Dear Mr. Hacene, design of electrical machines is a full semester course, requires time, love for el. machines and a good essential knowledge about them. I could teach you (via skype courses) but in english or in german. I am talking about the "classical desing" based on empirical data, on tested and manufactured machines. Modern design is based on FEM and software packages. Although modern design is gaining ground, I would suggest the old time classical design because in that way, an engineer learns better. If you are interested in, you could send me an email, to discuss it with more details. ([email protected]     or    at    [email protected])