This lesson covers the concept of generating a rotating magnetic field, a topic that is both important and exciting. It delves into the history of the concept, highlighting the contributions of Nicholas Tesla in creating a rotating field without moving anything. The lesson further explains the concept of a balanced polyphase winding and how it can be used to create a rotating magnetic field. It also discusses the speed of the rotating field, the concept of electrical speed, and the difference between electrical and mechanical speed. The lesson concludes with an explanation of how to calculate the induced voltage in a coil.
02:31 - Discussion on balanced polyphase winding
06:37 - Explanation of the speed of the rotating field
09:42 - Difference between electrical and mechanical speed
23:22 - Calculation of induced voltage in a coil
- A balanced polyphase winding, when excited by a balanced polyphase supply, can create a rotating magnetic field.
- The speed of the rotating field is determined by the supply frequency and is referred to as the electrical speed.
- The mechanical speed of the rotating field is different from the electrical speed and depends on the number of poles in the machine.
- The induced voltage in a coil can be calculated using the relative speed between the coil and the field, the flux per pole, and the effective number of turns.