Bilevel Programming Theory Applying In Reactive Power Optimization Of Electric Power System

In the electric power system, each network has different voltage level, some local lines seek to the optimal plosses and stability voltage level for themselves profits in their controlled fields, which blindly adjusted without considering global profit and results not only the instability voltage level of the whole system but also not the best plosses, even the whole networks ellapse accidents.The bilevel programming is an optimization problem which has bilevel hierarchy decision .The first level and the lower level both have their objective functions and constraint conditions, the objective function and constraint conditions of the first level not only have relations with the upper decision variable, but also depends on the optimal value(or the optimal solution) of the lower level. The lower optimal solution is also influenced by the upper decision variable, which is feed back to the upper level, furthermore influence the upper programming problem's optimal solution. The relations between the dispatch center and each networks is a canonical two-level decision problemConsidering the electric power system's factual problem and the theory of the two-level programming, we present the reactive optimization model on the basis of the two-bilevel optimization theory. Because the reactive optimization is a problem that has character multiple constraint, non-liner, continuous variable and discrete variable, combinatorial optimization, the genetic algorithm which has no messages of the objective functions' differential and continuous variable, can simply solve the continuous variable and discrete variable ,and the good global convergence simulated annealing algorithm are applied to solve the model. Testing results of applying the algorithm to an IEEE-6 bus system and an IEEE-30 bus system shows feasibility and efficiency of algorithm.