[1] Univ Florida, Dept Elect & Comp Engn, Gainesville, FL 32611 USA
[2] Pontificia Univ Catolica Rio Grande do Sul, Sch Technol, BR-90619900 Porto Alegre, RS, Brazil
[3] Sandia Natl Labs, Energy Storage Technol & Syst Dept, Albuquerque, NM 87123 USA
[4] Univ Sao Paulo, Dept Elect & Comp Engn, BR-13566590 Sao Carlos, SP, Brazil