Electrical distribution systems expansion planning considering service restoration

Author(s)

Leonardo Henrique Faria Macedo Possagnolo

• Document type: Doctoral Thesis
• Press: Ilha Solteira. 2019-04-18.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Engenharia. Ilha Solteira
• Defense date: 2019-02-25
• Advisor: Rubén Augusto Romero Lázaro

Abstract

The vast majority of electricity distribution systems are operated radially. This means that each load is supplied by only one substation through a single path. However, distribution networks have a meshed structure so that, in the case of a contingency, the supply is restored to as many customers as possible. The works that deal with the distribution systems expansion planning problem, however, generally consider the expansion of the system for only one radial topology, disregarding the restoration aspects to improve reliability indices. In this context, this work deals with the planning of distribution systems considering economic and reliability aspects, to include the service restoration in the planning problem. In the formulation of the problem, it is considered the expansion of new substations, the reinforcement of existing substations, the construction of new feeders in new paths, the exchange of existing conductors, and the allocation of distribution generation, besides multistage expansion and service restoration to improve the reliability indices of the system. Two alternative methods are proposed to solve the described problem: the first one considers relaxed or approximated mathematical models to be solved by exact methods, and the second one is a variable neighborhood search metaheuristic, which solves the complete model for the problem approximately, without guarantee of optimality. The initial solution of the metaheuristic is generated by a strategy that constructs a solution to the problem using neighborhood search. The mathematical models and the meta-heuristic were implemented in the mathematical modeling language AMPL, and the models were directly solved by the commercial solver CPLEX, which was also used to solve the optimization subproblems of the metaheuristic. Tests were carried out using the 24 and 54 nodes systems presented in the literature, and the results show that the inclusion of the service restoration in the distribution systems expansion planning problem leads to solutions that present higher investment costs than the traditional models. However, the reliability indices of the network are improved, and in this way, the solutions obtained considering the proposed approach present lower overall costs of investment and operation, and better reliability indices than those solutions available in the literature. (AU)

• FAPESP's process: 14/23741-9 - Expansion planning of distribution systems of electric power
• Grantee: Leonardo Henrique Faria Macedo Possagnolo
• Support Opportunities: Scholarships in Brazil - Doctorate