Monitoring and Diagnosis for the DC–DC Converter Using the Magnetic Near Field Waveform

A new diagnostic method for the dc-dc converter, which utilizes the magnetic near field as the diagnostic criterion, is proposed in this paper. The magnetic near field of the converter is captured using a loop magnetic near field probe. The frequency information in the measured waveform is extracted by the fast Fourier transfer; the interested low-order harmonic components are classified by the neural network while the interested high-order harmonic components are evaluated using the simple mathematical method. Finally, by compromising the results of the two parts, the detailed diagnostic conclusions are obtained. In this paper, the methodologies of the measurement and diagnosis are clearly described; then, the proposed method is used to monitor and diagnose the buck and phase shift full bridge converters. The experimental results are presented to show the validity of the analysis. Since the two chosen examples include most of the potential situations, the proposed method can be generalized and applied to many other types of converters.