How do torque speed and position differ as forms of electric motor output control?

In the context of electric motor technology, torque, speed, and position represent distinct aspects of motor output that are managed through electronic control systems.

• Speed Control: The speed of an induction motor is primarily determined by the frequency of the power supply. By using an electronic inverter to adjust the frequency (f) and voltage, the motor’s speed can be regulated to approach the synchronous speed, calculated as $120f/p$ revolutions per minute. A tachometer is often used to monitor the shaft speed, allowing the system to compare the actual output against a desired value and adjust the inverter frequency accordingly.1
• Position Control: Achieving accurate position control requires a feedback loop similar to speed control, but it utilizes a position sensor to track the shaft's orientation. By comparing the sensor's data to a target position, the controller adjusts the inverter to move the motor to the precise required location.1
• Torque Control: Torque is the rotational force produced by the motor. The direction of this torque can be reversed by changing the phase sequence of the power supply (e.g., from abc to acb).1