⑴ Without brush and commutator, more reliable work, low-maintenance and maintenance requirements.
⑵ Cooling stator winding is more convenient.
⑶ Inertia is small, it is easy to improve the rapidity of system.
⑷ It is suitable for high-speed high torque working condition.
⑸ Under the same power, sizes and weights are smaller.
A, High starting torque.
Because of the big resistance of rotor, compared its torque characteristics curve with ordinary asynchronous motor torque characteristics curve, there is a significant difference. It allows critical slip S0> 1, so that not only the torque characteristics (mechanical properties) is closer to linear, but has a larger starting torque. Therefore, when the stator have control torque, the rotor rotate immediately, namely with a fast starting, high sensitivity characteristic.
B, A wider operating range
C, No rotation
Output power of AC servo motor is generally 0.1-100W. When the power frequency is 50Hz, voltages are 36V, 110V, 220,380V; when the power frequency is 400Hz, voltages are 20V, 26V, 36V, 115V and more.
AC servo motor runs smoothly with low noise But the control characteristic is non-linear, and because the resistance of rotor is big, so loss is big and efficiency is low. Compared with the same capacity DC servo motors, it is bulky and heavy, so it only applies to 0.5-100W small power control system.