https://bvl.center/spravochnye-materialy/vektornoe-i-skalyarnoe-upravlenie-chastotnym-preobrazovatelem/

What is the key practical difference between vector control and scalar control?
Scalar control regulates only frequency and voltage (according to the V/f law) without feedback, which is suitable for simple applications like water pumping. Vector control regulates torque and speed in real time, providing high precision and stability even during sudden load changes on the shaft.