Abstract：A rotor position detection strategy based on virtual neutral point was proposed to realize position

sensorless control of BLDC motor. Through the three-phase terminal voltage with the same value of three resistances

star connection to construct a virtual neutral point，the relationship between the virtual neutral point voltage and

commutation time of BLDC motor was analyzed. A conclusion was drawed that the moment when the virtual neutral

point voltage through the DC bus midpoint is the zero-crossing time of the back electromotive force（BEMF），and

the operation of the motor in each state，the effectiveness of zero-crossing signal of BEMF was further analyzed. The scheme was further verified by experiments，and the output of zero-crossing signal was realized by comparator.

Compared with the conventional terminal voltage detection method，the system reduced two comparison detection

circuits and has no phase shift. Experimental results show that the position of zero-crossing signal can be accurately

determined by using this strategy，and the phase error caused by traditional BEMF method can be avoided.

      Key words：BLDC motor；position sensorless；virtual neutral point；zero-crossing detection