4 ms·

Love it. Using it for load balancing of substation transformers. The grid is a graph.

isotropy 3y ago
V. cool! It's off topic, but what do the algorithms look like in that task?
ok_dad 3y ago
Interesting you should say that, as I am trying to start a project where I need to make an electric grid graph, but I am not sure where to find the node/edge data for substations and transmission lines that include their specs and capacities. Is that stuff open source somewhere, like with the ISOs, or do you need to build it from scratch?
- gkoller 3y ago
  Have a look at IEC CIM (Common Information Model) - https://en.m.wikipedia.org/wiki/Common_Information_Model_(electricity) - https://zepben.bitbucket.io/cim/cim100/ - https://ontology.tno.nl/IEC_CIM/
  - ok_dad 3y ago
    Thanks!
- maliker 3y ago
  That data is privately held by utilities, and the high voltage transmission infrastructure is highly confidential (CEII/NERC CIP). If you just need sample data, I'd recommend checking out the test data provided with power flow simulators like OpenDSS for distribution systems [1] or MATPOWER for generation + transmission [2]. The IEEE test systems are what are used in research, they have the component specs you're looking for, and are provided with those tools. [1] https://sourceforge.net/projects/electricdss/ https://sourceforge.net/projects/electricdss/ [2] https://matpower.org https://matpower.org
  - rwlincoln 3y ago
    MATPOWER and OpenDSS test cases are also available in CSV format: https://github.com/casecsv https://github.com/casecsv https://github.com/cktcsv https://github.com/cktcsv
    - ok_dad 3y ago
      Thanks to you and the next commenter up, these synthetic data sets are perfect for my current use case.
- zubiaur 3y ago
  Take a look here: https://electricgrids.engr.tamu.edu/electric-grid-test-cases/ https://electricgrids.engr.tamu.edu/electric-grid-test-cases... I’m working on the distribution side, I take my graph data from the inputs for power flow: cyme, synergi etc
jncfhnb 3y ago
I have tried to talk to engineers about contingency analyses for what would happen if a unit went down, and they tend to have very wishy washy answers. Or giant tediously compiled reports that can model exactly one change. Any idea why that is?
- soundarana 3y ago
  Not in the field, but don't forget the grid is dynamic and has feedback loops, control algorithms and humans in the loop. It's closer to an unstable chaotic system which needs constant balancing and tweaking.
  - jncfhnb 3y ago
    Is that true? Surely things regress to a stable mean most of the time of a few archetypes, no?
    - diroussel 3y ago
      Yes. It’s generally stable in most localities. “Instabilities” in this system are browns outs power failures and other events. There are stabilising features within most electricity grids, but they can only cope so much. In general forward planning is down so the amount of dynamic adjustment needed is within allowable range. But to be honest i don’t know how modern grids have adapted with many more micro generators than in the old days.
- scrlk 3y ago
  Good question. Are you talking about generation, transmission or distribution? From my experience as an electrical engineer working for a distribution network: * The traditional approach to network planning: take your edge cases (e.g. winter peak demand), and apply your engineering knowledge and intuition to manually study the most onerous outage conditions. * This will vary on where you are in the world, but networks tend to have a good amount of slack built in. * As networks become more complex, and the cost of computing has fallen, it's more feasible to automate contingency analysis (think about the number of different outage combinations for an N-2 scenario). FWIW, the internal tools that I work on makes use of networkx to determine contingency cases.

V. cool! It's off topic, but what do the algorithms look like in that task?

Interesting you should say that, as I am trying to start a project where I need to make an electric grid graph, but I am not sure where to find the node/edge data for substations and transmission lines that include their specs and capacities. Is that stuff open source somewhere, like with the ISOs, or do you need to build it from scratch?

gkoller 3y ago
Have a look at IEC CIM (Common Information Model) - https://en.m.wikipedia.org/wiki/Common_Information_Model_(electricity) - https://zepben.bitbucket.io/cim/cim100/ - https://ontology.tno.nl/IEC_CIM/
- ok_dad 3y ago
  Thanks!
maliker 3y ago
That data is privately held by utilities, and the high voltage transmission infrastructure is highly confidential (CEII/NERC CIP). If you just need sample data, I'd recommend checking out the test data provided with power flow simulators like OpenDSS for distribution systems [1] or MATPOWER for generation + transmission [2]. The IEEE test systems are what are used in research, they have the component specs you're looking for, and are provided with those tools. [1] https://sourceforge.net/projects/electricdss/ https://sourceforge.net/projects/electricdss/ [2] https://matpower.org https://matpower.org
- rwlincoln 3y ago
  MATPOWER and OpenDSS test cases are also available in CSV format: https://github.com/casecsv https://github.com/casecsv https://github.com/cktcsv https://github.com/cktcsv
  - ok_dad 3y ago
    Thanks to you and the next commenter up, these synthetic data sets are perfect for my current use case.
zubiaur 3y ago
Take a look here: https://electricgrids.engr.tamu.edu/electric-grid-test-cases/ https://electricgrids.engr.tamu.edu/electric-grid-test-cases... I’m working on the distribution side, I take my graph data from the inputs for power flow: cyme, synergi etc

jncfhnb 3y ago

I have tried to talk to engineers about contingency analyses for what would happen if a unit went down, and they tend to have very wishy washy answers. Or giant tediously compiled reports that can model exactly one change. Any idea why that is?

soundarana 3y ago
Not in the field, but don't forget the grid is dynamic and has feedback loops, control algorithms and humans in the loop. It's closer to an unstable chaotic system which needs constant balancing and tweaking.
- jncfhnb 3y ago
  Is that true? Surely things regress to a stable mean most of the time of a few archetypes, no?
  - diroussel 3y ago
    Yes. It’s generally stable in most localities. “Instabilities” in this system are browns outs power failures and other events. There are stabilising features within most electricity grids, but they can only cope so much. In general forward planning is down so the amount of dynamic adjustment needed is within allowable range. But to be honest i don’t know how modern grids have adapted with many more micro generators than in the old days.
scrlk 3y ago
Good question. Are you talking about generation, transmission or distribution? From my experience as an electrical engineer working for a distribution network: * The traditional approach to network planning: take your edge cases (e.g. winter peak demand), and apply your engineering knowledge and intuition to manually study the most onerous outage conditions. * This will vary on where you are in the world, but networks tend to have a good amount of slack built in. * As networks become more complex, and the cost of computing has fallen, it's more feasible to automate contingency analysis (think about the number of different outage combinations for an N-2 scenario). FWIW, the internal tools that I work on makes use of networkx to determine contingency cases.