**Author details**

Laurence Miègeville *Department of Electrical Engineering, POLYTECH Nantes, University of Nantes, France Research Institute on Electrical Energy of Nantes Atlantique, St Nazaire, France* 

Patrick Guérin

*Department of Industrial Engineering and Maintenance, IUT Saint-Nazaire, University of Nantes, France Research Institute on Electrical Energy of Nantes Atlantique,St Nazaire, France* 
