Understanding Armature Reaction in Electrical Machines-1 — Lesson 1

This lesson covers the concept of armature reaction in electrical machines. It delves into the effects of armature reaction, how to mitigate these effects using compensating winding and Interpol winding, and the distribution of the armature current along the air gap of the machine. The lesson also explains the field pattern in the air gap of the machine due to the stator field and the armature currents. It further discusses the resultant flux, the concept of geometric neutral plane and magnetic neutral plane, and the distribution of armature MMF. The lesson uses the example of a DC machine to illustrate these concepts.

Video Highlights

00:32 - Explanation of the effects of armature reaction and how to mitigate them
14:17 - Explanation of the concept of the geometric neutral plane and the magnetic neutral plane
22:33 - Discussion on the MMF distribution due to the armature currents
23:43 - Explanation of how the armature MMF will look like when it carries current
30:55 - Discussion on the resultant field waveform due to the armature MMF

Key Takeaways

• Armature reaction refers to the effect on the magnetic field in the air gap due to the current in the armature winding.
• The effects of armature reaction can be mitigated using compensating winding and Interpol winding.
• The field pattern in the air gap of the machine is influenced by the stator field and the armature currents.
• The geometric neutral plane and the magnetic neutral plane are important concepts in understanding the distribution of armature MMF.
• The distribution of armature MMF can be approximated to a triangular wave function in a DC machine with a large number of conductors.