Analysis of stator current reconstruction method after current sensor faults in vector controlled induction motor drives

Current sensors (CSs) are the most important measurement elements in adjustable speed drives (ASD) with induction motor (IM). Because in many solutions (especially in systems such as electric vehicles (EVs)) safety is very important issue, thus the fault-tolerant control (FTC) strategies are more and more used. In the case of CS fault the best possible quality of stator current reconstruction should be ensured in active FTC system. In this article to compensate CS faults the modified adaptive Luenberger observer (MALO) is used. The quality of stator current estimation is analyzed an compared for two vector control strategies: direct rotor flux oriented control (DRFOC) and direct torque control (DTC) with space vector modulation (SVM). Different CS fault scenarios are analyzed under variable operating conditions of both ASDs in experimental studies.