%0 Journal Article
%J Resource and Energy Economics
%D 2014
%T Does a detailed model of the electricity grid matter? Estimating the impacts of the Regional Greenhouse Gas Initiative
%A Daniel L. Shawhan
%A John T. Taber
%A Di Shi
%A Ray D. Zimmerman
%A Yan, Jubo
%A Charles M. Marquet
%A Yingying Qi
%A Mao, Biao
%A Richard E. Schuler
%A William D. Schulze
%A Daniel J. Tylavsky
%K CERTS
%K electricity markets
%K reliability and markets
%K RM11-005
%X The consequences of environmental and energy policies in the U.S. can be severely constrained by physical limits of the electric power grid. Flows do not follow the shortest path but are distributed over all lines in accordance with the laws of physics, so grid operators must select which generation units to operate at each moment, not only to minimize production costs, but also to prevent the system from collapsing because of line overloads. Because of the complexity of power grid operation, computing limitations have until very recently made it impossible to solve a policy analysis or planning model that combines realistic modeling of flows with a detailed transmission system model and the prediction of generator investment and retirement. We construct and solve a model of the eastern US and Canada that combines these characteristics. Then, because a smaller model would be usable for some additional purposes, we explore the effects of transmission model simplification on the accuracy of simulation results. To evaluate the amount of detail necessary, we simulate the short- and long-term effects of imposing a price on the carbon dioxide emissions from the power plants in nine northeastern US states, as the Regional Greenhouse Gas Initiative does. We consider three grid models that simplify the actual 62,000-node system to varying degrees. Our 5000-node model matches the 62,000-node model very closely. We use it as the basis for evaluating the more simplified models: a 300-node model and a model with just one node, i.e. no transmission constraints. With each of the three models, we predict the carbon dioxide emission impacts, electricity price impacts, and generator entry and exit impacts of the emission price, over the next 20 years. We find that most of the impact predictions produced by the 300- and one-node models differ from those of the 5000-node model by more than 20%, and some by much more. Fortunately, the 5000-node model, and others with its combination of transmission detail, realistic flows, entry prediction, and retirement prediction can be used for many useful purposes.
%B Resource and Energy Economics
%V 36
%P 191 - 207
%8 01/2014
%N 1
%! Resource and Energy Economics
%R 10.1016/j.reseneeco.2013.11.015
%0 Conference Paper
%B 2014 North American Power Symposium (NAPS)
%D 2014
%T Improved dc network model for contingency analysis
%A Sood, P.
%A Daniel J. Tylavsky
%A Yingying Qi
%K CERTS
%K Power system modeling
%K RM11-005
%X Contingency analysis is employed by system operators to estimate post-disturbance power system robustness. For large system like WECC or the Eastern Interconnection (EI) the computational burden and time consumed for full blown ac analysis is tremendous. Also, a recent upsurge in the area of electric energy markets and transmission/generation planning has created a niche for computationally efficient and yet reliable, simple and robust power flow models. This has intensified the inclination of researchers to come up with equivalent dc networks that match ac solutions as close as possible. This paper introduces a novel method of deriving dc model using PTDF approach. The performance of this model is then compared to the several other dc models for single branch outage contingencies. Furthermore, shortcomings of several dc models shall be analyzed.
%B 2014 North American Power Symposium (NAPS)
%I IEEE
%C Pullman, WA, USA
%P 1 - 6
%8 09/2014
%R 10.1109/NAPS.2014.6965414
%0 Conference Paper
%B 2012 North American Power Symposium (NAPS 2012)
%D 2012
%T Impact of assumptions on DC power flow model accuracy
%A Yingying Qi
%A Di Shi
%A Daniel J. Tylavsky
%K CERTS
%K Power system modeling
%K RM11-005
%X The industry seems to be sanguine about the performance of dc power-flow models, but recent research has shown that the performance of different formulations is highly variable. Considering their pervasive use, the accuracy of dc power-flow models is of great concern. In this paper, three dc power-flow formulations are examined: the classical dc power-flow model, dc power-flow model with loss compensation and the so-called a-matching dc power-flow model. These three models are tested in three systems of different sizes, ranging from 10 buses to 62,000 buses. By comparing the dc power-flow results with the ac power-flow results, the paper concludes that the a-matching formulation has the highest accuracy among three dc power flow formulations.
%B 2012 North American Power Symposium (NAPS 2012)
%I IEEE
%C Champaign, IL, USA
%P 1 - 6
%8 09/2012
%@ 978-1-4673-2306-2
%R 10.1109/NAPS.2012.6336395