IEC TR 60787:2007 pdfダウンロード

IEC TR 60787:2007 pdfダウンロード。Application guide for the selection of high-voltage current-limiting fuse-links for transformer circuits
1 Scope and object
IEC/TR 60787, which is a technical report, serves as an application guide to the use, for distribution transformer circuit applications, of fuses complying with the requirements of IEC 60282-1 : High-voltage fuses – Part 1 : Current-limiting fuses. Therefore, this document is informative, not normative. The object of this application guide is to specify criteria for coordination of high-voltage fuses with other circuit components in transformer applications and to give guidance for the selection of fuse-links with particular reference to their time-current characteristics and ratings.
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.
IEC 60076-5: 2006, Power transformers – Part 5: Ability to withstand short- circuit
IEC 60076-7: Power transformers – Part 7: Loading guide for oil-immersed power transformers
IEC 60282-1 : 2005, High-voltage fuses – Part 1: Current-limiting fuses
IEC 60470: 2000, High-voltage alternating current contactors and contactor-based motor- starters
IEC 60905: Loading guide for dry-type power transformers
IEC 62271 -1 05: 2002, High-voltage switchgear and controlgear – Part 105: Alternating current switch-fuse combinations IEC 62271 -1 07: 2005, High-voltage switchgear and controlgear – Part 107: Alternating current fused circuit-switchers for rated voltages above 1 kV up to and including 52 kV 3 Features of current limitation
The use of high-voltage current-limiting fuses for the primary-side protection of distribution transformers provides significant advantages due to their current-limiting action. Under most short-circuit conditions, they are able to interrupt fault currents within a few milliseconds after fault initiation. Hence, the prospective peak of the fault current will not be reached and the resulting let-through current and energy will be significantly reduced.
This feature makes current-limiting fuses particularly suited for distribution transformer protection since they are able to prevent or minimize any major consequences of internal transformer faults.