A multiobjective optimization approach to loading balance and grounding planning in three-phase four-wire distribution systems

Abstract This paper proposes a multiobjective optimization approach to loading balance and grounding planning. A new formulation is presented of the optimal loading balance and grounding planning problem in three-phase four-wire distribution systems. This formulation is a multiconstraint, multiobjective and nondifferentiable optimization problem with both equality and inequality constraints. It encompasses four desired objectives related to investment, operational efficiency, security, and pollution of the system. A method based on simulated annealing was used to determine (i) the phase load pattern, (ii) the locations of the neutral to be grounded, and (iii) the types of numbers of ground electrodes to be installed such that the desired objective functions are minimized while the load variation and system operation constraints are met. The ϵ-constraint method was incorporated in the method to solve the multiobjective problem. A salient feature of the method is that it allows designers to find a desirable, global, noninferior solution of the problem.