1. Department of Electrical Engineering, Universidade Federal de Campina Grande, 154624 Campina Grande, PB, Brazil, (e-mail: vandilson.barbosa@ee.ufcg.edu.br)
2. Department of Electrical Engineering, Universidade Federal de Campina Grande, 154624 Campina Grande, PB, Brazil, (e-mail: george@dee.ufcg.edu.br)
3. Department of Electrical Engineering, Universidade Federal de Campina Grande, 154624 Campina Grande, PB, Brazil, (e-mail: marianna.dias@ee.ufcg.edu.br)
4. Department of Electrical Engineering, Universidade Federal de Campina Grande, 154624 Campina Grande, PB, Brazil, (e-mail: edson@dee.ufcg.edu.br)