Sensors and open-switch FDI of induction motor drives based on control reconfiguration

Abstract

This paper presents a fault detection and isolation (FDI) strategy designed to enhance the reliability of induction motor drives by addressing both sensor faults and open-circuit (OC) faults in inverter switches. For sensor faults, the proposed approach employs control reconfiguration by combining estimates from an observer bank with measured stator current and mechanical speed signals. Faults are diagnosed by analyzing discrepancies between estimated and measured variables, and faulty sensor signals are replaced with reliable estimates to ensure continuous operation under fault conditions. With respect to OC faults, the FDI strategy involves averaging the phase current over a half-cycle and comparing it to a predefined threshold to diagnose both single and multiple OC faults in the inverter switches. The effectiveness of the proposed FDI strategy is validated through experimental tests conducted under various fault scenarios.