Working with Cases

This notebook covers the gpf data model: obtaining a network and navigating its typed records. A small network is built in memory so that the notebook is self-contained; in practice a case is parsed from a file with GpfCase.from_raw, GpfCase.from_rawx, or GpfCase.from_matpower. Editing a device by identity, validating, and writing the result back are each shown as a recipe in Recipes.

import tempfile, pathlib
import gpf
from gpf import GpfCase, Bus, Generator, Load, Branch

case = GpfCase(
    sbase=100.0,
    buses=[
        Bus(ibus=1, ide=3, vm=1.02, area=1, baskv=230.0),  # slack
        Bus(ibus=2, ide=2, vm=1.01, area=1, baskv=230.0),  # PV
        Bus(ibus=3, ide=1, vm=1.0,  area=1, baskv=230.0),
        Bus(ibus=4, ide=1, vm=1.0,  area=1, baskv=230.0),
    ],
    generators=[
        Generator(ibus=1, machid="1", pg=0.0,  vs=1.02, qb=-300, qt=300),
        Generator(ibus=2, machid="1", pg=80.0, vs=1.01, qb=-150, qt=150),
    ],
    loads=[Load(ibus=3, pl=120, ql=40), Load(ibus=4, pl=60, ql=20)],
    branches=[
        Branch(ibus=1, jbus=2, r=0.01, x=0.08),
        Branch(ibus=2, jbus=3, r=0.01, x=0.08),
        Branch(ibus=3, jbus=4, r=0.01, x=0.08),
        Branch(ibus=1, jbus=3, r=0.01, x=0.10),
    ],
)

Navigating the model

A GpfCase holds typed lists of records (buses, branches, generators, loads, and the rest). Each record is a Pydantic model whose fields use the standard data names, so the network is inspected with ordinary Python.

len(case.buses), len(case.branches), len(case.generators), len(case.loads)

(4, 4, 2, 2)

case.buses[2]

Bus(ibus=3, name='', baskv=230.0, ide=1, area=1, zone=1, owner=1, vm=1.0, va=0.0, nvhi=1.1, nvlo=0.9, evhi=1.1, evlo=0.9, gl=0.0, bl=0.0)

Editing, validating, and writing back

Records are mutable and located by power-system identity, so a device is edited in place, the case is validated against the solver's capabilities, and the result is serialized back to a file. Each of these is shown as a recipe in Recipes.