1. Department of Electrical Engineering (Energy Center), University of Chile, Santiago, Chile
2. Department of Electrical and Electronic Engineering, Imperial College London, London SW7 2AZ, UK
3. Department of Electrical Engineering, Pontifical Catholic University of Rio de Janeiro, Rio de Janeiro, Brazil
4. Departamento de Ingeniería Eléctrica, Electrónica, Automática y Comunicaciones, Universidad de Castilla-La Mancha, Ciudad Real, Spain
5. Department of Electrical and Electronic Engineering, University of Melbourne, Parkville, VIC 3010, Australia
6. School of Electrical and Electronic Engineering, The University of Manchester, Sackville Street, Manchester M13 9PL, UK