Question: What do vector control and torque control of frequency converter mean?

Vector control: It is a technology that uses frequency converter (VFD) to control three-phase AC motor. The output of the motor is controlled by adjusting the output frequency, output voltage and angle of the inverter. Its characteristic is that it can control the magnetic field and torque of the motor separately, which is similar to the characteristics of separately excited DC motor. Because the three-phase output current and voltage will be represented by vectors during processing, it is called vector control.

Torque control: it is a way for inverter to control the torque of three-phase motor. The method is to calculate the estimated values of motor flux linkage and torque according to the measured motor voltage and current, and then control the motor speed after controlling the torque. Direct torque control is a patent of ABB in Europe.

Extended data:

Vector control of frequency converter requires torque control, low speed and large torque output, wide speed range beyond rated speed and good control characteristics, and so on.

According to the official documents issued by Siemens, it is forbidden to use vector control when driving in parallel. Moreover, the rationality of adopting V/F control for multi-machine parallel drive is also sufficient. Although the examples and arguments of multi-machine parallel vector control have been discussed in the website, there have been quite enthusiastic exchanges in the past, whether it is the industrial control network or the transmission column of this website. But in theory, I don't think it is meaningful and useful to use vector control in parallel. This is especially true for non-coaxial parallel drivers.

Baidu encyclopedia-vector control

Baidu Encyclopedia-Direct Torque Control