Abstract: Based on the noise problem of the air conditioner, the authors research the resonance problem of fan motor and pipeline blower, analyze the drawback of the present harmonic injection based noise suppression technology. Based on this, the authors proposed the adaptive noise suppression method. In the proposed method, a feedback loop is constructed from an acceleration sensor and realize the condition monitor of the system vibration resonance. The injected harmonics are automatically adjusted according to the vibration, and the best suppression is realized. The resonance noise is resolved by the proposed method.

Key words: Fan motor, Pipeline blower, Vibration resonance, Noise reduction