Computation of Power Extraction from Photovoltaic Arrays under Various Fault Conditions

Photovoltaic (PV) faults such as partial shading, bypass-diode defects, degradation of PV modules, and wiring issues greatly affect the power output and cause various peaks in P-V curves of a PV system. Although, commonly used Total-Cross-Tied (TCT) scheme in PV arrays is considered instrumental for reducing power losses there lies a great scope to evaluate power extraction through reconfiguration of modules with different PV materials. This paper presents detailed investigation of power extraction using number placement reconfiguration method under numerous faults. PV power extraction is carried out and compared with three different interconnections of PV modules, including series-parallel (SP), bridge-link (BL) and TCT. In order to conduct a thorough investigation and better evaluate the performance of PV arrays, we have studied reconfiguration of PV modules with polycrystalline and copper indium gallium selenide (CIGS) PV technologies. In addition, this paper contains detailed quantification of the impact of the studied PV faults on power grid. The results obtained in MATLAB/Simulink demonstrate that CIGS PV technology performs better than polycrystalline in terms of power output during different faulty conditions. It becomes evident from the presented results that optimal reconfiguration of PV arrays can increase the power extraction from PV system with reduced number of P-V peaks. Hence, leading to improved performance of the PV system.The research work is supported by Qatar University under its National Capacity Building Project (NCBP) Research Grant.Scopu

A novel hybrid methodology to secure GOOSE messages against cyberattacks in smart grids

: IEC 61850 is emerging as a popular communication standard for smart grids. Standardized communication in smart grids has an unwanted consequence of higher vulnerability to cyber-attacks. Attackers exploit the standardized semantics of the communication protocols to launch different types of attacks such as false data injection (FDI) attacks. Hence, there is a need to develop a cybersecurity testbed and novel mitigation strategies to study the impact of attacks and mitigate them. This paper presents a testbed and methodology to simulate FDI attacks on IEC 61850 standard compliant Generic Object-Oriented Substation Events (GOOSE) protocol using real time digital simulator (RTDS) together with open-source tools such as Snort and Wireshark. Furthermore, a novel hybrid cybersecurity solution by the name of sequence content resolver is proposed to counter such attacks on the GOOSE protocol in smart grids. Utilizing the developed testbed FDI attacks in the form of replay and masquerade attacks on are launched and the impact of attacks on electrical side is studied. Finally, the proposed hybrid cybersecurity solution is implemented with the developed testbed and its effectiveness is demonstrated

A New Family of Step-up Hybrid Switched-Capacitor Integrated Multilevel Inverter Topologies with Dual Input Voltage Sources

In the low voltage based renewable systems like PV and Fuel cell applications, the step-up of the output voltage to drive the loads is essential. For this, the integration of switched-capacitor (SC) units with the dc-ac converters will have the potential advantages like improved efficiency, optimal switching devices, small size of passive elements (L and C) as compared with traditional two-stage conversion system (dc/dc converter and dc/ac converter). This paper focuses on a new family of step-up multilevel inverter topologies with switched capacitor integration with dual input voltage sources. With the flexibility of 2 dc sources and switching capacitor circuits, four different topologies have been suggested in this paper with features of high voltage gain, reduced component count, reduced voltage stress and self-voltage balancing of the capacitor while achieving a higher number of levels. A detailed analysis of proposed multilevel inverters has been analyzed with the symmetrical and asymmetrical mode of operations and the associated gain, the number of levels, and other performance indices are presented. An in-depth study of all the topologies has been accomplished in this paper with several comparative studies in terms of components count, voltage gain and cost. The effectiveness and practicability of the suggested topology with 13 level output voltage has been explained by the experimental results obtained from a scale down prototype.Scopu

Impact on power quality due to large-scale adoption of compact fluorescent lamps-a review

The demand of electrical energy has grown tremendously in the last couple of decades across the globe. The energy conservation and management has attracted the attention of stake holders for efficient utilisation of the resources. One of the major steps taken by the authorities towards conservation of electrical energy is replacement of incandescent lamps (ILs) by compact fluorescent lamps (CFLs). CFL uses electronic circuit for its ignition, making them a non-linear load on utility grid. Large-scale replacement of ILs has enormous effects on utility grid in terms of power quality. This paper reviews the work conducted by several researchers investigating the effect of using CFLs on power quality. Basic terminologies related to power quality is defined. The experimental results elaborate the pollution on the grid in the term of total harmonic distortion in current due to adoption of CFLs. The methodologies of harmonic measurement system are reviewed. Different software used for the analysis is presented. The paper will help the researchers to receive a comprehensive overview of power-quality issues.This study was made possible by UREP [grant number 15-075-2-027] from the Qatar National Research Fund (a member of Qatar Foundation).Scopu

Utilization of EV Charging Station in Demand Side Management Using Deep Learning Method

Conventional energy sources are a major source of pollution. Major efforts are being made by global organizations to reduce CO2 emissions. Research shows that by 2030, EVs can reduce CO2 emissions by 28%. However, two major obstacles affect the widespread adoption of electric vehicles: the high cost of EVs and the lack of charging stations. This paper presents a comprehensive data-driven approach based demand-side management for a solar-powered electric vehicle charging station connected to a microgrid. The proposed approach utilizes a solar-powered electric vehicle charging station to compensate for the energy required during peak demand, which reduces the utilization of conventional energy sources and shortens the problem of fewer EVCS in the current scenario. PV power stations, commercial loads, residential loads, and electric vehicle charging stations were simulated using the collected real-time data. Furthermore, a deep learning approach was developed to control the energy supply to the microgrid and to charge the electric vehicle from the grid during off-peak hours. Furthermore, two different machine learning approaches were compared to estimate the state of charge estimation of an energy storage system. Finally, the proposed framework of the demand management system was executed for a case study of 24 hours. The results reflect that peak demand has been compensated with the help of an electric vehicle charging station during peak hours. 2013 IEEE.This publication was made possible by Qatar University Research grant# [QUCP-CENG-2020-2] from Qatar University, Qatar. The APC for the article is funded by the Qatar National Library, Doha, Qatar.Scopu

Review of policies encouraging renewable energy integration & best practices

This article provides policy-makers and renewable energy project developers with background information and analysis into the successful penetration of renewable energy policies. The analysis emphasizes on the different mechanisms to establish an encouraging regulatory framework for renewable energies and examines examples of both successful and failed experiences, through case studies and analysis of various countries. This analytic survey attempts to shed light on the factors which led to successful implementation of renewable energy depending not only on different countries experience, but also on the different sources and technologies for renewable electricity. The main objectives through the provision of this overview are to help policy implementers learn from each other's experiences and contribute to the efforts to meet indicative renewable energy targets. The methodology applied in this document is to collect all applied mechanisms helping deploying renewable energy projects with a reviewing of study cases analysis for some specific experiences. Then the information are classified and discussed from the financial, fiscal, legislative, political, technological and environmental points of view in order to make it a reference and a guideline for other renewable energy policies studies. 2015 Elsevier Ltd. All rights reserved.Actions for the financial supportScopus2-s2.0-8492254922

Recommendations on renewable energy policies for the GCC countries

Energy security was the major driver for several countries in the world to opt for alternative sources of energy and reduce CO2 emissions. Being blessed with oil and gas reserves, the situation in the Gulf Cooperation Council (GCC) countries may look different, in a way that investments on Renewable Energy (RE) projects do not create adequate short-term financial returns. However, considering the extreme increase of energy demand locally caused by the industrial and economic development in the region will make seizing the emerging opportunity to develop RE projects a strategic decision. This paper targets regional decision-makers as well as multilateral stakeholders, in an attempt to formulate a set of recommendations on policies to promote RE deployment. It presents the results of the study that covered all GCC countries (Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain and Oman). The document summarizes GCC countries' RE targets and highlights the main projects and measures established to start this transition. Furthermore, this paper provides an updated and comprehensive overview of the RE situation in the GCC countries, and it includes an assessment of the region's RE potential, current installed RE capacity and project pipeline, institutional and market frameworks. This study analyses the main gaps concerning RE deployment in the region while discussing the financial, fiscal, political, legislative, technological and environmental aspects. Based on that, a set of recommendations is proposed to fill their gaps and help achieving their politically endorsed targets particularly in the electricity sector. The proposed recommendations will help to accelerate the development rate of GCC RE market, support governments' efforts towards fulfilling future RE targets, and overcome potential barriers. However such policies analysis should be carried out individually for each country of the GCC region taking into consideration the specificity of each market and economic strategies with more adapted measures. 2015 Elsevier Ltd.Suggesting new financial supportScopus2-s2.0-8493126636

Simple voltage regulation method for smart grid applications

The complexity of power systems and the change of demand load at the consumer make it necessary to control the voltage to avoid any unnecessary voltage drop beyond the limits allowed within the international standards and achieve optimum energy efficiency. This paper introduces a simple method that can regulate the voltage of a system without the sophisticated electronic devices. The method that controls the minimum voltage at one of the buses in a system has been studied on IEEE 13-node test feeder. This method has been proposed to control the voltage using more-than-a-step tap where the algorithm can decide what tap to choose based on the set features. The method has been simulated with three different scenarios - with loads connected at all buses, with one of the loads disconnected from a certain bus, and with a distributed generation (DG) connected to a certain bus. The results show effective over and under voltage controls and a considerable enhancement in energy efficiency. 2015 IEEE.Scopus2-s2.0-8496476602

Optimal sizing of a stand-alone hybrid PV-WT-BT system using artificial intelligence based technique

Nowadays, conventional energy system is being replaced by renewable energy system. Especially, PV systems and wind energy systems are gaining much attention due to their future sustainability and eco-friendly nature. However, for these types of systems, optimization and control is a challenging task because of their unpredictable nature. In this paper, an artificial intelligence (AI) based method named as multidimensional particle swarm optimization with weights induced fitness function (MDPSO-WIFF) approach is proposed for achieving the best combination size between the hybrid photovoltaic, wind turbine and battery storage (PV-WT-BT) system. The AI algorithm handles multiobjective optimization and gives minimum cost and maximum reliability along with the minimization of unutilized surplus power. The algorithm is then justified by comparing its results with iterative-pareto-fuzzy technique. The findings show that the proposed approach is faster and capable of obtaining better quality solution in terms of total cost and reliability with trade-off to dump load.This publication was supported in part by Qatar University Internal Grant No. QUCG-CENG-2018/2019-2. The findings achieved herein are solely the responsibility of the authors.Scopu