Research on the positioning control of asynchronous motor - brake physical process

 Stator winding from three-phase power disconnected,bubbled into direct current,the stator magnetic field from the rotating state into a fixed position,same size constant magnetic field,because of diesel generating the influence of the mechanical inertia,rotor is rotating in a clockwise direction,the rotor conductor cutting constant magnetic field.Due to the cutting direction,asynchronous motor in contrast to the state of electric,so the rotor induction electric potential and the direction of the induced current,also in contrast to the state of electric,cause the torque of the motor reverse,counterclockwise.M torque and rotational speed n direction on the contrary,as the braking state,the asynchronous motor's kinetic energy into electrical energy,consumption on the motor rotor resistance of the circuit,so that braking energy.

The torque of the motor and load torque,under the electrical motor joint action of slow down soon.When rotation speed is equal to zero,the rotor conductors are no longer cutting magnetic field,rotor induction electric potential and induced current reduce to zero,the motor is no longer produce electromagnetic torque,which can control the production of mechanical parking.Analysis was conducted based on Xm = constant conditions.In the process of braking energy excitation reactance Xm is not constant.But due to the change of Xm for motor operation effect is not big,so think Xm is constant in the theoretical analysis.Using energy consumption braking,both must have bigger brake torque,and acmotortrading.blogspot.com don't make,rotor loop current is too large,the connection mode is shown in figure 3,determine the following relation can be used asynchronous motor stator dc excitation current I_ and rotor circuit of series resistance R Ω.