IEEE C57.153-2015 pdf free

IEEE C57.153-2015 pdf free.IEEE Guide for Paralleling Regulating Transformers.
This paralleling guide describes and compares control methods of paralleling regulating transformers. The control methods include: master/follower, circulating current, power factor, circulating reactive current, and negative reactance methods. This guide presents operating philosophy descriptions, sample wiring diagrams, typical operational variations, the provision of adequate backup protection, and typical misapplication consequences. This guide does not apply to phase-shifting regulating transformers.
The purpose of this guide is to provide power transformer paralleling users with an easily acessible source for comparing control methods of transformer paralleling. This comparison allows the proper choice of control method and proper operation to best maintain proper system operations. The guide also provides an operational understanding to assist in the analysis of changing system configurations on paralling operations.
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.
For thc purposes of this document, the following terms and definitions apply. The IEEE Standards Dicikmarv Online3 and IEEE Std C57. 12.80” should be consulted for terms not defined in this clause.
apparent circulating current: An expression of the difkrencc in currents between paralleled regulating transformers due to a transformer turns ratio discrepancy, transformer impedance, or other external factors. See also circulating current: system-induced circulating current; tap poshion—induced circulating current.
circulating current: An expression of the difference in currents between paralleled regulating transformers. See also apparent circulating current: system-Induced circulating current: tap position— induced circulating current.
general paralleling application (CPA): Two or more paralleled regulating transformers connected to a common source bus, with matching impedances. load tap changers with equal tap step sizes, and ranges.
hunting condition: A system condition in which no combination of parallekd regulating transfonncrs with either load tap changer or step-voltage regulator tap positions can satis the control requirements resulting in erratic voltage regulation.
matched impedances: A system condition where the impedances of paralleled regulating transformers at each transformer’s highest MVA rating are equal.
off-tap operation: An operating condition in which a paralleled regulating transformer’s tap position is not in the position to yield the lowest difl’erence in load currents between the paralleled regulating transformers relative to their MVA ratings.
operational transformer impedance variation: An operating condition of paralleled regulating transformers such that simultaneous Increasing or decreasing tap positions creates non-similar impedance changes.
regulating tra,isformer: For the purposes of this guide, a transformer equipped with a voltage-regulating device, which may be either a load tap changer or an external step-voltage regulator.IEEE C57.153 pdf download.