فهرست مطالب

  • Volume:7 Issue: 3, 2020
  • تاریخ انتشار: 1398/10/30
  • تعداد عناوین: 5
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  • Rotor flux and torque ripples minimization for direct torque control of DFIG by NSTSM algorithm
    Habib BENBOUHENNI Page 1

    In this work a direct torque control scheme based on neural super-twisting sliding mode (NSTSMC) algorithm and space vector modulation (SVM) of a doubly fed induction generator (DFIG) integrated in a wind energy conversion system is presented. The traditional DTC control with hysteresis controllers has significant torque and flux ripples at steady-state operation and also the switching frequency varies in a wide range. The proposed DTC control scheme based on NSTSMC algorithm reduces torque, flux and current ripples. Two different sliding surfaces such as torque and flux sliding surfaces are used to control them. The simulation results have been carried out using MATLAB/SIMULINK software. Simulation results show the effectiveness of the proposed DTC control scheme comparatively to the classical DTC one.

    Keywords: NSTSMC, DTC, SVM, DFIG
  • Optimal Reconfiguration of Intelligent Distribution Net-works in the Presence of DGs using TLBO Algorithm
    Bahman Taheri, Davar Mirabbasi, Keyvan Shirzad Page 2

    DG is a better alternative to meet power demand near the load centers than centralized power generation. Optimal placement and sizing of DGs plays a crucial role in improving the performance of distribution systems in terms of network loss reduction, voltage profile improvement, reliability of power supply and stability issues. In this paper, a new method is proposed to solve intelligent distribution network reconfiguration in the presence of DGs aiming to minimize active power loss and improve voltage profile. Meta-heuristic optimization algorithm based on training-learning (TLBO) is used to reconfigure distribution network. In order to investigate different operational conditions of distribution systems and efficiency of the proposed method, different scenarios of network reconfiguration are simulated and studied. In order to illustrate performance and effectiveness of the proposed method, IEEE-33 bus radial distribution network is simulated at three different levels. In the proposed scenarios, presence or absence of DGs in different buses and effect of capacity of these sources is studied and simulated.

    Keywords: Distributed Generation (DG), Optimization, intelligent distribution system, reconfiguration, TLBO
  • Numerical Investigations of Power Distribution Network
    morteza hadipour, Mohsen Aghazadeh Shiran, Farbod Zamani, Soheil Sadollahi, Bagher Karamzadeh Page 3

    This paper numerically evaluates the voltage drop, the current rating of the network, the voltage profile, the total active and reactive power losses, and the current rating of short circuits. The calculations of these parameters are performed at both sending and receiving ends of a practical feeder in an extensive network in Hamadan city in Iran, with more than 180 load points. Regarding the desired parameters, the best Substations is selected to supply the feeder. The numerical analyses are formulated in Microsoft Excel software. The numerical results highlight the fact that there is a good agreement between numerical outcomes and published data in which professional software is used. It is shown that the proposed numerical method can be utilized with excellent outcomes instead of studying power distribution networks using professional commercial software. The outcomes ensure that the numerical results are satisfactorily accurate, and the evaluation of the distribution network can be conducted in a short time. Besides, due to the compatibility of data, the results can be post-processed effortlessly in other software such as MATLAB. Consequently, compared to the conventional methods, the numerical proposed method is predominantly cost-effective in terms of evaluation of power distribution networks.

    Keywords: Power distribution network, Substations, numerical investigations, voltage drop, power flow
  • The Design of Nonlinear Multilayer Controller for Speed Control of Gas Turbine System Using Feedback Linearization Method
    arash aghakhalooei Page 4

    In this paper, a nonlinear model of a gas turbine system in a thermal power plant is studied. Due to the impact of the outlet temperature on the turbine speed performance and the multivariability of the system model, the design of the nonlinear multivariate controller has been considered. Comparison of the results with the PID industrial controller method shows the desired performance of the designed system.

    Keywords: Gas turbine, Thermal power plant, Feedback linearization, Multivariate control, Turbine speed, PID controlle
  • An DC-DC Boost Converter Interconnected With Parallel Fly-back Converter for Dual Load Applications
    medi pallavi Page 5