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Osman Kukrer - One of the best experts on this subject based on the ideXlab platform.

  • Control strategy for single-phase PWM ac/Dc Voltage-Source converters based on Lyapunov's direct method
    International Journal of Electronics, 2000
    Co-Authors: Hasan Komurcugil, Osman Kukrer
    Abstract:

    Several methods for Dc Voltage control of single-phase pulse width modulation ac/Dc Voltage-Source converters are known. They differ in their performance and the complexity of the hardware and software they use. One of the basic requirements of the control method is a nearly sinusoidal input current with unity power factor. However, global stability of the converter is not guaranteed by the methods proposed so far. This paper describes a new control method based on Lyapunov's direct method. It is shown that the converter can be stabilized globally to handle large signal disturbances. The closed-loop system not only ensures stability, but also exhibits excellent transient response for abrupt changes in the load. More importantly, the proposed control method can keep the advantages and remove the disadvantages of the existing methods. Computer simulations and experiments are presented to show the effectiveness and applicability of the proposed control method for the converter.

  • A novel current-control method for three-phase PWM AC/Dc Voltage-Source converters
    IEEE Transactions on Industrial Electronics, 1999
    Co-Authors: Hasan Komurcugil, Osman Kukrer
    Abstract:

    This paper presents a novel current-control-based control strategy, obtained in stationary frame, for a three-phase pulsewidth-modulated AC/Dc Voltage-Source converter. In this control strategy, an error Voltage is produced from the comparison of the output Dc Voltage with a Dc reference Voltage. This error Voltage is then utilized by a proportional plus integral controller to generate a command signal for the input line current amplitude and is automatically controlled to the desired value. Therefore, there is no need to measure the input line currents. Stability analysis of the closed-loop system is made, and the stability region for proportional and integral gains which makes the operating point stable is also found. The resulting closed-loop system not only exhibits good transient response, but also provides sinusoidal line currents and unity power factor, both in the rectifying and regenerating modes. Experimental results are presented and compared with simulations.

  • Lyapunov-based control for three-phase PWM AC/Dc Voltage-Source converters
    IEEE Transactions on Power Electronics, 1998
    Co-Authors: Hasan Komurcugil, Osman Kukrer
    Abstract:

    The three-phase pulsewidth modulation (PWM) AC/Dc Voltage-Source converter with the control laws proposed so far is not only unstable against large-signal disturbances, but also has the problem that its stability depends on the circuit parameters such as the Dc-output capacitance. This paper describes a new control law based on Lyapunov's stability theory. It is shown that the converter can be stabilized globally for handling large-signal disturbances. The resulting closed-loop system not only guarantees a sufficient stability region (independent of the circuit parameters) in the state space, but also exhibits good transient response both in the rectifying and regenerating modes. Also, a new simulation technique is introduced which increases the speed of the simulation process considerably. Computer simulations are presented to confirm the effectiveness of the proposed control strategy and the validity of the simulation technique. Experimental results are also presented to verify the theoretical and simulation studies.

P Viarouge - One of the best experts on this subject based on the ideXlab platform.

  • analysis and implementation of a real time predictive current controller for permanent magnet synchronous servo drives
    IEEE Transactions on Industrial Electronics, 1994
    Co-Authors: Hoang Lehuy, K Slimani, P Viarouge
    Abstract:

    A real-time current controller for PWM inverter-fed permanent-magnet synchronous motor drives is presented and analyzed. The proposed current control scheme is based on predictive control with a parallel integral loop added to compensate for the inaccuracy of the motor model and for the variations of motor parameters and Dc Voltage Source. The proposed current control scheme is analyzed and its performance is evaluated by computer simulation. An EPROM-based implementation is presented in which calculations and pulsewidth modulation are executed by lookup tables resulting in high-speed operation. The controller performance is evaluated using a prototype l kW PM synchronous servo drive. Experimental results are given and discussed. >

  • analysis and implementation of a real time predictive current controller for permanent magnet synchronous servo drives
    IEEE Industry Applications Society Annual Meeting, 1991
    Co-Authors: Hoang Lehuy, K Slimani, P Viarouge
    Abstract:

    A real-time predictive current controller for PWM inverter feeding PM synchronous motor is presented in which the accuracy and the robustness of the control are improved by integral compensation. In the proposed control scheme, a parallel control loop is used to compensate for the inaccuracy of the model and the variations in the motor parameters and in the Dc Voltage Source. The proposed current control scheme is described and analyzed. The performance is studied and evaluated by computer simulation. The implementation of a real-time EPROM-based predictive controller is considered and discussed. The performance of the controller is evaluated using a prototype 1 kW PM synchronous servo drive. Experimental results are given and discussed. >

Antonio T. Alexandridis - One of the best experts on this subject based on the ideXlab platform.

  • ECC - Nonlinear stability analysis for ac/Dc Voltage Source converters driven by PI current-mode controllers
    2014 European Control Conference (ECC), 2014
    Co-Authors: Konstantinos F. Krommydas, Antonio T. Alexandridis
    Abstract:

    Voltage Source converters operating under current-mode controllers perform a standard and extremely common scheme in many industrial applications. In this paper, the open problem of designing and analyzing such nonlinear systems is addressed. To this end, a novel passivity-based stability analysis is developed that takes into account the accurate entire nonlinear model of the system with the proposed current-mode proportional-integral (PI) controllers selected to be independent from the system parameters. In particular, a new sequential method is developed that provides the suitable Lyapunov function for the entire closed-loop system. Using this Lyapunov storage function input-to-state stability is proven; moreover, exploiting some new advanced nonlinear methods, it is shown that convergence of the closed- loop system states to the desired unique equilibrium is guaranteed. Simulation results verify the theoretical analysis providing a very good transient response and convergence to the desired steady state. I. INTRODUCTION The three-phase ac/Dc Voltage Source converters (VSC) are the widest used power electronic devices in industrial applications and renewable energy systems. They are

  • MED - Stable parameter-free nonlinear controller for AC/Dc Voltage Source converters
    21st Mediterranean Conference on Control and Automation, 2013
    Co-Authors: George C. Konstantopoulos, Antonio T. Alexandridis
    Abstract:

    In this paper, a novel nonlinear dynamic regulator for three-phase AC/Dc Voltage Source converters (VSC) is presented. The proposed control design approach is fully independent from the system parameters and simultaneously achieves precise Dc bus Voltage regulation and unity power factor operation. A traditional PI controller is used to achieve unity power factor, while the proposed nonlinear controller is used to regulate the Dc bus Voltage to the desired level. Due to the structure of the proposed scheme, closed-loop system stability is proven and an appropriate mathematical analysis shows that the solution remains bounded and converges to the desired equilibrium. Simulation results verify the controller efficiency under Dc bus Voltage reference and load changes.

  • Novel dynamic nonlinear control scheme for three-phase AC/Dc Voltage Source converters
    2012 IEEE International Conference on Industrial Technology, 2012
    Co-Authors: George C. Konstantopoulos, Antonio T. Alexandridis
    Abstract:

    In this paper, a new nonlinear dynamic controller for three-phase AC/Dc Voltage Source converters (VSC) is presented. The proposed control design approach simultaneously achieves precise Dc bus Voltage regulation and unity power factor operation. As it is proven, the proposed controller does not need any measurement of the system states other than the regulated ones; furthermore, it is independent from the system parameters. An extended passivity-based analysis shows that the proposed approach guarantees the damping characteristics of the closed-loop system, which is a fundamental property for achieving stability and convergence to the desired equilibrium. Simulation results verify a satisfactory controller performance under Dc bus Voltage reference and load changes.

  • Modeling and twin nonlinear controller design for ac/Dc Voltage Source converters driven Dc series motors
    2012 20th Mediterranean Conference on Control & Automation (MED), 2012
    Co-Authors: George C. Konstantopoulos, Antonio T. Alexandridis
    Abstract:

    Modeling, control design and stability of series-connected Dc motors fed by three-phase ac/Dc Voltage Source converters are investigated. The design developed in this paper results in a twin nonlinear controller structure each acting as an oscillator with damped frequency and complementary tasks, i.e. to achieve precise motor speed regulation and operation with unity power factor. An extended passivity-based analysis shows that the proposed approach guarantees the system damping which is essential for stability analysis. To this end, by using the sequence of linear time-varying approximations method, it is proven that the system with the external unknown input is attracted to the desired equilibrium. Furthermore, it becomes clear that the proposed controller does not need any measurement or knowledge of the system conditions and parameters. Stability analysis and these properties constitute the main advantages of this control design approach with respect to other existing schemes. Simulation results verify the controller performance under speed reference and load torque changes.

Wei Wang - One of the best experts on this subject based on the ideXlab platform.

  • a single Dc Source cascaded seven level inverter integrating switched capacitor techniques
    IEEE Transactions on Industrial Electronics, 2016
    Co-Authors: Xiaofeng Sun, Baocheng Wang, Yue Zhou, Wei Wang
    Abstract:

    In this paper, a novel cascaded seven-level inverter topology with a single input Source integrating switched-capacitor techniques is presented. Compared with the traditional cascade multilevel inverter, the proposed topology replaces all the separate Dc Sources with capacitors, leaving only one H-bridge cell with a real Dc Voltage Source and only adds two charging switches. The capacitor charging circuit contains only power switches, so that the capacitor charging time is independent of the load. The capacitor Voltage can be controlled at a desired level without complex Voltage control algorithm and only use the most common carrier phase-shifted sinusoidal pulse width modulation strategy. The operation principle and the charging–discharging characteristic analysis are discussed in detail. A 1-kW experimental prototype is built and tested to verify the feasibility and effectiveness of the proposed topology.

  • Design of Digital Control Dc Voltage Source Based on AT89C52 MCU
    Applied Mechanics and Materials, 2014
    Co-Authors: Wei Wang
    Abstract:

    the system to Dc Voltage Source as the core, AT89C52 MCU as the main controller, the output Voltage to set the Dc power supply through the keyboard, with a step function Voltage to reality, the actual output value. This design is divided into four modules: SCM control and display module, digital to analog (D/A) conversion module, a constant Voltage Source module, output module. MCU control module as the core, the input signal is converted to digital quantity output; constant current Source module Voltage D/A conversion to analog conversion into constant pressure through a constant Voltage circuit. The system has good reliability, high precision.

Hasan Komurcugil - One of the best experts on this subject based on the ideXlab platform.

  • Control strategy for single-phase PWM ac/Dc Voltage-Source converters based on Lyapunov's direct method
    International Journal of Electronics, 2000
    Co-Authors: Hasan Komurcugil, Osman Kukrer
    Abstract:

    Several methods for Dc Voltage control of single-phase pulse width modulation ac/Dc Voltage-Source converters are known. They differ in their performance and the complexity of the hardware and software they use. One of the basic requirements of the control method is a nearly sinusoidal input current with unity power factor. However, global stability of the converter is not guaranteed by the methods proposed so far. This paper describes a new control method based on Lyapunov's direct method. It is shown that the converter can be stabilized globally to handle large signal disturbances. The closed-loop system not only ensures stability, but also exhibits excellent transient response for abrupt changes in the load. More importantly, the proposed control method can keep the advantages and remove the disadvantages of the existing methods. Computer simulations and experiments are presented to show the effectiveness and applicability of the proposed control method for the converter.

  • A novel current-control method for three-phase PWM AC/Dc Voltage-Source converters
    IEEE Transactions on Industrial Electronics, 1999
    Co-Authors: Hasan Komurcugil, Osman Kukrer
    Abstract:

    This paper presents a novel current-control-based control strategy, obtained in stationary frame, for a three-phase pulsewidth-modulated AC/Dc Voltage-Source converter. In this control strategy, an error Voltage is produced from the comparison of the output Dc Voltage with a Dc reference Voltage. This error Voltage is then utilized by a proportional plus integral controller to generate a command signal for the input line current amplitude and is automatically controlled to the desired value. Therefore, there is no need to measure the input line currents. Stability analysis of the closed-loop system is made, and the stability region for proportional and integral gains which makes the operating point stable is also found. The resulting closed-loop system not only exhibits good transient response, but also provides sinusoidal line currents and unity power factor, both in the rectifying and regenerating modes. Experimental results are presented and compared with simulations.

  • Lyapunov-based control for three-phase PWM AC/Dc Voltage-Source converters
    IEEE Transactions on Power Electronics, 1998
    Co-Authors: Hasan Komurcugil, Osman Kukrer
    Abstract:

    The three-phase pulsewidth modulation (PWM) AC/Dc Voltage-Source converter with the control laws proposed so far is not only unstable against large-signal disturbances, but also has the problem that its stability depends on the circuit parameters such as the Dc-output capacitance. This paper describes a new control law based on Lyapunov's stability theory. It is shown that the converter can be stabilized globally for handling large-signal disturbances. The resulting closed-loop system not only guarantees a sufficient stability region (independent of the circuit parameters) in the state space, but also exhibits good transient response both in the rectifying and regenerating modes. Also, a new simulation technique is introduced which increases the speed of the simulation process considerably. Computer simulations are presented to confirm the effectiveness of the proposed control strategy and the validity of the simulation technique. Experimental results are also presented to verify the theoretical and simulation studies.