Electrical Machines - II

The course begins by explaining the basic principles governing the operation of different types of electrical rotating machines. It covers the conditions required for steady production of electromagnetic torque (Te) and explains both motoring and generating modes of operation. The primary focus is on three-phase induction machines, single-phase induction motors, and synchronous machines. A sound understanding of distributed windings is essential to grasp the working of rotating machines; therefore, a few lectures are dedicated to this topic. The concepts of electrical and mechanical angles are explained in detail, along with the nature of magnetic flux distribution in the air-gap of rotating machines. A clear understanding of the rotating magnetic field is emphasized as it is fundamental to the operation of induction and synchronous machines. For each machine, the equivalent circuit is derived and used to obtain torque expressions. Topics such as starting, speed control, and electrical braking of motors are discussed. While the main emphasis is on steady-state performance analysis, important transient conditions are also introduced. The course encourages students to develop a logical and efficient approach to solving numerical problems.

Source: NPTEL IIT Kharagpur [Youtube Channel]