A sensor fault-tolerant control solution based on current observers applied to three phase induction motor drive

This paper presents a fault-tolerant control (FTC) solution to enhance the reliability and sustainability of a three-phase induction motor drive (IMD) against open circuit sensor failures (or total sensor faults). The motor speed control in the investigated drive will operate based on a field-oriented control (FOC) strategy. A typical FTC function consists of two main processes: fault detection of feedback signals from the sensors and reconfiguration of the control methods. This paper proposes using two-phase current observers to diagnose various sensor failures, and then the corresponding sensorless methods are applied to the control reconfiguration. Using MATLAB/SIMULINK software, the IMD-integrated FTC function was operated and tested under different fault conditions. Simulation results have proved that the IMD-integrated FTC function has worked stably and sustainably even in sensor failure conditions.