Fault Diagnosis Of Wind Power Converter Based On Adaptive Kalman Filter

The rapid development of the wind energy industry puts forward higher requirements on the reliability and stability of various component devices in wind energy conversion system(WECS).Due to the elimination of gearboxes which effectively improves the reliability and safety of WECS,in addition to reducing maintenance costs greatly,WECS with permanent-magnet synchronous generator(PMSG)is widely used.The wind converter as the interface between grid and PMSG is the core,as well as most vulnerable component.With the influence of harsh environments,thermal variation,and alternating electromagnetic interference,its stability is even worse and more prone to failure.Thus,it is of great significance for state monitoring and fault diagnosis of the converter.Focused on the open-circuit fault diagnosis method of the converter,the major work is described as follows:Firstly,on the basis of converter in WECS with PMSG,discuss in depth the influence of open-circuit fault on the currents in PMSG-side and grid-side.Which is contributed to deriving a fault diagnosis method based on the currents.Secondly,owing to the key point of the fault diagnosis method adopted in this paper is to acquire dq-axis currents accurately,therefore,taking the PMSG-side converter fault as examples,design Luenberger observer in the light of mathematics model of PMSG for obtaining the effective parameters of the converter.Furthermore,test the feasibility of Luenberger observer applied for fault diagnosis method.Lastly,due to the randomness of wind,load changes,and other random processes,resulting in the Luenberger observer poor state observation and weak anti-interference ability.Therefore,aimed at the accuracy of current observation,an adaptive Kalman filter(AKF)algorithm is introduced.Then,select the Sage-Husa noise estimator to improve the robustness of the algorithm.Meanwhile,by means of resetting the error covariance matrix,the ability to track and estimate the parameter with mutation is enhanced.Several simulation results show that the fault diagnosis algorithm of converter based on AKF algorithm can improve the estimation accuracy within acceptable complexity of time,detect and identify open-circuit faults of IGBT accurately and quickly,further verifying the algorithm’s feasibility and excellent performance.