1. Department of Electronic and Electrical Engineering, Keimyung University, 1095 Dalgubeol-daero, Daegu 42601, Republic of Korea
2. KEPCO Research Institute (KEPRI), 105 Munji-ro, Yuseong-gu, Daejeon 34056, Republic of Korea
3. Department of Electrical Energy Engineering, Keimyung University, 1095 Dalgubeol-daero, Daegu 42601, Republic of Korea