Research On Wind Turbine Source Tracking And Recognition Based On Acoustic Array

With the rapid development of wind power industry,the noise problem caused by wind turbine operation is becoming increasingly prominent.Noise problems will cause serious environmental pollution as well as fatigue and damage to the structure.One of the keys to noise control engineering is the identification of noise source location.The acoustic array-based beamforming algorithm has been widely used in acoustic source location research in recent years.The noise generated by running rotor operating in the extremely complex condition is mainly aerodynamic noise,but the conventional beamforming technology has low resolution without considering the movement of sound source.Based on microphone array test technology,this paper develops a high-resolution method for acoustic identification of rotating wind wheel.Combined with the theory of rotation source and DAMAS2 algorithm,we derive a DAMAS2 correction algorithm suitable for rotor source recognition.The recognition effect of conventional beamforming algorithm and DAMAS2 correction algorithm is compared and analyzed by numerical simulation and rotating sound source simulation experiment,and the modified algorithm is successfully applied to tracking and identifying Wind Turbine sound source.The theory of the microphone array receiving model and the beamforming algorithm is deeply studied.By analyzing the performance of the microphone arrays of several topologies,it is clear that the different spatial arrangements of acoustic arrays have many effects on the performance of the array.The main parameters of 60-channel spoke array test performance that affect B&K were simulated and analyzed to provide a basis for reasonable selection of array test parameters.DAMAS2 algorithm theory is used to derive the DAMAS2 correction algorithm that is suitable for the identification of rotating sound sources which adds rotation speed to the original stationary frame to obtain corrected directional vectors and beamforming correction results.Then the array point propagation is established in combination with beamforming correction results.The convolution relationship between the function and the location of the real sound source,and the assumption of introducing the spatial translation invariance of the array propagation function are simplified.Finally,the position of the real sound source is obtained through iterative solution.Based on the theory of conventional beamforming algorithm and DAMAS2 correction algorithm,numerical simulation analysis indicates that the spatial resolution and sound pressure recognition accuracy of the DAMAS2 correction algorithm increase with the number of iteration calculations.The DAMAS2 correction algorithm can be more accurately identified.Rotates the sound source and exhibits higher spatial resolution than conventional beamforming algorithms for both low and high frequency sound sources.Then,according to the theory of laser speed measurement and beamforming,the experimental research of rotating sound source is carried out.The experimental results verify the correctness of the numerical simulation results.It further shows that this algorithm can be applied to the sound source tracking experiment of rotating rotor.The wind source identification experiment was conducted at the open end of the wind tunnel.The DAMAS2 correction algorithm can effectively suppress the false sound source and obtain a more accurate sound source position.The cabin noise of the rotating rotor mainly occurs near 674 Hz,The noise in the frequency range from 1 kHz to 6.4 kHz is mainly broadBand aerodynamic noise.The aerodynamic noise moves closer to the tip of the blade as the frequency or tip speed ratio increases.Based on the theory of rotating source and DAMAS2 algorithm,this paper derives the DAMAS2 correction algorithm.By reconstructing the position vector after adding the rotation speed,the algorithm obtains the modified directional vector and the beamforming correction result.It effectively eliminates the recognition error caused by the rotation motion.Based on the beamforming correction results,the deconvolution calculation is performed based on DAMAS2 algorithm theory,which further improves the resolution of the recognition results.Through numerical simulation and rotating sound source simulation experiments,it is verified that the DAMAS2 correction algorithm is better than the conventional beamforming algorithm in identifying the rotating sound source.The DAMAS2 correction algorithm is used to perform the wind turbine sound source tracking and recognition research in the wind tunnel,and the accuracy is obtained.The higher sound source position has accumulated experience for optimization of noise reduction in wind turbines.