Short Pitch Angle in Coils — Lesson 3

This lesson covers the concept of pitch factor in electrical machines, specifically focusing on the coil span and its impact on induced voltage. The lesson explains why short pitch coils are necessary and how they can be used to reduce certain harmonic voltages. It also introduces the concept of winding factor, which is the product of the distribution factor (KD) and the pitch factor (KP). The lesson further discusses the impact of space harmonics on the B distribution and how to eliminate predominant harmonics by selecting a suitable short pitch. The lesson concludes with a discussion on the placement of coil sides in slots for full pitched and short pitched coils.

Video Highlights

00:34 - Explanation of short pitch coils and their impact on induced voltage
05:15 - Introduction to winding factor and its calculation
10:10 - Calculation of pitch factor for different harmonics
13:33 - Discussion on the impact of short pitch on harmonic voltages
17:33 - Explanation of coil span and its impact on harmonic voltages

Key Takeaways

- The pitch factor in electrical machines refers to the coil span being slightly short of 180 degrees.
- Short pitch coils are necessary to reduce certain harmonic voltages.
- The winding factor is the product of the distribution factor (KD) and the pitch factor (KP).
- Space harmonics can impact the B distribution in electrical machines.
- By selecting a suitable short pitch, it is possible to eliminate predominant harmonics.
- The placement of coil sides in slots for full pitched and short pitched coils can significantly impact the induced voltage.