Texas Nodal

NMMS and The ERCOT CIM Network Model

By Nitika Mago, ERCOT, Network Modeling Group

2ERCOT Public

9/10/2010

Agenda

• ERCOT – An Introduction

• The Texas Nodal Project, CIM & NMMS

• NMMS – An overview

• NMMS CIM Schema Extensions

• NMMS Today

• Lessons Learnt & Future Outlooks

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ERCOT: An Introduction

• Electric Reliability Council of Texas (ERCOT) is the independent system operator for – Managing the flow of electric power to 22 million Texas customers

representing, 85 percent of the state’s electric load and 75 percent of the Texas land area.

– Under the regulation of the Public Utilities Commission of Texas (PUCT), ERCOT is tasked with the responsibility of ensuring reliability of electric supply for all its customers whilst maintaining a competitive electricity market.

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The Texas Nodal Project, CIM & NMMS

• In 2004, ERCOT began a complete system redesign to migrate from a zone-based market model to a node-based market model.

• Some reasons to move to a nodal market include:– Increased transparency in energy prices– Operational challenges in portfolio scheduling and bidding– Direct assignment of local congestion costs

• This redesign necessitated,– a centralized data warehouse with an all-encompassing model schema

to contain, maintain and deliver consistent model data representative of the Texas electric grid for all model driven activities including,

• Energy Management• Market Management• System Planning• Outage Scheduling• Congestion Revenue Rights Auctions

– Thus leading to the development of a Common Information Model (CIM) for ERCOT and the establishment of a Network Model Management System (NMMS) to maintain this model.

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NMMS: An Overview

• NMMS is used to manage, manipulate, prepare and provide models to the following ERCOT operational and planning systems,– Energy Management

System (EMS)– Market Management

System (MMS)– Outage Scheduler (OS)– Congestion Revenue Rights

System (CRR)– Operations Training

Simulator (OTS)– Settlements & Billings– ERCOT Planning

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NMMS: An Overview

• NMMS serves as a single point of entry and maintenance of the network model topology used by ERCOT.

• A subset of NMMS functionality is made available to ERCOT Transmission Service Providers to enter network model changes via both– Incremental CIM/XML files,

and/or– the built-in User Interface.

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NMMS CIM Schema

• NMMS began with a CIM10 version 7 core schema and has over the past 4 years incrementally improved this thru 21 full releases and numerous minor alterations.

• Some of the key ERCOT extensions are in the following areas– Market Operations– SCADA & ICCP Modeling– Planning & CRR Modeling– Contingencies & RAS Modeling– Operations Training Simulator

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NMMS CIM Schema Market Extensions

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NMMS CIM Schema SCADA & ICCP Extensions

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NMMS CIM Schema Planning & CRR Extensions

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NMMS CIM Schema Contingency & RAS Extensions

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NMMS CIM Schema OTS Extensions

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NMMS Today

• NMMS is being actively used by ERCOT TSPs as primary front end to enter network model changes, by ERCOT staff to manage, validate, build & provide models downstream, since September 1st, 2009.– 8000+ change requests have been submitted into NMMS thus far.– Weekly/Bi-weekly CIM models from NMMS have been delivered to

downstream test environments for consumption and use.– These CIM models have consistently solved using AREVA power flow

analysis tools.

• Quiet a few tools have been developed that leverage the flat structure of CIM/XML to provide enhanced updating capabilities to the network model. Some notable ones include,– Outage Scheduler model topology tracer,– Contingency definition builder,– Station one line generator, and– Granular model comparison viewer

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Lessons Learnt & Future Outlook

• Presence of legacy systems in the model consumption chain have forced some awkward requirements from the model, often necessitating the utilization of inelegant processes and procedures to support the same.

• Future Outlook– Texas Nodal project go-live December 1st, 2010. – Improve the handful seemingly “bulky” & redundant modeling

implementation prevalent in certain parts of NMMS CIM.– CIM extensions to support Smart Metering

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NMMS and The ERCOT CIM Network Model

Questions?