Tolerant Control Of Induction Motor Research Articles

Fault Tolerant Control of Induction Motor Drives Subject to Rotor Resistance Adaptation

This paper describes the synthesis of a vector fault tolerant control of induction motor drives using an adaptive observer. This observer is used to detect the rotor resistance and flux components using the stator terminal voltages and currents. The rotor resistance is adapted using a new algorithm which does not imply a high computational load. Stability analysis based on Lyapunov theory is performed in order to guarantee the closed loop stability. The rotor resistance is used for the correction of the controllers and the rotor time constant. To verify the tolerance and the applicability of this control, we consider the stator inter-turn fault which is frequently encountered in practice. An analytical method for the modelling of this fault is presented. The equations which describe the transient as well as steady state behavior of unsymmetrical induction machine including the computation of machine inductances are presented. These inductances are calculated analytically using the magnetic field distribution through the machine air-gap. Simulation results are provided to evaluate the consistency and performance of the proposed fault tolerant control of induction motor based vector control.

Sensorless fault tolerant control for induction motors

In this paper, a sensorless fault tolerant controller for induction motors is developed. In the proposed approach, a robust controller based on backstepping strategy is designed in order to compensate for both the load torque disturbance and the rotor resistance variation caused by the broken rotor bars faults. The proposed approach needs neither fault detection and isolation schemes nor controller re-design. Moreover, to avoid the use of speed and flux sensors, a second order sliding mode observer is introduced to estimate the flux and the speed. The observer converges in a finite time and leads to good estimates of the flux and the speed even in the presence of the rotor resistance variation and the load torque disturbance. Since the observer converges in the finite time, the stability of the closed-loop system (controller with observer) is shown in two steps. First, the boundedness of the closed-loop system trajectories before the convergence of the observer is proved. Second, the convergence of the closed-loop system trajectories is proved after the convergence of the observer. To highlight the efficiency and applicability of the proposed control scheme, simulation and experimental results are conducted for a 1.5 kW induction motor.

Observer-based fault diagnosis and field oriented fault tolerant control of induction motor with stator inter-turn fault

Observer-based fault diagnosis and field oriented fault tolerant control of induction motor with stator inter-turn fault This paper describes a fault-tolerant controller (FTC) of induction motor (IM) with inter-turn short circuit in stator phase winding. The fault-tolerant controller is based on the indirect rotor field oriented control (IRFOC) and an observer to estimate the motor states, the amount of turns involved in short circuit and the current in the short circuit. The proposed fault controller switches between the control of the two components of measured stator current in the synchronously rotating reference frame and the control of the two components of estimated current in the case of faulty condition when the estimated current in the short circuit is not destructive of motor winding. This technique is used to eliminate the speed and the rotor flux harmonics and to assure the decoupling between the rotor flux and torque controls. The results of the simulation for controlling the speed and rotor flux of the IM demonstrate the applicability of the proposed FTC.

Fault tolerant control of induction motor through observer techniques II

In the design of the control law due to sensor and actuator faults, it is very important to implement the fault tolerant control system. Unknown Input Observers (UIO) can be used in model based fault detection and isolation (FDI) schemes to reduce or almost eliminate the effect of unknown disturbances on the MIMO plant/system. Furthermore, they can be used to generate residuals that are insensitive to unknown disturbances or noise, and thus, lower the false alarm rate. Design of many faults isolation banks of UIOs has been done. To make sure the best detection and isolation of the faults is provided, these banks generate residuals which are sensitive to only one fault. Fault tolerant control is used to compensate both sensor and actuator faults. Key words: Fault tolerant control, actuator fault, and sensor fault unknown input observer, fault detection and isolation, MIMO system, induction motor.

Fault tolerant control of induction motor through observer techniques II

In the design of the control law due to sensor and actuator faults, it is very important to implement the fault tolerant control system. Unknown Input Observers (UIO) can be used in model based fault detection and isolation (FDI) schemes to reduce or almost eliminate the effect of unknown disturbances on the MIMO plant/system. Furthermore, they can be used to generate residuals that are insensitive to unknown disturbances or noise, and thus, lower the false alarm rate. Design of many faults isolation banks of UIOs has been done. To make sure the best detection and isolation of the faults is provided, these banks generate residuals which are sensitive to only one fault. Fault tolerant control is used to compensate both sensor and actuator faults. Key words: Fault tolerant control, actuator fault, and sensor fault unknown input observer, fault detection and isolation, MIMO system, induction motor.

Sensorless Fault Tolerant Control Based On Backstepping Strategy For Induction Motors

AbstractIn this paper, a fault tolerant control for induction motors based on backstepping strategy is designed. The proposed approach permits to compensate both the rotor resistance variations and the load torque disturbance. Moreover, to avoid the use of speed and flux sensors, a second order sliding mode observer is used to estimate the flux and the speed. The used observer converges in a finite time and permits to give a good estimate of flux and speed even in presence of rotor resistance variations and load torque disturbance. The simulation results show the efficiency of the proposed control scheme.

SENSOR AND INVERTER FAULT TOLERANT CONTROL IN INDUCTION MOTORS

Induction motor has increased its importance in industry over the last two decades thanks to its robustness and control performance improvement. Direct Torque Control (DTC) has been the base for multiple developments or modifications in control algorithms and models obtaining great performances against torque variations at any motor speed (including zero speed). In this paper DTC scheme has been chosen as the starting point to design a fault tolerant control for induction motors. Also, a study of the possible faults and solutions in the inverter-motor set is presented. The control algorithms used for open-switch and open-phase faults are developed and their results are presented. The supervisor and fault diagnosis system has not been included in this work though they have been taken into account during the research process.