Add new classes to describe different voltage levels of the energy grid

[Ludee]

Description of the issue

From #1828 and oeo-dev 89

It should be possible to differentiate the different voltage levels:

• High Voltage
• Low Voltage

And the type of network system:

• Transmission system
• Distribution System

Connecting terms would be:

• TSO
• DSO

Ideas of solution

Part of #1828

Workflow checklist

• [x] I discussed the issue with someone else than me before working on a solution
• [x] I already read the latest version of the workflow for this repository
• [x] The goal of this ontology is clear to me

I am aware that

• [ ] every entry in the ontology should have a definition
• [ ] classes should arise from concepts rather than from words

[stap-m]

And the type of network system:

• Transmission system
• Distribution System

These should become subclasses of power system. In oeo-dev 89 we had the idea of adding a power distribution function and a power transmission function to distinguish the power systems by their purpose. Add transmission network and distribution network as alternative labels?!

[UStucky]

Comment on https://github.com/OpenEnergyPlatform/ontology/issues/1828#issue-2198494373 (@koubaa-hmc) and https://github.com/OpenEnergyPlatform/ontology/issues/1828#issuecomment-2422326472 (@madbkr): The electricity distribution system cannot be a subclass of energy system because it is a part of the power system (subclass of energy system). It is not identical with the power system or with any kind of complete power system. In Germany, the highest voltage level is the level of the transmission system and it depends if and which 2nd level part of the grid is counted in transmission or in distribution system

Comment on https://github.com/OpenEnergyPlatform/ontology/issues/1828#issuecomment-2031559751 (@stap-m) This comment refers to the question if energy distribution system component is equivalent to grid component.

1. electricity distribution system component is more specific because the electricity distribution system is not the whole grid (I suppose grid is equivalent to power system or to transmission + distribution system together as parts of the power system?)
2. Since cables have been mentioned; in my opinion, it is problematic to have electrical devic-es/equipment as subclass of grid component. E.g. cable cannot be a subclass of it. Cables exist independently from grid components. And, grid component is more a role than a class so at least a further subclassing will always be problematic. It is more like a grid (or power system?) has a relation to devices/equipment (e.g. cables) which are their components: "grid" "has component" "cable"

Comments on https://github.com/OpenEnergyPlatform/ontology/issues/1960#issue-2628692551 (@Ludee): I think we should at least introduce the terminology used in Germany, defined by DIN norms (accord-ing to https://de.wikipedia.org/wiki/Hochspannung) Note that other countries may have a different mapping of voltage levels to network levels (transmis-sion system TS, distribution system DS) (I do not know if the term "network level" is correct as the generic term for TS and DS, but "network" is alternatively used instead of system in the various terms we have so far.) Voltage levels Germany: • low voltage (230/400 V up to 1kV) • medium voltage (10 kV up to 35 kV) • high voltage (110 kV) • extra high voltage (220 kV, 380 kV) TS is extra high, the others are DS (typically) E.g. USA: there is an ultra high voltage level beyond 1 MV

Comment on https://github.com/OpenEnergyPlatform/ontology/issues/1960#issuecomment-2451792877 (@stap-m): Definition of power system: "A power system is an energy system covering the generation, transpor-tation, distribution and consumption of electrical energy." Thus, TS and DS both cannot be subclasses since they do not include generation, consumption, and distribution respectively transport.

[stap-m]

Comment on #1828 (comment) (@koubaa-hmc) and #1828 (comment) (@madbkr): The electricity distribution system cannot be a subclass of energy system because it is a part of the power system (subclass of energy system). It is not identical with the power system or with any kind of complete power system. In Germany, the highest voltage level is the level of the transmission system and it depends if and which 2nd level part of the grid is counted in transmission or in distribution system

Thanks for the clarification of the part of relation @UStucky I also very much agree that there should be a grid component role. Based on your comments, the ontological model could look like this (not yet taking into accout the voltage levels):