motorsmount

In the AC line, people also widely used the AC induction motor to drag the working machinery; induction AC motor has a simple structure, it has the advantages of long life span, low cost, easy maintenance. However, compared with the DC motor, its peed performance is poor, the starting torque is small, and the overload ability and efficiency is low. The rotating magnetic field generation must reactive power from the grid, so the power factor is low, particularly at light loads, this will large increase in the losses of line and grid. It is hardly use synchronous motors in the past Electric drive, the main reason is that synchronous brush motors can not be rotating itself under the voltage, the average torque is zero when the still rotor pole under the effect of the rotating magnetic field.