Current mutual inductor residual magnetism detection method based on small-signal gradient mapping

The invention discloses a current mutual inductor residual magnetism detection method based on small-signal gradient mapping. A differential coefficient of an initial operating point magnetic flow with respect to an exciting current is computed by exerting small voltage signals on a current mutual inductor for a second time, magnetizing curves of an iron core of the current mutual inductor are used for gradient mapping so as to confirm residual magnetism of the iron core of the current mutual inductor. According to the current mutual inductor residual magnetism detection method based on small-signal gradient mapping, the practical current mutual inductor is magnetized, so that current mutual inductance produces residual magnetism of different quantities. Effectiveness of the residual magnetism detection method and theory and practicability of a detection system platform are assessed, and the detection result indicates that the detection system platform is capable of quickly and accurately reflecting the quantity of residual magnetism of the iron core of the detected current mutual inductor.