Current-Based Analytical Model for Fault Detection and Diagnosis in 7-phase Machines

This paper presents an analytical model of the currents flowing in a 7-phase machine. The analytical expressions of the currents are established in the stationary frames of the four fictitious machines (principal, secondary, tertiary, and homopolar). The model is parameterized to study any fault effect in the characteristics of the currents: amplitude, offset and phase shifting. After its validation with a numerical model, this flexible model is used to evaluate the relevance of the current characteristics as fault features for the different faults. We show that the currents in the stationary frames can provide sensitive fault signatures in the time and frequency domains.