Abstract

Abstract

Abstract
This paper presents an optimization model to help a hydro generating company to schedule its hydroelectric units in the short-term under a competitive environment. The hydro generating company considered has the ultimate goal of maximizing profits, taking also into account some risk aversion criterion. The problem is formulated as a mixed-integer nonlinear programming problem. An application to a real case study is presented. Conclusions are duly drawn.

Abstract
This paper briefly describes the Portuguese Lightning Location System, and presents an overview of wind energy in Portugal. The method for risk assessment due to lightning flashes to earth, proposed by the International Electrotechnical Commission, IEC, is used. A wind power plant is characterized for a case study, and the standard IEC 62305-2 is applied. Results obtained are able to support the advantage for investors to take into account the lighting activity in the region where the wind power plant shall be installed. Also, the use of a well established risk assessment method allows the adoption of adequate protection measures.

Abstract
This paper presents an artificial neural network approach for short-term wind power forecasting in Portugal. The increased integration of wind power into the electric grid, as nowadays occurs in Portugal, poses new challenges due to its intermittency and volatility. Hence, good forecasting tools play a key role in tackling these challenges. The accuracy of the wind power forecasting attained with the proposed approach is evaluated, reporting the numerical results from a real-world case study. © 2009 IEEE.

Abstract
This paper is on the problem of profit-based unit commitment with emission limitations. We propose a multiobjective approach to handle the problem with conflicting profit and emission objectives. A trade-off curve between profit and emission in a way to aid decision-makers concerning emission allowance trading is obtained due to this multiobjective approach. Numerical results based on the standard IEEE 30-bus test system illustrate the proficiency of the proposed approach.