A new sensorless control method for brushless permanent magnet DC motors

A novel sensorless control method for brushless permanent magnet DC motors is proposed in this paper. With this method, the usually used terminal voltage detection circuits are not required, so it can be carried out in general-purpose inverters without any change of the hardware. The current commutation points are obtained by reconstructing the line back Electromotive Force (EMF). The rotor speed is estimated from the rotor flux-linkage. Experimental results are also presented to verify the effectiveness of this proposed method.