In the study of electrical machines the fundamentals of electromagnetism and single- and three-phase circuits play the most important role. The main aim of this introductory chapter is to introduce the basics, which are the cornerstones of electrical machines.
When an electric current passes through a conductor, a magnetic field immediately builds up due to the motion of electrons. When a magnetic field encompasses a conductor and moves relative to the conductor, the electrons come in motion. This is the converse of the previous phenomenon. Electromagnetism is the study of electromagnetic force (emf) induced in the conductor when it cuts the magnetic flux or is cut by the magnetic flux.