1. Department of Electrical and Computer Engineering, Clarkson University, Potsdam, USA
2. Discipline of Electrical, Electronics, and Computer Engineering, University of KwaZulu-Natal, Durban, South Africa
3. School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg, Gauteng, South Africa
4. Department of Electrical Power Engineering, Durban University of Technology, Durban, South Africa