1. Department of Electrical and Electronic Engineering, Michael Okpara University of Agriculture, Umudike 440101, Abia State, Nigeria
2. School of Engineering, University of Aberdeen, Aberdeen AB24 3UE, UK
3. Department of Electrical Engineering, Tshwane University of Technology, Pretoria 0183, South Africa
4. Department of Electrical Engineering, University of Nigeria, Nsukka 410001, Enugu State, Nigeria