Fault-tolerant Control Of Induction Motor Research Articles

Fault-Tolerant Control of Induction Motor with Current Sensors Based on Dual-Torque Model

The safety of direct torque control (DTC) is strongly reliant on the accuracy and consistency of sensor measurement data. A fault-tolerant control paradigm based on a dual-torque model is proposed in this study. By introducing the vector product and scalar product of the stator flux and stator current vector, a new state variable is selected to derive a new dual-torque model of induction motor; it is combined with a current observer to propose a dual-torque model fault-tolerant control method. This technology calculates torque and reactive torque directly, reducing the system’s reliance on sensors, avoiding sensor-noise interference, and improving torque response speed while suppressing torque ripple. In addition, to improve system dependability and safety, a fault-tolerant control method is devised by combining the model with an adaptive virtual current observer. Ultimately, experiments validate the suggested method’s effectiveness and feasibility.

Discrete-time command filtered adaptive fuzzy fault-tolerant control for induction motors with unknown load disturbances

In this paper, a command filtered fault-tolerant control (CFFTC) approach is investigated for induction motors (IMs) discrete-time system in the presence of actuator faults and unknown load disturbances. Firstly, the IMs system discrete-time model is obtained by Euler method. Then, the fuzzy logic systems (FLSs) is utilized to compensate for unknown actuator faults. Besides, introducing the error compensation mechanism into discrete-time systems via command filters, “complexity of computation” and noncausal problem can be conquered, and the filtering error is avoided concurrently. Finally, simulation results demonstrate the validity of the presented fault-tolerant method for IMs system.

Speed sensorless fault-tolerant control of induction motor drives against current sensor fault

Current sensors are needed in conventional field-oriented control (FOC) in 3-phase induction motor (3-PIM) drives. Nevertheless, these sensors are exposed to different faults which reduce the reliability of drive systems. To solve this problem, a current sensor fault-tolerant control (FTC) for 3-PIM drives without speed measurement is proposed in this paper. In the proposed scheme, a sensorless FOC strategy based on open-loop speed estimator is utilized for normal condition. A third-difference operator performs the task of fault detection and isolation (FDI). After FDI, a sensorless FOC strategy based on extended Kalman filter (EKF) is used for the faulty condition. In this paper, the EKF is used for stator currents and speed estimation during post-fault operation. Such scheme is appropriate for sensorless 3-PIM drives to increase safety and reliability of the system, in the case of current sensor fault. The proposed FTC scheme is experimented for a 1HP 3-PIM drive system through a DSP/TMS320F28335. The experimental results show that the proposed FTC system can accurately and effectively control the 3-PIM during both healthy and faulty conditions.

Neuroadaptive observer-based discrete-time command filtered fault-tolerant control for induction motors with load disturbances

In this paper, a neuroadaptive observer-based discrete-time command filtered fault-tolerant control method is proposed for induction motors (IMs) with possible actuator faults and load disturbances. Firstly, the problem of “complexity of computation” and noncausal problem result from the traditional backstepping method are solved using the command filtered technique. Secondly, fault-tolerant control considering possible actuator faults is realized by adaptive neural control. In addition, a neuroadaptive observer is utilized to estimate the rotor position, angular velocity, and settle unknown load disturbances of IMs. The results of simulation demonstrate that the new design scheme can get rid of the effect of actuator faults and guarantee satisfactory position tracking performance.

Comparative study between luenberger observer and extended kalman filter for fault-tolerant control of induction motor drives

Comparative study between luenberger observer and extended kalman filter for fault-tolerant control of induction motor drives

Wavelet-based prognosis for fault-tolerant control of induction motor with stator and speed sensor faults

This paper presents a wavelet-based prognosis technique for fault-tolerant control (FTC) of an induction motor (IM) drive. The wavelet is used for analysis in fault detection due to its good filtering characteristics, localized capability and superior de-noising. The fault-tolerant algorithm is applied to a 1-kW IM to maintain the performance of the machine at an acceptable level. The FTC algorithm has been implemented in a new topology to ensure the best performance recovery in case of open and short stator winding faults, as well as speed sensor faults. In the worst-case scenario of operation, a protection stage has been implemented to stop motor operation. Experimental results demonstrate the reliability and effectiveness of the technique for diagnosis and prognosis of stator and speed sensor faults. The Texas Instrument TMS 320F28335 is used for the real-time implementation of the proposed wavelet-based prognosis and the FTC of the IM drive under different fault situations.

A modified direct torque control with fault tolerance

The use of inverters in induction motor control has reduced classical motor faults, such as broken rotor bars or windings short-circuit, besides improving control performance. The control becomes faster and more precise, reducing peaks in current and torque, so that the motor can have a softer operation. On the other hand, new elements are included in the system and it will be necessary to take into account their faults. These elements are sensors and power electronic devices that since a control point of view are the system sensors and actuators. Fault tolerance tries to maintain the system under control in case a fault appears in the system. If this is not possible, it takes the system to a safe operational point. In this paper a fault-tolerant control for induction motors is designed. Based on a direct torque control, new control strategies have been added in case current sensor and power switch faults are detected. The challenge is to overcome these faults without any physical redundancy of sensors or power switches as other authors propose. With the proposed control, it will be possible to guarantee the motor operation in the whole speed–torque range with one or none current sensors instead of the two usually used, though the performance will be slightly worsened. In case of inverter faults, the operation range will be restricted but the performance with respect to the fault situation is improved.