The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform

Saleem Abbas - One of the best experts on this subject based on the ideXlab platform.

  • An Active Boost Power Converter for Improving the Performance of Switched Reluctance Generators in DC Generating Systems
    IEEE Transactions on Power Electronics, 2020
    Co-Authors: Qing Wang, Hao Chen, He Cheng, Saleem Abbas
    Abstract:

    In this article, an active boost power converter is proposed for switched reluctance generators (SRGs) that support low-voltage dc loads or dc microgrids. In the proposed converter, a front-end circuit is added to a conventional asymmetric half bridge power converter. With the front-end circuit, excitation voltage and demagnetization voltage can be regulated flexibly to improve the system efficiency and increase the maximum output power under constant phase current constraints. Then a Multiloop control strategy is developed to control the power converter. The Multiloop Controller contains a power Controller and a boost voltage Controller. The power Controller is designed to control SRG over the entire operating range. The boost voltage Controller is designed to control the front-end circuit. Two strategies are compared for the boost voltage control: voltage hysteresis control strategy and power flow control strategy. Comparing with voltage hysteresis control, proposed power flow control shows improvements in minimizing output voltage ripple and is suggested for the proposed converter. In the end, simulation and experimental results are given to verify the feasibility of the proposed power converter and control strategy. Comparisons between the proposed converter and the conventional converter are also given for evaluation.

Reza Katebi - One of the best experts on this subject based on the ideXlab platform.

  • Adaptive envelope control design for a Buoyant Airborne wind energy system
    2015 American Control Conference (ACC), 2015
    Co-Authors: Jonathan Samson, Reza Katebi
    Abstract:

    The focus of this paper is centered on the Buoyant Airborne Turbine (BAT) developed by Altaeros Energies. This system is part of a new class of wind energy system known as Airborne wind energy systems (AWES). To inform the reader, a brief review of the current control architecture for different types of AWES is presented. The paper then evaluates the control architecture for the Altaeros system and illustrates through a frequency domain analysis the impact that operating conditions will have on movement in roll, pitch and altitude. The primary contribution of this paper rests in the design of a Multiloop novel adaptive low level PD Controller that is developed from linearized models covering the full operating envelope. PD gains are adapted as a function of the system operating conditions and tuned as a function of the multi-loop bandwidth. As such it is shown that the control design varies with wind conditions and so facilitates the need for this adaptive approach. This work illustrates that a model free Multiloop Controller can be achieved without the need for extensive calibration parameters as in the classic LQR approach and demonstrates the merits of simplified PD tuning strategies when faced with complex multivariable problems.

  • ACC - Adaptive envelope control design for a Buoyant Airborne wind energy system
    2015 American Control Conference (ACC), 2015
    Co-Authors: Jonathan Samson, Reza Katebi
    Abstract:

    The focus of this paper is centered on the Buoyant Airborne Turbine (BAT) developed by Altaeros Energies. This system is part of a new class of wind energy system known as Airborne wind energy systems (AWES). To inform the reader, a brief review of the current control architecture for different types of AWES is presented. The paper then evaluates the control architecture for the Altaeros system and illustrates through a frequency domain analysis the impact that operating conditions will have on movement in roll, pitch and altitude. The primary contribution of this paper rests in the design of a Multiloop novel adaptive low level PD Controller that is developed from linearized models covering the full operating envelope. PD gains are adapted as a function of the system operating conditions and tuned as a function of the multi-loop bandwidth. As such it is shown that the control design varies with wind conditions and so facilitates the need for this adaptive approach. This work illustrates that a model free Multiloop Controller can be achieved without the need for extensive calibration parameters as in the classic LQR approach and demonstrates the merits of simplified PD tuning strategies when faced with complex multivariable problems.

Tongwen Chen - One of the best experts on this subject based on the ideXlab platform.

  • Frequency domain Multiloop control synthesis for unstable systems: An approach based on μ interaction measure
    2008 American Control Conference, 2008
    Co-Authors: Adarsha Swarnakar, Horacio Jose Marquez, Tongwen Chen
    Abstract:

    This paper presents a new practical framework for Multiloop Controller design in which Controllers are designed independently, i.e., a Controller in one loop is designed without exploiting information of Controllers used in other loops. The method is based on the (block) diagonal approximation of a system that is different from its (block) diagonal elements. The focus of this work is on unstable systems and the approximated systems are obtained by minimizing a scaled Linfin norm for the error systems. This extends the applicability of conventional mu-interaction measure to a more general scenario. The validity of the proposed approach is demonstrated through numerical simulation and application to an industrial boiler system.

  • Multivariable robust Controller design for a boiler system
    IEEE Transactions on Control Systems Technology, 2002
    Co-Authors: H.j. Marquez, Tongwen Chen
    Abstract:

    In an industrial boiler system, Multiloop (decentralized) proportional-integral (PI) control is used because of its implementational advantages. We show that such control schemes sacrifice robustness and performance of the overall system. In particular, under normal boiler operating conditions, we design a robust multivariable Controller using H/sub /spl infin// loop-shaping techniques; for consideration in implementation, we then reduce this Controller to a multivariable PI Controller. Both the H/sub /spl infin// Controller and its PI approximation are tested extensively in letdown the frequency domain as well as in the time domain, using a valve complex nonlinear simulation software; the results show that the designed Controllers are superior in robustness and performance to the existing Multiloop Controller.

S.s. Choi - One of the best experts on this subject based on the ideXlab platform.

  • Performance improvement of the dynamic voltage restorer with closed-loop load voltage and current-mode control
    IEEE Transactions on Power Electronics, 2002
    Co-Authors: M. Vilathgamuwa, A.a.d. Ranjith Perera, S.s. Choi
    Abstract:

    The performance of a dynamic voltage restorer (DVR) in improving the quality of power supply is examined. It is shown that the existing open-loop control strategy used in the DVR to regulate load voltage can produce poorly damped response due to the presence of the switching harmonic filter in the restorer. Damping is shown to be improved if the proposed Multiloop Controller is used. Furthermore, the new control scheme permits a closer tracking of the reference load voltage under varied load conditions. The analysis of the proposed method is then validated by simulation studies and laboratory experimental tests which show the efficacy of the new control scheme.

E.e. Carbajal-gutierrez - One of the best experts on this subject based on the ideXlab platform.

  • CCA - Multiloop Controller for N-Stage Cascade Boost Converter
    2007 IEEE International Conference on Control Applications, 2007
    Co-Authors: M.g. Ortiz-lopez, J. Leyva-ramos, L. H. Diaz-saldierna, E.e. Carbajal-gutierrez
    Abstract:

    In recent years, the development of new technologies is requiring wider conversion ratios. A possible solution to this problem is to use n-stages connected in cascade; however, the major drawbacks are: (a) the total losses are increased mainly by the active switches, and (b) a more complex control circuitry is required. An alternative solution is to use a cascade boost converter with a single active switch. In this paper, nonlinear and linear models are given for the above converter. A Controller is developed using average current-mode control where the current of the first inductor is selected for feedback purposes. For the inner loop, a current gain and a high gain compensator are selected. For the output loop, a conventional PI-Controller is designed.

  • Multiloop Controller design for a quadratic boost converter
    IET Electric Power Applications, 2007
    Co-Authors: J.a. Morales-saldana, R. Galarza-quirino, J. Leyva-ramos, E.e. Carbajal-gutierrez, M.g. Ortiz-lopez
    Abstract:

    A Controller design methodology is given for a quadratic boost converter with a single switch using current-programmed control. Nonlinear and linear models are developed, the later exhibits fourth-order characteristic dynamics with complex right-half plane zeros. The proposed control scheme is based on sensing the current of the switch and using it for feedback purposes. When the current loop is introduced, the fourth-order dynamics of the converter are changed to a dominant first order, which simplifies substantially the Controller design of the outer loop. For this loop, a conventional Controller is designed. The design-oriented analytic results allow the designer to easily pinpoint the control circuit parameters that optimise the converter's performance. At the end, experimental results are given for a 23 W quadratic boost converter where open loop and closed-loop response are compared

  • Multiloop Controller for N-Stage Cascade Boost Converter
    2007 IEEE International Conference on Control Applications, 2007
    Co-Authors: M.g. Ortiz-lopez, J. Leyva-ramos, L. H. Diaz-saldierna, E.e. Carbajal-gutierrez
    Abstract:

    In recent years, the development of new technologies is requiring wider conversion ratios. A possible solution to this problem is to use n-stages connected in cascade; however, the major drawbacks are: (a) the total losses are increased mainly by the active switches, and (b) a more complex control circuitry is required. An alternative solution is to use a cascade boost converter with a single active switch. In this paper, nonlinear and linear models are given for the above converter. A Controller is developed using average current-mode control where the current of the first inductor is selected for feedback purposes. For the inner loop, a current gain and a high gain compensator are selected. For the output loop, a conventional PI-Controller is designed.