Resultant Field in Synchronous Machines — Lesson 11

This lesson covers the operations of a synchronous machine, focusing on the changes that occur from no-load to full-load conditions. It explains the concept of flux per pole, which is directly proportional to the field current and varies with the load. The lesson also discusses the impact of armature current on the flux per pole and the resultant field in the machine. It further elaborates on the relationship between the terminal voltage and the resultant induced voltage. The lesson uses the example of a synchronous machine connected to a lagging power factor load to illustrate these concepts.

Video Highlights

01:20 - Explanation of flux per pole and its relation to field current
08:17 - Understanding the resultant field in the machine
22:58 - Explanation of the relationship between terminal voltage and resultant induced voltage

Key Takeaways

- In a synchronous machine, the flux per pole changes from no-load to full-load conditions.
- The flux per pole is directly proportional to the field current (I F) and is influenced by the armature current when the machine is loaded.
- The resultant field in the machine is determined by the combined effect of the flux due to the field current (Phi F) and the flux due to the armature current (Phi a).
- The terminal voltage of the machine is related to the resultant induced voltage, which is determined by the resultant flux per pole.
- The operations of a synchronous machine can be understood more clearly through practical examples, such as a machine connected to a lagging power factor load.