J.-M. Retif

Institut National des Sciences Appliquées de Lyon, Lyons, Rhône-Alpes, France

Are you J.-M. Retif?

Claim your profile

Publications (19)21.73 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: As capacitor voltages are necessary for the three-cell DC–DC chopper control, the estimation of such voltages by an observer is attractive solution in terms of cost. However, due to the hybrid behavior of this structure, the capacitor voltages may be partially or even not observable for a given switching configuration. In other words, the observability matrix associated to the capacitor voltages never has a full rank. In order to make the observer conceivable, this paper proposes a new design by establishing sufficient conditions under which the capacitor voltages can be reconstructed within appropriate specific switching sequence and not necessarily instantly. An interconnected high gain observer is then designed for the considered structure. Furthermore, the analysis of convergence is given according to specific switching sequence, and the bounds of the observer tuning parameters are numerically verified. A significant load current benchmark including a three-cell chopper is used as prototype to show the performance and the effectiveness of the proposed observer. Copyright © 2013 John Wiley & Sons, Ltd.
    International Journal of Robust and Nonlinear Control 04/2014; 24(6). · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A digital current and voltage predictive controller (CVP) is proposed for high switching frequency, low power SMPS. The predictions of the inductor current and capacitor output voltage are performed simultaneously by adopting a flexible PWM pattern that enables dynamic adjustment of the time of the voltage events. The CVP controller preserves the merits of predictive current-mode control and allows to further improve the dynamic performances. With the knowledge of the inductor current, the performances of the CVP controller are analyzed compared to a deadbeat controller. Experimental results of a current sensorless implementation verify better closed-loop performances than those of PID, RST and sliding-mode controllers. The lab-scale prototype implemented in an FPGA supports a switching frequency up to 4 MHz only limited by the discrete buck converter.
    IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society; 01/2012
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a comparative study of three predictive current control schemes for permanent-magnet synchronous machine (PMSM) drives. The first control scheme predicts the future evolution of the currents for each possible configuration of the inverter legs. Then, the switching state which minimizes a given cost function is selected and applied during the next sampling time. The second control scheme uses a modulator to apply two configurations of the inverter legs during a computation period. Among these configurations, one leads to null voltages. The duration of the other configuration is calculated in order to minimize the distance between the obtained state vector and the desired one. The third control scheme uses a model of the PMSM in order to predict the stator voltages which allows us to reach the desired currents after one modulation period. An algebraic method is presented to compute the duty cycle of each leg of the inverter in a direct manner. These control schemes are detailed and tested using the same switching frequency on the same test bench (1.6-kW PMSM drive). A simulation study is performed in order to compare sensitivity to parameters of each control scheme. Experiments confirm the simulation results.
    IEEE Transactions on Industrial Electronics 08/2009; · 6.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a control scheme for a multilevel multi-cell converter. For this type of converters, load current and capacitor voltages must be jointly controlled. Moreover the real-time constraint is important. This constraint leads us to propose a control based on a simplified state-space model. The model allows predicting the state vector evolution for every converter configuration. The control algorithm directly determines the converter switching state which minimizes a simple cost function. A normalization of the state variables is proposed for the cost function calculation in order to ensure a trade-off between the tracking of the load current and the tracking of the capacitor voltages. The proposed control scheme is detailed and compared with a classical control scheme with simulations. Finally, experimental results are presented to show the effectiveness of the proposed method.
    Power Electronics Specialists Conference, 2008. PESC 2008. IEEE; 07/2008
  • Source
    J.-M. Retif, Xuefang Lin-Shi, F. Morel
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a predictive current control (PCC) strategy applied to an induction motor (IM) drive. In contrast to conventional vector control, where the inverter is not taken into account by the controller, the PCC considers the state of the inverter as a discrete control variable. Based on a simplified state space model of the IM and the inverter, the proposed control scheme calculates the state vector evolution direction in the d- and q-reference frame for all possible switching states of the inverter. The switching state which minimizes a given cost function is selected and is applied during an adapted duration which is calculated for each computation cycle. As the control requires the knowledge of the instantaneous rotor fluxes and in order to improve the control robustness, a reduced-order extended high gain observer is proposed for estimation of rotor fluxes and inverse rotor time constant. The simulation results validate the observer. The controller is implemented on a 5.5 kW IM drive with a digital-signal-processor (DSP) on a DSpace1103 board. Experimental results show the effectiveness and the performances of the proposed control.
    Power Electronics Specialists Conference, 2008. PESC 2008. IEEE; 07/2008
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the experimental results-based comparison of two predictive current controls (PCC) for permanent magnet synchronous machines (PMSM) drives. The first tested control scheme is based on a model including the inverter and the PMSM and taking into account the discrete nature of the inverter leg states. It predicts the future evolution of the currents for each possible configuration of the inverter. The switching state which minimizes a given cost function is selected. The selected inverter state is applied during the next sampling time. The second tested control scheme uses a model of the PMSM to predict the output voltages which allow to reach desired currents after one modulation period. A new algebraic method is presented to directly compute the duty cycle of each leg. Then a modulator generates the corresponding gate drive pulses of the inverter. These two control schemes are tested with a 1.6 kW PMSM drive at several operating points during steady state and transient operation. A detailed comparison of results is given. Advantages and drawbacks of each method are discussed.
    Power Electronics Specialists Conference, 2008. PESC 2008. IEEE; 07/2008
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Many research efforts have been dedicated to matrix converters for several years. As major technological issues are now solved, this structure will widespread in industrial applications, in particular with AC motors. Current control is a key issue for AC motor drives, so many control schemes have been proposed. Some of them proposed at first for inverters, were applied to matrix converters. Among algorithms used with inverters, predictive control shows very good performances. In this paper a new control scheme is proposed for a matrix converter- fed permanent magnet synchronous machine. Literature about matrix converter technology and control and about predictive control for inverter-fed AC machines is reviewed. The proposed predictive control principle, the model of the whole machine - converter and the cost-function are detailed. The method offers a trade-off between the quality of motor currents and input power factor. Finally experimental results are reported. The feasibility and the effectiveness of the proposed method is assessed.
    Power Electronics Specialists Conference, 2008. PESC 2008. IEEE; 07/2008
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a control scheme suitable for systems composed of a continuous process modulated in energy by a power converter with a finite number of topologies. To track the continuous reference values, a topology of the power converter is determined from a criterion based on a process state variable model and taking into account the possible topologies of the power converter. The proposed hybrid control scheme is applied to an electrical motor drive composed of an inverter coupled to a permanent magnet synchronous machine. An evolution which insures a fixed modulation frequency is also proposed. Experimental results validate the feasibility and effectiveness of the proposed schemes.
    IEEE Transactions on Industrial Electronics 03/2008; · 6.50 Impact Factor
  • H. Ziane, J.M. Retif, T. Rekioua
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, fixed-frequency direct torque control (DTC) of a permanent magnet synchronous motor (PMSM) is presented. In this method, the stator voltage vector is generated according to the increase stator flux components in the stationary frame ( alpha,beta ). A control algorithm based on predictive control to reduce the effect of the computing time on the stator flux vector position is also presented. The implementation of this method in the case of a PMSM, which is done without hysteresis regulators, is simple and does not require any filter. Simulation and experimental results show that the proposed method reduces the torque ripple while achieving a good dynamic response.
    Canadian Journal of Electrical and Computer Engineering 02/2008; · 0.33 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the implementation of a hybrid-control strategy applied to a permanent-magnet synchronous-motor (PMSM) drive. Hybrid control is a general approach for control of a switching-based hybrid system (HS). This class of HS includes a continuous process controlled by a discrete controller with a finite number of states. In the case of ac motor drives, in contrast to conventional vector control like proportional-integral control or predictive control, where the inverter is not taken into account by the controller, hybrid control integrates the inverter model and considers the state of the inverter as a control variable. It allows to obtain faster torque dynamics than vector-control algorithms. The hybrid control algorithm requires both computing velocity for real-time implementation and code flexibility for management of low-performance functions and analog-digital interfaces. Codesign appears as a promising methodology for partitioning hybrid-control algorithm between software (flexible) and hardware (velocity) while taking care of overall time constrains. In this paper, the implementation of hybrid-control algorithm for a PMSM drive is performed through a codesign approach on an Excalibur board, embedding a CPU-core (Nios-2 by Altera) inside an APEX20KE200EFC484-2X field-programmable gate array. The partitioning of software and hardware parts is explained. Experimental results show the effectiveness of the implementation. Performances, advantages, and limitations are discussed.
    IEEE Transactions on Industrial Electronics 09/2007; · 6.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Analogue control of monolithic DC/DC converters is technologically coming to a limit due to high switching frequency and a request for large regulation bandwidth. Digital control is now experimented for low-power low-voltage switch-mode power supply. Digital implementation of analogue solutions does not prove real performances. This paper compares a classical digital controller to a candidate alternative strategy. Sensitivity functions are used to compare controller performances. An off-line approach using fuzzy logic to quantify controller performances and a genetic algorithm to obtain an optimal controller is presented. A so-called RST algorithm optimized with this approach shows better performances.
    Industrial Electronics, 2007. ISIE 2007. IEEE International Symposium on; 07/2007
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Analogue control of monolithic DC/DC converters is coming to a limit due to high switching frequency and a request for large regulation bandwidth. Digital control is now experimented for low-power low-voltage switch-mode power supply. Digital implementation of analogue solutions does not prove real performances. Other digital controllers have been experimented but applied to discrete converters. This paper compares a classical digital controller to a possible alternative strategy. Sensitivity functions are used to compare controller performances. RST algorithm determined by robust pole assignment shows better performances
    IEEE Industrial Electronics, IECON 2006 - 32nd Annual Conference on; 12/2006
  • F. Morel, J.M. Retif, X. Lin-Shi, A.M. Llor
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we present a novel control strategy for motor drivers, which we have called fixed switching frequency hybrid control (FSPHC). Based on models of both motor and inverter, the hybrid control uses a formal representation of the inverter-machine group behaviour. For one constant period modulation, switching states and different vector application times are determined. This control scheme is applied to a permanent magnet synchronous motor and satisfactory experimental results are showed.
    Industrial Technology, 2004. IEEE ICIT '04. 2004 IEEE International Conference on; 01/2005
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hard switching DC/DC converters have been studied for decades. Many control techniques have been reported, and textbooks detail so-called classical control design methods. The buck converter is known as a simple topology of satisfying stability. However the monolithic integration of a buck converter including the control system leads to a possible non-stable converter in case of large load transient. More generally it is difficult to certify the accuracy of the control system. Integrated switch-mode power supplies needs to be investigated focusing control design issues. Global efficiency dictates to limit the budgets in biasing current of control loops, hence limits their bandwidth. Among others, this latter limitation renders the classical control design methods non satisfying. The paper investigates the control design challenge related to integration of switch-mode power supplies (SMPSs). Applications are discussed from simulation point-of-view. Particularly a trade-off must be set between control accuracy and performances on load transients. As it is not possible to specify the worst-case load transient, classical control design methods do not offer satisfying results. Alternative control design methods are investigated. Sensitivity transfer functions are introduced and an application method is detailed. Hybrid system methods are also investigated and their application is discussed. The design of integrated SMPSs requires adequate modifications of CAE-tools and design flows.
    Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual; 07/2004
  • [Show abstract] [Hide abstract]
    ABSTRACT: Direct-torque-control (DTC) is nowadays a classical technique for variable speed control of induction machines. Many implementations have been presented in literature DTC algorithm requires velocity for some parts and flexibility for other parts. Digital-signal-processors (DSP) have been used for flexibility, but field-programmable-gate-arrays (FPGA) have been preferred for velocity. Using one device (DSP or FPGA) for DTC implementation has been reported as not optimal. Codesign appears as a promising methodology for partitioning the DTC algorithm between flexible and fast parts. Codesign requires user-specifications to help the partitioning with regard to the awaited control performances. Authors discuss two experimental implementations at extremities of the codesign space, i.e. full-software or full-hardware implementation. For each implementation, the DTC algorithm requires adaptations. Authors detail each development, and full-codes are available on a dedicated web-site. Validation results are presented for both implementations. Performances, advantages, and limitations of both implementations are compared. The necessary specifications for codesign development may then be identified.
    Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual; 07/2004
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we present a novel control strategy for motor drivers, which we have called 'hybrid direct-torque control'. Based on models of both motor and inverters, the hybrid control uses a formal representation of inverter-machine behavior to determine the optimal switching state and vector application time. In contrast to conventional direct-torque control, which is based on the presence of hysteresis controllers and a switching table, the hybrid control involves tracking reference values of the electrical state in the state space. Observers and estimators of torque and flux are unnecessary. This control scheme is applied to a winding rotor synchronous motor.
    Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual; 07/2004
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a new and simple approach for sensorless speed control of asynchronous machine. It shows a self-contained electronic module which determines the speed of the machine with only two phase current measurements. Thus, the speed calculation is independent on the machine parameters and on control laws; this allows to design the control by considering the speed as an input. The principle of the method is based on rotor slot harmonics without high frequency injection. In fact, the rotor slot harmonics depend on rotor speed. These signals appear in the stator's spectrum with very low amplitude, in particular for a motor with skewed rotor slots. Moreover, the harmonics move with stator frequency. An analog adaptive band pass filter follows and amplifies this harmonics. As the response time is high at low speed, a digital algorithm is included in the microcontroller in order to decrease the response time. The proposed indirect speed sensor requires only some classical analog components and a low cost microcontroller. A short time calibration is necessary for the first start time of the inverter and the motor. Experimental results on a testing bench with different speed benchmarks are presented.
    Power Electronics Specialists Conference, 2004. PESC 04. 2004 IEEE 35th Annual; 07/2004
  • [Show abstract] [Hide abstract]
    ABSTRACT: A direct stator flux linkage control for permanent magnet synchronous motor is presented. Contrary to conventional direct torque control (DTC), the proposed control, which works with fixed switching frequency, can reduce torque ripple and current distortion. The implementation in a test bench shows the effectiveness of this control.
    Power Electronics Specialist Conference, 2003. PESC '03. 2003 IEEE 34th Annual; 07/2003
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents an implementation and comparison of three approaches for an energy-optimized synchronous-drive control. A digital control is carried out allowing an energy saving with widely sufficient dynamic operation for Electric and Hybrid Vehicles (E&HV) applications. The experimental results show a good current controller performance and a considerable efficiency gain compared to a non optimized control.
    09/2001;