Small Electric Motors (Fractional Horsepower Motors)

This course is offered in German.

Learning objective:

The module deepens the basic knowledge of electrical machines specific insights into the various types of fractional horsepower motors and their special design and features. The students learn to

• independently analyze the operating behavior of stepper motors, universal motors, AC induction motors and AC synchronous motors,
• select and asses the electronic circuits used for these types of machines for low-loss adaptation of the operating characteristics,
• assess which of the numerous possible design variants of the winding and magnetic circuit of these motors are particularly suitable or less suitable.

Contents:

• Introduction (motor categories, categories of electronic circuits, general information on actuators, permanent-magnet materials)
• Stepper motors (structure and mode of operation, designs, reduction of the step angle, control, power rate, damping method, step angle error)
• Universal motors (design and operation, equivalent circuit diagram and phasor diagram, calculation for non-sinusoidal current, variation of torque-speed characteristics)
• Single-phase induction motors (WIM) (design and mode of operation, motors with one, two and three phases, rotating fields in WIM, operating behavior, symmetrical operation, conductance locus curve, effects of spatial harmonics, variation of torque-speed characteristics, shaded pole motors)
• Single-phase synchronous motors (WSM) (design and mode of operation, operating behavior, PM rotor, reluctance rotor, hysteresis rotor)
• Standards and protection classes for small machines