Equivalent Circuit and Circle Diagram of Induction Motor — Lesson 6

This lesson covers the concept of the circle diagram of a three-phase induction motor. It delves into the equivalent circuit for the circle diagram, which includes the effects of all parameters. The lesson explains how the total current drawn from the supply is the sum of the fixed current and the reflected current. It also discusses the locus of the circle diagram and how it varies with resistance. The lesson further elaborates on the concept of air gap power, stator copper loss, and rotor copper loss. It also introduces the concept of slip lines in the circle diagram. For instance, if a motor is operating at a 0.04 slip, the operating point on the circle diagram can be determined by joining the 0.04 point on the slip line to the point on the circle diagram where the slip line intersects the torque line.

Video Highlights

00:32 - Explanation of the equivalent circuit for the circle diagram
02:05 - Understanding the locus of the circle diagram
07:37 - Explanation of air gap power, stator copper loss, and rotor copper loss
24:02 - Introduction to the concept of slip lines in the circle diagram

Key Takeaways

- The total current drawn from the supply is the sum of the fixed current and the reflected current.
- The locus of the circle diagram varies with resistance.
- The air gap power, stator copper loss, and rotor copper loss can be determined from the circle diagram.
- The concept of slip lines in the circle diagram helps in determining the operating point of the motor.