| 摘要 |
PROBLEM TO BE SOLVED: To provide a ventilation system with high safety, a ventilation method and a control device.SOLUTION: A ventilation system includes: an inverter circuit 51c that has switching elements S1 to S6 and modulates a DC voltage to output an AC voltage; a motor 71b that is driven by an AC voltage supplied through the inverter circuit 51c; a jet fan with freely rotatable impellers that are rotated normally or reversely along with the drive of the motor 71b and are also rotatable freely by inertia or air flow while the motor 71b stops; and a control device 510 that outputs a control signal to the switching elements S1 to S6 to control the drive of the motor 71b. When starting the motor 71b from a stop state, the control device 510 starts the motor 71b after stopping the rotation of the impellers by performing DC braking of the motor 71b using an AC voltage for a preset first time. |
