Analysis of Converter Fault in Switched Reluctance Motor using Finite Element Method

This work investigates the effect of asymmetric bridge converter switch open and short-circuit faults in a Switched Reluctance Motor (SRM) drive using Finite Element Analysis (FEA). The analysis is executed for different fault conditions such as (i) Single-switch open-circuit (ii) Single-phase (two switches) open-circuit (iii) Single-switch short-circuit (iv) Single-phase (two switches) short-circuit. Simulation is performed on a 550 W, 220 V, 4-phase, 1050 rpm, 8/6 pole SRM utilizing ANSYS Maxwell FEA tool and different electromagnetic factors namely current, speed, torque, flux line distribution inside SRM, and flux density in the airgap of SRM are analyzed under healthy and converter fault conditions. Unbalance in phase currents, reduction in speed, and asymmetry in magnetic flux distribution are noticed for single switch open-circuit fault. Whenever SRM experiences single switch short-circuit converter fault, increased oscillations in speed and phase current magnitudes and severe asymmetry are observed in radial element of flux density present in the airgap.