Minimum allowable values of energy efficiency and the energy efficiency grades for power transformers English
1 Scope
This standard specifies the minimum allowable values of energy efficiency, energy efficiency grades and test methods for three-phase power transformers.
This standard is applicable to three-phase oil-immersed distribution transformers with voltage class of 10kV, no excitation voltage regulation and rated capacity of 30 kVA~2500kVA, dry-type distribution transformers with rated capacity of 30 kVA~2500 kVA, three-phase oil-immersed power transformers with rated frequency of 50 Hz, voltage class of 35 kV~500 kV and rated capacity of 3150 kVA or above.
This standard does not apply to inflatable transformers and high impedance transformers.
2 Normative references
The following referenced documents are indispensable for the application 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/T1094.1-2013 Power transformers - Part 1: General
GB/T1094.11 Power transformers - Part 11: Dry-type transformers
GB/T 2900.95 Electrotechnical terminology - Transformers, voltage regulators and reactors
GB/T 6451 Specification and technical requirements for oil-immersed power transformers
GB/T 10228 Specification and technical requirements for dry-type power transformers
GB/T 22072 Specifications and technical requirements for dry-type amorphousalloy 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 purpose of this standard, the definitions given in GB/T 1094.1, GB/T 1094.11 and GB/T 2900.95 as well as the following ones apply.
3.1
minimum allowable values of energy efficiency for power transformer
maximum allowable limits of no-load loss and load loss for transformer under specified test conditions
4 Energy efficiency grade
The energy efficiency of power transformer is classified into 3 grades, among which Grade 1 represents the highest energy efficiency, with the lowest loss.
