What does vector control mean?

Vector control mode: magnetic field oriented control.

Because the dynamic mathematical model of asynchronous motor is a high-order, nonlinear and strongly coupled multivariable system. It was put forward by Hasse of darmstadt University in the late 1960s.

In the early 1970s, the doctoral thesis published by Siemens engineer blaschke in Tubraunchweig put forward the magnetic field oriented control method of three-phase motor, and solved the torque control problem of AC motor through the vector control theory of asynchronous motor.

The basic principle of vector control is to measure and control the stator current vector of asynchronous motor, and control the excitation current and torque current of asynchronous motor according to the principle of magnetic field orientation, so as to control the torque of asynchronous motor.

Vector control, also known as field-oriented control (FOC), is a technology to control a three-phase AC motor by using a frequency converter (VFD), and the output of the motor is controlled by adjusting the output frequency, output voltage and angle of the frequency converter.

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.

Vector control can be applied to AC induction motors and DC brushless motors. The purpose of early development is for high-performance motor application, which can run in the whole frequency range, output rated torque at zero speed, and can accelerate and decelerate quickly.

However, compared with DC motor, vector control can be used with AC motor, which is small in size, low in cost and low in energy consumption, so it has attracted the attention of the industry. Vector control is not only used in high-performance motor applications, but also in some household appliances.