Title :
Sensitivity analysis on different types of electrical network modeling for the network constrained hydrothermal scheduling problem
Author :
Costa, L.M.P. ; Diniz, A.L. ; Santos, T.N.
Author_Institution :
Brazilian Electr. Power Res. Center, Fed. Univ. of Rio de Janeiro, Rio de Janeiro
Abstract :
The network constrained hydrothermal scheduling problem determines an optimal hourly dispatch considering line capacities and security constraints. The electrical network can be modeled either by a multi-area approach, with only interchange limits among areas, or by a detailed approach, where each individual branch is represented as a transportation model, a dc model with or without line losses, or as an ac model. This paper compares these types of representation in a real study case for the Brazilian system. We compare hydro and thermal generation, flows in system interconnections, individual line flows, and system operation costs. Numerical results suggest that a poor representation of the transmission lines and losses can lead to an insecure system dispatch related to electrical constraints. For low load levels, a dc model with line flow losses yields quite reasonable results. However, as congestion increases, the need to represent the nonlinear ac flow relations becomes apparent.
Keywords :
costing; hydrothermal power systems; power generation dispatch; power generation economics; power generation scheduling; power system interconnection; sensitivity analysis; Brazilian system; ac model; dc model; electrical network modeling; multi-area approach; network constrained hydrothermal scheduling problem; optimal hourly dispatch; power system interconnections; security constraints; sensitivity analysis; system operation costs; transportation model; Approximation methods; Equations; Load flow; Mathematical model; Numerical models; Power transmission lines; Propagation losses; Benders decomposition; power generation scheduling; security constraints; transmission losses;
Conference_Titel :
Transmission and Distribution Conference and Exposition: Latin America, 2008 IEEE/PES
Conference_Location :
Bogota
Print_ISBN :
978-1-4244-2217-3
DOI :
10.1109/TDC-LA.2008.4641784