Most of the existing bus air-conditioning condensing fan systems use brushed condensing fans, which are noisy during operation, and there is friction between the brush and the commutator during commutation, which is easy to generate commutation sparks. speed, resulting in very low efficiency at low speeds, and because the brushed motor uses carbon brushes for commutation switching, it has the disadvantage that the carbon brushes are easy to wear, and the brushes need to be replaced after a period of use; at the same time, the brushes will produce some conductive The powder left on the commutator can easily cause short-circuit failure of the motor. The existing brushed condensing fans have obvious shortcomings such as short life, poor reliability, and large starting current, resulting in short life of the motor and requiring frequent maintenance.