Introduction to Starting of Single Phase Induction Motors — Lesson 2

This lesson covers the in-depth analysis of single phase induction motors. It explains the equivalent circuit, torque slip characteristics, and the operation of the motor on a single winding. The lesson also discusses the concept of forward and backward fields, and how the strength of these fields affects the operation of the motor. It further elaborates on the concept of the resultant field and its locus. The lesson also introduces the concept of an auxiliary winding, which is used to provide starting torque to the motor. The auxiliary winding is connected in parallel with the main winding and is disconnected once the motor reaches a certain speed. The lesson concludes with the mathematical representation of the torque in terms of the currents in the main and auxiliary windings.

Video Highlights

00:16 - Introduction to single phase induction motors and their equivalent circuit
05:14 - Concept of resultant field and its locus
12:39 - Introduction to auxiliary winding and its role in providing starting torque
27:45 - Mathematical representation of torque

Key Takeaways

- Single phase induction motors operate on a single winding and use an auxiliary winding to provide starting torque.
- The strength of the forward and backward fields in the motor affects its operation.
- The locus of the resultant field in a single phase induction motor is an ellipse.
- The auxiliary winding is disconnected once the motor reaches a certain speed, allowing the motor to run on a single winding.
- The torque in a single phase induction motor can be mathematically represented in terms of the currents in the main and auxiliary windings.