Time series and scenarios

Some sources declare more than one value, and PowerIO keeps the structure they declare. An ordered sequence of values is a time series, a set of named alternatives is a scenario set, and the element type says what varies from one entry to the next.

A time point keeps the source’s exact label and, when the source gives one, an interval duration; PowerIO imposes no calendar meaning on labels. Scenario identifiers are the source’s own strings, and you look scenarios up by identifier rather than by position. An operating point entry refers to its shared base network instead of copying the network tables. Core concepts says what an operating point can and cannot change.

using PowerIO
dataset = parse("gridfm_case14/")          # PioModule{ScenarioSet{BalancedNetwork}}
scenarios = dataset.value
keys(scenarios)                            # the scenario identifiers
one = scenarios["7"]                       # BalancedNetwork

series_module = parse("pypsa_folder/")     # PioModule{TimeSeries{BalancedNetwork}}
series = series_module.value
length(series)                             # the number of declared time points
first_hour = series[1]                     # one based, like every Julia axis

Indexing returns the contained entry or a view rooted in the owning module; nothing reparses and no complete network is copied. If an entry needs diagnostics, history, emission, or serialization of its own, wrap it in a module.

Only the facade reads the Egret time series. powerio::parse returns the series, while the component crate’s powerio_tx::parse reads only the static profile and refuses a document with system.time_keys.

Data outside a source’s profile, such as PyPSA investment periods, stochastic scenarios, and unit commitment coupling, or Egret reserve and contingency data, stays in the retained source, is reported as uninterpreted, and survives a same format emission. Formats and fidelity says where each profile ends.

Egret electrical time series

Egret branch ratings use null (or an absent scalar field) for unlimited flow. Canonical output writes, for example, [null, 150.0] when PowerIO’s rate_a values are [0.0, 150.0]. This applies to long-term, short-term, and emergency ratings. A native Egret numeric zero imposes a zero thermal limit, which PowerIO’s branch rating fields cannot represent because they reserve zero for unlimited flow. PowerIO 0.11 still reads such a zero, scalar or at any time point, as unlimited, as earlier releases did. Refusing it is tracked for 0.12.

PowerIO 0.11.10 and earlier reject null inside rating time series. Upgrade those readers before reimporting corrected canonical output. Native Egret accepts these unlimited points.

Earlier PowerIO output could put numeric zero in mixed rating series. Regenerate those files from the original model. Change zero to null in an existing Egret file only after confirming that the source intended unlimited flow. A PowerIO IR document made from a native Egret zero holds unlimited and has lost that distinction; regenerate it from its original Egret input if the zero limit matters. The PowerIO IR layout and branch convention are unchanged.

Egret system.time_keys and per-element data_type: "time_series" values parse into TimeSeries<BalancedNetwork>. Labels must be unique. A stated time_period_length_minutes must be finite and positive and is retained in each time point. Canonical Egret emission survives IR serialization and also accepts balanced operating-point series, including the supported PyPSA profile. It writes native branch results pf, qf, pt, qt in MW/MVAr, with each end’s injection sign. Partial DC-only results remain partial; missing reactive values are not invented.

The writer supports changing loads, dispatch and bounds, voltage states and bounds, shunts, branch ratings/taps/shifts/status, and complete branch flows. Topology, element identities and unsupported attributes must remain static, and all points must share one optional duration. Unsupported variation is refused, including a single-point series. This is an electrical snapshot profile, not Egret’s unit-commitment formulation: commitment, ramping, reserve and other intertemporal optimization semantics are not modeled. Selecting a snapshot can feed any compatible static writer; arbitrary temporal export to every format is not promised. Retained source bytes still provide exact same-format replay.