Renewable Power Forecast to Scheduling of Thermal Units

Abstract

Part 13: Optimization Issues in Energy - IInternational audienceIn this work is discussed the importance of the renewable production forecast in an island environment. A probabilistic forecast based on kernel density estimators is proposed. The aggregation of these forecasts, allows the determination of thermal generation amount needed to schedule and operating a power grid of an island with high penetration of renewable generation. A case study based on electric system of S. Miguel Island is presented. The results show that the forecast techniques are an imperative tool help the grid management

Unit commitment based on risk assessment to systems with variable power sources

“…Contrary to widely used scenarios-based approach, in this work it is proposed the probabilistic estimation of costs based on estimation risk, directly using the probability density function of the random variables. Knowing the probability function of net load (LN), obtained by load minus the renewable production (L-RES) [1], [5], [6], [9], [15], for each hour h of the scheduling period, the ability of each thermal GENeration mix SET (GENSET) to meet the net load is verified. Notice that in the risk assessment approach there are no infeasible solutions, only more or less costly solutions.…”

“…This problem is boosted in low power networks, particularly in islands without any connection to continental networks. Large variations on renewable production can introduce stability problems in the network, which can originate generation or load shed and, at limit, black-outs a strong possibility [ 1]. When available, the RES production allows thennal production decrease, especially during the peak load periods.…”

Analysis of Spinning Reserves in Systems with Variable Power Sources

“…1 an example of the proposed risk assessment is depicted. The probability density function fL-RES represent the forecasted net load (LN) obtained by subtraction of the forecasted load by the forecasted renewable production (L-RES) [5], [8]- [10], and is defined by a Beta distribution bounded by the limits of net load, minL-RES and maxL-RES. In other words (L-RES) represents the amount of power that must be produced by the thermal units.…”

“…For each hour ahead, the load and RES production forecasts are received and aggregated as net load, which are the input of the algorithm. This process is deeply described in [8]. Very often, in this specific case study, during the off-peak periods with low load and high RES, the thermal units are forced to work below the technical minimum.…”