Understanding Electrical Machines: Transformer Connections — Lesson 6

This lesson covers the concept of using three single-phase transformers to step up or step down voltage. It delves into the different types of connections, such as star and DD, and how they affect the line to line voltage and phase shift of the secondary voltage with respect to the primary voltage. The lesson also introduces the concept of an open delta connection, which is derived from a DD connection. It further explores the scenario of removing one transformer from the connection and the resulting changes in voltage levels. For instance, if transformer A is removed, the lesson explains how the voltage is applied across transformers B and C, and the impact on the line to line voltage.

Video Highlights

00:24 - Discussion on the use of three single-phase transformers to step up or step down voltage
06:58 - Discussion on the induced voltage in the connection
18:48 - Explanation of the advantages of using three single-phase transformers
30:49 - Explanation of the flux path in a three-phase transformer
33:14 - Discussion on the removal of the central iron portion in a three-phase transformer

Key Takeaways

• Three single-phase transformers can be used to step up or step down voltage.
• The type of connection, such as star or DD, determines the line to line voltage and phase shift of the secondary voltage with respect to the primary voltage.
• An open delta connection can be derived from a DD connection.
• Removing a transformer from the connection changes the voltage levels. For example, if transformer A is removed, the voltage is applied across transformers B and C.