linear interpolation.
5 Technical requirements
5.1 Basic requirements
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Energy efficiency grades
5 Technical requirements
6 Test Methods
