Starting of Single Phase Induction Motors — Lesson 6

This lesson covers the intricate details of single phase induction motors. It delves into the starting case of these motors, explaining why they cannot have any starting torque when running on a single winding. The lesson further discusses the incorporation of starting torques by using an auxiliary coil or a starting coil. It also explains the concept of a cage rotor, main winding, and auxiliary winding. The lesson then moves on to the expression for starting torque and its proportionality to the sine of the angle between the auxiliary and main winding currents. The lesson also covers the concept of a capacitor split phase induction motor and the maximization of starting torque. Towards the end, the lesson discusses the use of single phase induction motors in small power ratings and their operation on the main winding after starting.

Video Highlights

01:07 - Discussion on cage rotor, main winding, and auxiliary winding
03:33 - Maximization of starting torque
04:30 - Concept of a capacitor split phase induction motor
21:55 - Use of single phase induction motors in small power ratings
26:22 - Operation of single phase induction motors on the main winding after starting

Key Takeaways

- Single phase induction motors cannot have any starting torque when running on a single winding.
- The starting torque can be incorporated by using an auxiliary coil or a starting coil.
- The starting torque is proportional to the sine of the angle between the auxiliary and main winding currents.
- A capacitor split phase induction motor is a type of single phase induction motor where a capacitor is used to split the phase.
- The starting torque can be maximized by adjusting the impedance of the main winding.
- Single phase induction motors are typically used in small power ratings and operate on the main winding after starting.