Wind Speed Closed-Loop Control of Sensorless High-Speed BLDC Based on IFOO and DBC for Hair Dryer

The sensorless control of high-speed brushless dc motors (BLdc) is one of the key technologies that need to be solved for the development of high-speed hair dryers at present. However, the existing control methods have problems such as slow start-up response, out-control of the current loop, and large fluctuation. A wind speed closed-loop control of sensorless high-speed BLdc based on improved full-order observer (IFOO) and dead-beat control (DBC) (IFOO-DBC) for hair dryer is proposed. The IFOO is designed based on the improved mathematical model with differential feedback. The DBC is designed based on linear interpolation. The wind speed closed-loop control is designed based on the performance matching of the speed system and the impeller optimised by the adjoint method. The experiment results show that compared with the traditional method, the high-speed sensorless system designed by the proposed method has a faster start-up response and smaller speed fluctuation in the steady-state process at a high carrier frequency ratio. The error of observed back electromotive force is smaller at a low carrier frequency ratio, which in turn improves the tracking performance of the current loop of the drive system. The system using the proposed method has a great dynamic response and more stable operation.