Douglas J. Gotham

Power flow control and power flow studies for systems with FACTS devices

In this paper, the modeling of flexible AC transmission system (FACTS) devices for power flow studies and the role of that modeling in the study of FACTS devices for power flow control are discussed. FACTS devices are solid-state power converters that have the capability of control of various electrical parameters in transmission circuits. A number of power flow study programs were developed in order to model various types of FACTS devices. Three main generic types of FACTS devices are suggested and the integration of those devices into power flow studies, studies relating to wheeling and interchange power flow control are illustrated.

POWER FLOW CONTROL IN SYSTEMS WITH FACTS DEVICES

ABSTRACT The modern trend for consolidating electric power companies, even though the participants in these mergers may be not well connected electrically, suggests that technologies that permit power flow control in AC power networks may be favored for some applications. In this paper, the analysis of steady state power flow control in the presence of flexible AC transmission system devices (FACTS devices) is discussed. Objectives such as wheeling, line loading and unloading, ‘electronic fence’ methods to block power transfer, prevention of loop flows, and steady state security enhancement using FACTS are discussed. Newton-Raphson power flow studies for systems with FACTS devices are discussed. An example based on a large American power system is presented.

A large oligopoly competition model with an application to the Midwest electricity markets

This paper presents a large spatial gaming model with price caps for the Midwest electricity markets. Price caps are enforced in several deregulated regional electricity markets in the USA, a logical step is to reflect this reality in imperfect competition modeling. Unfortunately, most current gaming models have not included any price cap formulation. This paper is one of the first to address the issue. A transportation formulation is used for representing the spatial nature of an electrical network. An algorithm is proposed to find a Nash equilibrium under the enforcement of price caps based on the Kuhn-Tucker vector optimization theorem. Case studies show the successful application of the model. The conclusion is that, given appropriate price caps, market power impact can be reduced in the short run.

Additional EIPC Study Analysis. Final Report

Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.

Modeling Power Portfolio with Supply Contracts for Mitigating Risks of Serving Uncertain Demand

Electricity suppliers are always confronted with demand uncertainty even though the state-of-the-art forecast and sophisticated control systems are employed to ensure both security and reliability. With the emergence of power market, the market participants such as generation companies, load serving entities, etc., even face higher degree of uncertainty in its operation planning. This is due to the unique characteristics of electricity which could result in unprecedented price spikes. A portfolio of supply contracts including forwards and options is a set of tools for reducing the impacts of both demand uncertainty and price volatility by increasing production flexibility. Thus, a procurement strategy can be implemented by providing more choices via contracting in addition to self generation and spot market transactions. In this framework, a two-stage planning model is developed for improving the short-term operation by incorporating risk hedging strategy in the planning problem so as to meet stochastic demand

Preserving low cost electricity while improving the riverine environment: A case study of Ghana’s Akosombo hydro complex

This paper presents the strategy for development of a stochastic programming model of the operation and capacity additions to a large hydro/thermal electricity generation complex. The proposed model minimizes the incremental costs of operating the complex so as to return river flows to pre-dam patterns. The paper focuses on a representative year made up of wet and dry seasons far enough into the future to allow adjustment of thermal and hydro generating capacities and the initial level of the reservoir, but not the capacity of the reservoir itself. The model was run first to find the operating and investment strategies which minimize electricity costs, and then run so as to minimize cost subject to equating seasonal reservoir inflows to seasonal outflows - so called ldquorun of river, RORrdquo operation. Using data from Ghanapsilas Akosombo/Kpong complex, likely outcomes of the model are presented and compared, based on existing capacities of the system.

Preserving low cost electricity while improving the riverine environment: Part two — Model results

This paper reports on a case study for Ghanas thermal/hydroelectric generation system that evaluates the incremental cost of returning dam outflows to pre-dam or near pre-dam conditions. This mode of operation is termed Run of River (ROR) operation. It appears that two key factors — the availability of alternatives for economically expanding hydro generation and the existence of well developed markets for energy and electricity — have a large influence on the increase in cost of ROR operation relative to the least cost operating rules.

The projected impacts of NOx emissions reductions on electricity prices: a case study for the State of Indiana

Abstract This paper examines the impact of various nitrogen oxides (NOx) emission control scenarios on the price of electricity. Specifically, various scenarios are presented to illustrate the price impacts for the state of Indiana. The scenarios represent different methods for reducing NOx emissions levels to either 0.15 or 0.25 lb/mmBtu. The analyses were performed using a traditional regulation forecasting model that equilibrates between price and demand. Thus, the effects of price changes on demand levels were captured. Price impacts are presented at an overall average level as well as by customer class. The impacts of various assumptions made in the selection of the scenarios are analyzed.

Assessment of the reliability of Indiana's electricity generation system

The objective of this research was to determine the adequacy of the rule-of-thumb reserve margin for Indianas electricity generation system and the adjustment of the reserve margin. To achieve the objective, a statistical model is constructed to evaluate system reliability. Monte Carlo Simulation is applied to build the capacity availability probability distribution as the generation model. Hourly loads and daily peak loads of 2003, 2004 and 2005 are used to form the load models. Then, the generation model and the load model are convoluted to calculate the loss of load probability (LOLP) for Indianas electricity generation system. Results show that the reliability standard is more than satisfied for 2003 and 2004. However, for 2005, the estimated LOLPs do not satisfy the standard, suggesting capacity expansion for the system is needed. By uniformly shifting load curves up or down to adjust the estimated LOLPs until the industry standard is satisfied, the new reserve margin for each load model is found. This analysis suggests that even for 2005 only a small increase in generating capacity is needed.

A Two-Stage Stochastic Unit Commitment with Electricity Derivatives

A unit commitment problem has long been known in the class of short-term functions and decisions, inherited from vertically integrated utility. In the competitive environment, the problem has become more complicated due to the fact that any action taken will now influence profitability of decision maker such as generation companies, load serving entities, and so forth. Thus, not only do economic agents face operational risks, but they also need to procure their operations against financial risks from volatility in fuel contract, and electricity prices. This leads to the evolution of stochastic unit commitment in this paper integrating risk management tools, ie., electricity derivatives, so as to reduce the impacts from both operational and financial risks in the short run. The planning model is structured of stochastic mixed-integer program with recourse cost A case study will be addressed with preliminary result presenting an improved solution.