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Walid Issa received his B.Sc. and M.Sc. degrees in electrical engineering from Islamic University of Gaza (IUG), Palestine, in 2007 and 2011, respectively; and his PhD in Renewable Energy from University of Exeter, UK in 2015. He is currently working as a senior lecturer at Sheffield Hallam University (SHU), UK. His main research interests include power electronics, power converters control and energy systems within microgrids and smart buildings. He worked at University of Exeter as a postdoc for two years leading a funded EPSRC project (RESCUES) with Indian partners. He got several internal grants for power electronics converters development and worked with industry and European companies for EV projects. He is a reviewer for several IEEE Transactions and Elsevier journals.
High temperature and overheating of photovoltaic panels lead to efficiency losses and eventual degradation. For solar PV systems, this is a significant impediment for achieving economic viability. In this study, a novel Window-Integrated Concentrated Photovoltaic (WICPV) system is proposed for window integration. This offers high (50%) transparency and is fabricated and characterised indoors at an irradiance of 1000 Wm−2. Its electrical performance is tested (a) without applied cooling (i.e., under natural ventilation) and (b) with a heat sink to accommodate passive cooling media. The results are compared to study the effects of reduction in operating temperature on system performances. The effectiveness of a sensible cooling medium (water) and two latent heat removal media, phase change materials (or PCMs, RT50 and RT28HC), is investigated. This paper reports the passive temperature regulation of this WICPV at ambient testing conditions. The results demonstrate an increase in electrical power output by (i) 17% (RT28HC), (ii) 19% (RT50), and (iii) 25 % (circulating water) compared with the naturally ventilated system. This shows that PCMs are considerably useful for thermal regulation of the WICPV. Any improvement in efficiencies will be beneficial for increasing electrical energy generation and reducing peak energy demands.
Shivangi Sharma; Nazmi Sellami; Asif Tahir; Tapas Mallick; Rohit Bhakar. Performance Improvement of a CPV System: Experimental Investigation into Passive Cooling with Phase Change Materials. Energies 2021, 14, 3550 .
AMA StyleShivangi Sharma, Nazmi Sellami, Asif Tahir, Tapas Mallick, Rohit Bhakar. Performance Improvement of a CPV System: Experimental Investigation into Passive Cooling with Phase Change Materials. Energies. 2021; 14 (12):3550.
Chicago/Turabian StyleShivangi Sharma; Nazmi Sellami; Asif Tahir; Tapas Mallick; Rohit Bhakar. 2021. "Performance Improvement of a CPV System: Experimental Investigation into Passive Cooling with Phase Change Materials." Energies 14, no. 12: 3550.
Semi-transparent Building Integrated Photovoltaics provide a fresh approach to the renewable energy sector, combining the potential of energy generation with aesthetically pleasing, multi-functional building components. Employing a range of technologies, they can be integrated into the envelope of the building in different ways, for instance, as a key element of the roofing or façade in urban areas. Energy performance, measured by their ability to produce electrical power, at the same time as delivering thermal and optical efficiencies, is not only impacted by the system properties, but also by a variety of climatic and environmental factors. The analytical framework laid out in this paper can be employed to critically analyse the most efficient solution for a specific location; however, it is not always possible to mitigate energy losses, using commercially available materials. For this reason, a brief overview of new concept devices is provided, outlining the way in which they mitigate energy losses and providing innovative solutions for a sustainable energy future.
Reza Khalifeeh; Hameed Alrashidi; Nazmi Sellami; Tapas Mallick; Walid Issa. State-of-the-Art Review on the Energy Performance of Semi-Transparent Building Integrated Photovoltaic across a Range of Different Climatic and Environmental Conditions. Energies 2021, 14, 3412 .
AMA StyleReza Khalifeeh, Hameed Alrashidi, Nazmi Sellami, Tapas Mallick, Walid Issa. State-of-the-Art Review on the Energy Performance of Semi-Transparent Building Integrated Photovoltaic across a Range of Different Climatic and Environmental Conditions. Energies. 2021; 14 (12):3412.
Chicago/Turabian StyleReza Khalifeeh; Hameed Alrashidi; Nazmi Sellami; Tapas Mallick; Walid Issa. 2021. "State-of-the-Art Review on the Energy Performance of Semi-Transparent Building Integrated Photovoltaic across a Range of Different Climatic and Environmental Conditions." Energies 14, no. 12: 3412.
For the past twenty years, there has been increasing interest and investment in solar photovoltaic (PV) technology. One particular area of interest is the development of concentrating PV (CPV), especially for use in building integration. Many CPV designs have been developed and investigated. This paper aims at producing a mathematical modelling using MATLAB programme to predict the current-voltage (I-V) and power-voltage (P-V) characteristics of a static CPV. The MATLAB programme could also simulate the angular response of the CPV designs-which has never been explored in the previous literature. In this paper, a CPV known as the rotationally asymmetrical dielectric totally internally reflecting concentrator (RADTIRC) was analysed. A specific RADTIRC design that has an acceptance angle of ±40° was investigated in this paper. A mathematical modelling was used to simulate the angular characteristics of the RADTIRC from −50° to 50° with an increment 5°. For any CPV, we propose that the value of opto-electronic gain, Copto-e needs to be included in the mathematical model, which were obtained from experiments. The range of incident angle (±50°) was selected to demonstrate that the RADTIRC is capable of capturing the sun rays within its acceptance angle of ±40°. In each simulation, the I-V and P-V characteristics were produced, and the short circuit current (Isc), the open-circuit voltage (Voc), the maximum power (Pmax), the fill factor (FF) and the opto-electronic gain (Copto-e) were determined and recorded. The results from the simulations were validated via experiments. It was found that the simulation model is able to predict the I-V and P-V characteristics of the RADTIRC as well as its angular response, with the highest error recorded for the Isc, Voc, Pmax, FF and Copto-e was 2.1229%, 5.3913%, 9.9681%, 4.4231% and 0.0000% respectively when compared with the experiment.
Firdaus Muhammad-Sukki; Haroon Farooq; Siti Abu-Bakar; Jorge Ardila-Rey; Nazmi Sellami; Ciaran Kilpatrick; Mohd Muhtazaruddin; Nurul Bani; Muhammad Zulkipli. Mathematical Modelling of a Static Concentrating Photovoltaic: Simulation and Experimental Validation. Applied Sciences 2021, 11, 3894 .
AMA StyleFirdaus Muhammad-Sukki, Haroon Farooq, Siti Abu-Bakar, Jorge Ardila-Rey, Nazmi Sellami, Ciaran Kilpatrick, Mohd Muhtazaruddin, Nurul Bani, Muhammad Zulkipli. Mathematical Modelling of a Static Concentrating Photovoltaic: Simulation and Experimental Validation. Applied Sciences. 2021; 11 (9):3894.
Chicago/Turabian StyleFirdaus Muhammad-Sukki; Haroon Farooq; Siti Abu-Bakar; Jorge Ardila-Rey; Nazmi Sellami; Ciaran Kilpatrick; Mohd Muhtazaruddin; Nurul Bani; Muhammad Zulkipli. 2021. "Mathematical Modelling of a Static Concentrating Photovoltaic: Simulation and Experimental Validation." Applied Sciences 11, no. 9: 3894.
This paper presents a novel cooperative control technique concerning fully-distributed AC/DC microgrids. Distributed generation based on inverters has two types, i.e., Current Source Inverter (CSI), also referred to as PQ inverter, and Voltage Source Inverter (VSI). Both inverter forms have a two-layer coordination mechanism. This paper proposes a design method for the digital Proportional-Resonant (PR) controller that regulates the current inside an inverter. The inverters will improve the voltage quality of the microgrid while maintaining the average voltage of buses at the same desired level. There is comprehensive detail on the computations specific to resonant and proportional gains and digital resonance path coefficients. The paper includes a digital PR controller design and its analysis in the frequency domain. The analysis is based on the w-domain. The main contribution of this paper is the proposed method, which not only focuses on the transient response but also improves the steady-state response which smoothens the voltage; furthermore, all inverters are effectively involved to increase the capacity of the microgrid for better power management. The suggested cooperative control technique is used on an IEEE 14-bus system having fully distributed communication. The convincing outcomes indicate that the suggested control technique is an effectual means of regulating the microgrid’s voltage to obtain an evener and steady voltage profile. The microgrid comprises distributed resources and is used as the primary element to analyse power flow and quality indicators associated with a smart grid. Lastly, numerical simulation observations are utilised for substantiating the recommended algorithm.
Bilal Naji Naji Alhasnawi; Basil H. Jasim; Walid Issa; M. Dolores Esteban. A Novel Cooperative Controller for Inverters of Smart Hybrid AC/DC Microgrids. Applied Sciences 2020, 10, 6120 .
AMA StyleBilal Naji Naji Alhasnawi, Basil H. Jasim, Walid Issa, M. Dolores Esteban. A Novel Cooperative Controller for Inverters of Smart Hybrid AC/DC Microgrids. Applied Sciences. 2020; 10 (17):6120.
Chicago/Turabian StyleBilal Naji Naji Alhasnawi; Basil H. Jasim; Walid Issa; M. Dolores Esteban. 2020. "A Novel Cooperative Controller for Inverters of Smart Hybrid AC/DC Microgrids." Applied Sciences 10, no. 17: 6120.
DC microgrids are gaining more and more popularity and are becoming a more viable alternative to AC microgrids (MGs) due to their advantages in terms of simpler power converter stages, flexible control algorithms and the absence of synchronization and reactive power. However, DC-MGs are prone to instability issues associated with the presence of nonlinear loads such as constant power loads (CPL) known by their incremental negative impedance (INI), which may lead to voltage collapse of the main DC Bus. In this paper, H∞-based controller of a source side buck converter is designed to avoid the instability issues caused by the load-side converter acting as a CPL. Besides, the proposed controller allows a perfect rejection of all perturbations that may arise from parameter variations, input voltage and CPL current fluctuations. The design process of H∞-based controller is based on the Golver Doyle Optimization Algorithm (GDOA), which requires an augmented system extracted from the small-signal model of the DC/DC converter including the mathematical model of parameter variations and overall external perturbations.The H∞ based controller involves the use of weight functions in order to get the desired performances. The proposed controller is easy to implement and lead to reducing the implementation cost and avoid the use of current measurement that may have some disadvantages. The derived controller is validated by simulation performed in Psim software and experimental setup.
Mahdi Boukerdja; Aissa Chouder; Linda Hassaine; Belkacem Ould Bouamama; Walid Issa; Khalil Louassaa. H∞based control of a DC/DC buck converter feeding a constant power load in uncertain DC microgrid system. ISA Transactions 2020, 105, 278 -295.
AMA StyleMahdi Boukerdja, Aissa Chouder, Linda Hassaine, Belkacem Ould Bouamama, Walid Issa, Khalil Louassaa. H∞based control of a DC/DC buck converter feeding a constant power load in uncertain DC microgrid system. ISA Transactions. 2020; 105 ():278-295.
Chicago/Turabian StyleMahdi Boukerdja; Aissa Chouder; Linda Hassaine; Belkacem Ould Bouamama; Walid Issa; Khalil Louassaa. 2020. "H∞based control of a DC/DC buck converter feeding a constant power load in uncertain DC microgrid system." ISA Transactions 105, no. : 278-295.
This paper presents the experimental investigation of a novel cross-compound parabolic concentrator (CCPC). For the first time, a CCPC module was designed to simultaneously work as an electricity generator and collect the thermal energy present in the module which is generated due to the incident irradiation. This CCPC module consists of two regions: an absorber surface atop the rig and a reflective region below that to reflect the irradiation onto the photovoltaic (PV) cell, coupled together to form an absorptive/reflective CCPC (AR-CCPC) module. A major issue in the use of PV cells is the decrease in electrical conversion efficiency with the increase in cell temperature. This module employs an active cooling system to decrease the PV cell temperature, optimizing the electrical performance and absorbing the heat generated within the module. This system was found to have an overall efficiency of 63%, which comprises the summation of the electrical and thermal efficiency posed by the AR-CCPC module.
Alok Dayanand; Muhsin Aykapadathu; Nazmi Sellami; Mehdi Nazarinia. Experimental Investigation of a Novel Absorptive/Reflective Solar Concentrator: A Thermal Analysis. Energies 2020, 13, 1281 .
AMA StyleAlok Dayanand, Muhsin Aykapadathu, Nazmi Sellami, Mehdi Nazarinia. Experimental Investigation of a Novel Absorptive/Reflective Solar Concentrator: A Thermal Analysis. Energies. 2020; 13 (5):1281.
Chicago/Turabian StyleAlok Dayanand; Muhsin Aykapadathu; Nazmi Sellami; Mehdi Nazarinia. 2020. "Experimental Investigation of a Novel Absorptive/Reflective Solar Concentrator: A Thermal Analysis." Energies 13, no. 5: 1281.
Semi-transparent photovoltaic (PV) technology is attractive for building-integrated photovoltaics (BIPV) due to its ability to lower the admitted solar heat gain, to control the penetrating daylight and to generate onsite benevolent direct current power. In this work, semi-transparent cadmium telluride (CdTe) based BIPV as window was experimentally characterized using outdoor test cell in temperate UK climate. Spectral measurement confirmed its 25% visible transmission and 12% solar transmission. Thermal transmission and solar heat gain coefficient were calculated from measured thermal data. Overall heat transfer coefficient (U-value) of 2.7 W/m2 K was found for outdoor and indoor characterization of CdTe BIPV window. A comparison with single glazed window has been produced emphasis its feasibility for Facade buildings.
Hameed Alrashidi; Aritra Ghosh; Walid Issa; Nazmi Sellami; Tapas.K. Mallick; Senthilarasu Sundaram. Thermal performance of semitransparent CdTe BIPV window at temperate climate. Solar Energy 2019, 195, 536 -543.
AMA StyleHameed Alrashidi, Aritra Ghosh, Walid Issa, Nazmi Sellami, Tapas.K. Mallick, Senthilarasu Sundaram. Thermal performance of semitransparent CdTe BIPV window at temperate climate. Solar Energy. 2019; 195 ():536-543.
Chicago/Turabian StyleHameed Alrashidi; Aritra Ghosh; Walid Issa; Nazmi Sellami; Tapas.K. Mallick; Senthilarasu Sundaram. 2019. "Thermal performance of semitransparent CdTe BIPV window at temperate climate." Solar Energy 195, no. : 536-543.
Façade buildings are generally highly glazed and energy-intensive especially in countries with hot weather. Power consumption in these buildings is even more significant when air conditioning (AC) is added to the figures. Building with semi-transparent photovoltaic (STPV) materials is bringing advantageous energy-saving features to these façade structures. Energy is saved by more heat being reflected resulting in less AC power consumption with the STPV thermal properties. In addition, the optical and electrical properties provide indoor sunlight with power generation. This paper investigates the net potential energy saving via applying cadmium telluride (CdTe) in Façade buildings. The analysis has been carried out using indoor and outdoor experiments considering different orientations and transparencies. Compared to a single glazing case as a reference, the application CdTe achieved a net energy saving to be as high as 20%. Furthermore, a trade-off between saving energy and environment comfort has been discussed as less transparency windows lead to more artificial light consumption. The findings indicate that STPV is a promising solution for sustainable buildings.
Hameed Alrashidi; Walid Issa; Nazmi Sellami; Aritra Ghosh; Tapas K. Mallick; Senthilarasu Sundaram. Performance assessment of cadmium telluride-based semi-transparent glazing for power saving in façade buildings. Energy and Buildings 2019, 215, 109585 .
AMA StyleHameed Alrashidi, Walid Issa, Nazmi Sellami, Aritra Ghosh, Tapas K. Mallick, Senthilarasu Sundaram. Performance assessment of cadmium telluride-based semi-transparent glazing for power saving in façade buildings. Energy and Buildings. 2019; 215 ():109585.
Chicago/Turabian StyleHameed Alrashidi; Walid Issa; Nazmi Sellami; Aritra Ghosh; Tapas K. Mallick; Senthilarasu Sundaram. 2019. "Performance assessment of cadmium telluride-based semi-transparent glazing for power saving in façade buildings." Energy and Buildings 215, no. : 109585.
In a microgrid (MG) topology, the secondary control is introduced to compensate for the voltage amplitude and frequency deviations, mainly caused by the inherent characteristics of the droop control strategy. This paper proposes an accurate approach to derive small signal models of the frequency and amplitude voltage at the point of common coupling (PCC) of a single-phase MG by analyzing the dynamics of the second-order generalized integrator-based frequency-locked loop (SOGI-FLL). The frequency estimate model is then introduced in the frequency restoration control loop, while the derived model of the amplitude estimate is introduced for the voltage restoration loop. Based on the obtained models, the MG stability analysis and proposed controllers’ parameters tuning are carried out. Also, this study includes the modeling and design of the synchronization control loop that enables a seamless transition from island mode to grid-connected mode operation. Simulation and practical experiments of a hierarchical control scheme, including traditional droop control and the proposed secondary control for two single-phase parallel inverters, are implemented to confirm the effectiveness and the robustness of the proposal under different operating conditions. The obtained results validate the proposed modeling approach to provide the expected transient response and disturbance rejection in the MG.
Ahmed Ben Dib; Aissa Chouder; Kamel Kara; Abdelhammid Kherbachi; Said Barkat; Walid Issa. New modeling approach of secondary control layer for autonomous single-phase microgrids. Journal of the Franklin Institute 2019, 356, 6842 -6874.
AMA StyleAhmed Ben Dib, Aissa Chouder, Kamel Kara, Abdelhammid Kherbachi, Said Barkat, Walid Issa. New modeling approach of secondary control layer for autonomous single-phase microgrids. Journal of the Franklin Institute. 2019; 356 (13):6842-6874.
Chicago/Turabian StyleAhmed Ben Dib; Aissa Chouder; Kamel Kara; Abdelhammid Kherbachi; Said Barkat; Walid Issa. 2019. "New modeling approach of secondary control layer for autonomous single-phase microgrids." Journal of the Franklin Institute 356, no. 13: 6842-6874.
Achieving an accurate steady-state averaged active power sharing between parallel inverters in islanded AC microgrids could be realised by a traditional droop control. For identical inverters having the same droop gains, it is assumed that the transient average power responses will be similar, and no circulating current will flow between the units. However, different line impedances could influence the instantaneous power significantly and thus circulating power flows among the inverters particularly during sudden disturbances such as load changes. This power, if absorbed by an inverter, will lead the DC link voltage to rise abruptly and trip the inverter, thus, degrading the performance of the whole microgrid. The problem becomes worse when hybrid generators are serving as a unidirectional power source. This study assesses the performance of hybrid generators within an islanded microgrid against the mismatch in line impedances. Two schemes to stabilise the microgrid are proposed. In addition, a participation factor analysis is developed to select the most effective controller scheme to bound the DC link voltage and minimise the circulating power. Simulation and experimental results are presented to verify the analysis and the capability of the proposed controller.
Walid Issa; Suleiman Sharkh; Mohammad Abusara. Hybrid generators‐based AC microgrid performance assessment in island mode. IET Power Electronics 2019, 12, 1973 -1980.
AMA StyleWalid Issa, Suleiman Sharkh, Mohammad Abusara. Hybrid generators‐based AC microgrid performance assessment in island mode. IET Power Electronics. 2019; 12 (8):1973-1980.
Chicago/Turabian StyleWalid Issa; Suleiman Sharkh; Mohammad Abusara. 2019. "Hybrid generators‐based AC microgrid performance assessment in island mode." IET Power Electronics 12, no. 8: 1973-1980.
Solar energy has demonstrated promising prospects in satisfying energy requirements, specifically through solar photovoltaic (PV) technology. Despite that, the cost of installation is deemed as the main hurdle to the widespread uptake of solar PV systems due to the use of expensive PV material in the module. At this point, we argue that a reduction in PV cost could be achieved through the usage of concentrator. A solar concentrator is a type of lens that is capable of increasing the collection of sun rays and focusing them onto a lesser PV area. The cost of the solar module could then be reduced on the assumption that the cost of introducing the solar concentrator in the solar module design is much lower than the cost of the removed PV material. Static concentrators, in particular, have great promise due to their ability to be integrated at any place of the building, usually on the building facade, windows and roof, due to their low geometrical concentration. This paper provides a historic context on the development of solar concentrators and showcases the latest technological development in static PV concentrators including non-imaging compound parabolic concentrator, V-trough, luminescent solar concentrator and quantum dot concentrator. We anticipated that the static low concentrating PV (LCPV) system could serve to enhance the penetration of PV technology in the long run to achieve the Sustainable Development Goal (SDG) 7—to open an avenue to affordable, reliable, sustainable, and modern energy for all by 2030.
Abdullah Alamoudi; Syed Muhammad Saaduddin; Abu Bakar Munir; Firdaus Muhammad-Sukki; Siti Hawa Abu-Bakar; Siti Hajar Mohd Yasin; Ridoan Karim; Nurul Aini Bani; Abdullahi Abubakar Mas’Ud; Jorge Alfredo Ardila-Rey; Radhakrishna Prabhu; Nazmi Sellami. Using Static Concentrator Technology to Achieve Global Energy Goal. Sustainability 2019, 11, 3056 .
AMA StyleAbdullah Alamoudi, Syed Muhammad Saaduddin, Abu Bakar Munir, Firdaus Muhammad-Sukki, Siti Hawa Abu-Bakar, Siti Hajar Mohd Yasin, Ridoan Karim, Nurul Aini Bani, Abdullahi Abubakar Mas’Ud, Jorge Alfredo Ardila-Rey, Radhakrishna Prabhu, Nazmi Sellami. Using Static Concentrator Technology to Achieve Global Energy Goal. Sustainability. 2019; 11 (11):3056.
Chicago/Turabian StyleAbdullah Alamoudi; Syed Muhammad Saaduddin; Abu Bakar Munir; Firdaus Muhammad-Sukki; Siti Hawa Abu-Bakar; Siti Hajar Mohd Yasin; Ridoan Karim; Nurul Aini Bani; Abdullahi Abubakar Mas’Ud; Jorge Alfredo Ardila-Rey; Radhakrishna Prabhu; Nazmi Sellami. 2019. "Using Static Concentrator Technology to Achieve Global Energy Goal." Sustainability 11, no. 11: 3056.
In grid-connected mode, the grid normally absorbs all the power generated by each inverter in a microgrid. Droop control-based microgrid power management employs the frequency as a wireless communication to determine the power outage. However, in the cases of grid loss, each inverter should receive, from a supervisory controller, new settings of the output power suitable to the microgrid load. Because of the supervisory controllers are slower than the droop control loops, this might produce unstable dynamics caused by the excess generated power circulating between the inverters if the microgrid load is low. This case degrades the microgrid stability leading the DC link voltage of each inverter to rise to trip point. In this paper, a PD voltage control loop is proposed to stabilize the system and minimize the circulating power so providing more time for the supervisory control to respond without tripping any inverter. A detailed small signal model is developed and stability analysis is performed to tune the controller’s gain. Matlab/Simulink results validate the performance of the proposed controller.
Walid Issa; Faris Al-Naemi; George Konstantopoulos; Sulieman Sharkh; Mohammad Abusara. Stability Analysis and Control of a Microgrid against Circulating Power between Parallel Inverters. Energy Procedia 2019, 157, 1061 -1070.
AMA StyleWalid Issa, Faris Al-Naemi, George Konstantopoulos, Sulieman Sharkh, Mohammad Abusara. Stability Analysis and Control of a Microgrid against Circulating Power between Parallel Inverters. Energy Procedia. 2019; 157 ():1061-1070.
Chicago/Turabian StyleWalid Issa; Faris Al-Naemi; George Konstantopoulos; Sulieman Sharkh; Mohammad Abusara. 2019. "Stability Analysis and Control of a Microgrid against Circulating Power between Parallel Inverters." Energy Procedia 157, no. : 1061-1070.
Solar and luminous light transmission control using Cadmium Telluride (CdTe) based PV glazing systems (15cm × 15 cm × 0.6 cm) were evaluated in this work. Indoor spectral characterisation showed that average solar transmission for investigated three different CdTe glazing systems were 5.77% (CdTe1), 9.54% (CdTe2) and 12.34% (CdTe3). Spectral behaviour of reflections in the range of solar and visible wavelengths was similar for these three different transparent CdTe glazing. Near infrared (NIR) reflection was higher compared to luminous reflection after 1500 nm for all three glazing systems. Solar factor (SF) for CdTe1, CdTe2 and CdTe3 glazing were 0.23, 0.28, 0.26. CdTe3 is the best candidate for glazing application as it has 113% higher luminous transmission while SF only increases by 21% compared to CdTe1.
Hameed Alrashidi; Aritra Ghosh; Walid Issa; Nazmi Sellami; Tapas K. Mallick; Senthilarasu Sundaram. Evaluation of solar factor using spectral analysis for CdTe photovoltaic glazing. Materials Letters 2018, 237, 332 -335.
AMA StyleHameed Alrashidi, Aritra Ghosh, Walid Issa, Nazmi Sellami, Tapas K. Mallick, Senthilarasu Sundaram. Evaluation of solar factor using spectral analysis for CdTe photovoltaic glazing. Materials Letters. 2018; 237 ():332-335.
Chicago/Turabian StyleHameed Alrashidi; Aritra Ghosh; Walid Issa; Nazmi Sellami; Tapas K. Mallick; Senthilarasu Sundaram. 2018. "Evaluation of solar factor using spectral analysis for CdTe photovoltaic glazing." Materials Letters 237, no. : 332-335.
The different nature of the energy resources requires high reliable power inverters to supply regulated power to the end customer and to ease its integration within the microgrid. In this paper, modeling, design and control of inverters are presented for two different topologies. The study addresses the feasibility of the single loop and double loop control of inverters. The bode plot technique is used to analyze the system behavior when the inductor and the capacitor currents are used as feedback signals. The different output impedance natures affect the power sharing between inverters and stability. Therefore, a proposed virtual impedance is implemented to enhance the control performance. Simulation results are presented to show the validity of the control strategy.
Walid Issa; Ahmad Elkhateb. Virtual Impedance Impact on Inverter Control Topologies. 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) 2018, 1423 -1428.
AMA StyleWalid Issa, Ahmad Elkhateb. Virtual Impedance Impact on Inverter Control Topologies. 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA). 2018; ():1423-1428.
Chicago/Turabian StyleWalid Issa; Ahmad Elkhateb. 2018. "Virtual Impedance Impact on Inverter Control Topologies." 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA) , no. : 1423-1428.
As the electrical power grids are extending in capacity with connection of distributed generations, the fault current level is increasing and approaching the capacity limits of the circuit breakers. In this paper, a saturated inductor fault current limiter (FCL) based on permanent magnet biasing has been developed to overcome the inherent disadvantages associated with many previous technologies such as superconducting based techniques. A 3D Finite Element Modeling (FEM) is used to develop and validate the proposed design and compared it with air-cored inductor. A lab-scale prototype was built to verify the design. Furthermore, a scaled up model which could be introduced to 11 kV network is introduced and its electromagnetic performance is evaluated.
Faris Al-Naemi; Walid Issa; Asmaiel Ramadan; Jeremy Hall. Design and Modelling of Permanent Magnet Fault Current Limiter For Electrical Power Applications. 2018 53rd International Universities Power Engineering Conference (UPEC) 2018, 1 -5.
AMA StyleFaris Al-Naemi, Walid Issa, Asmaiel Ramadan, Jeremy Hall. Design and Modelling of Permanent Magnet Fault Current Limiter For Electrical Power Applications. 2018 53rd International Universities Power Engineering Conference (UPEC). 2018; ():1-5.
Chicago/Turabian StyleFaris Al-Naemi; Walid Issa; Asmaiel Ramadan; Jeremy Hall. 2018. "Design and Modelling of Permanent Magnet Fault Current Limiter For Electrical Power Applications." 2018 53rd International Universities Power Engineering Conference (UPEC) , no. : 1-5.
A crossed compound parabolic concentrator (CCPC) is a non-imaging concentrator which is a modified form of a circular 3D compound parabolic concentrator (CPC) obtained by orthogonal intersection of two 2D CPCs that have an optical efficiency in line with that of 3D CPC. The present work is about the design and fabrication of a new generation of solar concentrator: the hybrid photovoltaic (PV)/thermal absorptive/reflective CCPC module. The module has a 4× CCPC structure truncated to have a concentration of 3.6× with a half acceptance angle of 30°. Furthermore, an experimental rig was also fabricated to test the performance of the module and its feasibility in real applications such as building-integrated photovoltaic (BIPV). 3D printing and Computer Numerical Control (CNC) milling technologies were utilized to manufacture the absorber and reflective parts of the module.
Muhsin Aykapadathu; Mehdi Nazarinia; Nazmi Sellami. Design and Fabrication of Absorptive/Reflective Crossed CPC PV/T System. Designs 2018, 2, 29 .
AMA StyleMuhsin Aykapadathu, Mehdi Nazarinia, Nazmi Sellami. Design and Fabrication of Absorptive/Reflective Crossed CPC PV/T System. Designs. 2018; 2 (3):29.
Chicago/Turabian StyleMuhsin Aykapadathu; Mehdi Nazarinia; Nazmi Sellami. 2018. "Design and Fabrication of Absorptive/Reflective Crossed CPC PV/T System." Designs 2, no. 3: 29.
Climate change poses profound threats to the Earth and its people. Its mitigation, therefore, demands common but differentiated actions with comprehensive and coordinated approach. The global community has pledged to mitigate various greenhouse gases in some international soft law instruments. Exploitation of renewables to generate energy and produce electricity is simultaneously suggested for the last couple of decades as a viable alternative in mitigating climate change. This gets momentum with the adoption of the historical and universally ratified Paris Agreement in 2016 where energy is placed at the heart of the Agreement. Energy, where renewable energy is a branch, is generally regulated and governed domestically and so, international legal regime is still evolving in this regard. In the absence of any specific and direct international instrument on energy and renewable energy, published literatures have considered this topic from different directions ranging from climate change to the principle of national sovereignty, economic, trade and investment issues. In this backdrop, this paper aims to introduce various renewable sources, prospects and challenges in their promotion that may help to mitigate the adverse effects of climate change. Relevant international law provisions have been evaluated, performances of the relevant regional and international organizations active in this sector are highlighted and some of the disputes in this area considered in international forums are duly addressed. It is revealed that strong political will of the global community in fulfilling their commitments made so far in different international forums is the key to transforming the world into a better one for the future generation.
Ershadul Karim; Abu Bakar Munir; Mohammad Ataul Karim; Firdaus Muhammad-Sukki; Siti Hawa Abu-Bakar; Nazmi Sellami; Nurul Aini Bani; Mohamad Zaki Hassan. Energy Revolution for Our Common Future: An Evaluation of the Emerging International Renewable Energy Law. Energies 2018, 11, 1769 .
AMA StyleErshadul Karim, Abu Bakar Munir, Mohammad Ataul Karim, Firdaus Muhammad-Sukki, Siti Hawa Abu-Bakar, Nazmi Sellami, Nurul Aini Bani, Mohamad Zaki Hassan. Energy Revolution for Our Common Future: An Evaluation of the Emerging International Renewable Energy Law. Energies. 2018; 11 (7):1769.
Chicago/Turabian StyleErshadul Karim; Abu Bakar Munir; Mohammad Ataul Karim; Firdaus Muhammad-Sukki; Siti Hawa Abu-Bakar; Nazmi Sellami; Nurul Aini Bani; Mohamad Zaki Hassan. 2018. "Energy Revolution for Our Common Future: An Evaluation of the Emerging International Renewable Energy Law." Energies 11, no. 7: 1769.
This paper presents a microgrid control strategy to unify the control topology for energy storage systems and renewable energy sources inverters in an ac microgrid and to protect the microgrid reliability from unintentional islanding instability using control loops, which use thedc link voltage as a feedback. This bounds the dc link voltage and provides reliable operation in the microgrid. Simulation validates the proposed control strategy, and experiment results extol the concept.
Walid R. Issa; Ahmad H. El Khateb; Mohammad A. Abusara; Tapas K. Mallick. Control Strategy for Uninterrupted Microgrid Mode Transfer During Unintentional Islanding Scenarios. IEEE Transactions on Industrial Electronics 2017, 65, 4831 -4839.
AMA StyleWalid R. Issa, Ahmad H. El Khateb, Mohammad A. Abusara, Tapas K. Mallick. Control Strategy for Uninterrupted Microgrid Mode Transfer During Unintentional Islanding Scenarios. IEEE Transactions on Industrial Electronics. 2017; 65 (6):4831-4839.
Chicago/Turabian StyleWalid R. Issa; Ahmad H. El Khateb; Mohammad A. Abusara; Tapas K. Mallick. 2017. "Control Strategy for Uninterrupted Microgrid Mode Transfer During Unintentional Islanding Scenarios." IEEE Transactions on Industrial Electronics 65, no. 6: 4831-4839.
Walid Issa; Ahmad El Khateb; Nader Anani; Mohammad Abusara. Smooth mode transfer in AC microgrids during unintentional islanding. Energy Procedia 2017, 134, 12 -20.
AMA StyleWalid Issa, Ahmad El Khateb, Nader Anani, Mohammad Abusara. Smooth mode transfer in AC microgrids during unintentional islanding. Energy Procedia. 2017; 134 ():12-20.
Chicago/Turabian StyleWalid Issa; Ahmad El Khateb; Nader Anani; Mohammad Abusara. 2017. "Smooth mode transfer in AC microgrids during unintentional islanding." Energy Procedia 134, no. : 12-20.
Distributed generation (DG) is one of the key components of the emerging microgrid concept that enables renewable energy integration in a distribution network. In DG unit operation, inverters play a vital role in interfacing energy sources with the grid utility. An effective interfacing can successfully be accomplished by operating inverters with effective control techniques. This paper reviews and categorises different control methods (voltage and primary) for improving microgrid power quality, stability and power sharing approaches. In addition, the specific characteristics of microgrids are summarised to distinguish from distribution network control. Moreover, various control approaches including inner-loop controls and primary controls are compared according to their relative advantages and disadvantages. Finally, future research trends for microgrid control are discussed pointing out the research opportunities. This review paper will be a good basis for researchers working in microgrids and for industry to implement the ongoing research improvement in real systems.
Alamgir Hossain; Hemanshu Roy Pota; Walid Issa. Overview of AC Microgrid Controls with Inverter-Interfaced Generations. Energies 2017, 10, 1300 .
AMA StyleAlamgir Hossain, Hemanshu Roy Pota, Walid Issa. Overview of AC Microgrid Controls with Inverter-Interfaced Generations. Energies. 2017; 10 (9):1300.
Chicago/Turabian StyleAlamgir Hossain; Hemanshu Roy Pota; Walid Issa. 2017. "Overview of AC Microgrid Controls with Inverter-Interfaced Generations." Energies 10, no. 9: 1300.