Understanding Practical Transformers and Their Models — Lesson 3

This lesson covers the concept of practical transformers and their models. It delves into the realistic model of a practical transformer, explaining the addition of parameters to an ideal transformer to represent a practical one. The lesson discusses the winding resistance, leakage flux, and magnetizing current, and how these elements affect the transformer's operation. It also explains the concept of mutual and leakage flux and their impact on the transformer's performance. The lesson further illustrates the feather diagram to understand the voltage and current flow in a practical transformer. Towards the end, it introduces the concept of cold loss and its components, which will be discussed in detail in the next lesson..

Video Highlights

00:30 - Explanation of the ideal transformer and its characteristics
06:40 - Discussion on the effect of leakage flux on the transformer and its representation in the model
09:48 - Discussion on the voltage drop caused by the leakage flux
26:51 - Explanation of the change in flux level in a practical transformer from no load to full load condition
27:19 - Introduction to the topic of core loss in transformers to be discussed in the next lecture

Key Takeaways

• A practical transformer model is represented by adding parameters to an ideal transformer. These parameters include winding resistance, leakage flux, and magnetizing current.
• Mutual flux and leakage flux play a significant role in a transformer's operation. While mutual flux is responsible for transformer action, leakage flux causes an extra voltage drop.
• The feather diagram helps visualize the voltage and current flow in a practical transformer.
• The concept of cold loss, comprising of Eddy current loss and hysteresis loss, is crucial in understanding the operation of a practical transformer.