A Fault Diagnosis Algorithm for Microgrid Three-Phase Inverter Based on Trend Relationship of Adjacent Fold Lines

This is the authors' abstract. We don't add key points for this paper.

Fault diagnosis of a microgrid inverter is susceptible to asymmetric interference such as overcurrent component and bias component. It may lead to uncertain fluctuation of diagnosis features, even false alarm and erroneous triggering of protection units. Therefore, for a microgrid inverter, a robust fault diagnosis algorithm is necessary to cope with such asymmetric interference. Motivated by this observation, first, a new fault feature extraction method is proposed in this paper by the trend relationship of adjacent fold lines for data curve. It can be used to extract the fault feature and it is not affected by asymmetric interference. Second, a trend encoding method is proposed to encode the trend feature of a fold line, which is well visualized, easily identified, stored, and calculated. Third, two main indexes are calculated by the encoded features to represent the degree of abnormal and location information. Fourth, the diagnosis results are realized through the logical relation operations. Compared with the existing fault diagnosis algorithms, multiswitches fault can be accurately diagnosed in the case of asymmetric interference. Finally, the detailed experiment results and comparisons are shown to validate the proposed algorithm.