1. Electric Power System Design Team, Hyundai-Transys, Hawseong-si, South Korea
2. E-Drive Materials Research Team, Hyundai Motor Company, Uiwang-si, South Korea
3. Department of Electrical Engineering, Suwon University, Suwon-si, South Korea
4. School of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon-si, South Korea