User documentation topic: interface between satellite model and market

New section: Market/satellite interface

The interface between the market and satellite models has been reasonably defined by now (mostly in src/demoses-coupling/coupling.py), but is not explicitly documented anywhere.

Part of #56

Summary of the required documentation

The interface consists of two kinds of messages:

• Bids
• Market information

Bids

Bids are sent by each satellite model to the central market model to be used for the market clearing process. Bids are expected as a pandas Dataframe with a fixed layout:

• two data columns: "price" and "quantity"
• two index 'columns': "timestamps" and "demand" (where "demand" is an integer value to distinguish between different non-overlapping bids at the same timestamp)

This layout is probably most concisely encoded in the compact/extract functions in src/demoses-coupling/coupling-components.py.

Market information

The market information is sent from the central market model to each satellite model. This consists of three pieces of information for each satellite model:

• market price at each timestamp
• supplied demand for the specific satellite model per timestamp
• configuration file location for that satellite model

The market price and supplied demand are vectors of rolling_horizon_step elements. The configuration file location for that satellite model is included to give the satellite its configuration information so it can be initiallized at the first message.

• NOTE: Because of the current implementation, the messages have to remain consistent throughout the runtime to prevent code duplication. Ideally, we'd like to use something like MUSCLE3's receive_with_settings to send this configuration, but I haven't been able to get that to work yet. -Sander

Checklist

• I have checked the list of existing issues and couldn't find an issue about this.