ABB software breaks the 40,000-bus barrier for northeastern U.S. model

Santa Clara, CA

ABB Inc. announced that the firm’s security constrained unit commitment (SCUC) software has been run successfully using a 40,000-bus model that encompasses the entire northeastern U.S. and major portions of WSCC.

Anticipating the need for a software system capable of supporting the proposed RTO Northeast region, the company scaled up the system currently in use at the New York ISO to handle the demands of what would be the world’s largest electricity market.

ABB Vice President and General Manager of US Business Management Systems, Hisham Othman, says, “We’re very pleased with the results of this test. Regardless of the outcome of the political process now underway with regard to RTO Northeast, larger energy markets are likely to become a reality. We wanted to see if our software could make the transition to a super-size market on the order of RTO Northeast, and I’m happy to report that it passed this test with flying colors.”

Using test data from NERC, the SCUC system was given typical bids from over 1,500 generation plants within the RTO-NE territory as well as over 100 bids each from 38 large plants outside the Northeast. SCUC matches hourly generation, and computes locational marginal prices based on the optimized unit commitment schedules.

At the same time, the software also takes transmission thermal constraints and other factors into account to determine an optimized generation schedule that recognizes high voltage grid constraints, while serving load with minimum generation operational cost.

The NYISO currently uses a 3000 bus transmission network data file to model the Northeast grid. The 40,000-bus data model used by ABB represents a detailed and accurate representation of the high voltage grid that is greater than the entire eastern United States.

The milestone is significant because it represents the first successful test of a software system capable of operating a market of the magnitude envisioned by RTO Northeast. The SCUC system is also unique in its ability to concurrently optimize the energy as well as the ancillary services and reserve markets, and to efficiently enforce network security constraints corresponding to the bulk power and locational reliability requirements.

As ABB’s Othman notes, however, “The core security constrained unit commitment algorithm is essentially the same as the system that NYISO relies on every day to manage their deregulated market. The combined Northeast RTO is expected to manage an integrated power system of approximately 140 GW and a single wholesale market exceeding $20 billion per year, including a spot market exceeding $5 billion per year. It will span a geographical area including well over 20 percent of the nation’s population, the nation’s capital, it’s financial center, and five of the largest metropolitan areas in the country. I think the results of this test speak volumes about the software’s robustness, its scalability, and it’s reliability for use in such a market.

This accomplishment is a crucial first step since other advanced market interface and scheduling applications have to be integrated around the core SCUC functionality to support a ‘super-RTO’, but I think it is a great first step.”

ABB is a global provider of central market systems for ISOs and RTOs. The company’s software is in use today supporting energy markets from California to Ontario to the United Kingdom.

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