Electrical monitoring for fault detection in an EMA

The concept of a "More Electric Aircraft" (MEA) leads, among other actions, to the substitution of hydraulic-based actuators for Electro-Mechanical Actuators (EMA). Removal of the engine hydraulic pumps requires fully-operative electrical power actuators and mastery of the flight control architecture. However, unexpected faults and lack of safety hinder the massive use of EMAs in flight control actuators and force the development of new systems and methods for supervision in aircrafts actuators. On-line supervision of the motor drive, by means of electrical signature and harmonics analysis, can detect motor faults in its most preliminary state, thus allowing increasing the EMA reliability. However, for typical non-stationary conditions in EMA operation, classical Fourier transform cannot be applied, and other time-frequency decompositions must be explored. This presents an application of Discrete Wavelet Transform to electrical and mechanical Permanent Magnet Synchronous Motor fault detection. Experimental results are shown and prove that affordable Predictive Testing and Inspection technologies can be used to assure the reliability of the new EMAs.