Understanding Transformer Connections and Frequencies — Lesson 10

This lesson covers the intricate details of transformer connections and their relationship with frequencies. It delves into the concept of the BH curve in transformers, explaining that it is not a straight line but a thin loop. The lesson further discusses the impact of a sinusoidal 50 Hertz magnetizing current on the core flux, which results in both 50 Hertz and 150 Hertz components. It also explores the scenario where the core flux is only 50 Hertz, leading to a magnetizing current with both 50 Hertz and 150 Hertz components. The lesson concludes by examining specific situations where the current may not have a 150 Hertz component, such as connections without a neutral connection.

Video Highlights

01:05 - Discussion on the sinusoidal magnetizing current and its effects on core flux
03:14 - Discussion on the impact of distorted flux on the transformer
17:53 - Explanation of the issues with single phase loading in a YY connected transformer
27:34 - Discussion on the solution to avoid third harmonic current in a star-delta transformer connection
35:24 - Explanation of the benefits of having a delta winding in a transformer connection

Key Takeaways

• The BH curve in transformers is a thin loop, not a straight line.
• A sinusoidal 50 Hertz magnetizing current results in a core flux with both 50 Hertz and 150 Hertz components.
• If the core flux is only 50 Hertz, the magnetizing current will have both 50 Hertz and 150 Hertz components.
• In certain situations, such as connections without a neutral connection, the current may not have a 150 Hertz component.