The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper presents and discusses some typical market clearing and dispatch mechanisms based on security-constrained (SC) optimal power flow (OPF) techniques that are currently being utilized in various jurisdictions throughout the world, concentrating on how system security is accounted for in these auction systems and the effect that this has on the system dispatch schedules and energy prices. The...
Conventional economic power dispatch problem uses deterministic models, which are however not able to reflect some real situations in practical applications. Since certain inaccurate and uncertain factors are normally involved in system operations, stochastic models are more suited for investigating some of the power dispatch problems. In this paper, the stochastic model for combined heat and power...
Today's European electricity grids have evolved over more than hundred years. The increasing penetration of renewable energy sources and other distributed sources in the energy supply in distribution grids leads to numerous technical challenges, which need a European approach. To cope with this, European pilot installations and field tests in research projects under the 5th framework programme as...
Summary form only given. The unit commitment problem with tertiary reserve requirements has been broadly studied. Such reserves, when needed, are centrally deployed with relatively slow time constants of the order of minutes. In contrast, the scheduling of units offering primary frequency regulation reserve deployable in a decentralized manner within seconds of a contingency has received relatively...
Load forecast (LF) is the prediction of the system load over a defined time interval that ranges from one hour to one week for power system operation purposes. Due to the random nature of the load and its dependency on numerous factors forecasting is never 100% accurate. Inaccuracies in the LF lead to inefficient daily system operation. On the one hand, if at a given period the load is under-forecasted...
An overview of ERCOT's background and the ERCOT RUC process is presented. The three steps of clearing the ERCOT RPRS Market are described. Settlements of the RPRS market are briefly described. Finally, several typical challenges with RUC in ERCOT are briefly discussed
Throughout the world significant development is being encouraged in wind energy for electricity generation. A complete cost and benefit analysis has been conducted in this paper on grid connected wind generation. It takes into account system costs such as reserve requirements, start-up and ramping implications for conventional plants as well as wear and tear costs. The benefits of wind generation...
In this paper, an algorithm to solve environmental constrained unit commitment problem (UCP) with operational and power flow constraints has been developed to plan an economic and secure generation schedule. Both economic load dispatch (ELD) and economic emission dispatch (EED) have been applied to obtain optimal fuel cost and optimal emission of generating units for the entire time horizon. The unit...
This paper proposes the inclusion of transient stability constraints in generation dispatch algorithms used in electricity markets to ensure dynamic security. The proposed security constraint is derived by applying a non-linear surface fitting technique to a database generated off-line. The technique used has two key features that enables very fast computation of an accurate transient stability constraint...
As part of managing of system reliability, Midwest ISO operates a reliability unit commitment market. The panel speaker speaks about the recent opening of the day-ahead and real-time EMP based markets and in particular experiences and challenges with operating the reliability unit commitment market including: 1) ability to handle load forecast errors; 2) look-forward RUC studies: seven-day ahead,...
This paper put forward to an interactive flexible SCADA system in which information shared, on the basis of analyzing and summarizing the defections of former SCADA. It not only solves the interaction of data and function in the information islands, but also solves functions coordination and data exchange of distributed application system in different location. The paper proposes the concept of general...
Continuation power flow (CPFLOW) with multiple load variation and generation re-dispatch patterns is developed in this paper. The power injection variations are determined by both load variation and real generation dispatch in power systems. To model power injection variations, a piecewise linear model in the power injection space is used to model multiple load variations while the economic dispatch...
Nash equilibrium is usually used as the solution of generator's strategic bidding in electricity markets. The available literatures have demonstrated by simulation that multiple market equilibria or no pure equilibrium may be induced with the inclusion of network constraints (e.g. transmission constraints). This paper presents a systematical analysis of the impacts of network constraints on the market...
This paper presents a novel and efficient method for solving the economic dispatch problems with non-smooth cost functions, by integrating the particle swarm optimization (PSO) with the chaotic sequences. The proposed improved particle swarm optimization (IPSO) combines the particle swarm optimization algorithm with chaotic sequences technique. A particle swarm optimization is one of the most powerful...
This paper developed an OPF model including price caps based on the duality theory of linear programming. Implementing price caps on the nodal prices is equivalent to implementing an upper bound on a function of the Lagrange multipliers of the primal problem, which are the variables in the dual problem. By solving the dual of the modified dual problem, we can find how the price caps affect the power...
This paper presents a preliminary study of simultaneous optimal dispatch of both active power and reactive power. In the current economic dispatch practice only optimal active power allocation is considered since all cost functions are characterized as functions of the active power. Reactive power requirements are mostly mandated by utilizing a fixed power factor or based on system operators' judgment...
The following topics were dealt with: power quality; industry restructuring; IEEE 1453 flicker standard; transmission expansion planning; system stability; power systems computer simulation; distribution economics; load forecasting; price forecasting; VAr allocation; distribution analysis; DSM; energy markets; distributed generation; FACTS; power generation control; power engineering education; power...
In electrical systems, one of the main factors that limits the energy transport is the temperature of the conductor. Knowing the transmission system, its lines, the critical sections and the climate of the region where they are located, the real temperature of the conductor can be calculated, providing, in determined conditions, an increase of the transmission capacity, without compromising the operational...
In last years, Italian distribution network is registering a progressive diffusion of distributed generation (DG), in both HV and MV grids, driven by European and national incentives, especially for renewable energy sources (RES). The increase of generation in MV network may produce several problems in a regulatory context with high focus on quality of service and costs reduction. In fact, MV grid...
Part II of the joint papers analyzes CO2 capture cost to the state of Indiana through scenario-based technique. An optimization modeling system is used for scheduling and dispatching the generation units to minimize the production costs. The new power plants, with and without CO2 capture are used for deriving the costs, and the extra costs associated with CO2 capture are used to measure the "burden"...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.