Vektorstyrning

Vektorstyrning, also known as vector control or field-oriented control (FOC), is an advanced control method used for AC electric motors. It allows for precise control of both the motor's torque and speed independently, mimicking the behavior of a DC motor. This is achieved by mathematically transforming the stator currents of the AC motor into a rotating reference frame aligned with the rotor's magnetic flux.

The core principle of vektorstyrning is to decompose the stator current into two components: one that generates magnetic flux (flux current) and another that produces torque (torque current). By controlling these components separately, the motor's output torque can be precisely regulated, even at low speeds or during rapid changes in load. This contrasts with simpler scalar control methods, which primarily control the motor's voltage and frequency but do not offer the same level of independent torque and flux management.

The implementation of vektorstyrning typically requires a motor model, a speed sensor (though sensorless versions exist), and a digital signal processor (DSP) or microcontroller to perform the complex calculations in real-time. The advantages of vektorstyrning include high efficiency, smooth operation, excellent dynamic response, and precise speed and torque regulation. These benefits make it widely used in applications demanding high performance, such as electric vehicles, industrial automation, robotics, and servo drives.