Aging degradation diagnosis apparatus and aging degradation diagnosis method

An aging degradation diagnosis apparatus comprising:

• processing circuitry,
• to generate, from phase signals obtained at a plurality of times, the phase signals indicating a phase of an alternating voltage applied to an apparatus to be diagnosed, and from measured signals measured at a plurality of times by a sensor that is measuring a degradation state of the apparatus, a degradation pattern indicating a distribution of signal intensities of the measured signals and the phase of the alternating voltage;
• to calculate a gradient vector of a signal density at each of distribution points of the degradation pattern, and calculate, for each of phase ranges different from each other, from the calculated gradient vector, a histogram in a gradient direction of the signal density within the relevant phase range;
• to generate a feature vector in which bin values of the histogram for each of the phase ranges are lined up;
• and
• to search for, from among feature vectors by degradation cause, a feature vector similar to the feature vector, and identify a degradation cause of the apparatus.