Magnetic Fields in DC Machines — Lesson 3

This lesson covers the concept of magnetic fields in electrical machines, focusing on Direct Current (DC). It explains the principles of magnetic fields and winding structures, and how they relate to different types of machines. The lesson delves into the types of magnetic fields present in DC and machine, the concept of rotating magnetic fields, and why they are essential in AC machines. It also discusses the role of field winding at the stator side in a DC machine and how the magnetic fields are constant. The lesson further explains the concept of rotating magnetic fields in a DC machine and how they are not symmetrical with respect to 360-degree rotation. The lesson concludes with the magnetic fields in AC machines.

Video Highlights

00:00 - Introduction to magnetic fields in electrical machines
00:17 - Discussion on magnetic fields in DC machines
30:58 - Magnetic fields in AC machines

Key Takeaways

- Magnetic fields in electrical machines are realized from the basic principles of magnetic fields and winding structures.
- In DC machines, the magnetic fields are constant and do not change with excitation to the windings.
- Rotating magnetic fields are present in AC machines, unlike in DC machines.
- In a DC machine, the rotating magnetic field is not symmetrical with respect to a 360-degree rotation.
- The magnetic fields in AC machines are analyzed with respect to the stator side, where there is a distributed winding.