EMO:Input Data

The input data types processed by EMarketOffer:

• Generation Data
• Price data
• Offers data
• Demand data
• Transmission data
• Static (user-defined) data

Generation Data

Generation data is used:

• As information-only in theUnits Information Grid for the Market Data Source
• To calculate Powerflows for the Market Data Source
• To calculate Powerflows for the Powerflow Case Data Source

Loading Generation Data

Historical Generation data can be loaded from an online database (see Connecting to a Networked Database). Historical or user-created Generation data can be loaded into Powerflow Case Definitions from file as a generation profile.

Price Data

Historical Price data is used as information-only in the Units Information Grid for the Market Data Source

Loading Historical Price Data

Historical Price data can only be loaded into EMarketOffer through direct connection to an online database (see Connecting to a Networked Database).

Offers Data

Historical Offers data is used:

• As information-only in the Units Information Grid' for the Market Data Source
• As input into the seven-day Offers Profile in forecast Definitions
• As input into Scenario Data Sources based on historical Trading Periods (when available)

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NOTE: EMarketOffer does NOT use Offers to calculate Powerflows for historical Trading Periods.

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Loading Historical Offers Data

Historical Offers can be loaded either through:

• direct connection to an online database
• from pre-formatted Offers files
• Offers profile files (Forecast Definitions only)

Pre-formatted Offers files must use the same formatting used by the COMIT service for providing Offers data and be named in the following manner:

Offersyyyymmdd.csv

Where:

'Offers' is the text 'Offers'

'yyyy' is the numerical 4 digit year (e.g. 2012)

'mm' is the numerical 2 digit month (e.g. 06)

'dd' is the numerical 2 digit day (e.g. 08)

You can download Offers files directly from COMIT and use them without further editing (once renamed).

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NOTE: Date format is important - the date in the file name is used to allocate offers data to specific week days. One Offers files cannot contain data for periods from two different calendar days.

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Offers files are processed row by row without regard to overall integrity. This allows you to edit the raw Offers files prior to loading to:

• Alter Offer Prices and Quantities
• Restrict the number of offered periods to less than a full day
• Restrict the number of offering Generation Units to less than those actually offering on the day

The formatting for the Offers files can be found in the Appendix.

Offers profile files can also be used. An Offers profile file uses a proprietary format designed to capture a complete seven-day profile suitable for importing into a Forecast Definition. The format of this file can be found in the Appendix.

Using Offers with Forecast Definitions

EMarketOffer's Forecast Definitions are based on a weekly Offers Profile, organised by day of week (as opposed to date). Offers for no more than seven consecutive days can be loaded into a Forecast Definition.

The following points should be noted:

• Where a 'Forecast Effective Date Range extends beyond seven days, Offers from the loaded profile will be re-used (by corresponding day of the week) from day eight onward
• Where Offers for fewer than seven days are loaded into a Forecast Definition , any periods in the Effective Date Range not covered by the loaded Offers will fail to dispatch
• New Offers can be loaded over the top of existing Offers. examples of how this might be useful include:
  • producing modified historical offers by loading a week profile from the database and then loading an edited and/or partial Offers file containing different data
  • Modifying a single generator's offering behaviour by loading an edited file containing Offers for only the Generation Unit and specific Trading Periods of interest leaving all previously loaded Offers (for this or any other generator) unchanged.
• Offers files are loaded consecutively by date from earliest to latest. Loading more than seven-days of Offers data from file will cause over-writing of the weekly Offer profile. for example if ten days of offers are loaded from file the first three days will be lost.

Demand Data

Historical Demand data is used:

• As input into calculating the Powerflows in the Market Data Source
• As input into the seven-day Demand profile for Forecast Definitions and Powerflow Cases

Which Demand data to use with EMarketOffer?

For best results EMarketOffer's database connection should be configured to use reconciled SPD Daily Demand data (available to subscribed COMIT users) as this most closely matches the historical Offers used in final dispatch. However, EMarketOffer can be configured to work with SCADA or other Demand data. Where SCADA data is used the net final Load at each Market Node should also be used.

Loading Historical Demand Data

Historical Demand can be loaded into EMarketOffer either through:

• direct connection to an online database,
• from pre-formatted Demand files
• from demand profile files

Pre-formatted files

Pre-formatted Demand files must comply with EMarketOffer's Demand file format (see [[EMO:Appendix|Appendix) and named in the following manner:

Loadyyyymmdd.csv

Where:

'Load' is the text 'Load'

'yyyy' is the numerical 4 digit year (e.g. 2012)

'mm' is the numerical 2 digit month (e.g. 06)

'dd' is the numerical 2 digit day (e.g. 08)

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NOTE: The date format is important. EMarketOffer uses the date in the file name to allocate the Demand data to specific days. One demand file cannot contain data for periods from more than one calendar day.

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EMarketOffer processes the Demand files row by row and does not check overall integrity. This allows you to edit the raw files prior to loading into EMarketOffer to:

• Alter Demand Quantities
• Restrict the number of Demand periods to less than a full day
• Restrict the number of Demand Nodes to less than those actually drawing down power on the day

The formatting for the Demand files can be found in the Appendix

Demand Profile Files

A Demand profile file uses a proprietary format designed to capture a complete seven-day profile suitable for importing into a Forecast Definition or Powerflow Case. The format of this file can be found in the Appendix.

Using Demand with Forecast Definitions and Powerflow Cases

EMarketOffer's Forecast and Powerflow Case Definitions are based on a weekly Demand profile, by day of week. Demand figures for no more than seven consecutive days can be loaded into a Definition.

The following points should be noted:

• Where a Forecast or Powerflow Case Effective Date Range extends beyond seven days EMarketOffer will re-use the loaded Demand by day of the week from the profile for all weeks in the Effective Date Range.
• Where Demand for fewer than seven days is loaded into a Definition, any periods in the Effective Date Range not covered by the loaded Demand will fail to dispatch
• New Demand data can be loaded over the top of existing data. For example it is possible to load a full week profile from the database and then load a partial Demand file that has been edited to contain Demand for a single Node for a specific number of periods on a specific day. In this case only those periods for the selected Node will be overwritten with new data, all other Demand figures will remain unchanged.
• Demand files are loaded consecutively by date from earliest to latest. Loading more than seven days of data from file will cause over-writing of the weekly Demand profile. For example if ten days of Demand figures are loaded from file the first three days will be lost.
• When loading Demand data from database it is possible to specify a date range covering several weeks of Demand data. In this case an averaged Demand profile is created by day-of-the-week and Trading Period. It is not possible to create averaged Demand profiles by loading from file.

Transmission System Data

Transmission System data supplied by the System Operator through the EM6 and COMIT information services is used to:

• Calculate Powerflows for the Market Data Source
• Define the Transmission System configuration in Forecast and Powerflow Case Definitions

EMarketOffer requires the following Transmission System data:

• Network configuration (default values for base grid)
• Circuit electrical properties
• Circuit Re-ratings
• Group Constraint descriptions

By preference EMarketOffer automatically loads Transmission System data from any files found in the EM6/COMIT sub-folders on start-up (unless the Use Grid File Inputs box in the Source Data Administration Window is checked). A full 'map' of the historical and expected network is created, allowing the exact configuration of the Transmission System to be determined for any Trading Period covered by the file data. Where Transmission System data must be obtained from an online database, the 'map' is built up period by period in response to requests made through the Presentation Interface.

Base Transmission System

The Branch_Data file (obtainable as a downloaded from the EM6 service) defines the properties of all Circuits (including Summer and Winter ratings) and how they are connected. Both historical and expected changes to these properties are stored in the file. Files downloaded from EM6 should be placed in the Grid\EM6\BaseGrid sub-folder named according the the following convention (the same as used by EM6):

Branch_Data_ddmmyyyy.csv

Where:

• 'Branch_Data' is the text 'Branch_Data'
• 'ddmmyyyy' is the date the file was downloaded from EM6

On start-up EMarketOffer uses the Branch_Data file with the latest date. Where no Branch_Data file exists, EMarketOffer attempts to access data through a database connection. Branch_Data files will always be used preferentially to source Transmission System data regardless of whether a current database connection for the data has been defined or not.

EMarketOffer will fail to operate if no Transmission System data can be found from any source at startup.

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NOTE: You will need to download new branch data files from EM6 from time to time. These should be named according to the above convention and placed in the EM6\BaseGrid sub-folder. It is not necessary to remove previous Branch_Data files as only data from the file with the latest date will be used.

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WARNING! Files provided by the system operator no longer accurately reflect historical system changes prior to 2002. If you wish to model the pre-2002 system you should use Transpower branch data files that were created close to the time you are interested in analysing. This will require removing Branch_Date files with later create dates from the EM6\BaseGrid sub-folder.

Security Constraints

Files, in CSV format, of historical and expected Security Constraints are provided through both the EM6 and COMIT free to air services. The following table summarises the files that can be processed by EMarketOffer:

Source	Data Content	EMO Location	EMO File Name	Comment
EM6	Security Constraints	Input\Grid\EM6\Reratings	branch_constraints_ddmmyyyy_ddmmyyyy.csv	Contains all security constraints (circuit re-ratings) in effect on any Trading Period with the date range contained in the file name (naming as used by EM6).
EM6	Security Constraints	Input\Grid\EM6\Equations	constraints_ddmmyyyy_ddmmyyyy.csv	Contains all security constraints (equations) in effect on any Trading Period with the date range contained in the file name (naming as used by EM6).
EM6	Security Constraints	Input\Grid\EM6\Constraints	constraints_change_ddmmyyyy_ddmmyyyy.csv	Contains all security constraints in effect on any Trading Period with the date range contained in the file name (naming as used by EM6).
COMIT	Security Constraints	Input\Grid\COMIT	constraints_change_ddmmyyyy_ddmmyyyy.csv	Contains all security constraints in effect on any Trading Period with the date range contained in the file name (naming as used by EM6).
Ellsoft	Security Constraints	Input\Grid\Ellsoft	ellsoft_constraints_ddmmyyyy_ddmmyyyy.csv	Contains an Ellsoft generated file containing all security constraints in effect on any Trading Period with the date range contained in the file name (naming as used by EM6).

Warning! Ellsoft provides Constraint files to cover the historical period from the beginning of the market to a date subsequent to the mass circuit renaming exercise conducted by Transpower on the 8th December 2007. The file has been constructed using historical TPIX and recent EM6 data files and for the period 1 Jan 2007 to 31 May 2008 has used the maximum capacities from arcflow data to construct realistic branch re-ratings. This file is intended to overcome inconsistencies in constraint source data. It is provided without guarantee of accuracy; you are advised to independently confirm any data found in this file.

How EMarketOffer processes Transmission System data

When constructing its internal Transmission System database, EMarketOffer first analyses the base grid and creates a period-by-period 'map' of the system which includes the tracking of all changes in rating, electrical properties and overall configuration. Secondly the Branch re-ratings are applied 'over the top' of the initial map. Finally the Group Constraints are examined and a parallel map of these Constraints is created.

Two rules are observed when loading Constraint data from file:

1. Data is loaded from folders in the following preference order:
   1. Input\Grid\Ellsoft
   2. Input\Grid\EM6\Constraints
   3. Input\Grid\COMIT
   4. Input\Grid\EM6\Equations and Input\Grid\EM6\Reratings
2. Where files in different folders contain data for overlapping time periods, data will be taken from the file with the latest data, and from the first date in that file (see Figure 1 below)

File:Transmission system data.PNG

Figure 1 - Constraints File Handling Example