L.E. Thiele Consulting

About LETC

ATRAC
free public domain load flow software

Power flow modeling verification

If you have been presented and must review electric transmission power flow or load flow simulation analyses prepared by other organizations or you need to evauluate load flows to resolve a dispute involving transmission access, L.E. Thiele Consulting can provide an independent third party assessment and verification.

Our assessments can include:

working with very large power flow cases up to 100,000 buses
verifying raw data
verifying typical base flow and contingency analyses
verifying modeling of the interregional networks
tracking transactions from source to end-user
quantifying line use
assessing vulnerability to limitations
establishing the impact transactions have on parallel power flows and losses
verifying scheduling or control of transmission use
assessing quotations of Available Transfer Capability

The ATRAC model

The power flow software model we use is ATRAC, which we developed for the specific purpose of analyzing transmission congestion in a deregulated environment. It is a state-of-the-art full-solution pseudo-optimal power flow model. It performs a full non-linear network solution without taking modeling shortcuts. It is pseudo-optimal in the sense that it can model the dispatch of generation and therefore minimize a company's power generation costs. When cases produce suspicious results or do not converge, ATRAC has features to quickly home in on the suspected data.

With the large size of networks being modeled today, input data is especially prone to errors, missing elements, and improper application, resulting in incomplete or faulty analyses. It is easy for subtle errors to become hidden in the mass of data, potentially tainting the results and conclusions. To specifically address these issues, ATRAC emphasizes data integrity capability for large network models with techniques not available in popular commercial power flow software.

Deregulation-ready

ATRAC is a transaction-driven power flow. It has the capability to directly simulate deregulated network components, including the transactions of power marketers and brokers. These simulations can track transactions across large multi-regional networks, through parallel paths, and through multiple traders buying from and selling to several parties simultaneously. The power flow simulation can include non-facility transacting parties such as power marketers and reflect the transmission use impact of scheduling their physical transactions through designated delivery/receipt points. These features make ATRAC paticularly attractive for congestion analysis.

To use our verification services

You will need to get access to the raw power flow data from which the analyses you have were prepared so that we can then start with that same data to run our independent assessment. We will also need to put together a list of issues you would like to see addressed in the verification process.