Ventilator and control device and control method of ventilator

The invention relates to a ventilator and a control device and method of the ventilator, the ventilator is powered by an alternating current power supply or a direct current power supply and driven by an asynchronous motor, and the alternating current power supply or the direct current power supply is selected for independent power supply by detecting the working state of the alternating current power supply. After electric signals output by an alternating-current power supply or a direct-current power supply are processed, the inverter module is shared, alternating-current signals with controllable frequency are output, and an asynchronous motor is driven to drive a ventilator to operate. Stepless speed regulation can be carried out on the ventilator according to needs, the problem that only a fixed wind speed gear is needed when a fixed-frequency draught fan is selected is solved, ventilation efficiency is improved, and the cost of a ventilator unit is saved due to the fact that a synchronous motor does not