A Resilient Current Sensor Fault-Tolerant Strategy for Vector-Controlled Induction Motor Drive

A resilient-type current sensor fault-tolerant control (FTC) scheme for indirect vector control (IVC) of induction motor (IM) drives has been developed in the present work. The FTC scheme utilizes fundamental equations of IM to estimate the stator current and a mathematical differential operator to detect the fault of a current sensor. The formulation of the current estimator for the FTC scheme is accomplished in a stationary reference frame. This choice does not necessitate slip or synchronous speed information, simplifying the FTC structure. Besides, the fault detection process is independent of the machine model. Even partial sensor fault conditions like gain-drop and dc offset can be detected satisfactorily using such an operator. The proposed concept of FTC for IVC-IM drive is validated experimentally with a 5.5-kW IM drive laboratory prototype by conducting different case studies, including the cases of partial sensor failure.