IEEE 2746-2020 pdf free

IEEE 2746-2020 pdf free.IEEE Guide for Evaluating AC Interference on Linear Facilities Co-Located Near Transmission Lines.
Conductive coupling in ac electrical systems is the method of energy transfer of which most engineers are familiar. When time-varying electric fields are present in energized transmission lines, a voltage gradient and electrical current are established within the conductors. If inadvertent physical contact is made between one of the energized conductors and another conductive object, (commonly referred to as an electrical fault), the conductive coupling can result in significant energy transfer and cause severe damage. If the voltage gradient is high enough to exceed the breakdown voltage of the surrounding material, an ionized current conducting channel can be formed, which is referred to as an arc fault.
In the context of ac interference on co-located facilities, coupling involving a grounded object (line-to-ground fault) is the most prevalent concerm, as the earth becomes part of the returm path for the fault current and can energize other objects also in contact with the soil. Unbalanced faults, especially single-line-to-ground faults,which occur near the co-located linear facility or beyond the shared corridor, typically represent the greatest risks to personnel and equipment. Some common modes of triggering a ground fault include encroaching foliage, lightning -induced flashovers, animals, and equipment failures.
Co-located linear facilities, equipment, and other objects susceptible to the efects of conductive coupling include shield wires and OPGW cables, above-grade metallic objects, metallic fencing. handrails, and other adjacent overhead lines. Below-grade metallic objects, such as pipelines and grounding systems, can be directly afected by the voltage gradients in the soil.
AC interference analysis is a complex combination of several ffcts, as addressed above. In all but the simplest cases, the use of software is necessary to completely analyze these interference ffects, incorporating a large amount of site-specific data. The following subseetions discuss the general considerations for ac interference analysis, speifieally related to aspeets regarding the transmission line and items common to most interference studies. Specifies related to pipeines and railroads are found in Clause 5 and Clause 6,respectively. An example of a simple ac interference project is described in Annex B, while Annex C provides example results from a complex ac interference project.
4.2.1 Data collection
Performing an ac interference analysis requires a significant amount of data. This data is generally shared with all parties involved in a co-located project as applicable. At a minimum, a GIS based map providing accurate and detailed locations of the co-located facilities can be made available to all ffected parties. For any data collection, mutual testing requirements can be coordinated among affected parties (such as soil resistivity testing, data from which may be used for other unrelated analyses).
Transmission line companies generally have information about geometry of their transmission lines but may not have all the information about grounding details, soil conditions, future loading, or fault forecasts readily available. Significant delays may result while utilitieis are gathering this data. If scheduling constraints or data unavailability dictates, conservative assumptions may be necessary to perform the ac interference analysis. Any assumptions made can be documented and vetted with the appropriate stakeholders.
4.2.2 Electrical system geometry
The longitudinal voltage induced in linear facilities from parallel transmission line(s) depends on a number of parameters. Gathering as much of the following data as practical for each transmission line that is co-located in a corridor improves the accuracy of the ac interference analysis.IEEE 2746 pdf download.