Selection of Rotor Slots — Lesson 6

This lesson covers the intricate process of rotor core design for induction machines. It delves into the factors to consider when selecting the air gap length, such as peripheral speed, magnetizing current, power factor, reluctance theme, harmonics, and thermal management. The lesson also explains how to calculate the rotor outer diameter and the number of slots required for the rotor. It further discusses the effects of cogging, crawling, noise, and vibrations on the rotor core design. The lesson provides equations and guidelines to help learners understand how to avoid these effects and select the appropriate number of rotor slots. For instance, the lesson explains how skewing the rotor can minimize crawling, cogging, and other effects.

Video Highlights

00:00 - Introduction
00:16 - Factors to consider when selecting the air gap length
05:27 - Calculation of the rotor outer diameter
06:10 - Selection of the number of slots for the rotor
06:39 - Effects of cogging, crawling, noise, vibrations, and synchronous cusps on rotor core design
22:51 - Conclusion and summary of the lesson

Key Takeaways

- The air gap length in rotor core design is influenced by several factors including peripheral speed, magnetizing current, power factor, reluctance theme, harmonics, and thermal management.
- The rotor outer diameter can be calculated using the stator inner diameter and the length of the air gap.
- The number of slots in the rotor is determined based on the effects of cogging, crawling, noise, and vibrations.
- Skewing the rotor can help minimize the effects of cogging, crawling, noise, and vibrations.