Home / Journals / ENERGY / Vol.117, No.6, 2020
  • Open Access

    ARTICLE

    Wind Farm-Battery Energy Storage Assessment in Grid-Connected Microgrids

    Shafiqur Rehman1, Umar T. Salman2,*, Luai M. Alhems1
    Energy Engineering, Vol.117, No.6, pp. 343-365, 2020, DOI:10.32604/EE.2020.011471
    Abstract Renewable energy has received much attention in the last few decades and more investment is being attracted across the world to boost its contribution towards the existing energy mix. In the Kingdom of Saudi Arabia (KSA), many studies have been conducted on the potential of renewable energy sources (RES), such as wind, solar, and geothermal. Many of these studies have revealed that the Kingdom is blessed with an abundance of RES with wind energy being the best after solar. This paper presents an analysis of windfarm distributed generation (WFDG) for energy management strategy in the Eastern Province of KSA. The… More >

  • Open Access

    ARTICLE

    Improved Thermal Efficiency of Salinity Gradient Solar Pond by Suppressing Surface Evaporation Using an Air Layer

    Asaad H. Sayer1, Hameed B. Mahood2,*
    Energy Engineering, Vol.117, No.6, pp. 367-379, 2020, DOI:10.32604/EE.2020.011156
    Abstract Salinity gradient solar ponds (SGSPs) provide a tremendous way to collect and store solar radiation as thermal energy, and can help meet the critical need for sustainable ways of producing fresh water. However, surface evaporation results in the loss of both water and heat. This study therefore theoretically investigates the effect on temperatures within an SGSP when its surface is covered with a layer of air encased in a nylon bag. An earlier SGSP model was slightly modified to add the air layer and to estimate the temperature distributions of the upper layer or the upper convective zone (UCZ) and… More >

  • Open Access

    ARTICLE

    Energy Retrofitting of School Buildings in UAE

    Abdelsalam Aldawoud*, Fatma Elzahraa Hosny, Rasha Mdkhana
    Energy Engineering, Vol.117, No.6, pp. 381-395, 2020, DOI:10.32604/EE.2020.011863
    Abstract The opportunities for energy savings by retrofitting of the existing school buildings in the United Arab Emirates (UAE) are significant because of their excessive energy consumption and space cooling demand. In this research, energy modeling and simulation are utilized with the use of Design Builder software to examine the influence of various retrofitting measures of air-conditioning (A/C) system and building envelope components on the energy use. Several combined measures are implemented and assessed to achieve the main goal of this research of selecting the best course of action to reduce cooling energy consumption for existing school buildings in the UAE.… More >

  • Open Access

    ARTICLE

    Research on Distribution Network Full Cost-Benefit Optimization Considering Different Renewable Energy Penetration

    Tanzhong Fu1,2,3, Yu Xue1,*, Tancai Xia1, Wang Jing1, De Gejirifu1
    Energy Engineering, Vol.117, No.6, pp. 397-411, 2020, DOI:10.32604/EE.2020.011633
    Abstract To further study the impact of renewable energy penetration on the technical transformation of distribution networks. Based on the output power characteristics of wind power and photovoltaics, a renewable energy grid-connected capacity model and a distribution network full cost-benefit model were constructed. Based on this, to maximize the comprehensive income of the distribution network and the renewable energy penetration rate, to establish the technical reform optimization model and search for the optimal solution through the improved NSGA-II algorithm. Finally, the effectiveness of the proposed model was verified by setting up three scenarios of simultaneous wind power, grid-connected wind power, grid-connected… More >

  • Open Access

    ARTICLE

    Research on Effect of Icing Degree on Performance of NACA4412 Airfoil Wind Turbine

    Yuhao Jia1, Bin Cheng1,2,*, Xiyang Li1,2, Hui Zhang1,2, Yinglong Dong1
    Energy Engineering, Vol.117, No.6, pp. 413-427, 2020, DOI:10.32604/EE.2020.012019
    Abstract In order to study the effect of icing on the wind turbine blade tip speed ratio and wind energy utilization coefficient under working conditions, it is important to better understand the growth characteristics of wind turbine blade icing under natural conditions. In this paper, the icing test of the NACA4412 airfoil wind turbine was carried out using the natural low temperature wind turbine icing test system. An evaluation model of icing degree was established, and the influence of wind speed and icing degree on the performance parameters of wind turbines was compared and analyzed. It is shown that icing is… More >

  • Open Access

    ARTICLE

    Investigation of Core Loss Calculation Methods for Nanocrystalline Core in Medium Frequency Range

    Yunxiang Guo1, Cheng Lu1,2, Feng Yu1, Liang Hua1, Xinsong Zhang1,*
    Energy Engineering, Vol.117, No.6, pp. 429-438, 2020, DOI:10.32604/EE.2020.011673
    Abstract Nanocrystalline core is often adopted in high-power medium-frequency transformer, whose excitation voltage is usually a rectangular wave with an adjustable duty ratio. In this paper, several kinds of methods are proposed for core loss calculation under non-sinusoidal voltage excitation by modifying the original Steinmetz equation (OSE). Firstly, these correction methods are compared in theory, and their analytical equations under rectangular voltage with an adjustable duty ratio are deduced. Then, a hysteresis loop measurement system is established to measure the core loss density of a nanocrystalline core. Based on the measured results of the core loss density under sinusoidal voltage excitation,… More >

  • Open Access

    ARTICLE

    A Subsynchronous Oscillation Suppression Method Based on Self-Adaptive Auto Disturbance Rejection Proportional Integral Control of Voltage Source Converter Based Multi-Terminal Direct Current System with Doubly-Fed Induction Generator-Based Wind Farm Access

    Miaohong Su1, Haiying Dong1,2,*, Kaiqi Liu1, Weiwei Zou1
    Energy Engineering, Vol.117, No.6, pp. 439-452, 2020, DOI:10.32604/EE.2020.011805
    Abstract A subsynchronous oscillation suppression strategy based on self-adaptive auto disturbance rejection proportional integral controller is proposed for doublyfed induction generator-based wind farm integrated into grid through voltage source converter based multi-terminal direct current. In this strategy, the nonlinear PI controller is constructed by fal function to replace the traditional linear PI controller, and then the tracking differentiator is used to arrange the appropriate transition process in combination with the idea of active disturbance rejection control, and the self-adaptive auto disturbance rejection proportional integral controller is designed. By applying the controller to the inner loop of the converter on the rotor… More >

  • Open Access

    ARTICLE

    Accurate Study and Evaluation of Small PV Power Generation System Based on Specific Geographical Location

    Lian Zhang1,2,3,5,*, Zijian Chen2, Heng Zhang3, Zenghong Ma4, Baowen Cao1, Lihong Song5
    Energy Engineering, Vol.117, No.6, pp. 453-470, 2020, DOI:10.32604/EE.2020.013276
    Abstract As an important new energy, solar energy has been extensively used in the world and different types of solar energy systems have been used in different fields. The photovoltaic power generation system has obvious advantage and high stability compared with other energy systems. Furthermore, the small-scale photovoltaic power generation system has a wider application in the field of power generation due to the performance of high efficiency. In this paper, the optimization research and system evaluation of small-scale photovoltaic power system have been studied in different areas by simulation and experimental methods. Based on the determination of photovoltaic model system,… More >

  • Open Access

    ARTICLE

    Research on Intelligent Energy Storage Control Method with Ethernet Communication

    Lu Wang1,2, Yulong Guo2, Jianbin Liang3,*, Haitao Tian4
    Energy Engineering, Vol.117, No.6, pp. 471-480, 2020, DOI:10.32604/EE.2020.011131
    Abstract The increasingly severe global energy crisis has brought great challenges to the energy field, and renewable energy power generation system has been widely concerned because of its characteristics of green and inexhaustible. However, renewable energy also has some limitations in its specific application, and affects the grid-connected power generation of new energy. In this paper, based on the background of photovoltaic power station, the intelligent energy storage control method for single inverter is put forward to assist a single inverter, and the DC component of fluctuating power is extracted by using the moving average function; furthermore, the intelligent energy storage… More >

  • Open Access

    ARTICLE

    Design of Nonlinear Uncertainty Controller for Grid-Tied Solar Photovoltaic System Using Sliding Mode Control

    D. Menaga1, M. Premkumar2, R. Sowmya1,*, S. Narasimman3
    Energy Engineering, Vol.117, No.6, pp. 481-495, 2020, DOI:10.32604/EE.2020.013282
    (This article belongs to this Special Issue: Advancements in Renewable Energy Systems with AI, Big Data, BlockChain, IoT, and Machine Learning Applications)
    Abstract The proposed controller accompanies with different sliding surfaces. To understand maximum power point extraction as opposed to nonlinear uncertainties and unknown disturbance of a grid-connected photovoltaic system to various control inputs (ud, uq) is designed. To extract maximum power from a solar array and maintain unity power flow in a grid by controlling the voltage across the dclink capacitor (Vpvdc) and reactive current (iq). A multiple input-output with multiple uncertainty constraints have considered designing proposed sliding mode controllers to validated their robustness performance. An innovative controller verifies uncertain inputs, constant and changes in irradiances, and temperature of the photo-voltaic system.… More >

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