Multiobjective Technical-economic Optimization of New Investments in Power Distribution Systems

Abstract

This paper presents a new method for determining the best number and the ideal locations of switching and protection devices, i.e. circuit breakers, sectionalizers and fuses, in order to achieve the best reliability improvement in power distribution systems at the lowest economical investment cost (feeder reconductoring sizes and/or new feeder installation investments can also be considered). Thus, a multiobjective non-linear optimization model was used with two objective functions to be optimized: a) an objective function of reliability, corresponding to an ENS or energy non-supplied index (or TIEPI and NIEPI index); and b) an objective function of economic investment costs, which included investment costs of new elements to be installed in the distribution system. Finally all the non-dominated planning solutions (Pareto's solutions) were obtained from the multiobjective optimization model, i.e. the best optimal planning solutions that can help engineers to propose suitable power distribution investments plans through detailed analyses of such non-dominated solutions in order to obtain the best distribution system reliability with the most economical investments.