Understanding Transformer Connections and Vector Groups — Lesson 5

This lesson covers the concept of transformer connections and vector groups. It delves into the different ways of connecting windings in transformers, such as Delta-Star, Delta-Delta, Star-Delta, and Star-Star. The lesson explains how to identify the vector group of a connection, with a focus on the phase angle difference. It also discusses the concept of balanced three-phase transformers and the importance of maintaining phase sequence. The lesson uses illustrative examples to explain how to draw the primary voltage phasors and how to identify the phase displacement in Start-Delta connections. It concludes with a brief introduction to three-phase transformers as a single unit.

Video Highlights

00:33 - Explanation of phase voltages and line to line voltages
04:12 -Explanation of how to draw the primary voltage phasors
16:54 - Explanation of Delta Delta connection
24:58 - Explanation of how to draw the phasor diagram for the secondary side
32:30 - Discussion on the various ways of connecting the windings

Key Takeaways

• There are various ways of connecting windings in transformers, including Delta-Star, Delta-Delta, Star-Delta, and Star-Star.
• The vector group of a connection can be identified by looking at the phase angle difference.
• In Start-Delta connections, the phase displacement can only be 30 degrees.
• A three-phase transformer can also be built as a single unit, and the same connection principles apply.