The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Christos Mademlis - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Efficiency Control in a Wind System With Doubly Fed Induction Generator
    IEEE Transactions on Power Electronics, 2019
    Co-Authors: Nektarios Karakasis, Evangelos Tsioumas, Nikolaos Jabbour, Ali M. Bazzi, Christos Mademlis
    Abstract:

    This paper proposes an Optimal Efficiency control scheme for a wind system with doubly fed induction generator (DFIG). The suggested control scheme combines loss minimization (LM) in the DFIG and maximum power point tracking (MPPT) in the wind turbine and therefore maximum electrical energy generation, by the same wind energy potential, is achieved. Moreover, since the cut-in wind speed is reduced, extension of the exploitable wind speed range toward the lower speed region is attained. The LM is achieved by properly controlling the flux-linkage of the DFIG with respect to the stator current and the MPPT is accomplished by regulating the rotor speed through the rotor current. The parameters of the LM and MPPT controllers can be determined experimentally, and thus, the knowledge of the wind energy conversion system (WECS) model is not required. For the implementation of the proposed control strategy, a new structure of the WECS has been adopted. However, the hardware requirements of the WECS and considerably the cost have not been considerably affected compared to the conventional configuration. Selective simulation and experimental results are presented to validate the effectiveness of the proposed control strategy and demonstrate the operational improvements.

  • Optimal Efficiency control strategy in wind energy conversion system with induction generator
    IEEE Journal of Emerging and Selected Topics in Power Electronics, 2013
    Co-Authors: A Mesemanolis, Christos Mademlis, Iordanis Kioskeridis
    Abstract:

    This paper presents an Optimal Efficiency control strategy for wind energy conversion systems (WECSs) with squirrel cage induction generators (SCIGs). The developed control scheme provides an Optimal Efficiency of the induction generator and maximum power extraction from the wind turbine. Thus, maximum power harvesting from the whole WECS is achieved and additionally expansion of the exploitable wind speed region toward the lower speed range is accomplished. A minimum electric loss (MEL) controller is introduced to minimize the generator electric loss and a maximum power point tracking (MPPT) controller is used to maximize the wind turbine output power. Common input to the two Optimal controllers is only the generator speed, while the measurement of the wind speed is not required. The controllers determine the Optimal d- and q-axis stator current components of the SCIG through Optimal conditions and, therefore, fast dynamic response of the WECS is accomplished. An experimental procedure is proposed to determine the MEL and MPPT controller parameters. Therefore, neither the knowledge of SCIG loss model, nor the characteristic curves of the wind turbine are required. The effectiveness and the operational improvements of the suggested Optimal control scheme have been verified experimentally.

  • Optimal Efficiency control of switched reluctance generators
    IEEE Transactions on Power Electronics, 2006
    Co-Authors: Iordanis Kioskeridis, Christos Mademlis
    Abstract:

    This paper investigates the problem of Optimal control for accomplishing maximum energy conversion in switched reluctance generators. A controller that determines the Optimal turn-on and turn-off angles in the mode of single-pulse operation is proposed. The structure of the controller and its implementation are simple, since the knowledge of the magnetization curves is not required. The suggested generator drive operates in a wide speed range and provides constant dc-link voltage at a desired value, with maximum energy Efficiency. Simulation and experimental results are presented to validate the effectiveness and the resulting improvements of the proposed control scheme.

  • Optimal Efficiency control strategy for interior permanent magnet synchronous motor drives
    IEEE Transactions on Energy Conversion, 2004
    Co-Authors: Christos Mademlis, Iordanis Kioskeridis, N. Margaris
    Abstract:

    In this paper, the problem of Efficiency optimization in vector-controlled interior permanent-magnet (PM) synchronous motor drives is investigated. A loss model controller is introduced that determines the Optimal d-axis component of the stator current that minimizes power losses. For the implementation of the suggested controller, the knowledge of the loss model is not required since an experimental procedure is followed to determine its parameters. Furthermore, it is shown that the loss model of the interior PM motor can be used as a basis for deriving loss minimization conditions for surface PM synchronous motors and synchronous reluctance motors as well. Experimental results of an interior PM motor are presented to validate the effectiveness of the proposed method and demonstrate the operational improvements.

  • Optimal Efficiency Control Strategy for Interior
    2004
    Co-Authors: Christos Mademlis, Iordanis Kioskeridis, N. Margaris
    Abstract:

    In this paper, the problem of Efficiency optimiza- tion in vector-controlled interior permanent-magnet (PM) syn- chronous motor drives is investigated. A loss model controller is introduced that determines the Optimal -axis component of the stator current that minimizes power losses. For the implementa- tion of the suggested controller, the knowledge of the loss model is not required since an experimental procedure is followed to determine its parameters. Furthermore, it is shown that the loss model of the interior PM motor can be used as a basis for deriving loss minimization conditions for surface PM synchronous motors and synchronous reluctance motors as well. Experimental results of an interior PM motor are presented to validate the effective- ness of the proposed method and demonstrate the operational improvements.

Iordanis Kioskeridis - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Efficiency control strategy in wind energy conversion system with induction generator
    IEEE Journal of Emerging and Selected Topics in Power Electronics, 2013
    Co-Authors: A Mesemanolis, Christos Mademlis, Iordanis Kioskeridis
    Abstract:

    This paper presents an Optimal Efficiency control strategy for wind energy conversion systems (WECSs) with squirrel cage induction generators (SCIGs). The developed control scheme provides an Optimal Efficiency of the induction generator and maximum power extraction from the wind turbine. Thus, maximum power harvesting from the whole WECS is achieved and additionally expansion of the exploitable wind speed region toward the lower speed range is accomplished. A minimum electric loss (MEL) controller is introduced to minimize the generator electric loss and a maximum power point tracking (MPPT) controller is used to maximize the wind turbine output power. Common input to the two Optimal controllers is only the generator speed, while the measurement of the wind speed is not required. The controllers determine the Optimal d- and q-axis stator current components of the SCIG through Optimal conditions and, therefore, fast dynamic response of the WECS is accomplished. An experimental procedure is proposed to determine the MEL and MPPT controller parameters. Therefore, neither the knowledge of SCIG loss model, nor the characteristic curves of the wind turbine are required. The effectiveness and the operational improvements of the suggested Optimal control scheme have been verified experimentally.

  • Optimal Efficiency control of switched reluctance generators
    IEEE Transactions on Power Electronics, 2006
    Co-Authors: Iordanis Kioskeridis, Christos Mademlis
    Abstract:

    This paper investigates the problem of Optimal control for accomplishing maximum energy conversion in switched reluctance generators. A controller that determines the Optimal turn-on and turn-off angles in the mode of single-pulse operation is proposed. The structure of the controller and its implementation are simple, since the knowledge of the magnetization curves is not required. The suggested generator drive operates in a wide speed range and provides constant dc-link voltage at a desired value, with maximum energy Efficiency. Simulation and experimental results are presented to validate the effectiveness and the resulting improvements of the proposed control scheme.

  • Optimal Efficiency control strategy for interior permanent magnet synchronous motor drives
    IEEE Transactions on Energy Conversion, 2004
    Co-Authors: Christos Mademlis, Iordanis Kioskeridis, N. Margaris
    Abstract:

    In this paper, the problem of Efficiency optimization in vector-controlled interior permanent-magnet (PM) synchronous motor drives is investigated. A loss model controller is introduced that determines the Optimal d-axis component of the stator current that minimizes power losses. For the implementation of the suggested controller, the knowledge of the loss model is not required since an experimental procedure is followed to determine its parameters. Furthermore, it is shown that the loss model of the interior PM motor can be used as a basis for deriving loss minimization conditions for surface PM synchronous motors and synchronous reluctance motors as well. Experimental results of an interior PM motor are presented to validate the effectiveness of the proposed method and demonstrate the operational improvements.

  • Optimal Efficiency Control Strategy for Interior
    2004
    Co-Authors: Christos Mademlis, Iordanis Kioskeridis, N. Margaris
    Abstract:

    In this paper, the problem of Efficiency optimiza- tion in vector-controlled interior permanent-magnet (PM) syn- chronous motor drives is investigated. A loss model controller is introduced that determines the Optimal -axis component of the stator current that minimizes power losses. For the implementa- tion of the suggested controller, the knowledge of the loss model is not required since an experimental procedure is followed to determine its parameters. Furthermore, it is shown that the loss model of the interior PM motor can be used as a basis for deriving loss minimization conditions for surface PM synchronous motors and synchronous reluctance motors as well. Experimental results of an interior PM motor are presented to validate the effective- ness of the proposed method and demonstrate the operational improvements.

Franklin Bien - One of the best experts on this subject based on the ideXlab platform.

  • Tracking Optimal Efficiency of Magnetic Resonance Wireless Power Transfer System for Biomedical Capsule Endoscopy
    IEEE Transactions on Microwave Theory and Techniques, 2015
    Co-Authors: Kyungmin Na, Heedon Jang, Franklin Bien
    Abstract:

    This paper presents a new method to track the Optimal Efficiency of a magnetic resonance (MR)-wireless power transfer (WPT) system for biomedical capsule endoscopy. Recently, capsule endoscopy technology has been developed and emerged as an alternative to small bowel endoscopy, gastroscopy, and colonoscopy, all of which cause discomfort to patients because of their relatively large-diameter and flexible cables. However, commercialized capsule endoscopy still suffers from limited battery capacity. This paper presents a theory for tracking the Optimal Efficiency of an MR-WPT system, along with its experimental verification. An MR-WPT system with a 9-mm-diameter receiver is implemented, which is small enough to fit in the current capsule endoscope. The proposed system improves the Efficiency despite variations in the distance, angle, and axial misalignment, with maximum increases of 2.45, 4.69, and 1.48 dB, respectively. Penetrative transfer through biological tissue is demonstrated with a low degradation in Efficiency of 0.390 dB. The proposed system was found to have a very low specific absorption rate of 1.74 W/kg, which demonstrated that it is safe to use in the human body.

Chunbo Zhu - One of the best experts on this subject based on the ideXlab platform.

  • Optimal Efficiency Tracking Control Scheme Based on Power Stabilization for a Wireless Power Transfer System with Multiple Receivers
    Energies, 2018
    Co-Authors: Li Yang, Kai Song, Jinhai Jiang, Chunbo Zhu
    Abstract:

    With the increase of charging requirements in electrical equipment, the wireless power transfer (WPT) system with multiple receivers has gained more attention as the charging power and Efficiency of a WPT system depends on the equivalent reflected impedance of the load. Based on the circuit model analysis of a single receiver WPT system, this paper investigated the multiple-receiver WPT system. The relationship between the mutual inductance, load, and system Efficiency was discussed and the Optimal load, the equivalent reflected impedance, and power division method were analyzed to design the proposed system control scheme. With the use of the perturbation and observation (P&O) algorithm control method, the current of transfer and receivers were regulated to achieve stable constant power charging. Furthermore, when searching the minimum input power of the system, the Optimal Efficiency under a fixed power division ratio was also received. The validity of the proposed system control method was confirmed by simulation and experimental results. Under the proposed control method, an Efficiency above 80% can be achieved for a multiple-receiver WPT system with a fixed power division ratio working at 6.78 MHz.

D A Torrey - One of the best experts on this subject based on the ideXlab platform.

  • closed loop control of excitation parameters for high speed switched reluctance generators
    IEEE Transactions on Power Electronics, 2004
    Co-Authors: Yilmaz Sozer, D A Torrey
    Abstract:

    This paper presents a new approach to the automatic control of excitation parameters for the switched-reluctance generator (SRG) where the SRG system operates at sufficiently high speed that it operates in the single pulse mode. The turn-on and turn-off angles are the two parameters through which we can control the electric power generation. The objective of the work is to develop an easily implementable control algorithm that automatically maintains the most efficient excitation angles in producing the required amount of electric power. The work is focused on finding the most efficient excitation angles and characterizing them for easy implemention under closed loop control. Through modeling of an experimental SRG and extensive simulation, it can be seen that the Optimal-Efficiency turn-off angles can be characterized as a function of power and speed level. Within the closed-loop power controller, the Optimal-Efficiency turn-off angle is determined from an analytic curve fit. The turn-on angle is then used as the degree of freedom necessary to regulate the power produced by the SRG. Given that the turn-off angle is associated with Optimal-Efficiency at each speed and power point, overall operation is achieved at Optimal-Efficiency. The SRG, inverter and control system are modeled in Simulink to demonstrate the operation of the system when implemented within a voltage regulation system. The control technique is then applied to an experimental SRG system. Experimental operation documents that the technique provides for efficient operation of the SRG system through tuning the controller at only four operating points.

  • Optimal Efficiency excitation of variable reluctance motor drives
    IEE Proceedings B Electric Power Applications, 1991
    Co-Authors: D A Torrey, J H Lang
    Abstract:

    The paper examines the Optimal Efficiency excitation of a variable-reluctance motor (VRM) drive operating at constant speed. The drive comprises a motor, an inverter, an excitation and a control strategy. The excitation refers to a prescribed relationship between the phase currents and rotor position that results in the desired drive behaviour. The excitation is considered from an integrated viewpoint such that overall drive Efficiency is maximised for a given torque and speed. An algorithm for the determination of Optimal excitation is presented. The algorithm is based on the determination of excitation that nominally meets the drive torque-speed requirement, followed by optimisation of this excitation to improve Efficiency. Other performance criteria, such as torque ripple or acoustic noise, could be considered in a similar manner, with appropriate models. The paper applies the algorithm to high-power (60 kW) VRM drive. The results of the optimisation indicate the importance of considering inverted losses when performing the optimization. Inverter losses are shown to be comparable to motor losses, imparting significant influence on the excitation design. The stability implications of the Optimal-Efficiency excitation are discussed, including the necessity for closed loop control. In addition, the experimental VRM drive design is critically reviewed based on the breakdown of inverter and motor losses. Allowable excitation parameter variations and the dependence of the Optimal excitation on load torque are also discussed.