Electric vehicles are the latest form of technology developed to create an environmentally friendly transportation sector and act as an additional energy source to minimize the demand on the grid. ...This comprehensive research review presents the vehicle-to-grid (V2G) and the vehicle-to-home (V2H) technologies, along with their structures, components, power electronic topologies, communication standards, socket structure, and charging methods. In addition, the charging topologies in V2G and V2H are given in detail. This study is planned as a useful guide for future studies that can be achieved in that it compares the results obtained and analyzes the studies in the literature, finding the advantages and disadvantages of charging topologies in V2G and V2H.
Solar energy is a safe, clean, environmentally-friendly and renewable energy source without any carbon emissions to the atmosphere. Therefore, there are many studies in the field of solar energy in ...order to obtain the maximum solar radiation during the day time, to estimate the amount of solar energy to be produced, and to increase the efficiency of solar energy systems. In this study, it was aimed to predict the daily photovoltaic power production using air temperature, relative humidity, total horizontal solar radiation and diffuse horizontal solar radiation parameters as multi-tupled inputs. For this purpose, grey wolf, ant lion and whale optimization algorithms were integrated to the multilayer perceptron. In addition, the effects of sigmoid, sinus and hyperbolic tangent activation functions on the prediction performance were analyzed in detail. As a result of overall accuracy indictors achieved, the grey wolf optimization algorithm-based multilayer perceptron model was found to be more successful and competitive for the daily photovoltaic power prediction. Furthermore, many meaningful patterns were revealed about the constructed models, input tuples and activation functions.
This paper proposes a proportional resonant and proportional integral based control strategy for single phase quasi-Z-source inverters (qZSIs) which is able to operate in buck and boost modes. ...Switching signals of the qZS inverters can be generalized as shoot through and non-shoot through states. The DC-link voltage of the qZSIs can be controlled by generating proper shoot through signals. The control strategy for qZSIs should be able to control both DC and AC-sides at the same time. First, the average state-space model of qZSI is obtained for closed loop control in this paper. Thereafter, the proportional resonant control is designed to achieve AC-side voltage control. Also, voltage control of DC-side capacitor is achieved by using proportional integral control method. Finally, the switching signals are obtained by applying the control outputs to modulation strategy. Experimental results are presented to demonstrate the effectiveness of the control method. The results verify that the proposed control strategy successfully regulates both DC and AC-side control variables.
A successful distribution network can continue to operate despite the uncertainties at the charging station, with appropriate equipment retrofits and upgrades. However, these new investments in the ...grid can become complex in terms of time and space. In this paper, we propose a dynamic charge coordination (DCC) method based on the battery state of charge (SOC) of electric vehicles (EVs) in line with this purpose. The collective uncoordinated charging profiles of EVs charged at maximum power were investigated based on statistical data for distances of EVs and a real dataset for charging characteristics in the existing grid infrastructure. The proposed strategy was investigated using the modified Roy Billinton Test System (RBTS) performed by DIgSILENT Powerfactory simulation software for a total 50 EVs in 30 different models. Then, the load balancing situations were analyzed with the integration of the photovoltaic (PV) generation and battery energy storage system (BESS) into the bus bars where the EVs were fed into the grid. According to the simulation results, the proposed method dramatically reduces the effects on the grid compared to the uncoordinated charging method. Furthermore, the integration of PV and BESS system, load balancing for EVs was successfully achieved with the proposed approach.
This paper provides a comprehensive review of the major concepts associated with the μgrid, such as constant power load (CPL), incremental negative resistance or impedance (INR/I) and its dynamic ...behaviours on the μgrid, and power system distribution (PSD). In general, a μgrid is defined as a cluster of different types of electrical loads and renewable energy sources (distributed generations) under a unified controller within a certain local area. It is considered a perfect solution to integrate renewable energy sources with loads as well as with a traditional grid. In addition, it can operate with a conventional grid, for example, by energy sourcing or a controllable load, or it can operate alone as an islanding mode to feed required electric energy to a grid. Hence, one of the important issues regarding the μgrid is the constant power load that results from the tightly designed control when it is applied to power electronic converters. The effect of CPL is incremental negative resistance that impacts the power quality of a power system and makes it at negative damping. Also, in this paper, a comprehensive study on major control and compensation techniques for μgrid has been included to face the instability effects of constant power loads. Finally, the merits and limitations of the compensation techniques are discussed.
The charging load forecasting of residential Electric Vehicles help grid operators make informed decisions in terms of scheduling and managing demand response. The residence can include integrated ...residential appliances with multi‐state and high‐frequency features. For this reason, it is difficult to estimate the total load of residence accurately. To overcome this problem, this paper proposes a hybrid forecasting model using the empirical mode decomposition and Bayesian optimised Long Short‐Term Memory for load balancing based on residential electricity meter data. The residential electricity meter data includes three datasets as Electric Vehicle, heat pump and photovoltaic system. To decompose of the data characteristics, the empirical mode decomposition method performs to the original data. Then, the Bayesian optimised Long Short‐Term Memory is applied to forecast for each sub‐component of the data sequentially. The main features of the proposed model include a significant improvement in prediction accuracy and capture the local maximums. The advantage of the proposed method over existing methods are also verified over with experiments of data‐driven on the IEEE 33 busbar test system. The result of simulation forecasting model indicates that predict closely the busbar outflow power, voltage drop, transformer loading states and power losses to compare with actual load model.
Renewable energy sources are replacing other energy sources to minimize the cost of due to the conventional sources of energy. Solar and wind are readily available sources which will minimize the ...cost of electricity if implemented properly. Considering the weather and other relevant advantages, solar energy is a favorable option for a particular site. But it is extremely difficult for the implementation of the suggested renewable energy in a site which already has specific resources and existing infrastructure to replace. Several factors should be counted in for the selection and implementation of appropriate renewable source for fulfilling the demand. As a possible energy option, on-grid infrastructure is selected looking at its low necessity of development and hardware cost. This paper aims to impart the detailed designs of alternative energy options that will offset the annual irrigation costs of the Rainbow Youth Golf Education Program in Klamath County. Using simulator, a practical modeling of the system is performed to look at the cost associated with each case. After selecting a combination with the minimum cost, it is shown that the model decreases the irrigation cost compared to previous year. Other technological implications are also evaluated. Finally, worst case scenario is modeled using the simulator to show that even in the bad weather, the site’s energy supply model serves well both electrically and economically.
Microgrids are distribution networks consisting of distributed energy sources such as photovoltaic and wind turbines, that have traditionally been one of the most popular sources of energy. ...Furthermore, microgrids consist of energy storage systems and loads (e.g., industrial and residential) that may operate in grid-connected mode or islanded mode. While microgrids are an efficient source in terms of inexpensive, clean and renewable energy for distributed renewable energy sources that are connected to the existing grid, these renewable energy sources also cause many difficulties to the microgrid due to their characteristics. These difficulties mainly include voltage collapses, voltage and frequency fluctuations and phase difference faults in both islanded mode and in the grid-connected mode operations. Stability of the microgrid structure is necessary for providing transient stability using intelligent optimization methods to eliminate the abovementioned difficulties that affect power quality. This paper presents optimization and control techniques that can be used to provide transient stability in the islanded or grid-connected mode operations of a microgrid comprising renewable energy sources. The results obtained from these techniques were compared, analyzing studies in the literature and finding the advantages and disadvantages of the various methods presented. Thus, a comprehensive review of research on microgrid stability is presented to identify and guide future studies.
One of the most significant issues arising from the intermittency of renewable sources is the discrepancy between the hours of peak generation and hours of peak load. This issue complicates the ...process of supply and demand balancing because the electrical energy generated by photovoltaic arrays cannot be directly stored. Energy storage systems provide a solution to this issue by storing the excess energy generated during peak generation time which will be delivered to the grid during peak load, increasing system energy efficiency. In this work, the possibility of utilizing a Megawatt scale energy storage system, such as a battery bank, to improve the efficiency of a proposed 10-MW Biglow Canyon solar array through solar peak shaving is discussed in detail. With an overview of the benefits of peak shaving and a comparative study of energy storage technologies, an assessment of the most suitable commercially available storage systems is broadly discussed in the paper. Three control algorithms based on battery storage, state of charge, and constant output are proposed to balance the difference between generation and usage using appropriate energy storage system. Simulations are performed with System Advisor Model software to gain an insight of the possible losses and to forecast the monthly energy production costs.
Renewable energy sources are becoming a popular choice of energy, due to their sundry advantages and more convenient environmental impacts. Wind certainly emerges as one of the most plausible energy ...sources in modern power generation. However, large-scale wind energy is associated with fluctuations in voltage and power due to its intermittent nature. The proposed pumped hydroelectric energy storage system offers one of the best solutions in solving this problem. It is shown that large-scale integration of wind energy becomes more feasible and efficient when a proper energy storage system is added to achieve appropriate energy charging or discharging. Upon comparing the potential of different storage systems, pumped hydroelectric energy storage is found to be highly promising for wind integration. In order to demonstrate the behavior of the integrated system with respect to time constant and to verify the feasibility of the energy storage in different case studies, simulations are performed in Matlab/Simulink. This work would open new doors toward the investigation of large-scale wind power integration. It is also expected that pumped hydroelectric energy storage would become a possible alternative for energy reserves for large-scale wind power applications.
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