Application of EEMD-HHT Method in Fault Signal Analysis of Electric Power System in LNG Carriers

The unit capacity of the LNG carriers propulsion motor is almost equal to that of the electric generator, and random changes of this kind of high power load are tend to cause faults and system crashes.Therefore, the effective extraction of transient signal feature information is the core of fault diagnosis in electric propelling ship power system.Based on the Ensemble Empirical Mode Decomposition (EEMD), the method of Hilbert-Huang Transform (HHT) has solved the mode mixing problem which exists when the method of Empirical Mode Decomposition (EMD) is used during the process of fault signal diagnosis in electric power system, and HHT can successfully get the accurate position and feature information extraction of the fault time.Digital simulation analysis indicates that the method is correct and effective.