Proposal:Monitoring transformers
| Instrument transformers proposal | |
|---|---|
| Proposal status: | Draft (under way) |
| Proposed by: | fanfouer |
| Tagging: | transformer=instrument |
| Applies to: | 
|
| Definition: | Improve tagging for operating transformers used to accurately measure power lines currents and voltages mostly in substations |
| Statistics: |
|
| Draft started: | 2025-02-19 |
Power transformers classification was introduced by Proposal:Substation_refinement in 2013.
It was then extended in 2017 with Proposal:Transformer_extension_proposal and in 2022 with Proposal:Transformers_classification_refinement
Experience and past discussions show introducing transformer=instrument and combining it to measurement=* would bring benefit to power tagging.
Proposal
Power transformers current classification is done with transformer=* on OSM.
It is proposed to introduce a new value transformer=instrument intended to describe transformers that reduce voltage or current for monitoring purpose.
Additional sub keys of measurement=* could complete description as follow:
- measurement:voltage=* to describe voltage measurement practice
- measurement:current=* to describe current measurement practice
Rationale
Classification of transformers should cover all roles they could get in industrial or domestic power grids.
As monitoring of power grids is done with specific devices running at low voltage and current, high voltage grids got transformers intended to expose voltage and current at lower scale.
Such transformers are installed on power bays in substations, along electrified railways or next to machinery that requires specific monitoring.
They could be designed to transform voltage, current or both at the same time in combined cases (see below).
Instrument transformers are covered by area 321 of IEC 60050 norm.
Combined transformers
Some instrument transformers provide several measurements as combined units. Proposed tagging should reflect it accurately.
As it's less desirable to use semicolon lists as measurement=* value, it is proposed to use values in the measurement:*=* namespace as flags.
Tagging
Casual power=transformer tagging with mandatory transformer=instrument.
Voltage measurement
| Key | Value | Comment |
|---|---|---|
| measurement:voltage | yes | This instrument transformer lowers voltage to measure it |
Current measurement
| Key | Value | Comment |
|---|---|---|
| measurement:current | yes | This instrument transformer lowers current to measure it |
Change management
Affected pages
- Edit transformer=* and add instrument value
- Create transformer=instrument page
- Create measurement:voltage=* page
- Create measurement:current=* page
Values to be replaced
External discussions
Examples
| Photo | Location | Tagging | Note |
|---|---|---|---|
 |
- |
power=transformer
|
This is a typical voltage instrument transformer as a cable is branched to monitored line without any power transit, as a probe. |
 |
Russia |
power=transformer
|
This is a typical current instrument transformer as probed line goes through it with power transit. |
Voting
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