Power Flow Based Fault State Propagation Model and its Application to Aircraft Actuation System

In order to optimize the layout of sensor measuring points for accurate fault location, this paper establishes the power transfer model from the view of power flow existing in the complex electromechanical system and studies the power-transfer based fault state propagation process. Taking aircraft actuation system as an illustration, this paper analyzes the power flow transferring process from permanent magnet DC motor to piston pump and hydraulic cylinder. Based on the power transfer model, the fault state propagation process is then established and analysed. The detectable condition and the attenuation law of fault detection sensitivity are found by the first-order trajectory sensitivity theory. The results indicate that as the distance between the measuring point of the sensor and the fault location becomes farther, the fault detection sensitivity attenuates. Therefore, it should be detected as close as possible to the fault location. The proposed method in this paper can describe the fault state propagation process of the system and verify the validity and accuracy of the theoretical analysis, which provide the basis for fault location and diagnosis based on power flow.