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The most severe failures in power grids are often characterized as cascading failures where an initial event triggers consequent failures all along the grid often leading to blackouts. Upon identifying a failure and its cascade potential, timely control actions should be performed by the grid operators to mitigate the effect of the cascade. These actions have to be delivered to one or more control devices, creating a dependency between the power grid and its control network. This paper examines the dependency of the operation of the power grid on the control network. Different from literature studies on failure control, our dependency model captures the impact of networking parameters. We formulate an algorithmic model that describes the impact of this dependency on cascade control. Based on this model, we propose an efficient cascade control algorithm using load shedding with consideration of delays in the communication network for power grids. Finally, we evaluate the impact of the power-communication network dependency with uncontrolled grids, ideal/simple control grids and our proposed control scheme. The results demonstrate that the proposed algorithm can significantly reduce the failure of power lines while sustaining larger power demand for users.

AbstractNumerical study of the influence of Prandtl number on free convection flow phenomena in a solar collector having glass cover plate and sinusoidal absorber is done. The working fluid is water-Al2O3 nanofluid. The cover plate has initially constant temperature Th, while bottom absorber is at temperature Tc, with Th > Tc. The remaining walls are considered adiabatic. By Penalty Finite Element Method the governing differential equations with boundary conditions are solved. The effect of the Prandtl number on the flow pattern and heat transfer has been depicted. Comprehensive average Nusselt number, average temperature and mean velocity inside the collector are presented as a function of the governing parameter mentioned above. The highest Pr causes the greatest heat transfer. The enhancing performance of heat transfer rate is more effective for the water-Al2O3 nanofluid than the base fluid.

The use of renewable energy in Latin America has increased significantly in recent years as a result of social pressure due to the negative effects generated by the use of polluting energy. However, there is still limited empirical evidence on the effect of clean energy on the output. The objective of this research is to examine the causal link among the growth rates of sustainable energy consumption, non-sustainable energy and the real per capita output in Latin America, a region with a high potential to generate clean energy. We used Pedroni (1999) and Westerlund (2007) cointegration techniques, and Dumitrescu and Hurlin (2012) causality test to evaluate the relationship among the variables. In order to evaluate the strength of the cointegration vector, we applied the dynamic ordinary least squares for individual countries and the panel dynamic ordinary least squares model for country groups. We find robust empirical evidence that suggests that the growth rate of renewable energy consumption, non-renewable energy and the rate of growth of real per capita output have a short-term and long-term equilibrium relationship. The force of the cointegration vector among the output and the renewable energy is more forceful in the countries of medium-high and medium-low incomes. The cointegration vector among the output and non-renewable energy is stronger in high-income countries. The results of the causality test suggest that renewable energy and the real per capita output have a bidirectional relationship in low-middle income countries. The output causes renewable energy in all groups of countries. Likewise, there is a unidirectional causality from the real per capita output towards non-renewable energy. One possible policy implication derived from this research is that high-income countries in the region should look for alternative sources of energy to achieve sustainable growth, and medium-high and medium-low income countries should encourage the use of energy clean, which does not limit the economic growth. Keywords: Energy. output. Cointegration. Causality. Panel data. Latin America, JEL classification: F43, P28, C23

Environmental quality indicators are crucial for responsive and cost-effective policies. The objective of the study is to examine the relationship between environmental quality indicators and financial development in Malaysia. For this purpose, the number of environmental quality indicators has been used, i.e., air pollution measured by carbon dioxide emissions, population density per square kilometer of land area, agricultural production measured by cereal production and livestock production, and energy resources considered by energy use and fossil fuel energy consumption, which placed an impact on the financial development of the country. The study used four main financial indicators, i.e., broad money supply (M2), domestic credit provided by the financial sector (DCFS), domestic credit to the private sector (DCPC), and inflation (CPI), which each financial indicator separately estimated with the environmental quality indicators, over a period of 1975-2013. The study used the generalized method of moments (GMM) technique to minimize the simultaneity from the model. The results show that carbon dioxide emissions exert the positive correlation with the M2, DCFC, and DCPC, while there is a negative correlation with the CPI. However, these results have been evaporated from the GMM estimates, where carbon emissions have no significant relationship with any of the four financial indicators in Malaysia. The GMM results show that population density has a negative relationship with the all four financial indicators; however, in case of M2, this relationship is insignificant to explain their result. Cereal production has a positive relationship with the DCPC, while there is a negative relationship with the CPI. Livestock production exerts the positive relationship with the all four financial indicators; however, this relationship with the CPI has a more elastic relationship, while the remaining relationship is less elastic with the three financial indicators in a country. Energy resources comprise energy use and fossil fuel energy consumption, both have distinct results with the financial indicators, as energy demand have a positive and significant relationship with the DCFC, DCPC, and CPI, while fossil fuel energy consumption have a negative relationship with these three financial indicators. The results of the study are of value to both environmentalists and policy makers.

More and more renewable energy sources are integrated into power grids, leading to a power electronic-based low-inertia power system. The grid-forming (GFM) inverter is an effective method for improving the inertia of the system. However, with the increased GFM inverters in the system, how the multiple control parameters affect the frequency response is still not clear. In this study, first, the power-phase model of the power grid is established; then, a small-signal distributed frequency model of the GFM inverter-based power system is established associating with the power-phase model of the power grid and the power-frequency model of the GFM inverter. Based on the proposed model, the influence of the multiple parameters to the frequency response is analyzed. It is concluded that both the inertia and damping coefficient affect the settling time, overshoot, and oscillation of the frequency. Finally, the simulation results verify the proposed model and the conclusion.

This paper presents a finite control-set model predictive control (FCS-MPC) based technique to reduce the switching loss and frequency of the on-grid PV inverter by incorporating a switching frequency term in the cost function of the model predictive control (MPC). In the proposed MPC, the control objectives (current and switching frequency) select an optimal switching state for the inverter by minimizing a predefined cost function. The two control objectives are combined with a weighting factor. A trade-off between the switching frequency (average) and total harmonic distortion (THD) of the current was utilized to determine the value of the weighting factor. The switching, conduction, and harmonic losses were determined at the selected value of the weighting factor for both the proposed and conventional FCS-MPC and compared. The system was simulated in MATLAB/Simulink, and a small-scale hardware prototype was built to realize the system and verify the proposal. Considering only 0.25% more current THD, the switching frequency and loss per phase were reduced by 20.62% and 19.78%, respectively. The instantaneous overall power loss was also reduced by 2% due to the addition of a switching frequency term in the cost function which ensures a satisfactory empirical result for an on-grid PV inverter.

Ionic liquids (ILs) are molten salts that are entirely composed of ions and have melting temperatures below 100 °C. When immobilized in polymeric matrices by sol–gel or chemical polymerization, they generate gels known as ion gels, ionogels, ionic gels, and so on, which may be used for a variety of electrochemical applications. One of the most significant research domains for IL-based gels is the energy industry, notably for energy storage and conversion devices, due to rising demand for clean, sustainable, and greener energy. Due to characteristics such as nonvolatility, high thermal stability, and strong ionic conductivity, IL-based gels appear to meet the stringent demands/criteria of these diverse application domains. This article focuses on the synthesis pathways of IL-based gel polymer electrolytes/organic gel electrolytes and their applications in batteries (Li-ion and beyond), fuel cells, and supercapacitors. Furthermore, the limitations and future possibilities of IL-based gels in the aforementioned application domains are discussed to support the speedy evolution of these materials in the appropriate applicable sectors.

Pure drinking water is one of the major concerns all over the world as 97% of water resource is not drinkable due to high salinity. Fresh drinking water is one of the indispensable needs for human being as well as other living creatures' survival. Like many others countries in the world, Bangladesh is one of the developing countries that has not been able to overcome the freshwater crisis yet, especially for its people of the coastal regions. To assist the rural or isolated communities by fulfilling their pure drinking water demand, a small scale brackish water reverse osmosis purification system assisted by solar photovoltaic (PV) energy as the renewable energy source has been proposed in this work. It has been revealed that solar PV source serves the best for a small scale power generation for the rural or remote region and reverse osmosis process is the most economical system for brackish water purification. After a thorough experimental investigation and analysis, it was found that the system fulfilled the national and international standard of pure drinking water, where 0.19BDT/litre (0.0022USD/litre) has been achieved as the most cost-efficient outcome of the water purification system. Other existing pure drinking water systems that offers around 1.0BDT/litre (0.013USD/litre) as the retail price in Bangladesh at present.