Torque Slip Characteristics and Operating Point in Induction Motor — Lesson 6

This lesson covers the torque slip characteristics of a three-phase induction motor. It explains how the machine settles down to a particular operating point under different load conditions. The lesson also discusses the concept of stable and unstable operating zones, and how the full load torque should be decided to avoid instability. An example of a motor running under no load condition and then suddenly subjected to a full load torque is used to illustrate these concepts.

Video Highlights

00:15 - Introduction to the torque slip characteristics of a three-phase induction motor
03:05 - Explanation of the concept of opposing torque and its impact on the machin
15:09 - Explanation of the concept of full load torque and its importance in the design of the motor
21:27 - Discussion on the importance of designing the full load torque midway between zero and T Max
31:42 - Explanation of the concept of stable and unstable zones in the torque slip characteristics

Key Takeaways

- The torque slip characteristics of a three-phase induction motor are crucial in understanding its operation under different load conditions.
- The motor settles down to a particular operating point which is determined by the balance between the electromagnetic torque and the opposing load torque.
- The operating point under no load condition is very close to the synchronous speed.
- A sudden increase in load torque can cause the motor to decelerate and eventually stop if the load torque exceeds the maximum torque the motor can produce.
- The full load torque should ideally be decided midway between zero and the maximum torque to avoid instability.