IEEE C57.110:2018 pdf download.IEEE Recommended Practice for Establishing Liquid Immersed and Dry-Type Power and Distribution Transformer Capability when Supplying Nonsinusoidal Load Currents.
This recommended practice applies only to two winding transformers covered by IEEE Std C57.12.0O, IEEE Std C57. 12.01, and NEMA ST2O. It does not apply to rectifier transformers.
1.2 Purpose
The purpose of this document is to establish uniform methods for determining the capability of transformers when supplying nonsinusoidal load currents of known characteristics.
2. Normative references
The following referenced documents are indispensable for the application of this document (i.e., they must be understood and used, so each referenced document is cited in text and its relationship to this document is explained). For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments or corrigenda) applies.
IEEE Std C57.12.OOTNI, IEEE Standard General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers.
IEEE Std C57.12.0lTh1, IEEE Standard General Requirements for Dry-Type Distribution and Power Transformers Including Those with Solid Cast and/or Resin-Encapsulated Windings.
IEEE Std C57.12.90Thi, IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating
Transformers.
IEEE Std C57. 12.9 lT%t, IEEE Standard Test Code for Dry-Type Distribution and Power Transformers.
IEEE Std C57.9 1 TM, IEEE Guide for Loading Mineral-Oil-Immersed Transformers.
IEEE Std C57.96TM, IEEE Guide for Loading Dry-Type Distribution and Power Transfbrrners.
IEEE Std C57. I 54Th1, IEEE Standard for the Design, Testing, and Application of Liquid-Immersed Distribution, Power, and Regulating Transformers Using High-Temperature Insulation Systems and Operating at Elevated Temperatures.
NEMA ST2O, Dry-Type Transformers for General Applications.
3. Definitions
For the purposes of this document, the following terms and definitions apply. The IEEE Standards Dictionary Online should be consulted for terms not defined in this clause.
harmonic loss factor: The ratio of the total winding eddy current losses due to the harmonics, to the winding eddy current losses at the power frequency, when no harmonic currents exist.
4. General considerations
4.1 Transformer losses
IEEE Std C57.12.90 and IEEE Std C57.12.91 categorize transformer losses as no-load loss (excitation loss), load loss (impedance loss), and total loss (the sum of no-load loss and load loss). Load loss is subdivided into ER loss and stray loss. Stray loss is determined by subtracting the FR loss (calculated from the measured resistance) from the measured load loss (impedance loss).
Stray loss can he defined as the loss due to stray electromagnetic flux in the windings, core, core clamps, magnetic shields, enclosure or tank walls, and so on. Thus, the stray loss is subdivided into winding stray loss and stray loss in components other than the windings (Ps1). The winding stray loss includes winding conductor strand eddy-current loss and loss due to circulating currents between strands or parallel winding circuits. All of this loss may be considered to constitute winding eddy-current loss (P1.). The total load loss can then be stated as follows in Equation (1).IEEE C57.110 pdf download.