Smooth switching controllers for reliable induction motor drive operation after sensor failures

Abstract

This paper presents a switching control method that can be actuated by a supervisory controller, with emphasis on smooth transitions between various open and closed loop controllers in real time. Through conversion of commands into non-periodic voltage values in the synchronous qd0 reference frame, hand-off transient reduction is achieved by controlling the rate of change of stator voltage commands during changeover. Through this method, smooth switched supervisory control can be achieved without synchronization or phase coordination between different commands from different controllers. Controllers are selected based on available sensor feedback. A system containing three controllers is simulated and tested with simulated sensor loss. Results of the proposed smooth switching controller compared to abrupt switching between control commands are compared. The proposed scheme is shown to reduce current and torque transients and maintain smooth operation of the drive. Given that multiple controllers and the switching logic are computationally intensive from an embedded system perspective, the proposed method is verified to operate in a processor-in-the-loop (PIL) environment on a Texas Instruments C2000 microcontroller. Keywords-Supervisory control, smooth switching, transient reduction, processor in the loop, induction motor drive 978-1-4799-6735-3/15/$31.00 ©2015 IEEE

An Active Fault-Tolerant Control Strategy for Current Sensors Failure for Induction Motor Drives Using a Single Observer for Currents Estimation and Axes Transformation

“…Another type of FTC methods has been also presented in the literature, in which the sensors FTC algorithm changes the control according to the type of the faulty sensor, as proposed in Refs. [11][12][13][14]. A smooth FTC of IM drives with sensor failures is presented in the works [11,12].…”

“…[11][12][13][14]. A smooth FTC of IM drives with sensor failures is presented in the works [11,12]. In the healthy state, the IM drive's operation is accomplished using direct torque control; indirect field-oriented control is then used when the dc-link voltage sensor fails, and v/f control is utilized during current sensors failure.…”

Current sensors fault detection and tolerant control strategy for three-phase induction motor drives

“…Four different controllers are used in this method: Indirect Rotor Field Oriented Control (IRFOC) to overcome faults caused by the voltage sensor, speed sensorless vector control to compensate for interruptions coming from the speed sensor breakdown, scalar current magnitude control to overcom failures provoked by abnormal functioning of current sensors, and open-loop control in case where no sensor is operating correctly. A smooth FTC of IM drives with sensor failures is presented in [30,31]. Comparing to the method mentioned previously, the authors have successfully reduced the number of controllers from four to three, using direct torque control, IRFOC, and volt/hertz (V/f) control.…”

A Single Observer for Currents Estimation in Sensor’s Fault-Tolerant Control of Induction Motor Drives

“…The results obtained in [8] offer a solution to the succession of faults in the different sensors but the number of the used adaptive observers is still three. Another type of FTC methods has been also presented in the literature, in which the sensors FTC algorithm changes the control according to the type of the faulty sensor, as proposed in [11]- [14]. A smooth FTC of IM drives with sensor failures is presented in [11], [12].…”

“…Another type of FTC methods has been also presented in the literature, in which the sensors FTC algorithm changes the control according to the type of the faulty sensor, as proposed in [11]- [14]. A smooth FTC of IM drives with sensor failures is presented in [11], [12]. In the healthy state, the IM drive's operation is accomplished using direct torque control; indirect field oriented control is then used when the dc-link voltage sensor fails, and v/f control is utilized during current sensors failure.…”