Research On Fault Diagnosis Of Wind Turbine Impeller Imbalance Based On Generator Stator Current Analysis

Recently,the wind power industry developed rapidly,and the capacity of the installed wind turbine has gradually increased around the world.However,it is apparent that the failure rate of wind tuibine is high.And the fault occurs to the wind power system may lead to unit interconnected failure,and cause huge economic losses.The impeller imbalanced fault is one of the most common faults occur to wind turbine.If the impeller imbalanced fault can be detected and maintained at early stage,not only the fault rate of wind turbine is reduced but also the maintenance costs are reduced,thus the operating life of the wind turbine power generation can be extended and the overall cost of the wind turbine maybe greatly reduced as a result.It is of great significance to develop the impeller imbalanced fault diagnosis system of the healthy and sustainable development of wind power industry.In recent years,permanent magnet direct drive wind turbine has become a research hotspot of wind power generation technology due to its advantages of better economy and higher reliability.Therefore,this paper focuses on the diagnosis of impeller imbalanced fault in permanent magnet direct drive wind turbine.In this paper,the mechanism of impeller imbalance faults including mass imbalance and aerodynamic imbalance faults are analyzed in detail,and the influence of impeller imbalance faults on the electrical characteristics of the permanent magnet direct drive wind turbine is presented.And the impeller imbalance fault diagnosis is realized based on Hilbert spectral analysis and improved Multiple Signal Classification algorithm(MUSIC)to amplify the fault features of generator current signals.The main work of this thesis is summarized as follows:(1)A complex electromechanical model of permanent magnet direct drive wind turbine with impeller imbalanced fault is built in Maltab/Simulink,where the wind turbine aerodynamics,blade element moment(BEM)theory,structural dynamics of engine room and tower,characteristics and control strategy of the permanent magnet wind generator are considered.(2)Based on the established electromechanical model,the fault behavior of the permanent magnet direct drive wind turbine with impeller mass imbalanced fault is analyzed.A fault diagnosis method for impeller mass imbalance based on Hilbert spectral analysis and improved MUSIC stator current analysis was proposed,and its simulation and experimental verification were carried out.(3)Based on the established mechanical and electric model of permanent magnet wind turbine,the mechanism of impeller aerodynamic imbalance fault is analyzed,and the fault behavior of permanent magnet wind turbine under aerodynamic imbalance fault is analyzed.A fault diagnosis method of impeller aerodynamic imbalance based on Hilbert spectral analysis and improved MUSIC stator current analysis was proposed.In this paper,the mechanism of impeller imbalance fault of permanent magnet wind turbine is systematically studied,the influence of impeller imbalance fault on of permanent magnet wind turbine is analyzed,and fault diagnosis method of impeller aerodynamic imbalance based on Hilbert spectral analysis and MUSIC stator current analysis is proposed.