scholarly journals Continuous-Input Continuous-Output Current Buck-Boost DC/DC Converters for Renewable Energy Applications: Modelling and Performance Assessment

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2208 ◽  
Author(s):  
Nahla E. Zakzouk ◽  
Ahmed K. Khamis ◽  
Ahmed K. Abdelsalam ◽  
Barry W. Williams

Stand-alone/grid connected renewable energy systems (RESs) require direct current (DC)/DC converters with continuous-input continuous-output current capabilities as maximum power point tracking (MPPT) converters. The continuous-input current feature minimizes the extracted power ripples while the continuous-output current offers non-pulsating power to the storage batteries/DC-link. CUK, D1 and D2 DC/DC converters are highly competitive candidates for this task especially because they share similar low-component count and functionality. Although these converters are of high resemblance, their performance assessment has not been previously compared. In this paper, a detailed comparison between the previously mentioned converters is carried out as several aspects should be addressed, mainly the converter tracking efficiency, conversion efficiency, inductor loss, system modelling, transient and steady-state performance. First, average model and dynamic analysis of the three converters are derived. Then, D1 and D2 small signal analysis in voltage-fed-mode is originated and compared to that of CUK in order to address the nature of converters’ response to small system changes. Finally, the effect of converters’ inductance variation on their performance is studied using rigorous simulation and experimental implementation under varying operating conditions. The assessment finally revels that D1 converter achieves the best overall efficiency with minimal inductor value.

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3922
Author(s):  
Bernadette Fina ◽  
Hubert Fechner

The Renewable Energy Directive and the Electricity Market Directive, both parts of the Clean Energy for all Europeans Package (issued in 2019), provide supranational rules for renewable energy communities and citizen energy communities. Since national transpositions need to be completed within two years, Austria has already drafted corresponding legislation. This article aims at providing a detailed comparison of the European guidelines and the transposition into Austrian law. The comparison not only shows how, and to what extent, the European guidelines are transposed into Austrian law, but also helps to identify loopholes and barriers. The subsequent discussion of these issues as well as positive aspects of the Austrian transposition may be advantageous for legislators and policy makers worldwide in their process of designing a coherent regulatory framework. It is concluded that experts from different areas (i.e., project developers, scientists concerned with energy communities, energy suppliers and grid operators) should be closely involved in the law-making process in order to introduce different perspectives so that a consistent and supportive regulatory framework for energy communities is created.


2021 ◽  
Vol 22 (1) ◽  
pp. 113-127
Author(s):  
Mulualem Tesfaye ◽  
Baseem Khan ◽  
Om Prakash Mahela ◽  
Hassan Haes Alhelou ◽  
Neeraj Gupta ◽  
...  

Abstract Generation of renewable energy sources and their interfacing to the main system has turn out to be most fascinating challenge. Renewable energy generation requires stable and reliable incorporation of energy to the low or medium voltage networks. This paper presents the microgrid modeling as an alternative and feasible power supply for Institute of Technology, Hawassa University, Ethiopia. This microgrid consists of a 60 kW photo voltaic (PV) and a 20 kW wind turbine (WT) system; that is linked to the electrical distribution system of the campus by a 3-phase pulse width modulation scheme based voltage source inverters (VSI) and supplying power to the university buildings. The main challenge in this work is related to the interconnection of microgrid with utility grid, using 3-phase VSI controller. The PV and WT of the microgrid are controlled in active and reactive power (PQ) control mode during grid connected operation and in voltage/frequency (V/F) control mode, when the microgrid is switched to the stand-alone operation. To demonstrate the feasibility of proposed microgrid model, MATLAB/Simulink software has been employed. The performance of fully functioning microgrid is analyzed and simulated for a number of operating conditions. Simulation results supported the usefulness of developed microgrid in both mode of operation.


2021 ◽  
pp. 69-76
Author(s):  
Mourad Talbi ◽  
Nawel Mensia ◽  
Hatem Ezzaouia

Nowadays, renewable energy resources play an important role in replacing conventional fossil fuel energy resources. Solar photovoltaic (PV) energy is a very promising renewable energy resource, which rapidly grew in the past few years. The main problem of the solar photovoltaic is with the variation of the operating conditions of the array, the voltage at which maximum power can be obtained from it likewise changes. In this paper, is first performed the modelling of a solar PV panel using MATLAB/Simulink. After that, a maximum power point tracking (MPPT) technique based on artificial neural network (ANN) is applied in order to control the DC-DC boost converter. This MPPT controller technique is evaluated and compared to the “perturb and observe” technique (P&O). The simulation results show that the proposed MPPT technique based on ANN gives faster response than the conventional P&O technique, under rapid variations of operating conditions. This comparative study is made in terms of temporal variations of the duty cycle (D), the output power ( out P ), the output current ( out I ), the efficiency, and the reference current ( ref I ). The efficiency, D, out P , and out I are the output of the boost DC-DC, and ref I is itsinput. The different temporal variations of the efficiency, D, ref I , out P , and out I (for the two cases: the first case, when T = 25°C and G =1000 W/m2 and the second case, when T and G are variables), show negligible oscillations around the maximum power point. The used MPPT controller based on ANN has a convergence time better than conventional P&O technique.


2018 ◽  
Vol 34 (1) ◽  
pp. 135-143 ◽  
Author(s):  
Kyle D Palmer ◽  
Mark A Severy ◽  
Charles E Chamberlin ◽  
Anthony J. Eggink ◽  
Arne E Jacobson

Abstract. An All Power Labs PP20 gasifier generation set (Berkeley, Calif.) was tested to evaluate its suitability for powering biomass conversion technologies (BCT) at remote forest operations sites. Feedstock of the species tanoak (), coast redwood (), and Douglas fir () were tested at moisture contents of 15% and 25% (wet basis). The PP20 was connected to a load bank with five different load profiles designed to simulate possible BCT loads. Two parameters of power quality, voltage variability, and frequency deviation, were determined to be within acceptable limits. The unit also successfully powered a remote biochar operation in Branscomb, California. Emissions of the PP20, when compared to diesel generator regulations, would meet non-methane hydrocarbons (NMHC) and NOX requirements but exceed the CO emissions limits by a factor of ten. The CO emissions could be reduced by adding a catalytic converter. The results indicate that it is possible to use a PP20 unit to provide electric power for the highly variable loads of a BCT system. Keywords: Bioenergy, Biomass conversion technology, Gasification, Renewable energy.


2018 ◽  
Vol 7 (2.12) ◽  
pp. 198
Author(s):  
Neeraj Priyadarshi ◽  
Amarjeet Kr. Sharma ◽  
Akash Kr. Bhoi ◽  
S N. Ahmad ◽  
Farooque Azam ◽  
...  

This paper mainly presents the fault analysis of Photovoltaic (PV) grid power system. The fuzzy logic controller (FLC) based intelligent maximum power point tracking (MPPT) algorithm has been employed in this work. Moreover, the hysteresis controller has been implemented for inverter control. Simulation results based on MATLAB/SIMULINK justify the effectiveness of the proposed PV power system under different fault operating conditions. 


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