http://hdl.handle.net/10016/2738 Thu, 23 May 2013 10:39:16 GMT 2013-05-23T10:39:16Z http://hdl.handle.net/10016/15772 Title: Optimal operation of a pumped-storage hydro plant that compensates the imbalances of a wind power producer Author(s): Jaramillo Duque, Álvaro; Castronuovo, Edgardo D.; Sánchez, Ismael; Usaola, Julio Abstract: The participation of wind energy in electricity markets requires providing a forecast for future energy production of a wind generator, whose value will be its scheduled energy. Deviations from this schedule because of prediction errors could imply the payment of imbalance costs. In order to decrease these costs, a joint operation between a wind farm and a hydro-pump plant is proposed; the hydro-pump plant changes its production to compensate wind power prediction errors. In order to optimize this operation, the uncertainty of the wind power forecast is modeled and quantified. This uncertainty is included in an optimization problem that shifts the production of the hydro-pump plant in an optimal way, aiming at reducing the imbalance costs. The result of such a method is profitable for both participants, the wind farm and the hydro-pump plant. A realistic test case is used to evaluate the proposed method. Wed, 31 Aug 2011 22:00:00 GMT http://hdl.handle.net/10016/15772 2011-08-31T22:00:00Z http://hdl.handle.net/10016/8971 Title: Probabilistic load flow in systems with wind generation Author(s): Usaola, Julio Abstract: A method for solving a probabilistic power flow that deals with the uncertainties of (i) wind generation, (ii) load and (iii) generation availability in power systems is proposed. Dependence between random variables has been considered. The method is based on the properties of cumulants of random variables. Cornish-Fisher expansion series are used to obtain the cumulative distribution function (CDF) of the output variables. Multimodal CDF are obtained by convolutions, whose number has been minimised in order to decrease the computation requirements. Mon, 30 Nov 2009 23:00:00 GMT http://hdl.handle.net/10016/8971 2009-11-30T23:00:00Z http://hdl.handle.net/10016/5289 Title: Probabilistic load flow with wind production uncertainty using cumulants and Cornish–Fisher expansion Author(s): Usaola, Julio Abstract: This paper proposes a method for probabilistic load flow in networks with wind generation, where the uncertainty of the production is non-Gaussian. The method is based on the properties of the cumulants of the probability density functions (PDF) and the Cornish–Fisher expansion, which is more suitable for non-Gaussian PDF than other approaches, such as Gram–Charlier series. The paper includes examples and comparisons between different methods proposed in literature. Wed, 31 Dec 2008 23:00:00 GMT http://hdl.handle.net/10016/5289 2008-12-31T23:00:00Z http://hdl.handle.net/10016/3633 Title: Combined hydro-wind generation bids in a pool-based electricity market Author(s): Angarita, Jorge; Usaola, Julio; Martínez-Crespo, Jorge Abstract: Present regulatory trends are promoting the irect participation of wind energy in electricity markets. The final result of these markets sets the production scheduling for the operation time, including a power commitment from the wind generators. However, wind resources are uncertain, and the final power delivered usually differs from the initial power committed. This imbalance produces an overcost in the system, which must be paid by those who produce it, e.g., wind generators among others. As a result, wind farm revenue decreases, but it could increase by allowing wind farms to submit their bids to the markets together with a hydro generating unit, which may easily modify its production according to the expected imbalance. This paper presents a stochastic optimization technique that maximizes the joint profit of hydro and wind generators in a pool-based electricity market, taking into account the uncertainty of wind power prediction. Wed, 31 Dec 2008 23:00:00 GMT http://hdl.handle.net/10016/3633 2008-12-31T23:00:00Z