Proposed features/Power switching extension
|Power switching extension|
|Status:||Proposed (under way)|
|Definition:||Extends available description for power switching devices. Mappers may be invited to use switch=* to give extra details about them.|
Here is a little but necessary technical introduction
A switching device is intended to break the current in a given power line or equipment. Many sorts actually exist in power grids, at different scales to protect or control how electricity flows through the network both for maintenance or security purposes.
To know where and how they operate in the network can allow data consumers to improve a lot their own comprehension of the network.
This proposal can be directly linked the the IEC 441 section where many useful definitions can be read.
Here are an extract of the most useful to have in mind :
- Mechanical switch (441-14-10) : Is the most common form of power switch devices. Such a switch can carry normal currents and currents under abnormal specification but only breaks the first one. Furthermore, it can't offer enough protection to high currents even in open position.
- Disconnector (441-14-05) : A disconnector is capable to open circuits when a negligible current have to be broken. It provides a sufficient protection to high currents when open but mustn't be operated when the power circuit is loaded.
- Circuit-breaker (441-14-20) : This device is capable to break both normal or abnormal power currents and offer an enough protection to high currents when open.
It is possible to combine these different devices to meet security or breaking capabilities according to the environment of operation.
As you may understand, power switches won't offer any kind of overload detection. Switches have to be controlled by appropriate devices which will operate as quickly as they can to protect the power transmission chain.
A power switch is equivalent to a railway switch or a pipeline valve and they are both widely mapped around the world.
As other features like valves, the map can easily be cluttered if mappers add all - sometimes irrelevant - switches. Only a certain amount of them are described here and are proposed to be mapped.
How to map
Please don't go inside power substations if you're not invited to do so, it's illegal.
Aerial imagery will help to see outdoor switch facilities and you'll be safe.
It is necessary to make a difference between multi-phase switches and single-phase linked switches.
The first kind always operate the same way on several phases of a power circuit and the second operate in different situations on (one/some) phase(s) of a power circuit.
As seen in examples with phases=* key, multi-phase switches can correspond to only one OSM node but linked switches have to be distinguished and you are encouraged to use several OSM nodes.
|power||switch||The switch is normally mapped as a . This tags says it's a power switch||mandatory|
|switch||<switch type>||The functional type or role of the switch. Values are mainly inspired by definitions in this proposal's Rationale.||recommended|
|location||<location>||The physical location of the switch, such as indoor. See below for possible values.||recommended|
|voltage||<voltage>||The voltage at which the power switch operates. The switch is mechanically designed to cut two parts of a circuit apart and the voltage is linked to the distance of these two parts when the switch is open. This key is optional since the ways leading to switch are also described with equivalent information.||optional|
|phases||<number of phases>||A power switch can cut several phases, or poles for direct current. If so, just gives the number with this key. Defaults to 1.||optional|
|gas_insulated||yes||Use this tag for gas insulated switches using pressurized SF6 or SF6/nitrogen gas as insulation medium. Gas insulation allows to reduce distances needed to cut circuits.||optional|
|operator||<operator>||Name of the company that operates the switch.||optional|
|ref||<reference>||Abbreviation / number of the switch.||optional|
This key gives information about the function of the switch, answering to the question why have we to put a switch there ?. It's not question of its shape or whatever else.
|switch||mechanical|| A Mechanical switch is the most common power switch you'll find in your environment. It can enable or cut normal power currents to turn on and off devices.
As such switch can have many different looks, you'll find some examples in the next section of this proposal.
|disconnector||A Disconnector is intended to put devices or network parts offline, permanently or temporarily.|
|circuit_breaker||A Circuit-breaker is the only kind of switch which offers enough protection (safety) against abnormal power currents.|
|earthing||A earthing switch is connected on one of its side to earth and can be operated to connect a device or network part to the ground.|
|location||outdoor||A switch located in the open air outside, taking mainly advantage of it to cur power currents.|
|indoor||A substation located indoor. Higher the voltage to cut is high, bigger are the dimensions. Some of them can use special insulating gas.|
|underground||A switch located underground|
|platform||A switch placed on a platform|
|rooftop||A switch located on a rooftop|
And you can obviously add as much precise values as you may need to this incomplete list.
Substation and transmission switches
Sun, mountains and French Alps substations, here you get some big switches.
Sevral pictures are taken from the outside of power facilities. It is possible to safely collect information as shown below.
Coupling and power bays
|225kV disconnector switch allowing operator to disconnect busbar from coupling chain.|
|lack of illustration||Such switches can be seen on country poles at a distribution level. These have to be operated locally by a technician.|
|Such switches can be seen on country poles at a distribution level. The antenna allows operator to remotely open and close the switch to control the power flow.|