Abstract: When the air conditioner fan starts, it may be in a rotating state due to the external wind, which is called flying start. Accurate initial position and speed detection are the basis for flying start. Firstly, the principle of zero-voltage vector pulse method is analyzed, and then the current of PMSM under the action of zero-voltage vector pulse is solved, and then the initial position and speed detection method of PMSM based on zero-voltage vector pulse method is given. On this basis, the determination method of pulse width and interval is designed, and finally experimental verification is carried out. The experimental results show that the zero-voltage vector pulse method can effectively observe the initial position and speed of the air conditioning fan under rotating state, and realize the start of the vehicle.

Key words: Air conditioning fan, Flying start, Zero-voltage vector pulse method