Orientadores: Ariovaldo Verandio Garcia, Marcos Julio Rider FloresTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoAbstract: In this work the Distribution System Integrated Planning (DSIP) problem is modeled as a mixed integer (binary) nonlinear program problem. Two techniques were investigated to solve this problem. First, a specialized Constructive Heuristic Algorithm (CHA) was implemented. A sensitivity index is used in each step of the CHA to add a circuit, a substation, a capacitor bank or a voltage regulator to the distribution system. This sensitivity index is obtained by solving the DSIP problem considering the numbers of circuits and substations to be added as continuous variables (the DSIP relaxed problem). The objective of the DSIP is to minimize the operation costs and the construction costs of circuits, substations, capacitors and voltage regulators, which are subjected to constraints of power balance, voltage magnitude, maximum circuit and substation capacities, taps control and radiality constraint. In addition, a local improvement phase to improve the initial solution of the CHA and a branching technique to avoid the infeasibility cases in the distribution system operation were includedDoutoradoEnergia EletricaDoutor em Engenharia Eletrica