Proposal:Power circuits routing
| Power circuits routing | |
|---|---|
| Proposal status: | Draft (under way) |
| Proposed by: | fanfouer |
| Tagging: | power=circuit |
| Applies to: | 
|
| Definition: | Consistent tagging model for power circuits going along physical power infrastructure |
| Statistics: |
|
| Draft started: | 2025-03-21 |
Power routing aims to document how power flows over a physical network, mainly between actual substations and along power lines. This proposal has been written in 2025 and largely based upon Bahnpirat and Surly work in the original power routing proposal. Several plea for finalizing what could be immediately implemented remain stuck. This is an attempt to push forward what could be achieved for now.
This presentation made on SOTM-EU 2023 intends to bring a summary of what is actually proposed there and what actually matters.
Proposal
It is proposed to approve relations with type=power + power=circuit, involving power lines (in a global sense, including lines cables and minor lines) and substations. They represent the continuous actual paths along which power flows through physical grids.
A new key topology=* will state if circuits are linear with 2 ends or branched with 3 or more ends.
Another power relation would be useful to describe power line sections, with type=power + power=line_section. It is a subpart of an actual circuit, composed of several line segments (otherwise, the only segment is the section itself without requiring to involve it in a singleton relation).
It is also proposed to review two new physical properties for both lines and circuits as to allow proper power modelisation of power flow.
- impedance=* a numerical value quantifying the ability for a conductor to oppose to an electrical current
- resistance=* a numerical value quantifying the ability for a conductor to oppose to a continuous electrical current
- reactance=* a numerical value quantifying the ability for a conductor to oppose to a alternative electrical current
Rationale
As OpenStreetMap represent physical power lines in a synthetic way, often aggregating different lines sharing the same towers on the same way, the power lines won't reflect the actual flow of power.
It is nevertheless possible to use the relational model to assemble different line sections to compose actual power paths just like it's done for public transportation over highways ways.
Mapping power circuits as relations is an established practice since 2017. The point of this proposal is to promote a single tagging model instead of several (at least two, maybe more).
This proposal isn't intended to overload mapping practice with relations. We will remove them as often as possible.
Its authors and many people involved in the seek of describing power circuits had been concerned by finding the most neat solution as possible. However, some situations require to use relations as to provide a robust description of logical concepts over physical assets of power grids without information redundancy.
Power circuits
A power circuit is defined by 601-02-28 IEC60050 definition. It consists in the most extended part of a power grid between circuit breakers, mostly located in substations. Circuit breakers prevent electrical defaults occurring on a given circuit to spread on neighboring circuits and make power grids finally collapse.
It is composed of as many power line sections as necessary.
In practice, we should find continuous conductors going along power line sections without breakers and join them as member of a relation.
Circuits are first of all linear between two points and can also be branched as to involve more than two substations in them, always limited by circuit breakers.
Power line sections
A power line section is defined by 601-02-30 IEC60050 definition. It consist in one or more continuous line segments (a consistent part of a power line mapped as a way with tags in OSM) forming a link between substations or tap points.
A section always have exactly two ends.
In practice, we should find continuous conductors going along power line segments between substations or tapping points.
For sake of mapping simplicity, describing a section as a relation will only be required when this section if composed of at least two segments that need to be combined.
Otherwise, the section and the segment concepts are merged into the existing power=line way without further change and no need of relation.
Power circuits aren't routes
Power circuits are not similar to transportation routes. Power lines allow power to flow over them and aren't similar to transportation networks with intermediate stops.
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".
Proposed tagging will enable a better split between transportation and power software as the last will only rely on power=* and won't have to look for any route=* in input datasets.
So the structure of power circuit relations is very different from structure of a route relation.
That is why we should not tag power circuits with type=route + route=power. We should introduce a dedicated relation, and type=power + power=circuit are suggested for this purpose.
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 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 summarize the physical properties (defined below) of the whole section instead of qualifying each individual segment.
Otherwise, when a section is composed of a single segment, this segment (
) can be directly involved as a member of the circuit relation with role section.
Physical properties
All power lines aren't equivalent when it comes to make power flows along them.
They are first of all designed for a given voltage=* we are used to document in OSM.
Power lines have important physical properties: resistance (IEC 131-12-04) and reactance (IEC 131-12-46). Together, they form the line's impedance (IEC 131-12-43), which is a quantity that describes how the line resists the flow of alternating current.
Resistance accounts for energy losses due to heat, while reactance arises from the line's inductance and capacitance.
How will we get such information?
Resistance and reactance values depends on the nature of conductors, mainly their material and cross section and impedance is a combination of both.
At first, they are barely guessable from ground unless conductors nature would be printed on poles or wherever else. That's why refining power=line with material and cross section tagging will lead to poor results.
Public information, scientific datasets or open data could help to find impedance, resistance and reactance as many scientists and researchers currently build static network models.
They should be handled carefully, particularly about licensing and accuracy questions.
Proposed keys are obviously optional and a placeholder to organize consistent knowledge.
We choose to add them on the proposal as to state explicitly how they combine when defined both on power line sections and circuits relations.
How to aggregate?
Physical properties of line can be summed over continuous segments but won't be aggregated on branched circuits.
Branched circuits won't get physical properties and they will be given on each linear section involved.
Why aren't we prompted for capacity in MW?
Public communication often deal 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 varies along 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.
Less tagging redundancy between lines, sections and circuits
This proposal is an opportunity to solve some redundancy issues we had between lines and circuits from the beginning.
Just like other fields of knowledge, using relations on top of a physical network of lines allows to get a more precise meaning of tags.
See the following table summarizing how tagging should be:
| Tags | Single segment merged with section | Meaning on circuits | Comments | |
|---|---|---|---|---|
| Meaning on line segments | Meaning on sections | |||
| frequency=* | - | - | The frequency at which the circuit is operated | Frequency is an operational value independent from physical conductors. It only matter for circuits. |
| wires=* | Conductors bundles arrangement | - | - | Bundles arrangement only regard physical line. A given circuit can go through several line sections with different bundles. |
| cables=* | How many cables on the physical line | How many cables the section involves | How many cables the circuit involves | Cables can be used on both. The sum of all operating circuits over a given line should be <= of the line total amount of cables. |
| voltage=* | The maximum voltage the line has been designed for | The maximum voltage the section has been designed for | The operating voltage of the circuit | Circuits can be operated at lower voltages than permitted by the actual line design |
| name=* | - | The line section's name | The circuit's name, usually involving substations' names at its ends | Circuits will combine several line sections and they should all be named after what they actually represent |
| impedance=* | Recommended for sections only | The line section's own impedance | The circuit's global impedance (if linear only) | |
| resistance=* | Recommended for sections only | The line section's own resistance | The circuit's global resistance (if linear only) | |
| reactance=* | Recommended for sections only | The line section's own reactance | The circuit's global reactance (if linear only) | |
Tagging
Power lines
Power line segments mapping isn't changed by this proposal and practices explained in power=line, power=minor_line and power=cable remain valid.
Pages will be updated to explain it's about mapping line segments, as per 601-02-31 IEC60050 definition.
Proposed keys impedance=*, resistance=* and reactance=* will be added to available tags.
Circuits relations
| 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 |
| impedance | <Circuit's impedance> | If linear, the circuit's global impedance in Ohm | Optional |
| resistance | <Circuit's resistance> | If linear, the circuit's global resistance in Ohm | Optional |
| reactance | <Circuit's reactance> | If linear, the circuit's global reactance in Ohm | Optional |
| ref | <Reference> | The circuit's reference | Optional |
| name | <Name> | The circuit's readable name | Optional |
| operator | <Company name> | The company in charge of circuits operation | Optional |
Defining physical properties on branched circuits (with topology=branched and/or with 3 or more substations as members) isn't allowed and mappers should be discouraged to do so.
Relation's roles
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 |
|
one or more | Power line section | A section of the power circuit |
| tap | 
|
one or more | Power line tap, related to line_management=branch | A node at which several sections connect to form a tap point |
| substation | 
|
two or more | Substation | A substation in where the circuit starts / ends |
Circuits topology
The key topology=* is intended to be generaly used on any relation on which the topology nature need to be explicitly stated.
| Key | Value | Comment |
|---|---|---|
| topology | linear | The relation involves several sections in a given order and continuous manner, with exactly two ends |
| branched | The relation involves several sections that aren't continuous with 3 or more ends |
Sections relations
| Key | Value | Comment | Recommendation |
|---|---|---|---|
| type | power | This is a power relation | Mandatory |
| power | line_section | This relation represents a section of a power line | Mandatory |
| voltage | <Operating voltage> | The voltage at which the section operates, in volts | Recommended |
| cables | <Section's cables> | The amount of cables involved by the section | Recommended |
| impedance | <Section's impedance> | The section's global impedance in Ohm | Optional |
| resistance | <Section's resistance> | The section's global resistance in Ohm | Optional |
| reactance | <Section's reactance> | The section's global reactance in Ohm | Optional |
| ref | <Reference> | The section's reference | Optional |
| name | <Name> | The section's readable name | Optional |
| operator | <Company name> | The company in charge of section operation | Optional |
Relation's roles
The relation combines two or more line segments.
A relation with a single line segment is not permitted and mappers should be discouraged to add them. They will prefer involving the power=line segment directly in a circuit relation.
| Member's role | Member's type | Count | Member | Description |
|---|---|---|---|---|
| line |
|
two or more | Power line segment | A segment of power line involved in the power section |
Change management
Affected pages
- Edit power=line page to add segment definition and physical properties
- Edit power=minor_line page to add segment definition and physical properties
- Edit power=cable page to add segment definition and physical properties
- Edit type=* page
- Edit power=circuit page
- Create power=line_section page
- Create type=power page
- Create topology=* page
- Create impedance=* page
- Create resistance=* page
- Create reactance=* page
Tags to be replaced
| Obsolete tag | Usage | Used for ? | New tag(s) to use |
|---|---|---|---|
| type=route + route=power | 23 484 on 2025-03-21 | A route used to describe a power circuit | type=power + power=circuit |
| power=branch | 244 on 2025-03-26 | A relation to link trunk and branches | To replace by power=circuit and case by case required power=line_section relations |
| frequency=* | 45 654 ways on 2025-03-24 query | Frequency mention on power line sections members of an existing power circuit relation | Remove frequency=* from the line section |
| wires=* | 12 447 relations on 2025-03-24 query | Wires mention on existing power circuit relations | Remove wires=* from the relation |
External discussions
- See all previous comments in power routing proposal
Examples
A linear circuit with two ends
This circuit is said simple 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 line segments in the circuit relation that will hold physical properties of the single section.
We are able to complete physical properties of the circuit only from JAO static grid model published online.
| 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 |
| resistance | 1.65 | The circuit's global resistance in Ohm from JAO dataset |
| reactance | 21.04 | The circuit's global reactance in Ohm from JAO dataset |
| ref:FR:RTE | CORNIL71M.LAN | The circuit's reference |
| ref:EU:ENTSOE_EIC | 17T-FR-00000066P | The circuit's 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 5459750 5459750 that will need to be refined, because using the discouraged type=route tagging, if this proposal gets adopted.
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 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.
It is not relevant to define physical properties on branched circuits as they couldn't be merged linearly.
Each power section will get its own figures coming from the static grid model.
| 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 5465785 5465785 that will need to be refined, because using the discouraged type=route tagging, if this proposal gets adopted.
The most complex circuit with sections as relations
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