Experimental Research On The Detection Of AC Arc Faults In Aircraft Wiring

As a new type of protective appliance,arc fault detection device can make up the blind area of the traditional protection,which has important practical significance for the protection of aviation safety.The arc fault detection technology is the key technology of arc fault detection device.In China,the research in this field has just started,the standards remain vacant in the commercial and military aircraft,and the relevant products rely on imports from other developed countries.In this paper,according to the relevant standards and the difference of actual working conditions,four kinds of apparatus for generating arc fault has been designed.This enables to carry out the experiments of simulated arc fault under the linear load conditions,and the data of voltage and current signal have been collected.Then the difference between different impedance angle and different ways to generate arc has been shown.Through the experiments data obtained from the arc fault simulation experiments,a brief of the existing detection method both in time and frequency domain is made.With the advanced mathematical tools in the field of digital signal processing,two kinds of AC arc fault detection methods are proposed,the detection method of discrete wavelet transform combined with the Mahalanobis distance and the detection method of log spectral distance of the improved interharmonic component.The effectiveness of detection under the linear load experiments data are demonstrated.In order to further verify the feasibility of the proposed detection method which used in aviation working environment,the arc fault simulation experiments under the environmental conditions for airborne equipment and the conditions of the aviation load with disturbance is carried out.The results are analyzed and compared.At last,the advantages of the two detection methods have been summarized.Taking into account the dual requirements,detection reliability and system stability,of aircraft power distribution system,it is considered that the combination of the two detection methods achieved by establishing a strict fault diagnosis strategy in the microprocessor can be an application prospect method of aviation AC arc fault detection.At the end of this paper,the research hotspot of arc fault detection technology in the future is prospected.