Fuzzy set-based approach for grid integration and operation of ultra-fast charging electric buses

Abstract

This paper presents a fuzzy set-based approach, composed by multi-objective decision-making and energy management system methodologies, for the integration of an electric mobility system in the power distribution grid and its operation. At first, the proposed approach uses financial evaluation criteria to provide the minimum cost of implementing the system, reflecting the net present value of investments, expenses, and depreciation of assets. In the second stage, a fuzzy set-based energy management system provides the system operation considering the demand curves required by the vehicle, number of stops, and topographic conditions of the route. The paper results are validated by a case study of an electric bus system in Brazil, based on ultra-fast charging, with several alternatives and different electric mobility scenarios. The sizing of the storage system and the determination of the number and the location of the charging stations are defined, taking into account the impacts caused on the distribution grid and its power quality. The operating results confirm that the fuzzy set-based energy management system is able to provide flexibility and robustness for the hybrid energy storage system, ensuring a steady and efficient power control.