抄録
The position sensor-less drive technique based on the back electromotive force (EMF) has been widely used for brush-less DC motor drives. However, it is impossible to detect the rotor position at low-speed by using this technique. Therefore, the motor must be accelerated by the open loop based synchronous drive up to the middle speed. The open loop based synchronous drive extremely influences the motor performance. The torque pulsation and the over current can be occurred by using that.
This paper proposes a new start method for the brush-less DC motors. In this method, the rotor position can be detected the moment the motor is driven. As a result, the open loop based synchronous drive can be eliminated, rapid acceleration and high performance of the motor drives are achieved. Effectiveness of the proposed method is shown by experimental results.