1. Graduate Program in Electrical Engineering, Federal University of Santa Maria, Santa Maria 97105-900, Rio Grande do Sul, Brazil
2. Campus of Santo Ângelo, Integrated Regional University of Alto Uruguai and Missões, Santo Ângelo 98802-470, Rio Grande do Sul, Brazil
3. Academic Coordination, Federal University of Santa Maria, Cachoeira do Sul 96503-205, Rio Grande do Sul, Brazil