Understanding Three-Phase Transformer Connections-2 — Lesson 3

This lesson covers the concept of three-phase transformer connections, specifically focusing on the star-delta connection. It further discusses the phase difference maintained by the feathers when the coils are connected with red markings. The lesson also delves into the concept of delta connections and the series and closed nature of these connections. An example is provided to illustrate the concept of induced voltage and the possibility of a circulating current when three voltage sources are connected in series.

Video Highlights

01:22 - Discussion on the concept of induced voltage and circulating current
04:03 - Discussion on the concept of output in a delta connection
09:45 - Discussion on the concept of source of EMF and the consequences of incorrect delta connection
25:33 - Explanation of the concept of vector group of transformer connection
31:59 - Discussion on the importance of polarity marking in transformer connections
33:40 - Conclusion of the lecture and encouragement for further discussion and study

Key Takeaways

  • Three-phase transformer connections are crucial in electrical engineering.
  • The star-delta connection is a common type of three-phase transformer connection.
  • The primaries in Star HV are connected in a specific way to maintain a phase difference.
  • Delta connections are series and closed, leading to the possibility of induced voltage and circulating current.