Research On Enhanced Diagnosis Method For Weak Faults Of Rolling Bearings Of Wind Power Transmission System Based On Stochastic Resonance

With the awakening of human environmental protection awareness,the development and utilization of green energy has attracted more and more attention.Wind energy has the advantages of clean,green,pollution-free,renewable,and huge reserves,which has a prominent position among many green energy sources.As an important equipment of wind energy acquisition and conversion,the safe and reliable operation of wind turbine is very important.The state monitoring and fault warning of wind turbine,especially the warning of weak fault,can reduce the occurrence of major accidents and reduce the cost of operation and maintenance.The transmission system structure of a wind turbine is complex,has a high failure rate of parts,and as the transmission system faults will duce a long shutdown.Therefore,in this paper,aiming at the fault diagnosis of wind turbine transmission system,a study on the enhanced diagnosis method of the rolling bearing weak fault of the wind power transmission system based on stochastic resonance is carried out.The main contents of this paper are as follows:(1)For the weak fault diagnosis of rolling bearing using single stochastic resonance system,which needs further improvement,a single stable cascade double feedback stochastic resonance system is constructed.This system combines the system feedback control theory on the basis of the monostable cascaded stochastic resonance system making the system output waveform smoother and the output signal to noise ratio(SNR)larger and realized the extraction of the fault features of the rolling bearing of the wind turbine transmission system.Finally,the superiority of the proposed system is verified through experiments and practical engineering applications.(2)Aiming at the output saturation phenomenon of bistable stochastic resonance system,which limits the enhancement of weak fault characteristic signal of rolling bearing by bistable stochastic resonance system,an improved segmented unsaturated stochastic resonance system is proposed.Based on the bistable stochastic resonance potential function,a new piecewise function is introduced,which can adjust the well barrier freely,make the output saturation phenomenon of the stochastic resonance system is weakened,and has a better weak signal enhancement ability.Finally,the weakening ability of the output saturation phenomenon of the proposed system is verified by relevant experiments.(3)When stochastic resonance system is applied to fault diagnosis,steady-state matching is needed to determine the appropriate steady-state of stochastic resonance,and the output saturation of stochastic resonance system needs to be solved,the variable steady-state unsaturated stochastic resonance method is proposed.Based on the periodic steady-state stochastic resonance,this method realizes the adaptive structure of the barrier of the potential well,which can realize the steady-state adaptive selection of the stochastic resonance system and the weakening of the output saturation phenomenon.Finally,the performance of the proposed system is verified by experiments and practical engineering applications.