Tag:power=circuit

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power = circuit
Description
Arrangement of connected physical lines involved in the same connected power system. Edit this description in the wiki page. Edit this description in the data item.
Group: power
Used on these elements
should not be used on nodesshould not be used on waysshould not be used on areasmay be used on relations
Requires
Useful combination
See also
Status: approvedPage for proposal

A power circuit is defined by 601-02-28 IEC60050 definition. These are the actual paths the electricity follows through power grids.
It represents the longest continuous portion of a power grid between circuit breakers, which are typically located within substations. Circuit breakers isolate electrical faults occurring on a given circuit to avoid the propagation of the fault to other circuits and prevent power grids failure.

A circuit mapped with power=circuit is composed of as many power line sections as necessary that are used to be mapped as power=line, power=minor_line, power=cable or power=line_section on OpenStreetMap.
It has been reviewed in power routing and power circuits routing proposals.

Power routing in OSM

Tagging similar to transportation routes

Another approach has been used at first modelling power circuits as transportation routes with route=power and is now discouraged. You can refer to its own page for more information.

Tagging power circuits with a relation

Power line routes are not similar to transportation routes. Power lines have exactly two end point and have no "stops" in the middle. The beginning and the end (source and consumer of energy) of the line may exchange sometimes (e.g. in case of emergency switching). A power line may have T-shape connection to another one, but it is not an intermediate stop, it is a beginning of the other line. Also there are no traveling things like buses, passengers or travelers as in "common" routes. A traveling of electrons is rather physical abstraction, and it is not so simple as "small moving balls".

The relation for power circuits must be able, ideally, to tag splitting of phases to individual towers and gathering of them together; T-shaped circuits connections; supporting structures when part of wire does not transmit electricity but only acts as a holding device.

Among other issues, a special relation will help us not to confuse, when we make a map of transportation routes. Because a map of traveling routes and a map of power lines are different kinds of maps. In case of special relation for power lines a software will not have to fetch the values of route=* (is it equal to "power" or not?) but may rely on a type=power only.

So the structure of this relation is very different from structure of a route relation. That is why we should not tag power circuits with type=route + route=power.

How to map

Circuits can be deducted by looking at power lines from ground or on aerial imagery. A circuit is first of all a metallic continuation of conductors between substations. Mappers only have to follow the cables and stop as the conductor they follow end in a substation (more particularly connected to circuit breakers inside) to survey a given circuit.

Looking in details at particular points will help, particularly the towers which has got line_management=*, areas with power=substation or nodes with switch=circuit_breaker.
Doing so will allow mappers to connect the dots and finally the substations with their neighbors.
Readable labels or colours plates on towers can also help to know which substations are reachable by the given circuit passing by the tower.

Read more about circuits identification plates in UK.

Public documentation with valid license could help to solve undefined situations. Such knowledge should always be verifiable on ground.

There is no trunk and branch

This section relates on circuits with more than two ends.
Some models sometimes define a multi-tenant circuit as a trunk line and one or several branch lines. Such a distinction isn't relevant as the trunk line may be any valid combination of line sections linking two substations through the given circuit. Nothing but the geometry of lines allows to set the trunk line as the one which goes on without change in its direction (if applicable).

We'd be better defining only line sections which converge on tapping points and join them in a proper circuit relation.

If and only if a given section is composed of several segments, an intermediate relation could be used to group properties like cables=* and frequency=* for the good.
Otherwise, when a section is composed of a single segment, this segment (way) can be directly involved as a member of the circuit relation with role section.

Why aren't we prompted for capacity in MW?

Public communication often deals with actual power line capacity in MW as the amount of power that could flow in the power line without damage.

Such values aren't constant and vary due to seasons and upon operational conditions. They're sometimes restricted in a given time period (i.e 4 000 MW during 10 minutes) as to not overheat and finally destroy the power conductors.
We shouldn't add this value to OSM, despite interesting, as it won't be accurate and lead to wrong interpretation.

Tagging

Relation

This relation represent an electrical connection between two or more facilities, with dedicated and permanent properties and involving power line sections, substations and sometimes tap points.

Key Value Comment Recommendation
type power This is a power relation Mandatory
power circuit This relation represents a power circuit Mandatory
topology linear or branched Nature of power circuit topology Recommended
voltage <Operating voltage> The voltage at which the circuits operates, in volts Recommended
frequency <Operating frequency> The frequency at which the circuits operates, in Hertz Recommended
cables <Circuit's cables> The amount of cables involved by the circuit Recommended
ref <Reference> The circuit's reference Optional
name <Name> The circuit's readable name Optional
operator
operator:wikidata
<Company name> The company in charge of circuits operation Optional
wikidata <Link Qid> The wikidata item related to significant power lines, often interconnections between countries Optional

Please avoid duplicating wires=* on circuits relations at it only relates to physical lines members. Using this key is strongly discouraged.

Members

The relation combines one or more line sections, 0 or more tap points and two or more substations in which the circuits originates and ends.

Member's role Member's type Count Member Description
section way relation one or more line, minor_line, cable or line_section A section of the power circuit
tap node none or more Power line tap, related to line_management=branch A node at which several sections connect to form a tap point
substation node area two or more Substation A substation in where the circuit starts / ends

Early circuits relations has been created with following former roles. They are kept here for sake of documentation but shouldn't be used anymore.

Member's role Member's type Count Presence Member Description
line way one or more Recommended Power line An element of the power line
endpoint node way area relation 0, 1, 2 Recommended Terminal object A substation, a power tower, or another device where the circuit starts / ends

Retreive data

Exploring circuits relation may not be easy from an editor.
It is possible to retrieve existing defined circuits in OpenStreetMap with the following Overpass query (for instance in France but feel free to adapt the wikidata code):

area["wikidata"="Q212429"]->.france;

relation(area.france)["type"="power"]["power"="circuit"]->.circuits;

.circuits >->.circuitsMembers;
way.circuitsMembers["power"!="substation"];
out geom; // Simple sections as osm ways

way.circuitsMembers["power"="substation"];
out center; // Substations polygons as points

.circuits >>->.complexMembers;
relation.complexMembers["power"="substation"];
out center; // Subtations multipolygons as points

relation.complexMembers["power"="line_section"]->.sections;
.sections; >->.sectionsMembers;
way.sectionsMembers;
out geom; // Line members of line_section relations

.sections out body; // Sections members list
.circuits out body; // Circuits members list

{{style:
/* Substations */
area[power=substation][substation=transmission]{width:3;color:#FFD800;fill-color:#FFD800;fill-opacity:0.2;}
node[power=substation]{symbol-size:6; fill-color:#FFD800; color:#FFD800; }

/* Power lines */
way[power=line],way[power=cable]{width:3;color:#ABABAB;}

/* Relations */
relation[power=line_section] way{dashes:1,10,1,10;}

/* Tap points */
relation[power=circuit] node {symbol-size:3; fill-color:#000000; color:#000000;}
}}

Examples

General example

The following drawing illustrates a connection of the substation "H" with two other substations: "K" and "T".

At the substation "H" both of the circuits run on the same towers (line segment 1), then split (the segments 2 and 3). Then the phases of the circuit "H—T" split (4,5,6) and then gather together again (line 7).

Tagging relations

Relation Relation's tags Relation's members, in the following order
relation First circuit's relation type=power
power=circuit
cables=3
ref=H-K
topology=linear
area polygon of the substation "H" (role substation);
way ways 1, 2 (role section);
area polygon of the substation "K" (role substation)
relation Second circuit's relation type=power
power=circuit
cables=3
ref=H-T
topology=linear
area polygon of the substation "H" (role substation);
way way 1, 3 (role section);
way ways 4, 5, 6 in any order (role section);
way way 7 (role line);
area polygon of the substation "T" (role substation)

Tagging ways and polygons:

Way area H area K area T way 1 way 2 way 3 way 4 way 5 way 6 way 7
Tags power=substation
ref=H
power=substation
ref=K
power=substation
ref=T
cables=6
circuits=2
cables=3
circuits=1
cables=3
circuits=1
cables=1
circuits=1
phase=L1
cables=1
circuits=1
phase=L2
cables=1
circuits=1
phase=L3
cables=3
circuits=1

A linear circuit with two ends

This circuit is said linear because it links two substations with no tap point.
However, it runs over 5 different line sections and you will observe that the wires changes along its path.
As the circuit only have two ends, it is possible to directly involve way line segments in the circuit relation.

Key Value Comment
type power This is a power relation
power circuit This relation represents a power circuit
topology linear This power circuit is linear with 2 ends
voltage 400000 The voltage at which the circuits operates, in volts
frequency 50 Alternative public grids are operated at 50Hz in western Europe
cables 3 It's 3-phase without neutral power circuit
ref:FR:RTE CORNIL71M.LAN The circuit's French reference
ref:EU:ENTSOE_EIC 17T-FR-00000066P The circuit's European reference
name Cornier-Montagny les Lanches 1 The circuit's readable name
operator RTE French transmission grid is operated by RTE in France

Sections A to F are power=line ways and will get the section role. Substations are power=substation members with the role substation.
This circuit is currently described in relation 5459750.

The difficulty to produce an accurate model of the actual power path with the physical lines knowledge only appears clearly.

A more complex circuit with sections as single segment

This circuit involves 3 line sections and 1 tap point to link 3 substations together.
All 3 sections are composed of 1 way power=line segment, so no additional power=line_section is required.
It is still possible to involve the ways as circuit relation members and section role.

Key Value Comment
type power This is a power relation
power circuit This relation represents a power circuit
topology branched This power circuit has 3 ends so form a branched topology. 3 substation members are expected
voltage 225000 The voltage at which the circuits operates, in volts
frequency 50 Alternative public grids are operated at 50Hz in western Europe
cables 3 It's 3-phase without neutral power circuit
name Grandval-Lanau-Rueyres 1 The circuit's readable name
operator RTE French transmission grid is operated by RTE in France

Sections A to C are power=line ways and will get the section role. Substations are power=substation members with the role substation and tower #1 will be member with role tap.
This circuit is currently described in relation 5465785.

The most complex circuit with sections as relations

This circuit involves 3 line sections and 1 tap point to link 3 substations together.
The northern section is mapped as a relation as it involves 3 different segments, with different tags that can't be merged into a single one.
Two remaining sections are involved in the circuit relation as ways and get the section role.

Here is the circuit relation:

Key Value Comment
type power This is a power relation
power circuit This relation represents a power circuit
topology branched This power circuit has 3 ends so form a branched topology. 3 substation members are expected
voltage 225000 The voltage at which the circuits operates, in volts
frequency 50 Alternative public grids are operated at 50Hz in western Europe
cables 3 It's 3-phase without neutral power circuit
name Saint Auban-Salignac-Sisteron 1 The circuit's readable name
operator RTE French transmission grid is operated by RTE in France

Here is the section C relation:

Key Value Comment
type power This is a power relation
power line_section This relation represents a power line section
voltage 225000 The voltage at which the section operates, in volts
cables 3 It's 3-phase without neutral power section
operator RTE French transmission grid is operated by RTE in France
ref:FR:RTE SISTEL61ZSAL6 The French identifier of the power line section


Sections A and B are power=line ways and will get the section role. Section C is a power=line_section relation and will get the section role.<
Substations are power=substation members with the role substation and tower #1 will be member with role tap.
This circuit is currently described in relation 5977379.