IEEE Std 859:2018 pdf download.IEEE Standard Terms for Reporting and Analyzing Outage Occurrences and Outage States of Electrical Transmission Facilities.
IEEE Std 859 defines terminology and indices for reporting and analyzing outage occurrences of transmission facilities. Outage definitions and indices are given for two general types of facilities: units and components. Units are functional facilities that transfer power between designated points, while components are specific pieces of equipment.
Outage definitions are given both for describing the outage history of a particular facility and for describing groups of individual outage occurrences that are related in some way.
2. Purpose
This standard is intended to aid the electric power industry in reporting and analyzing outage occurrences of transmission facilities. Use of systematic, precise definitions is essential for meaningful exchange of data. It is expected that specific instructions for reporting outages ‘iIl be developed by the industry based on these definitions. The outage definitions and indices are intended for use in system planning models, operations and maintenance planning, and system design. The definitions and indices may not be sufficiently detailed to cover the information required for equipment design.
3. Equipment classifications
3.1 Component
A device which performs a major operating function and which is regarded as an entity for purposes of recording and analyzing data on outage occurrences.
NOTE 1—Some examples of components are line sections, transformers, ac/dc converters, series capacitors or reactors, shunt capacitors or reactors, circuit breakers, line protection systems, and bus sections.
NOTE 2 Sometimes it is necessary to subdivide a line section into segments to allow proper calculation of failure rates and exposure data. For example, if a line section is composed of an overhead line segment and an underground line segment, failure, and exposure data for each line segment may be recorded separately.
3.1.1 Termination
A facility where a transmission line ends within a terminal, typically at a circuit breaker.
3.1.2 Line section
A portion of an overhead line or a cable bounded by two terminations, a termination and a tap point, or two tap points.
3.2 Subcomponent
A part or portion of a component that is relevant for quantifying exposure to outage occurrences, or failures, or both, or for identifying the cause of an outage occurrence or failure.
NOTE—In general, a component-based system of outage data collection for a system will bc based on an inventory of components (the ‘population”) which is intended to be exhaustive: every relevant portion of the system is a part of one and only one component. A comprehensive inventory of subcomponcnts is not usually developed, although an inventory of a particular class or category of suhcomponents may bc developed to support a particular study. Performance indices such as failure rate are systematically calculated for all components in the relevant population but are rarely calculated for suhcornponents. Examples include: line segments, towers, and buses might he suhcomponenis of a line section; hushing, tank, and winding might bc subcomponents of a transformer.
3.2.1 Line segment
A portion of a line section that has a particular type of construction or is exposed to a particular type of failure, and therefore which may be regarded as a single entity for the purpose of reporting and analyzing failure and exposure data.
NOTE—A line segment is a subcomponent of a line section.
3.3 Unit
A group of components that are functionally related and are regarded as an entity for purposes of recording and analyzing data on outage occurrences.IEEE Std 859 pdf download.