برنامه ريزي توان راكتيو در سيستم هاي قدرت

چكيده انگليسي :

Abstract The key of reactive power planning RPP or Var planning is the optimal allocation of reactive power sources considering location and size Traditionally the locations for placing new Var sources were either simply estimated or directly assumed Recent research works have presented some rigorous optimization based methods in RPP Thus the aim of this project is reviwing different kind of formulations appeared in recent papers and presenting an appropriate formulation for reactive power planning Therefore this thesis will first review various objectives of RPP The objective function of RPP may be cost based which means to minimize the possible cost associated with RPP such as variable and fixed Var installation cost real power loss cost and or fuel cost Other possible objectives may be to minimize the deviation from a given schedule of a control variable such as voltage or to maximize voltage stability margin It is also reasonable to use a multi objective MO model as the goal of the RPP formulation Secondly different constraints in RPP will be discussed The constraints in RPP are even much more complicated than the objective functions Conventional constraints may include the normal state base case power flow limits and the contingency state power flow limits However more recent works proposed to include the voltage stability limits under both normal state and contingency state due to the increased pressure of voltage stability and stressed transmission systems These different constraints are the key of the classification of various optimization models identified as optimal power flow OPF model security constrained optimal power flow SCOPF model and security constrained optimal power flow with voltage stability constraints SCOPF VS the present state of the art in RPP The mathematical solution of RPP is also very challenging due to a large number of variables and uncertain parameters Based on the objective and constraint formulation RPP could be mathematically formulated with variables and equations that are partially discrete partially continuous nondifferentiable and nonlinear There are no known ways to find the exact global solution for this complicated optimization problem in a reasonable time The solution techniques for RPP have evolved over many years and dozens of approaches have been developed each with its particular mathematical and computational characteristics Therefore thirdly the optimization based models will be categorized as conventional algorithms intelligent searches and fuzzy set applications The conventional algorithms include linear programming nonlinear programming mixed integer nonlinear programming etc Recently heuristic methods based on intelligent search have been used in RPP to deal with local minimum problems and uncertainties Increasingly these heuristic methods are being combined with conventional optimization methods to solve the RPP problem The intelligent searches include simulated annealing evolutionary algorithms and tabu search The fuzzy set applications in RPP address the uncertainties in objectives and constraints Specifying candidate buses for reactive sources in a power system has been a challangable problem in power system planning therefore in this thesis at first previous works on Specifying candidate buses will be reviewed then a new method based on optimization will be presented and campared with previous methods At the last various formulation presented in this thesis will be tested on IEEE 30 bus test system Keywords 1 Ractive Power Planning 2 Optimisation 3 Candid Bus 4 Voltage Stability 5 Contingency

كرمي هرستاني، عليرضا

برنامه ريزي توان راكتيو در سيستم هاي قدرت

بهينه سازي , باسهاي كانديدا , پايداري ولتاژ , پيشامد