Ac servo motor control

The structure of the dc servo motor as the common dc motor, and is done in order to reduce the moment of inertia of long and thin. It's exciting winding and armature respectively by two independent power supply. There is also a permanent magnet, namely the pole is a permanent magnet. Usually adopt the armature control, that is, f certain excitation voltage, establish flux Φ is also a constant value, and the control voltage in the armature Uc, institutional characteristics of the dc servo motor (n = f (T)) and dc separately excited motor, three-phase asynchronous motor under different control voltage (Uc control voltage rating) of mechanical characteristic curve. By the graph is: under certain load torque, when magnetic flux unchanged, if the rise in the armature voltage, the electric vehicle motor speed of the motor is higher; On the other hand, the lower the armature voltage, speed dropped; When Uc = 0, motor immediately halt. To motor reversal, can change the armature voltage polarity. Compared with dc servo motors and ac servo motor, it has mechanical properties is stiff, the output power is larger, rotation, large starting torque, etc The normal operation of the servo motor, as long as out of control voltage, the motor stop immediately. When servo motor loss control voltage, it is in single phase operation state, due to the rotor resistance is big, the rotation of the two opposite directions in the stator rotating magnetic field and rotor effect produced by the two torque characteristics (T1, T2 S1 S2 curve) and synthetic torque characteristics (t-s curve, with the ordinary single-phase asynchronous motor torque characteristics (T '-s curve). Then the synthesis of torque T is the brake torque, so as to make the motor stop quickly. Servo motor is single-phase runtime mechanical characteristic curve. 

A certain load, the control voltage Uc, the higher the speed is higher, in the control voltage, load, speed down. The structure of the ac servo motor stator is basically similar to capacitance split-phase single-phase asynchronous motor. On the stator winding with two position difference of 90 ° to each other, one is Rf excitation winding, it always pick on the ac voltage Uf; L, another is the control winding connection control signal voltage Uc. So is also called the two ac servo motor servo motor. wholesalemotor.blogspot.com Hollow cup rotor servo motor structure without control voltage ac servo motor, the stator is only produced by the pulse excitation winding magnetic field, rotor motionless. When a control voltage, stator and then produce a rotating magnetic field, the rotor rotate along the direction of the rotating magnetic field, in the case of constant load, the speed of the motor changes with the size of the control voltage, when the control voltage of opposite phase, servo motor will be reversed. The output power of the ac servo motor is 0.1 100 w. When the power supply frequency 50 hz, voltage is 36 v, 110 v, 220, 110 v; When the power supply frequency is 400 hz, the voltage have 20 v, 26 v, 36 v, 115 v, etc. Ac servo motor smooth operation, low noise. But control characteristic is nonlinear, and the rotor resistance is big, loss is big, efficiency is low, so compared with capacity of Y series motor, big volume, heavy weight, so is only applicable to 0.5 100 w small power control system. The working principle of ac motor fan servo motor with split-phase single-phase asynchronous motor, though similar, but the rotor resistance of the former is much larger than the latter, so compared with the single asynchronous motor, servo motor has three significant characteristics, due to the rotor resistance is big, the torque characteristic curve 1, with normal asynchronous motor torque characteristic curve, compared to 2 a significant difference between the two. It can make the critical slip S0 > 1, this not only makes the torque characteristic closer to linear mechanical properties, and has a large starting torque. Therefore, when the stator's a control voltage, rotor rotating immediately, which has the characteristics of starting fast, high sensitivity. The rate in the range of 0 to 1 S servo motor can stable operation.