Dc motor controller in use, the start frequency cannot be too high. Because its speed is zero when just starting, electromagnetic torque in the process of starting to overcome the load resistance torque and overcome the masking of inertia of the rotating part, so a dc motor controller should assume greater power than when continuous operation. At startup time, if the pulse frequency is too high, so will lead to the rotor speed to keep up with the speed of the stator rotating magnetic field, after that, each step in the rotor speed increase is not much, but still to is proportional to the stator magnetic field of pulse frequency speed rotation, the rotor and the distance between the equilibrium position is more and more big, so that the motor controller can not start properly, will damage the motor controller.
