Multiobjective VAr planning using the goal-attainment method

In the paper, a new formulation of multiobjective optimisation (MO) for reactive power (VAr) planning is presented. The objectives are active power loss cost reduction, minimisation of the cost of the investment VAr sources, system security margin robustness and reduction of the voltage deviation of the system. The operating constraints, load constraints of the system and expansion constraints, are taking into consideration. Hence, the new formulation is a constrained, multiobjective and nondifferentiable optimisation problem with both equality and inequality constraints. The goal-attainment method, based on the simulated annealing (SA) approach to solving general multiobjective optimisation problems by assuming that the decision maker (DM) has goals for each of the objective functions, is presented. The solution methodology can find a desirable, global noninferior solution for the MO problem, even when the objective space is nonconvex. Results of application of the method to multiobjective VAr planning are also presented.<>