Because compared with the frequency converter, the servo motor can reach thousands of revolutions in a few millimeters, and because the servo is closed-loop, the speed is very stable. Torque control is mainly to control the output torque of the servo motor, but also because the servo motor responds quickly. Using the above two kinds of control, the servo driver can be regarded as a frequency converter, and generally adopts analog control.
The main application of servo motor is positioning control, and PLC controls the position of servo motor. Position control should control two physical quantities, namely speed and position. To be precise, it is to control how quickly the servo motor arrives and where it stops accurately.
The basic structure of extended data AC servo motor is similar to that of AC induction motor (asynchronous motor). On the stator, there are two excitation windings Wf and control windings WcoWf, which are offset by 90 degrees in the phase space and connected with a constant AC voltage. The purpose of controlling motor operation is achieved by using the change of AC voltage or phase applied to Wc.
Ac servo motor has the characteristics of stable operation, good controllability, fast response, high sensitivity, strict nonlinear indexes of mechanical characteristics and adjustment characteristics (less than 10% ~ 15% and less than 15% ~ 25% respectively).
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