Model load frequency Discussion

John Adams

January 5, 2010Nodal Advisory Task Force

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What issues are we trying to address?

Nodal Advisory Task ForceJanuary 5, 2010

ERCOT had considered supporting daily database loads in its Nodal design, and can support CIM case production at this periodicity. However, downstream acceptance of database loads at this interval is proving problematic.

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What issues are we trying to address?

• Process challenges:– In the past (zonal) it has taken ERCOT ~3 days to validate and

load a database.– With nodal; ERCOT needs to add additional processes to

examine market impacts of database loads.– Additional time between database loads adds complexity and

risk to TSP’s processes.• Program constraints:

– Supporting daily database loads, combined with multi-day validation, may require multiple parallel validation and load infrastructures. The nodal program has not planned, specified or built such infrastructure.

– ERCOT has not yet achieved a 3 day validation/load process in nodal

Nodal Advisory Task ForceJanuary 5, 2010

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What issue are we trying to address?

• Protocol Requirements3..10.1 Timeline for Network Operations Model Change Requests(1) ERCOT shall perform periodic updates to the ERCOT Network Operations Model.

Market Participants may provide Network Operations Model updates to ERCOT to implement planned transmission and Resource construction one year before the required submittal date below. TSPs and Resource Entities must timely submit Network Operations Model changes pursuant to the schedule in this Section to be included in the updates...

3) TSPs and Resource Entities shall submit Network Operations Model updates at least three months prior to the physical equipment change. ERCOT shall update the Network Operations Model according to the following table:

Nodal Advisory Task ForceJanuary 5, 2010

Deadline to Submit Information to

ERCOT

Note 1

Model Complete and Available for

Test

Note 2

Updated Network Operations Model Testing Complete

Note 3

Update Network Operations Model

Productuion Environment

Target Physical Equipment In-Service Date

Note 4January 01 February 15 March 15 April 01 Month of April

February 01 March 15 April 15 May 01 Month of May

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Difficulties imposed on Transmission Operators by infrequent database changes

• If models are loaded only 10 times/year; the ability of TSP’s to model changes on the day they expect them to be energized will be limited.– TSP’s may schedule energization of new equipment to match

ERCOT’s schedule or– TSP’s may submit Network Operations Model Change Requests

(NOMCR’s) to install equipment early, and simultaneously enter outage schedules to take this equipment out of service.

– Under some circumstances, when equipment is re-used for different topology; it will be impossible to model outages on the equipment during the construction process without interfering with accurate representation of interim topology. In these cases the absence of frequent model loads could require the introduction of non-existent switches to the model to produce accurate results. Management of these Pseudo switches is difficult.

January 5, 2010

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What should drive this decision

At this point; ERCOT does not fully understand the relationship between complexity, effort, days between loads, and data integrity

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• ERCOT trying to achieve a Nodal market load schedule of 2 database loads/month in our test program. This is a compromise between the Nodal protocol requirement of 10 Database loads/year; and the original proposal of daily.

• ERCOT will develop further experience during 2010 with our model load process; and will report upon our progress in improving that process.

• In the absence of daily model loads; ERCOT is proposing we discuss rules specifying the following:

1. How we will model/manage Pseudo devices if needed (Current protocols only allow TSP’s to create pseudo devices)

2. If TSPs will provide telemetry for Pseudo devices. (Current protocols required all switching devices to be telemetered)

3. How pseudo devices shall be managed for CRR, DAM, etc.4. Modifying the restrictions on Remedial Switching Actions to make it

like the current Equipment Status Change

January 5, 2010

Current Status

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Next Steps

• ERCOT– Continue to report to the market on the progress and support of

the database load and timing process.– Propose business processes and timing for participant

discussion.

• Market Participants– Facilitate feedback from Market Participants via NATF regarding

development of a database load business process which minimizes risk and complexity for the entire participant base.

Nodal Advisory Task ForceJanuary 5, 2010