Fault-Tolerant Control Against Speed Sensor Failure in Induction Motor Drives

International audienceA large number of adjustable speed drives in industry and emerging applications require high dynamic performances, robustness against parameter variation and also reliability. Parameter detuning and mechanical speed sensor faults lead to a deterioration of the performances and even to instability. Therefore condition monitoring is becoming mandatory. Using knowledge of the motor condition, a fuzzy-based approach is applied to discriminate load and parameter variations from the speed sensor faults. Both simulation and experimental results are presented in terms of accuracy in the detection of speed sensor faults and knowledge extraction feasibility. The study reported in this paper is also concerned with the development of a drive tolerant to the speed sensor failure. The proposed system adaptively reorganizes itself to sustain the best control performance.The control reorganization is managed by a voting algorithm system that assures smooth transition from the nominal controller to the sensorless one and back to the encoder-based controller.Simulations tests using collected experimental data, in term of speed and torque responses, have been carried out on a 1.2 kW induction motor to evaluate the consistency and the performance of the proposed fault-tolerant control approac