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popo

Low-voltage network simulation and state estimation for distributed energy resource studies.

popo is Swahili for bat. It is a companion to twiga, Swahili for giraffe: twiga sees far, which is forecasting ahead in time; popo sees in the dark, which is inferring the state of a network that is not measured.

Low-voltage distribution is largely unobservable. There are measurements at the secondary substation and very little downstream, yet the decisions that matter, how much solar or how many electric vehicles a feeder can take, depend on what is happening at every customer terminal. This library is about reconstructing that from what little is metered, and about simulating what a network would do under a given level of DER uptake.

Install

The solvers are optional, because reading a network definition or checking a voltage limit against a standard needs neither:

uv add popo-flow                  # core: networks, standards, results
uv add popo-flow[opendss]         # + time-series power flow
uv add popo-flow[estimation]      # + weighted-least-squares state estimation
uv add popo-flow[all]

The distribution is named popo-flow because popo was already taken on PyPI; the package itself is still imported as import popo.

What is in it

Learn it

The documentation has a quickstart, a user guide for each module and three tutorials that run end to end on real feeders:

• OpenDSS LV modelling: build an LV circuit, read it back as records and tables, and check it against EN 50160.
• Time series and DER: hosting capacity on a real 188-customer UK feeder, every customer's voltage alongside the substation's, and Volt-VAr, Volt-Watt and storage compared.
• LV state estimation: how much has to be measured to know every customer's voltage.

Development

uv sync --all-extras --group docs   # environment with both solvers and the docs tooling
make test                           # suite with the coverage gate, solvers deselected
make test-solver                    # only the tests that need OpenDSS or pandapower
make lint                           # ruff check
make fmt                            # ruff format
make typecheck                      # ty
make docs                           # build the docs, warnings as errors
make docs-serve                     # serve the docs locally, rebuilding on change

Commits follow conventional commits, checked by commitizen through a pre-commit hook. Install the hooks once with uv run pre-commit install --install-hooks -t pre-commit -t commit-msg.

Status

Alpha: the API may change before 1.0. Changes are listed in the changelog.

Citation

If you use popo in your work, please cite it:

Faustine, A. (2026). popo: low-voltage network simulation and state estimation (Version 0.2.1) [Computer software]. https://sambaiga.github.io/popo-docs

@software{faustine2026popo,
  author  = {Faustine, Anthony},
  title   = {popo: Low-Voltage Network Simulation and State Estimation},
  year    = {2026},
  version = {0.2.1},
  url     = {https://sambaiga.github.io/popo-docs},
  note    = {Python package \texttt{popo-flow}}
}

Licence

Apache-2.0.