Lülitusmootorite

Lülitusmootorid, commonly translated as switched reluctance motors (SRMs), are a type of electric motor that operates based on the principle of magnetic reluctance. Unlike conventional motors that rely on permanent magnets or wound rotors with excitation current, SRMs utilize the tendency of magnetic flux to follow the path of least reluctance. This means the motor's rotor is attracted to the stator poles when they are energized in a specific sequence.

The fundamental components of an SRM are a stator with a series of salient poles, each equipped with a winding, and a rotor also made of salient poles but without any windings or magnets. The stator windings are energized sequentially, creating a rotating magnetic field that pulls the rotor poles into alignment. As the rotor turns, the magnetic circuit's reluctance changes, and by switching the stator currents in synchrony with the rotor's position, continuous rotation is achieved.

Control of SRMs is typically achieved through electronic power converters, often using pulse-width modulation (PWM) techniques. This allows for precise control over torque and speed. The electronic commutation is essential, as the stator windings must be energized at the correct time relative to the rotor's position. Sensors, such as encoders or Hall-effect sensors, are often used to provide this rotor position information, although sensorless control strategies are also widely researched and implemented.

SRMs offer several advantages, including a simple and robust construction, high reliability, and the absence of brushes or permanent magnets, which can be costly and prone to demagnetization. They also possess good fault tolerance. However, they can exhibit higher torque ripple and acoustic noise compared to other motor types, which are areas of ongoing research and development to mitigate. Their efficiency can be very competitive, particularly in variable-speed applications.