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1

Fault Tolerant Control Based on Extended Kalman Filter of Squirrel-Cage Induction Machines

Khadar Saad, Mekhalfia Fadhila, Kouzou Abdellah

Acta Energetica

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2019

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nr 4

6--23

EN

Fault-tolerant control systems possess the ability of rejecting the effect of faults. They are capable of maintaining overall system stability and acceptable performance in degraded modes. Through many researches, the analysis, modeling, and simulation of various inverter and machine faults have been carried out for the purpose of providing a fault tolerance. However, most of them are based on systems redundancy principle. Among the real-time based approaches for the fault detection and diagnosis, there are several strategies such as the pseudo inverse method, the linear quadratic approach and Extended Kalman Filter based Fault Tolerant Control (EKF-FTC). In recent years the application of Kalman filter approaches has gained an increasing attention in fundamental research and application. In this paper, a FTC method dedicated to Induction Motor (IM) drive is presented. The proposed method based on an additive term to the backstepping control which based on the error of current during the appearance of fault and the adaptive gain of the Kalman filter. This method improves the performance of the backstepping control to maintain the operation despite the appearance of faults. The main objective is to ensure a minimum level of performance of the drive system that is malfunctioning.

PL

Odporne na błędy układy sterowania mają zdolność eliminacji wpływu zakłóceń. Potrafią one utrzymywać ogólną stabilność i akceptowalne działanie systemu w trybach awaryjnych. Dzięki wielu badaniom przeprowadzono analizę, modelowanie i symu- lację różnych błędów falownika i maszyny w celu zapewnienia odporności na błędy. Większość z nich wynika jednak z zasady redundancji systemów. Wśród strategii wykrywania i diagnozowania błędów w czasie rzeczywistym można wyróżnić przykładowo metodę pseudoodwrotną, metodę liniowo-kwadratową i sterowanie odporne na błędy przy użyciu rozszerzonego filtra Kalmana (EKF-FTC). W ostatnich latach metodom z użyciem filtra Kalmana poświęca się coraz więcej uwagi w podstawowych bada- niach i zastosowaniach. W niniejszym artykule przedstawiono metodę FTC zastosowaną do napędu silnika indukcyjnego (IM). Proponowana metoda polega na dodaniu do sterowania metodą całkowania wstecznego (ang. backstepping) członu addytywnego, która polega na wystąpieniu uchybu prądu w razie błędu i wzmocnienia adaptacyjnego filtra Kalmana. Metoda ta poprawia wydaj- ność sterowania za pomocą wstecznego całkowania w celu podtrzymania pracy pomimo wystąpienia błędów. Głównym celem jest zapewnienie minimalnego poziomu wydajności niesprawnego układu napędowego.

2

Interactive Education of Engineers in the Field of Fault Diagnosis and Fault-Tolerant Control

Moczulski W., Przystałka P., Wachla D., Panfil W.

Pomiary Automatyka Robotyka

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2013

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R. 17, nr 11

84--91

EN

The main purpose of this paper is to present how the new information technologies can be used to aid engineering education in the area of fault diagnosis and fault-tolerant control. A 3D virtual reality model of the second stage of a water filtration system together with its simulation model are pointed out as a useful learning mean for stimulating education in the domain of advanced control theory at the university level. Some applications of the elaborated tool for presenting either fault diagnosis or fault-tolerant control issues are given and the most important merits and limits of the proposed approach in the education process discussed.

PL

Głównym celem artykułu jest zaprezentowanie nowych technologii informacyjnych do wspomagania nauczania w zakresie diagnostyki procesów i sterowania odpornego na błędy i uszkodzenia. Zaproponowano trójwymiarowy wirtualny model układu filtracji wody stanowiący jeden ze stopni systemu przygotowania wody w elektrowni. Model ten połączono z jego modelem symulacyjnym, otrzymując narzędzie przydatne do stymulacji procesu nauczania akademickiego w zakresie zaawansowanych systemów sterowania. W artykule pokazano przykłady zastosowania opracowanego systemu informatycznego do prezentacji zagadnień z diagnostyki uszkodzeń oraz sterowania odpornego. Artykuł kończy dyskusja na temat zalet i ograniczeń proponowanego podejścia w zakresie procesu kształcenia.

3

Fault tolerance in networked control systems under intermittent observations

Georges J. P., Theilliol D., Cocquempot V., Ponsart J. C., Aubrun C.

International Journal of Applied Mathematics and Computer Science

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2011

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Vol. 21, no 4

639-648

EN

This paper presents an approach to fault tolerant control based on the sensor masking principle in the case of wireless networked control systems. With wireless transmission, packet losses act as sensor faults. In the presence of such faults, the faulty measurements corrupt directly the behaviour of closed-loop systems. Since the controller aims at cancelling the error between the measurement and its reference input, the real outputs will, in such a networked control system, deviate from the desired value and may drive the system to its physical limitations or even to instability. The proposed method facilitates fault compensation based on an interacting multiple model approach developed in the framework of channel errors or network congestion equivalent to multiple sensors failures. The interacting multiple model method involved in a networked control system provides simultaneously detection and isolation of on-line packet losses, and also performs a suitable state estimation. Based on particular knowledge of packet losses, sensor fault-tolerant controls are obtained by computing a new control law using fault-free estimation of the faulty element to avoid intermittent observations that might develop into failures and to minimize the effects on system performance and safety.

4

Fault diagnosis of networked control systems

Aubrun C., Sauter D., Yamé J.

International Journal of Applied Mathematics and Computer Science

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2008

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Vol. 18, no 4

525-537

EN

Networked Control Systems (NCSs) deal with feedback control systems with loops closed via data communication networks. Control over a network has many advantages compared with traditionally controlled systems, such as a lower implementation cost, reduced wiring, simpler installation and maintenance and higher reliability. Nevertheless, the network-induced delay, packet dropout, asynchronous behavior and other specificities of networks will degrade the performance of closed-loop systems. In this context, it is necessary to develop a new theory for systems that operate in a distributed and asynchronous environment. Research on Fault Detection and Isolation (FDI) for NCSs has received increasing attention in recent years. This paper reviews the state of the art in this topic.

5

Actuator fault tolerant control design based on a reconfigurable reference input

Theilliol D., Join C., Zhang Y.

International Journal of Applied Mathematics and Computer Science

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2008

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Vol. 18, no 4

553-560

EN

The prospective work reported in this paper explores a new approach to enhance the performance of an active fault tolerant control system. The proposed technique is based on a modified recovery/trajectory control system in which a reconfigurable reference input is considered when performance degradation occurs in the system due to faults in actuator dynamics. An added value of this work is to reduce the energy spent to achieve the desired closed-loop performance. This work is justified by the need of maintaining a reliable system in a dynamical way in order to achieve a mission by an autonomous system, e.g., a launcher, a satellite, a submarine, etc. The effectiveness is illustrated using a three-tank system for slowly varying reference inputs corrupted by actuators faults.

6

Actuator fault tolerance in control systems with predictive constrained set-point optimizers

Marusak P. M., Tatjewski P.

International Journal of Applied Mathematics and Computer Science

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2008

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Vol. 18, no 4

539-551

EN

Mechanisms of fault tolerance to actuator faults in a control structure with a predictive constrained set-point optimizer are proposed. The structure considered consists of a basic feedback control layer and a local supervisory set-point optimizer which executes as frequently as the feedback controllers do with the aim to recalculate the set-points both for constraint feasibility and economic performance. The main goal of the presented reconfiguration mechanisms activated in response to an actuator blockade is to continue the operation of the control system with the fault, until it is fixed. This may be even long-term, if additional manipulated variables are available. The mechanisms are relatively simple and consist in the reconfiguration of the model structure and the introduction of appropriate constraints into the optimization problem of the optimizer, thus not affecting the numerical effectiveness. Simulation results of the presented control system for a multivariable plant are provided, illustrating the efficiency of the proposed approach.