Generally, servo motors are equipped with corresponding servo controllers. AC servo motor can be connected with single chip microcomputer. When the microcontroller sends the speed value to the motor, the servo motor will complete the speed measurement inside, and compare the actual value with the given value to change the speed.
A single servo motor can't work, unlike ordinary three-phase asynchronous motors, the power supply on the machine turns.
Servo controller and servo motor cooperate to form a system, which has its own encoder. It is a closed-loop control with accurate speed, large torque and high resolution.
The motion state of the servo motor can be controlled by the input pulse of the server, or by analog and serial communication. Frequency conversion is mainly speed regulation, and servo is mainly position control.