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1

An observer for magnetic levitation system control based on a coefficient diagram method and backstepping

Haouari F., Bali N., Tadjine M., Boucherit M. S.

Archives of Electrical Engineering

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2018

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Vol. 67, nr 2

403-–417

EN

In this paper, we propose a robust nonlinear control design concept based on a coefficient diagram method and backstepping control, combined with a nonlinear observer for the magnetic levitation system to achieve precise position control in the existence of external disturbance, parameters mismatch with considerable variations and sensor noise in the case, where the full system states are supposed to be unavailable. The observer converges exponentially and leads to good estimate as well as a good track of the steel ball position with the reference trajectory. A simulation results are provided to show the excellent performance of the designed controller.

2

Wavelets and principal component analysis method for vibration monitoring of rotating machinery

Bendjama H., Boucherit M. S.

Journal of Theoretical and Applied Mechanics

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2016

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Vol. 54 nr 2

659--670

EN

Fault diagnosis is playing today a crucial role in industrial systems. To improve reliability, safety and efficiency advanced monitoring methods have become increasingly important for many systems. The vibration analysis method is essential in improving condition monitoring and fault diagnosis of rotating machinery. Effective utilization of vibration signals depends upon effectiveness of applied signal processing techniques. In this paper, fault diagnosis is performed using a combination between Wavelet Transform (WT) and Principal Component Analysis (PCA). The WT is employed to decompose the vibration signal of measurements data in different frequency bands. The obtained decomposition levels are used as the input to the PCA method for fault identification using, respectively, the Q-statistic, also called Squared Prediction Error (SPE) and the Q-contribution. Clearly, useful information about the fault can be contained in some levels of wavelet decomposition. For this purpose, the Q-contribution is used as an evaluation criterion to select the optimal level, which contains the maximum information.Associated to spectral analysis and envelope analysis, it allows clear visualization of fault frequencies. The objective of this method is to obtain the information contained in the measured data. The monitoring results using real sensor measurements from a pilot scale are presented and discussed.

3

Improved direct torque control of induction motors using adaptive observer and sliding mode control

Kouchih D, Tadjine M., Boucherit M. S.

Archives of Control Sciences

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2013

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Vol. 23, no. 3

361--376

EN

This paper presents the synthesis of an adaptive observer which is used for the improvement of the direct torque control of induction motor drives. The observer detects stator flux components in two-phase stationary reference frame, rotor speed and stator resistance by measure of the stator terminal voltages and currents. The observer is adapted using a simple 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. Simulation tests under load disturbance and stator resistance variation are provided to evaluate the consistency and performance of the proposed control technique in the low and high speeds.

4

Stabilization of multi DC bus link voltages of multilevel NPC VSI. Application to double stator induction motors

Beriber D., Talha A., Boucherit M. S.

Archives of Control Sciences

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2012

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Vol. 22, no. 1

107-120

EN

Voltage source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes of studying multilevel inverters are the generation of output voltage signals with low harmonic distortion and reduction of switching frequency. An important issue of the multilevel inverter is the capacitor voltage-balancing problem. The unbalance of different DC voltage sources of multilevel neutral point clamped (NPC) voltage source inverter (VSI) constitutes the major limitation for the use of this new power converter. In this paper, we present study on the stability problem of the input DC voltages of the three-level Neutral Point Clamping (NPC) voltage source inverter (VSI). This inverter is useful for application in high voltage and high power area. In the first part, we remind the model of double stator induction motors (DSIM). Then, we develop control models of this inverter using the connection functions of the semi-conductors. We propose a Pulse Width Modulation (PWM) strategy to control this converter. The inverter is fed by constant input DC voltages. In the last part, we study the stability problem of the input DC voltages of the inverter. A cascade constituted by two three-level PWM rectifiers - two three-level NPC VSI - DSIM is discussed. The results obtained show that the input DC voltages of the inverters are not stable. To solve this problem, we propose to use a half clamping bridge. This solution is very promising in order to stabilize the input DC voltages of this converters.

5

Evaluation of the Shunt Active Power Filter apparent power ratio using particle swarm optimization

Kouzou A., Mahmoudi M. O., Boucherit M. S.

Archives of Control Sciences

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2010

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Vol. 20, no. 1

47-76

EN

The main objective of this present paper is the study of the Shunt Active Power Filter (APF) compensations capability for different perturbations in AC power system such as current unbalance, phase shift current and undesired harmonics generated by nonlinear load and/or by the power system voltage. This capability is determined by the maximum rate of the apparent power that can be delivered. This study is based on the definition of the effective apparent power as defined in IEEE 1459-2000 which was proved to be the suitable amount to be concerned in the design process of different devices.

6

Novel digital PWM strategies of multilevel voltage source inverters

Beriber D., Talha A., Berkouk E. M., Francois B., Boucherit M. S.

Archives of Control Sciences

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2009

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Vol. 19, no. 1

43-57

EN

In this paper, two novel algorithms of algebraic PWM strategies for seven-level Neutral Point Clamped (NPC) Voltage Source Inverter (VSI) are presented. These algorithms use a control model of the inverter. In the first part, the authors develop a model of this inverter, without assumption on its control, by using design method associated to Petri nets and switching functions. In the second part, knowledge and control models of this converter are reviewed by using respectively instantaneous and continuous equivalent switching functions. In the last part, two algebraic PWM control strategies of the inverter are proposed. The obtained results are full of promise to use these digital strategies to control seven - level NPC VSI used in high voltage and high power applications as electrical traction.

7

Enslavement and control in dq synchronous frame for a cascade using multilevel inverter NPC

Beriber D., Boucherit M. S., Berkouk E-M.

Archives of Control Sciences

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2008

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Vol. 18, no. 4

497-513

EN

The aim of this paper is to give a solution to unbalance problem of the input DC voltages of the nine-level NPC-VSI in dq synchronous frame. For that, we used in high voltage and great power applications, one two-level PWM current rectifier-nine-level NPC VSI-PMSM cascade. In the first part, we develop a knowledge model of the Nine-level NPC VSI and propose a space vector modulation of this converter using eight bipolar carriers. After that, this study shows particularly the problem of the stability of the DC voltages of the inverter and its consequence on the performances of the PMSM speed control. Then, we propose a solution to the problem by employed closed loop regulation using classic PI controller mode in d-q synchronous frame. We add a Clamping bridge to stabilize the eight DC input voltages of the nine-level NPC VSI. This cascade found applications in great power and high voltage fields as electrical traction.

8

Novel harmonic elimination PWM technique for reducing torque-ripple in inverter-fed induction motor

Bouchhida O., Boucherit M.S.

Archives of Electrical Engineering

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2007

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Vol. 56, nr 3-4

197-211

EN

A novel harmonic elimination pulse width modulated (PWM) strategy for three-phase inverter is presented. The torque ripple of the induction motor can be significantly reduced by the new PWM lechnique. The three-phase inverter is associated with a passive LC filter. The commutation angles are predetermined off-line and stored in the microcontroller memory in order to speed up the online control of the induction motors. Pre-calculated switching is modelled to cancel the greater part of low-order harmonics and to keep a single-pole DC voltage across the polarized capacitors. A passive LC filter is designed to cancel the high-order harmonics. This approach allows substantial reduction of the harmonic ratio in the AC main output voltage without increasing the number of switches per period. Consequently, the duties of the semiconductor power switches are alleviated. The effectiveness of the new harmonic elimination PWM technique for reducing torque-ripple in inverter-fed induction motors is confirmed by simulation results.

PL

Przedstawiono nowy sposób eliminacji harmonicznych w 3-fazowym falowniku napięcia, sterowanym metodą regulacji szerokości impulsów, prowadzący do zmniejszenia tętnień momentu. Na wyjściu falownika zastosowano pasywny filtr LC. Kąty komutacji wyznaczana są wstępnie i gromadzone w pamięci mikrosterownika dla przyśpieszenia sterowania silnika "on-line". Obliczenia wstępne łączeń falownika modeluje się w celu eliminacji większości harmonicznych niskiego rzędu i utrzymania jednobiegunowego napięcia na spolaryzowanych kondensatorach. Pasywny filtr LC dobrany jest tak, aby wyeliminować harmoniczne wyższego rzędu. Taka strategia pozwala na istotne wyeliminowanie harmonicznych z napięcia wyjściowego falownika bez zwiększania liczby łączeń w okresie. Dzięki temu zmniejszone są kąty przewodzenia łączników półprzewodnikowych. Efektywność nowej strategii eliminacji harmonicznych metodą PWM potwierdzono symulacyjnie.

9

Decentralized direct adaptive fuzzy control of non-linear interconnected MIMO system class

Tlemcani A., Chekireb H., Boucherit M. S., Labiod S.

Archives of Control Sciences

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2007

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Vol. 17, no. 4

409-425

EN

In this paper, we propose a decentralized direct adaptive fuzzy control method for a class interconnected MIMO non linear plant encountered mainly in robotics. The establishment of the control law introduces very simplest assumptions. Indeed, the functions incorporating the plant dynamic must be continuous and the interconnection terms are bounded by unknown bounds. The fuzzy direct adaptive law is designed to compensate for the interconnections effect and to ensure the closed-loop stability, convergence of the controlled outputs and `boundedness' of adaptation parameters. The proposed method is tested by simulation on the robot Puma 560. In this test the robot is controlled in the operational space as that the robot tip follows a prescribed curve on the sphere where the orientation of the last link (sixth) is maintained radial related to the center of this sphere.

10

On sliding mode based non linear PID design for position control of permanent magnet synchronous machine with unknown load torque

Nezli L., Tadjine M., Boucherit M. S.

Archives of Control Sciences

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2006

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Vol. 16, no. 1

71-86

EN

This paper presents a new control design procedure for permanent magnet synchronous machine motion drive in the case of unknown load torque. The contol law is based on the combination of sliding mode, non linear proportional integral derivative regulators, and the backstepping approaches. More precisely, we determine the controllers imposing the current-position tracking in three recursive steps and by using appropriate sliding mode / PID gains that are non linear functions of the system state. Moreover, a comparative study between the proposed sliding mode PID/Backstepping approach and the feedback linearizing control is made by realistic simulation including load torque change, parametric variations and measurement noise. The results of current-position tracking show the effectiveness of the proposed method in presence of strong disturbances.

11

A new robust adaptive control of a class of MIMO nonlinear systems with fuzzy approximators

Tlemcani A., Chekireb H., Boucherit M. S.

Archives of Control Sciences

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2006

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Vol. 16, no. 3

341-358

EN

Based on the Lyapunov synthesis approach, several adaptive fuzzy control schemes have been developed during the last few years. In this paper we develop a robust adaptive fuzzy control law for MIMO nonlinear system class. The proposed method uses the Sugeno-Takagi fuzzy system as an universal approximator of continuous nonlinear functions. The adaptive controllaw is established based on the Lyapunov method. So, the output convergence, the boundedness of the parameters and the ststes are derived. Moreover, the fuzzy adaptive law incorporates a compensatory sliding term, which compensates for effects of the unavoidable reconstruction errors.

12

On robust state feedback control of a permanent magnet synchronous machine drive: an experimental evaluation

Benmansour K., Boucherit M. S., Tadjine M., Rezine H.

Archives of Control Sciences

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2005

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Vol. 15, no. 1

83-96

EN

This paper presents a theory and an experimental evaluation of robust control algorithm for permanent magnet synchronous machine (PMSM) speed drive fed by voltage source inverter. A simple control model is first obtained by performing field orintation through a nominal linearizing stste feedback. Then, the robust control algorithm based on pole placement is applied to the PMSM in order to deal with plant uncertainties. The adopted method uses the notion of geometric stability and the multi-model approach in order to synthesis the state regulation by robust pole placement. To show the validity of our control approach. DSP based experimental results are presented. These results are very satisfactory and prove the feasibility of our control algorithm.

13

Feedback and control cascade using seven - Level NPC voltage source inverter

Talha A., Berkouk E-M., Boucherit M. S.

Archives of Control Sciences

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2005

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Vol. 15, no. 2

159-174

EN

In this paper, the authors present a study of the stability problem of the input DC voltages of the seven-level neutral point clamping (NPC) voltage source inverter (VSI). In the first part, a knowledge model of this converter isdeveloped by using connection functions. In the second part, The authors propose a PWM strategy which uses six bipolar carriers to control the converter. In this part, The inverter is fed by constant input DC voltages. In the last part of the paper, the authors study the stability problem of the input DC voltages of the inverter. Thus, a cascade is studied constituted by three two-level PWM rectifiers - clamping bridge - seven-level NPC VSI. The obtained results show that the input DC voltages of the inverter are not stable. To improve the performances of the proposed cascade and stabilize the input DC voltages, the authors propose in this paper a solution which uses a linear feedback control of this cascade. This study allows to find a solution for the instability problem of the input DC voltages of the inverter. The results obtained with this solution confirm a good performance of the system.

14

Stable indirect adaptive fuzzy control for a class of SISO nonlinear systems

Labiod S., Boucherit M. S., Bouhali O.

Archives of Control Sciences

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2004

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Vol. 14, no. 1

27-43

EN

his paper proposed an indirect adaptive fuzzy control scheme for a class of unknown continuous-time nonlinear single-input single-output (SISO) dynamic systems. Within this scheme, the fuzzy systems are employed to approximate the unknown system dynamics. Based on these fuzzy approximations and a Lyapunov synthesis approach, suitable control laws and appropriate parameter adaptive algorithms are developed. It is shown that the proposed control scheme avoids the possible controller singularity problem, guarantes the convergence of the tracking error to zero and the global boundedness of all signals in the closed-loop system. Simulation results, performed on an inverted on a inverted pendulum system, are given to point out the good performance of the developed adaptive control approach.

15

Robust hybrid control based on feedback linearization and field-oriented controls of induction motor

Barazane L., Larbes C., Boucherit M.S., Ouiguini R.

Archives of Electrical Engineering

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2003

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Vol. 52, nr 2

115--135

EN

During the last decades pulse width modulation (PWM) voltage source inverter fed induction motor based drives have improved in many aspects and arc becoming a real alternative to DC drives. In order to obtain high performance speed response, field oriented control techniques are usually used to control the torque and the flux separately as in DC motors. However, it is well known that these methods suffer from the sensitivity to parameter variations and from the coupling problem between the torque and the flux variables when the flux changes. To try to solve the above problems an approach to the field oriented control is presented in this paper. It is based on the association of the feedback linearization control (FLC) with the field-oriented control (FOC) resulting in a hybrid system. The FLC is applied in the rotating field reference frame and with an adequate choice of the output variables a total linearization is obtained and the decoupling is maintained for the whole range of the rotating speed whatever the operating modes. Sliding mode regulators are used here to solve the problem of sensitivity to parameter variations and to external disturbances. A new smooth piecewise function is given to reduce the problem of chattering, which is inherent in sliding mode controllers. Furthermore, since the rotor fluxes components are not usually measurable, a closed-loop observer is derived to estimate these latters and the speed of the motor. The paper describes the different steps of the design of this control technique and gives both the theoretical analyses as well as the simulation results. These latters revealed very interesting features and showed that this method can be an alternative to the conventional FOC.

PL

W ostatnich dziesięcioleciach napędy z silnikami indukcyjnymi zasilanymi z inwertorów napięciowych z modulacją szerokości impulsów PWM zostały bardzo udoskonalone i stały się konkurencyjne do napędów z silnikami prądu stałego. Dla uzyskania dokładnej regulacji prędkości wykorzystuje się zazwyczaj sterowanie polowo zorientowane w celu niezależnej regulacji momentu i strumienia, jak w silnikach prądu stałego. Wiadomo jednak, że takie sterowanie jest czułe na zmiany parametrów i że zmiany strumienia pociągają za sobą zmiany momentu. Dla rozwiązania tego problemu w artykule zaprezentowano nowe podejście do sterowania polowo zorientowanego. Polega ono na połączeniu sterowania ze zlinearyzowanym sprzężeniem zwrotnym (FLC -feedback linearization control) ze sterowaniem polowo zorientowanym (FOC-field-oriented control) w system hybrydowy. FLC jest zastosowane w odniesieniu do pola wirującego i przy odpowiednim doborze zmiennych wyjściowych uzyskuje się całkowitą linearyzację i odsprzężenie momentu i strumienia w całym zakresie prędkości obrotowej dla dowolnego rodzaju pracy. Dla rozwiązania problemu czułości napędu na zmiany wartości parametrów i na zakłócenia zewnętrzne wykorzystano regulatory do sterowania z ruchem ślizgowym. Wprowadzono nową gładką funkcję odcinkową dla zredukowania pulsacji towarzyszących zastosowaniu takich regulatorów. Ponadto, ponieważ w praktyce składowe strumienia rotora nie są przeważnie mierzalne, wprowadzono obwody estymatorów pozwalających na określenie tych wartości i wartości prędkości obrotowej. Artykuł opisuje poszczególne stopnie projektowania tej techniki sterowania i przedstawia wyniki analizy teoretycznej i badań symulacyjnych. Badania te uwidaczniają bardzo interesujące właściwości metody i wskazują, że może być ona zastosowana zamiast konwencjonalnej POC.

16

Direct stable fuzzy adaptive control of a class of SISO nonlinear systems

Labiod S., Boucherit M. S.

Archives of Control Sciences

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2003

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Vol. 13, no. 1

95-110

EN

For class of unknown nonlinear single-output (SISO) systems a stable direct adaptive controller witch uses standard fuzzy systems is presented. The proposed scheme includes a proportional-integral-type adaptation law. global boundedness of the overall adaptive system and tracking within a desired precision are established with the new adaptive scheme. This adaptive scheme allows for the incorporation of linquistic information from human experts directly into the controller. Simulations performed on two examples illustrate the approach and exhibit its performance.

17

Decentralized neural network controller for trajectory tracking of robot manipulators

Boukhetala D., Boudjema F., Djebiri M., Boucherit M.S., M'Sirdi N.K.

Archives of Electrical Engineering

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2001

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Vol. 50, nr 3

295-311

EN

This paper deals with the decentralized supervised control of robot manipulators using neural networks. First, a control law is synthesized by using the computed torque method. Since this latter is a model-based control technique, it presents some drawbacks such as sensitivity to parameter variations. To ovoid this problem, the control law is supervised using neural networks. Simulation results with robustness tests are provided to demonstrate whether the neural controller is capable to mimic the existing controller in one hand, and on the other hand, to compensate disturbances for which the existing controller did not show satisfactory results in terms of performances. A comparative study of both the decentralized structure and the centralized structure of the supervised control is also given.

PL

Artykuł dotyczy zdecentralizowanego nadzoru sterowania manipulatorów robotów przy zastosowaniu sieci neuronowych. Podano syntetyczny opis metody sterowania opartej o obliczenia momentu obrotowego. Posługuje się ona modelem wrażliwym na zmienność wprowadzanych parametrów. Aby ograniczyć ten wpływ sterowanie manipulatorów nadzorowane jest za pomocą sieci neuronowych. Podano wyniki symulacji oraz rezultaty prób odporności na zakłócenia dla zademonstrowania, czy sterownik neuronowy jest w stanie zastąpić zwykły sterownik, wykazując jednocześnie zdolność kompensacji zakłóceń, której zwykły sterownik nie posiada. Podano analizę porównawczą zdecentralizowanego oraz scentralizowanego podejścia do zagadnienia nadzoru sterowania.