Particle Swarm Optimization of a Hybrid Energy Storage System

Abstract

The paper presents the energy loss minimization of a hybrid energy storage system used in an electric vehicle, composed by a battery and a supercapacitor. The optimization is carried out by searching the optimal power sharing between the energy storage devices. The power sharing factor is defined as a discrete time variable, with constant values during each subdivision of the driving cycle. The elements of the optimal solution vector are the power sharing factors and the time instants that define the subdivisions. The particle swarm optimization algorithms have been validated using the Rastrigin test function, and three versions of the boundary behaviour have been compared in case of the constrained optimization. The algorithms have been tested for the energy loss minimization in case of a simple driving cycle, and their performance has been assessed by statistical analysis for different swarm sizes.