Synchronous Motors: Permanent Magnet Applications and Characteristics

This lecture covers the principles and applications of synchronous motors, particularly those utilizing permanent magnets. It begins with an introduction to magnetic circuits and transformers, followed by a detailed discussion on the operation of synchronous motors. The instructor explains the induced voltage in relation to rotor speed and the importance of power balance and electromagnetic torque. Various types of commutation, including block commutation at 120 degrees, are explored, along with their implications for motor performance. The lecture also highlights the use of voltage source inverters (VSI) and the significance of rotor position sensing, whether through sensors or sensorless methods. An example involving the BMW 130i is presented to illustrate practical applications. The instructor emphasizes the relationship between induced voltage, rotor speed, and torque characteristics, concluding with a discussion on the advantages of brushless motors and their growing relevance in modern electric vehicles.