Detecting an electric arc by means of a Bragg grating

A diagnostic and detection device for an electrical power distribution network (10) of an aircraft comprising a harness of electrical cables (40) forming an electrical distribution route between a source (8) and at least one load (6), said harness comprising at least one section connected in series between the source (8) and the load or loads (6) by at least one connection interface member (38),

• wherein the diagnostic and detection device diagnoses and detects an electric arc type fault occurring in said electrical distribution route, said diagnostic and detection device being arranged at the connection interface members (38);
• the diagnostic and detection device comprising:
• an optical fiber (14) laid along at least a portion of said distribution route and comprising at least one Bragg grating (20) positioned at each connection interface member (38), making it possible to associate with each connection interface member (38) a characteristic reference wavelength of the respective Bragg grating (20), the optical fiber (14) having a reference spectral signature comprising said characteristic wavelengths of said Bragg gratings (20),
• an optical reflectometer (36) coupled to an upstream end of the optical fiber (14) and configured to emit a reference optical signal, said reference optical signal being composed of an incident light spectrum including the characteristic wavelength of each Bragg grating (20) of the optical fiber (14), and to receive a reflected optical signal composed of a light spectrum reflected by the optical fiber (14) which defines a current spectral signature of the optical fiber (14),
• an acquisition central processing unit (34) configured to detect and locate one or more arc faults over one or more connection interface members (38), on the basis of a comparison of the current spectral signature with a reference spectral signature of the optical fiber.