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The power transformer is one of the most important equipments that has a critical role in good electrical power delivery. Ageing of paper insulation inside the transformer is irreversible and hugely related to the operation of power transformer. This study involved inspection data from in-service and out-of-service 150 kV power transformers provided by the Indonesian electric company. The degree of polymerization (DP) of the cellulose paper insulation and furanic compound in the insulating oil can be used to estimate the transformer's lifetime. In this study, the correlation between HI decreasing rate (HI dec_rate ) and the loading factor of 115 transformers historical data was observed. The DP of the transformer paper was predicted (DP pred ) using the ANFIS model using the dielectric characteristics and dissolved gases as input. The results show that the correlation between the DP pred decreasing rate (DP dec_rate ) and the loading factor is more significant than that between the HI dec_rate and the loading factor

In this contribution a possibility of electrochemical production of chlorine for water disinfection, by using photovoltaic panels from solar energy, is described. A simple way of chloride production by means of a photovoltaic panel, comparable with classical electrical power source was performed on an experimental device. By using photovoltaic panel with nominal output 50 W and solar irrigation 380 – 550 W/m2 chlorine production was 0.3 mg/min, which represents amount of chlorine sufficient for disinfections of approximately 4000 l water per day.

The usage of palm oil empty fruit bunches (EFBs) in the gasification process adds value to the empty bunches as a renewable energy source. In this study, we design and manufacture a new updraft type of gasifier reactor without a blower so that it does not require electric power in its operation, but uses power from engine suction. Our test results compare the use of biomass waste in conjunction with diesel fuel to run a diesel power plant for 20 min at a load of 10,000 W: diesel with coconut shell charcoal (350 mL), diesel with acacia wood charcoal (380 mL), and diesel with EFB charcoal (400 mL). The test shows that the highest efficient and the most optimal biomass in the gasification process is coconut shell charcoal, because coconut shell charcoal has a dense structure and, at the time of the experiment, the coconut shell charcoal was filled 15 cm below the gas outlet pipe hole. From the standpoint of the economic value of the gasifier reactor that is proposed in this study, the result with the lowest cost is that of diesel with EFB charcoal, because, in this experiment, EFBs were the biomass that was not purchased. The additional use of empty fruit bunches of charcoal is able to save 50% diesel usage.

Solar energy, wind energy etc. are the main sustainable energy sources used around the world. These sustainable energy sources are used in day-to-day life in various forms for numerous purposes. One of the highly used sustainable energy sources is the solar energy which with the help of photovoltaic (PV) cells can be made use for the generation of electrical power. However, these sources generate less voltage values and thus it requires a high gain converter. In this paper, a modified Luo with flyback DC to DC converter is presented that assures high voltage gain, single switch, less stress across the components and less ripple current. Furthermore, the simulations along with the hardware prototype for the presented converter is carried out and presented in this paper.

In this paper, balancing electricity production using renewable energy such as wind power, PV cells, hydropower, and CHP (combined heat and power) with biomass is carried out in relation to electricity consumption in primarily one major region in Sweden, SE-3, which contains 75% of the country’s population. The time perspective is hours and days. Statistics with respect to power production and consumption are analyzed and used as input for power-balance calculations. How long periods are with low or high production, as well as the energy for charge and discharge that is needed to maintain a generally constant power production, is analyzed. One conclusion is that if the difference in production were to be completely covered with battery capacity it would be expensive, but if a large part of the difference were met by a shifting load it would be possible to cover the rest with battery storage in an economical way. To enhance the economy with battery storage, second-life batteries are proposed to reduce the capital cost in particular. Batteries are compared to hydrogen as an energy carrier. The efficiency of a battery system is higher than that of hydrogen plus fuel cells, but in general much fewer precious materials are needed with an H2/fuel-cell system than with batteries. The paper discusses how to make the energy system more robust and resilient.

У даній роботі було спроектовано промислово – опалювальну ТЕЦ для міста Кривий Ріг, із потребою у гарачій воді по графіку 150/70 0С 1000 МВт; із потребою у парі 1,3...1,5 МПа 1100 т/год; частка ГВП – 17%, вентиляції – 7%; кількість годин використання втановленої електричної потужності – 6250 год/рік; Основне паливо – АШ. Резервне паливо- мазут. На основі техніко-економічних розрахунків і порівняльного аналізу варіантів основного обладнання було обрано оптимальний варіант, який є найекономічнішим. Для покриття необхідного навантаження в гарячій воді та парі вибрані турбіни типу ПТ-135/165-130/15. Кількість турбін – 4 шт. У роботі надано детальний опис основного обладнання ТЕЦ, зроблено вибір допоміжного обладнання, проведено розрахунок теплової схеми та екологічний розрахунок. Виконані розрахунки стосовно паливного господарста (вугілля та мазут), розроблена схема підготовки води. В екологічному розрахунку було визначено шкідливі викиди оксидів сірки та азоту, а також розрахована необхідна висота димової труби для безпечної роботи станції. Також у роботі описано компоновку головного корпусу і допоміжних господарств. In this work, an industrial and heating CHP plant was designed for the city of Kryvyi Rih, with a demand for garage water according to the schedule of 150/70 0C 1000 MW; with a demand for steam of 1.3...1.5 MPa 1100 t/h; the share of hot water supply is 17%, ventilation - 7%; the number of hours of use of the installed electric power is 6250 h/year; the main fuel is ASH. The reserve fuel is fuel oil. Based on feasibility studies and a comparative analysis of the main equipment options, the optimal option was selected, which is the most economical. To cover the required load in hot water and steam, turbines of the PT-135/165-130/15 type were selected. The number of turbines is 4 pcs. The paper provides a detailed description of the main equipment of the CHP plant, selects auxiliary equipment, calculates the thermal scheme and performs environmental calculations. Calculations were made for the fuel economy (coal and fuel oil), and a water treatment scheme was developed. The environmental calculation determined the harmful emissions of sulfur and nitrogen oxides and calculated the required chimney height for safe operation of the plant. The paper also describes the layout of the main building and auxiliary facilities.

У даній роботі було спроектовано промислово – опалювальну ТЕЦ для міста Павлоград. На основі техніко-економічних розрахунків і порівняльного аналізу варіантів основного обладнання було обрано оптимальний варіант ТЕЦ з двома турбінами типу Т-110/120-130 та трьома турбінами з протитиском типу Р-50-130/13, три пікових водогрійних котли КВ-ГМ-180 та 5 парових котлів типу БКЗ-420/140-5, який є найекономічнішим. У роботі надано детальний опис основного обладнання ТЕЦ, зроблено вибір допоміжного обладнання, проведено розрахунок теплової схеми та екологічний розрахунок. В екологічному розрахунку було визначено шкідливі викиди оксидів сірки та азоту, а також розрахована необхідна висота димової труби для безпечної роботи станції. Також у роботі описано компоновку головного корпусу і допоміжних господарств. In this paper, we have designed an industrial and heating CHP plant for the city of Pavlohrad. On the basis of technical and economic calculations and comparative analysis of the main equipment options, the optimal variant of the CHP plant with two turbines of the T-110/120-130 type and three backpressure turbines of the P-50-130/13 type, three peak water boilers KV-GM-180 and 5 steam boilers of the BKZ-420/140-5 type was selected, which is the most economical. The paper provides a detailed description of the main equipment of the CHP plant, selects auxiliary equipment, calculates the thermal scheme and performs an environmental calculation. In the environmental calculation, the harmful emissions of sulfur and nitrogen oxides were determined, and the required chimney height for safe operation of the plant was calculated. The paper also describes the layout of the main building and auxiliary facilities.

Solar photovoltaic power plants are in rapid expansion throughout the world, with the total area occupied by panels being linked to the total electrical power produced. This paper considers this case as an instance of the generic problem of estimating the total area occupied by a class of interest in spaceborne hyperspectral images. As the spatial resolution characterizing these sensors is too coarse, spectral unmixing techniques identify the contribution of a specific material to the spectrum related to a single image element. Final results are obtained by summing all contributions in an area of interest, and favourably compared to pixel-based detection, also using higher resolution Sentinel-2 data. The data used in this paper are acquired by the currently operative DESIS sensor, mounted on the International Space Station, encouraging the use of spaceborne imaging spectrometers for such applications.

This paper presents the PLC-Based system for controlling the SCR power module which is AC–DC converter proposes to linearity output voltage with trigger signal. The technique converted the trigger signal by arccosine function and analog module in the PLC. Converted signal from PLC system is fed to SCR power module instant the traditional signal. Proposed of this paper describes the PLC hardware configuration, compute/math and trigonometric functions with Studio 5000 software. In addition, the interfacing, parameters configuration, and monitoring are considered for testing. The technique with PLC-based, devices configuration and experimental results have been presented will be useful for electric power supply in the industry with more and more demand to apply the PLC system to develop the traditional industry to semi or automatic control in the industry.

The United Arab Emirates is currently building and operating four units of the APR-1400 developed by a South Korean vendor, Korea Electric Power Corporation (KEPCO). This paper attempts to perform APR-1400 reactor core analysis by using the well-known two-step method. The two-step method was applied to the APR-1400 first cycle using the open-source nodal diffusion code, KOMODO. In this study, the group constants were generated using CASMO-4 fuel transport lattice code. The simulation was performed in Hot Zero Power (HZP) at steady-state and transient conditions. Some typical parameters necessary for the Nuclear Design Report (NDR) were evaluated in this paper, such as effective neutron multiplication factor, control rod worth, and critical boron concentration for steady-state analysis. Other parameters such as reactivity insertion, power, and fuel temperature changes during the Reactivity Insertion Accident (RIA) simulation were evaluated as well. The results from KOMODO were verified using PARCS and SIMULATE-3 nodal core simulators. It was found that KOMODO gives an excellent agreement.

Grid codes play a significant role in setting power system characteristics, such as ramp rate of different kinds of power plants. Using novel energy sources, like solar energy, for supplying electrical power demands, develops the requisite for controlling the characteristics of these sources such as their power ramp rates. While solar power is going to increase or decrease, ramp rate control is crucial. There have been suggested different strategies for power ramp rate control. Some of these strategies need batteries and some do not. Due to solar radiation uncertainties, it is necessary to use energy storage systems to control power ramp rate. On the other hand, batteries add huge costs and unreliability to the power systems. As a result, there is a trading-off among initial cost, reliability, security, and operation costs for selecting an optimal strategy. Also significance of the grid is a decisive factor. In this paper, some power ramp rate control schemes are discussed, and the advantages and disadvantages of different types of schemes have been analyzed. Also, in this literature different kinds of power ramp rate control strategies for photovoltaics have been clustered into some major sets. Besides, power ramp rate control is essential for novel schemes such as virtual synchronous machines, so emerging virtual inertia in novel power grids is another motivation to establish different methods for controlling the power ramp rate of renewable energy sources. Thus, in this paper, there is a section discussing the applications of power ramp rate control schemes.

Energy coming from large hydroelectric plants is recognized worldwide due to the great environmental impact caused by the deviation of the rivers during the construction period and the dams while they are operating. This paper shows the design and construction of a micro hydroelectric power plant (MHPP) that was carried out in Cundinamarca Department, in Colombia, in order to analyze the feasibility of generating electric power with micro-power plant, which can be dispatched to the National Interconnected System, taking into account technical and economic aspects for the recovery of the investment. On the other hand, different scenarios are considered, such as self-consumption or the sale of energy to users of the rural sector that are close to the project, performing the financial analysis with economic indicators such as Internal Rate of Return, Uniform Annual Equivalent Cost and Net Present Value. These types of initiatives take special relevance in Colombia because the country issued Law 1715 of 2014, whose purpose is to improve energy reliability, it supports these kinds of projects with tax incentives such as: Discount of Value Added Tax (19%), 50% deduction of the income tax for up to five (5) years and elimination of the tariff levies for the equipment that make up the project. Based on the considerations above and because of the testing of the 24 kVA micro hydroelectric power plant, a paper that deals with the entire construction process of the micro-plant has been prepared, which includes: Flow capacity, turbine selection, selection of the generator, design of the electrical installations and commissioning to verify the effective value of the energy generated and the feasibility of being dispatched to the National Interconnected System.

Today, power generation from clean and renewable resources such as wind and solar is of great salience. Smart grid technology efficiently responds to the increasing demand for electric power. Intelligent monitoring, control, and maintenance of wind energy facilities are indispensable to increase the performance and efficiency of smart grids (SGs). Integration of state-of-the-art machine learning algorithms and vision sensor networks approaches pave the way toward enhancing the wind farms performance. The generating power in a wind turbine farm is the most critical parameter that should be measured accurately. Produced power is highly related to weather patterns, and a new farm in a near area is also likely to have similar energy generation. Therefore, accurate and perpetual prediction models of the existing wind farms can be led to develop new stations with lower costs. The paper aims to estimate the angular velocity of turbine blades using vision sensors and signal processing. The high wind in the wind farm can cause the camera to vibrate in successive frames, and the noise in the input images can also strengthen the problem. Thanks to couples of solid computer vision algorithms, including FAST (Features from Accelerated Segment Test), SIFT (Scale-Invariant Feature Transform), SURF (Speeded Up Robust Features), BF (Brute-Force), FLANN (Fast Library for Approximate Nearest Neighbors), AE (Autoencoder), and SVM (support vector machines), this paper accurately localizes the Hub and track the presence of the Blade in consecutive frames of a video stream. The simulation results show that determining the hub location and the blade presence in sequential frames results in an accurate estimation of wind turbine angular velocity with 95.36% accuracy. (C) 2021 The Authors. Published by Elsevier Ltd.

The contribution of solar photovoltaic (PV) in the electrical power sector is increasing expeditiously. Recent interest in the integration of solar PV into the grid raises concerns about the synchronization technique. Continuous research has successfully replaced the small stand-alone system with a grid-tied PV system. A grid-tied PV system is popular due to the abundance of solar light and advanced power electronics techniques. This paper helps to provide a basic conceptual framework to develop a superior grid-tied system. Synchronization is a crucial problem in grid-tied inverters operation and control research indicates that frequency, phase, and amplitude of voltage are the most crucial parameters that need to be measured and controlled for grid-tied application. This paper presents the state of the art of various synchronization methods for both single-phase and three-phase units. A phase-locked loop (PLL) is a popular grid synchronization approach, which needs to sustain power system oscillations as its vulnerability influences the produced reference signal. Traditional PLL catches the frequency and phase through feedback loop-filter (LF) to improve steady-state capability during adverse grid conditions. The review paper focuses on the power stages architecture of PV fed grid synchronization along with a comparison of various PLL techniques based on their merits and demerits. This paper will be the one-stop reference for the researchers in the area of PV-fed grid.

Energy harvesting in the railway industry has great potential for many applications. Energy harvesters can provide electrical power for track-side, on-board, and infrastructure instruments, including health monitoring sensors, signaling, switches, and safety equipment. Due to the rapidly growing trend of the railway network, a considerable number of instrumentations need to be located in inaccessible, remote, and harsh locations where providing the energy through cable is almost impossible. In these cases, self-powered sensors and distributed power generators can be used based on energy harvesting techniques. High-intensity sound and vibration levels in the railway environment prove them to be promising sources of energy for self-powered devices. This paper aims to provide a comprehensive review on the railway sound and vibration energy harvesting, from the beginning to the most state-of-the-art. This paper addresses different energy harvesting resources for the railway environment, diverse methods of energy harvesting and their advantages and drawbacks, and at the end, energy harvesting applications in the railway industry. Different models and prototypes of energy harvesters are introduced and compared. Finally, the potential applications of railway energy harvesting are addressed, and future challenges and trends are discussed. The scheme of the present paper is designed in a way to provide readers the most significant principles that need to be considered in the design of railway energy harvesters.

This research paper attempts to investigate both the long-run and causality relationship among electric power consumption (EPC), technological transfer, financial development (FD), and environmental quality for the Saudi Arabia (KSA) economy from 1980 to 2019. In doing so, we propose a carbon emission function tested by incorporating multi-steps techniques such as autoregressive distributed lag (ARDL) has been exploited to determine the existence of cointegration or no; while vector error correction model (VECM) has been applied to decide the direction of causality. In this paper we have proposed two proxies of technological transfer, namely imported technology (MT) and Technical cooperation grants (TCG). The results indicate the existence of cointegration between the concerned series. Besides, the existence of a feed-back effect among variables (except TCG) in the long-run. However, in the short run feed-back effect exists among EPC and EnvQ; MT and EnvQ; EPC and MT. Thus, the paper provides original visions for policy makers to encourage the technological transfer by financing and supporting the electric energy sector which constitutes the main locomotive to improve the environment quality for the KSA.JEL classification : C32, C52, O11, Q43

Life Cycle Climate Performance (LCCP) is a widely accepted metric to evaluate the carbon footprint of air conditioning (AC) systems “from cradle to grave.” This paper: (1) reviews the invention and evolution of LCCP, including a comprehensive timeline and bibliography; (2) documents the successful application of LCCP in the replacement of HFC-410A with HFC-32 in room air conditioners; (3) compares the conceptual frameworks and the operational approaches; and 4) reflects on the drawbacks of current LCCP research and points out possible future work. The major policy-relevant findings are: 1. The indirect emissions caused by energy consumption is 70 to 80 percent of the LCCP of AC systems in most countries but will decline in importance as electric power supply shifts rapidly from fossil fuel to renewable energy sources, which have near-zero carbon intensity; 2. The embodied greenhouse gas (GHG) emissions in refrigerant manufacture are, in most cases, negligible but the physical and chemical properties are crucial for system optimization for low carbon footprint; 3. The LCCP metric can be used for multiple purposes such as refrigerant selection and AC system architecture optimization; and 4. Data limitations in material manufacturing and the carbon intensity of electric power are the most significant challenges. Finally, this paper describes a variety of methods to fill in data gaps, including the correction factor method, the data-driven method, and the database searching method. The next-generation LCCP will be an enhanced evaluation process considering local climate, heat islands, and local power supply characteristics.

This paper provides an overview of hyperloop technologies, including a brief discussion of key components of a hyperloop system that determine the electric power requirements as a function of time. At-scale hyperloop systems do not yet exist, so a model was used to generate a set of load profiles for conceptual hyperloop realizations at four locations in the United States: two systems in California and one each in Colorado and Ohio. In all four cases, the modeled hyperloop load profiles included pulses in both active and reactive power. Grid modeling was performed to estimate the grid impacts and for discussing grid integration challenges. The paper discusses how energy storage systems might be used to eliminate the pulsating load characteristics or significantly reduce it to accommodate current grid planning guidelines.

This paper reviews and compares the main doubly-fed induction generator (DFIG) models for stability assessment in the literature by PSCAD/EMTDC simulation. The main contribution of the paper is a detailed study on small- signal admittance-based modeling of DFIGs for stability analysis. A complete DFIG model characterized from a 2x2 admittance-based transfer matrix is proposed which has frequency coupling between positive and negative sequences resulting from considering the PLL and the DC capacitor. In addition, two simplified DFIG models in the literature are derived from the complete model and discussed. The models are applied to stability analysis using the generalized Nyquist criterion and the positive-mode-damping stability criterion. The predictions are validated for several mechanical speeds and short-circuit ratios by PSCAD/EMTDC time-domain simulation. The study shows the need to apply the complete model to accurately assess subsynchronous stability, as significant differences from simplified models may occur at low frequencies.

Compared to their predecessors, the next generations of aircrafts will be more electrified, require more electrical power and operate at higher voltage levels to meet strict weight and volume constraints. The combined effect of low-pressure environments, increased voltage levels and compact designs intensifies the risks of premature insulation degradation due to electrical discharge activity. This paper studies the resistance to surface discharges of PTFE (polytetrafluoroethylene) and ETFE (ethylene tetrafluoroethylene), two insulation materials widely used in today’s aircraft wiring systems due to their outstanding properties, such as a wide temperature operation range and a high dielectric strength. The study is carried out in a low-pressure chamber, which was pressurized within the pressure range of 10–100 kPa that includes most aircraft applications. There is a compelling need for experimental data to assess the resistance of insulation materials to surface discharges at a very early stage as a function of the environmental pressure. Data on resistance to surface discharges in low-pressure environments for aeronautical applications are lacking, while most standards for insulation systems are based on tests under standard pressure conditions. The results provided in this work can be useful to design wiring systems for future more electric aircrafts, as well as to design fault detection systems for an early detection and identification of faults related to surface discharges. Therefore, the data and analysis included in this paper could be of great interest to design and develop insulation systems for wiring systems and standard assessment methods, as well as to design fault detection strategies for the early detection and identification of surface discharges for future generations of more electric aircrafts. This research was partially funded by the Ministerio de Ciencia e Innovación de España, grant number PID2020‐114240RB‐I00 and by the Generalitat de Catalunya, grant number 2017 SGR 967.

Reliability in the supply of electricity depends on isolation from the electrical power system. Insulators are components that have the function of insulating and supporting the electrical grid. The design of electrical distribution network insulators can have a great influence on the distribution of the electric field over its surface. When there is a great intensity of electric field applied specifically in a location, there may be a greater chance of the development of a fault. An optimized insulator profile design can ensure that the network has better performance. In this paper, particle swarm optimization is applied to optimize the profile of an insulator of the conventional electric power grid, based on the electrical potential data obtained using the finite element method, defined in this paper as optimized finite element method. The component parameters are optimized to obtain a parametric model. The parametric model is evaluated and compared with the usually employed profiles to define an optimized design. The results show that the proposed method is a promising alternative for the design of electrical energy distribution insulators.

An uninterrupted chain of energy supplies is the core of every activity, without exception for the operations of the North Atlantic Treaty Organization. A robust and efficient energy supply is fundamental for the success of missions and a guarantee of soldier safety. However, organizing a battlefield energy supply chain is particularly challenging because the risks and threats are particularly high. Moreover, the energy supply chain is expected to be flexible according to mission needs and able to be moved quickly if necessary. In line with ongoing technological changes, the growing popularity of hydrogen is undeniable and has been noticed by NATO as well. Hydrogen is characterised by a much higher energy density per unit mass than other fuels, which means that hydrogen fuel can increase the range of military vehicles. Consequently, hydrogen could eliminate the need for risky refuelling stops during missions as well as the number of fatalities associated with fuel delivery in combat areas. Our research shows that a promising prospect lies in the mobile technologies based on hydrogen in combination with use of the nuclear microreactors. Nuclear microreactors are small enough to be easily transported to their destinations on heavy trucks. Depending on the design, nuclear microreactors can produce 1–20 MW of thermal energy that could be used directly as heat or converted to electric power or for non-electric applications such as hydrogen fuel production. The aim of the article is to identify a model of nuclear-hydrogen synergy for use in NATO operations. We identify opportunities and threats related to mobile energy generation with nuclear-hydrogen synergy in NATO operations. The research presented in this paper identifies the best method of producing hydrogen using a nuclear microreactor. A popular and environmentally “clean” solution is electrolysis due to the simplicity of the process. However, this is less efficient than chemical processes based on, for example, the sulphur-iodine cycle. The results of the research presented in this paper show which of the methods and which cycle is the most attractive for the production of hydrogen with the use of mini-reactors. The verification criteria include: the efficiency of the process, its complexity and the residues generated as a result of the process (waste)—all taking into account usage for military purposes.

Battery energy storage systems (BESSs) are key components in efficiently managing the electric power supply and demand in microgrids. However, the BESSs have issues in their investment costs and operating lifetime, and thus, the optimal sizing of the BESSs is one of the crucial requirements in design and management of the microgrids. This paper presents a problem framework and its solution method that calculates the optimal size of the BESSs in a microgrid, considering their cooperative operations with the other components. The proposed framework is formulated as a bi-level optimization problem; however, based on the Karush–Kuhn–Tucker approach, it is regarded as a type of operation scheduling problem. As a result, the techniques developed for determining the operation schedule become applicable. In this paper, a combined algorithm of binary particle swarm optimization and quadratic programming is selected as the basis of the solution method. The validity of the authors’ proposal is verified through numerical simulations and discussion of their results.

To reduce peak demand for electricity, smooth load curve shape, improvepower system safety and efficiency, this paper, by using intelligent homeappliance user operation comfort model is set up to quantify the acceptance,this paper proposes a maximum minimum load management algorithm basedon optimization strategy to change electric power use time and power con-sumption mode.The results show that the proposed model and algorithm canforecast and manage the power load well, and can reduce the peak to averageratio by 14.3% and the total expenditure by 15.3% while maintaining theoperating comfort of power users to the maximum.The load managementproblem of multiple power users can reach Nash equilibrium in a finitenumber of iterations, and this Nash equilibrium point is also the globaloptimal point.

This paper is aimed at proposing a short-term hybrid energy system robust optimization model for regional energy system planning and air pollution mitigation based on the inexact multi-stage stochastic integer programming and conditional value-at-risk method through a case study in Shandong Province, China. Six power conversion technologies (i.e., coal-fired power, hydropower, photovoltaic power, wind power, biomass power, and nuclear power) and power demand sectors (agriculture, industry, building industry, transportation, business, and residential department) were considered in the proposed model. The optimized electricity generation, capacity expansion schemes, and economic risks were selected to analyze nine defined scenarios. Results revealed that electricity generations of clean and new power had obvious increasing risks and were key considerations of establishing additional capacities to meet the rising social demands. Moreover, the levels of pollutants mitigation and risk-aversion had a significant influence on different power generation schemes and on the total system cost. In addition, the optimization method developed in this paper could effectively address uncertainties expressed as probability distributions and interval values, and could avoid the system risk in energy system planning problems. The proposed optimization model could be valuable for supporting the adjustment or justification of air pollution mitigation management and electric power planning schemes in Shandong, as well as in other regions of China.

Ocean energy is a kind of renewable energy contained in seawater, which has the characteristics of large total reserves, sustainable use, and its being green and clean. Influenced by rising oil prices and global climate change, an increasing number of countries are attaching great importance to the strategic position of ocean energy in the future energy sector, and are formulating national ocean energy development roadmaps and conducting research and development on ocean energy technologies. Ocean current energy is a widely existing kind of ocean energy with abundant reserves. However, due to the low current velocity in most of the deep sea, low current energy has not been effectively exploited. In this paper, the Blade element momentum (BEM) theory based on Vortex column theory is used to design a special airfoil for low current energy applications, and a prototype turbine with rotor diameter of 4.46 m and tip speed ratio (TSR) of 6 is fabricated. In order to achieve stable electric power output, this paper designs a hydraulic conversion power generation control system with flexible control, and the hydraulic system working pressure designed to 21 MPa. In this paper, we conducted towing experiments on the prototype of an ocean current energy turbine, with hydraulic transmission and a control power generation system applied to the low flow rate, and achieved the target of hydraulic motor speed in the range of 14.7~15.9 r/min and steady-state speed accuracy in the range of ±1%. The research conducted in this paper can provide a research basis for the efficient exploitation of low-flow ocean current energy.

The integration of hybrid renewable energy sources (HRESs) into the grid is currently being encouraged to meet the increasing demand for electric power and reduce fossil fuels which are causing environmental-related problems. Integration of HRESs into the grid can create some power quality (PQ) problems. To mitigate PQ problems and improve the performance of grid-connected HRESs some flexible devices should be used. This paper presents a distributed power flow controller (DPFC), as a type of flexible device to mitigate some PQ problems, including voltage sag, swell, disruptions, and eliminating the harmonics in a hybrid power system (HPS). The HPS presented in this work comprises a photo voltaic (PV) system, wind turbine (WT) and battery energy storage system (BESS). As a result, black widow optimization (BWO) with DPFC with real and reactive power (DPFC-PQ) is built in this paper to solve the PQ issues in HRES systems. The main aim of the work is to mitigate PQ problems and compensate for load demand in the HRES scheme. The controller used to drive this DPFC-PQ is a fractional-order PID (FOPID) controller optimized by the black widow optimization (BWO) technique. To assess the capability of BWO in fine-tuning the FOPID controller parameters, twelve optimization techniques were presented: P&amp, O, PSO, Cuckoo, GA, GSA, BBO, Whale, ESA, RFA, ASO, and EVORFA. Additionally, a comparison between the FOPID controller and the classical PI controller is introduced. The results showed that the proposed BWO-FOPID controller for DFPC had mitigated the PQ problems in grid-connected HRESs. The system’s performance with the presented BWO-FOPID controller is compared with eleven optimization techniques used to optimize the FOPID controller and also compared with the conventional PI controller. The design of the proposed system is implemented in the MATLAB/Simulink platform and performances were analyzed.

High rotor temperature of electrical machines can cause a series of insulation failures. In serious cases, it will lead to system operation failure. However, under the condition of high-speed rotation of rotor, the conventional temperature measurement by means of embedded temperature sensor is difficult to be utilized due to the limitation of power and data transmission. This paper proposes a parallel contactless transmission strategy of power and data based on magnetically-coupled resonance and capacitive radio frequency technology. Electric power is transferred contactlessly by means of magnetically-coupled resonance, while the parallel contactless transmission of data signals is realized by means of capacitive radio frequency technology. The experimental prototype was developed and installed on a 22kW induction motor. The results show that the clear data signal can be received on the stator side without filtering to realize parallel wireless transmission of electric energy and rotor temperature data. The research results of this paper can provide a good technical scheme for contactless rotor temperature measurement of large and medium-sized electrical machines.

This paper has tried to execute accurate demand forecasting by utilizing big data visualization and proposes a flexible and balanced electric power production big data virtualization based on a photovoltaic power plant. First of all, this paper has tried to align electricity demand and supply as much as possible using big data. Second, by using big data to predict the supply of new renewable energy, an attempt was made to incorporate new and renewable energy into the current power supply system and to recommend an efficient energy distribution method. The first presented problem that had to be solved was the improvement in the accuracy of the existing electricity demand for forecasting models. This was explained through the relationship between the power demand and the number of specific words in the paper that use crawling by utilizing big data. The next problem arose because the current electricity production and supply system stores the amount of new renewable energy by changing the form of energy that is produced through ESS or that is pumped through water power generation without taking the amount of new renewable energy that is generated from sources such as thermal power, nuclear power, and hydropower into consideration. This occurs due to the difficulty of predicting power production using new renewable energy and the absence of a prediction system, which is a problem due to the inefficiency of changing energy types. Therefore, using game theory, the theoretical foundation of a power demand forecasting model based on big data-based renewable energy production forecasting was prepared.

The evaluation of electrical load estimation is requisitely of any electrical power system. This manner is needed for system obligation, economical distribution and maintenance time of electrical system. In this paper, we propose electrical load estimation method based on fuzzy inference system which gives accurate results for estimated loads in Iraq (Diyala governorateBaaquba city). And it can assist the electrical generation and distribution system that depends on important parameters (temperature, humidity and the speed of the wind). By considering the parameters temperature, humidity and the speed of the wind. These parameters are applied as inputs to the fuzzy logic control system to obtain the normalize estimated load as output by electing membership functions. It is exceptionally valuable to form a choice by taking into consideration these assessed readings that come to from the proposed FIS that displayed in this paper with precision of 0.969 from the real stack request.

This paper introduces a new analytical method for the 3-dimensional analysis of heat sources installed underground. Such sources include primarily electric power cables and steam pipes in urban areas. For complex arrangements of the heat sources, the heat transfer and cable rating calculations require the application of numerical methods, which call for high level of expertise and are generally difficult to use. The computational algorithm presented in this paper uses a point sources approach and is an extension of the work published by the authors based on line source modeling, with the goal of simplifying the numerical calculations. The proposed approach is applicable for all heat sources, which are directly buried in a uniform or a partially dried out soil. The method is illustrated by several numerical examples. These examples are used for comparison with the existing standard approach.

As one of the core businesses of power grid enterprises, power marketing is not only a direct source of income for power grid enterprises, but also an important communication window between power grid enterprises and power users and power generation enterprises. The quality of electric power marketing will directly affect the company’s financial status and corporate image, which is the key work of leaders at all levels of power grid enterprises. As an important part of marketing business, electric power marketing audit plays a role in standardizing electricity consumption behavior of power users and maintaining normal electricity price order. This paper proposes to use big data algorithm to analyze customers’ illegal electricity use behavior. Taking the power supply company as an example, this paper uses big data algorithm to mine and analyze the data related to marketing business, so as to realize the judgment and early warning of users’ abnormal electricity use characteristics.

The paper presents a method for obtaining analytical dependences of the heat pump heat capacity and electrical power on the environment and the coolant parameters. A model based on polynomial approximation in two independent parameters is offered. The paper shows the model identification for the 7.5-12.5 kW air-to-water heat pumps from one manufacturer. The accuracy of the obtained model is estimated.

The global power industry is at the brink of a revolutionary change. For the survival of humanity, it is essential to tackle the grave issue of climate change. The power industry needs to shift to the utilization of clean energy to sustain the increasing energy demands without affecting the environment. Therefore, it is important to establish a power network which is sustainable, free fuel-based, ultra-low-cost, and reliable power network. This paper discusses solar and wind power as a sustainable energy source for such a power network. In addition to energy sources, the storage system to support the power infrastructure is discussed. The role of power electronics in reducing the cost of electrical power is also discussed. Finally, the paper is concluded along with a brief discussion.

Climate change problems cannot be addressed without a transformation of the energy production sector, since it is responsible for a significant share of total greenhouse gas emissions. For this reason, governments are promoting the use of Renewable Energy Sources (RES), especially wind and solar. In order to increase the penetration of RES, whose energy production cannot be controlled to follow the demand, more and more energy storage systems are needed, for ensuring adequacy and security to electrical power systems. This paper is focused on an innovative thermal energy storage technology based on fluidized solid particles, capable of receiving energy as electricity and storing it as heat for later use, e.g. produce steam for industrial applications. In such a system, electric energy is converted to heat by means of resistors, that can be supplied with AC and/or DC sources. In the paper, different use-case scenarios are presented, involving the grid and/or a photovoltaic plant as electric power sources. Then some possible configurations for power converters are described and compared, to find the most appropriate solution for each use-case scenario.

Among the various types of renewable energy sources (RES), the photovoltaic (PV) generators play a very significant role in the production of electrical power, as the technology of these generators has been well perceived for a long period. These generators have been trusted to be environment-friendly. In this paper, mainly photovoltaic (PV) system-generated power has been designed and installed for energy production. This paper aims to present a solar power predictive analysis using deep neural networks (DNNs). A variant of recurrent neural network (RNN), namely long short-term memory (LSTM), has been used to model a photovoltaic (PV) grid-connected array output and approximate the generated power. A new algorithm is proposed for assessing the PV power for different array setups. An extensive comparative study using the DNN techniques is performed for evaluating different types of grid-connected array setups. This study is beneficial for the reader and useful for engineers and researchers interested in DNNs applied to solar photovoltaic systems data generation.

As promising solutions to various social and environmental issues, the generation and integration of renewable energy (RE) into microgrids (MGs) has recently increased due to the rapidly growing consumption of electric power. However, such integration can affect the stability and security of power systems due to its complexity and intermittency. Therefore, an optimal control approach is essential to ensure the efficiency, reliability, and quality of the delivered power. In addition, effective planning of policies for integrating MGs can help promote MG operations. However, outages may render these strategies inefficient and place the power system at risk. MGs are considered an ideal candidate for distributed power systems, given their capability to restore these systems rapidly after a physical or cyber-attack and create reliable protection systems. The energy management system (EMS) in an MG can operate controllable distributed energy resources and loads in real-time to generate a suitable short-term schedule for achieving some objectives. This paper presents a comprehensive review of MG elements, the different RE resources that comprise a hybrid system, and the various types of control, operating strategies, and goals in an EMS. A detailed explanation of the primary, secondary, and tertiary levels of MGs is also presented. This paper aims to contribute to the policies and regulations adopted by certain countries, their protection schemes, transactive markets, and load restoration in MGs.

As a typical big data representative, the information of global Cellular Signal Strength (CSS), defined as the signal power received by mobile phones, plays an important role in geographic flow analysis, because the density of such information can reflect the urbanization variables such as population, gross domestic product, built-up area, electric power consumption, and etc. Despite the importance, the real-time analysis of global CSS distribution remains a challenging problem due to the large data scale. In this paper, a Display-driven Computing (DisDC) technique is designed and applied to provide efficient large scale interactive CSS visualization, generating results by calculating the value of each pixel that directly for display that can dramatically improve system capacity in big data handling. Specifically, we present an efficient CSS measurement algorithm, which introduces spatial indexes and a corresponding query strategy; besides, an optimized parallel computing architecture is proposed to ensure the ability of real-time visualization. Experiments show that our approach obviously outperforms traditional methods and is capable of handling more than 40 million base stations in real-time. Moreover, an online demonstration is provided at https://github.com/MemoryMmy/CSSMap.

In this paper, an integrated drive converter of segmented-double-stator switched reluctance machine (SDS-SRM) with isolation and non-isolation charging capabilities for electric vehicle (EV) is presented. The proposed converter can not only reduce the number of the power switches, but also implement multiple operation modes. In non-isolation charging mode, the motor windings and existing power switches constitute a buck/boost converter to charge the battery. The appropriate rotor positions are obtained to achieve torque-free control, and the interleaved phase currents control method is introduced to reduce the charging current ripples. In isolation charging mode, the inner-stator is powered by the utility grid to drive the middle-rotor, and converts electrical energy into mechanical energy. While, the outer-stator is operated in generation mode to convert mechanical energy into electrical energy. The SDS-SRM is served as a rotating transformer to transfer the electric power to charge the battery with the galvanic isolation function. A low power proof-of-concept prototype platform is built and experiments are carried out to verify the effectiveness of the proposed integrated drive converter and the corresponding control schemes.

This paper presents a suite of analytics that are proposed to be embedded in next-generation smart sensors in electric power grids. The proposed analytics take the electrical signals as the input and unlock the full potential in signal processing and machine learning for real-time event detection and classification. Meanwhile, a robust synchrophasor estimation mechanism is housed within the proposed sensor technology that will be triggered following a detected event and guides on the adaptive selection of the best-fit (most accurate) synchrophasor estimation algorithms at all times. Embedding such analytics within the sensor and closer to where the waveforms are captured, the proposed distributed intelligence solution technology mitigates the potential risks to communication failures and latencies as well as malicious cyber threats. Our experiments demonstrate that the introduced scheme achieves improved quality of measurements with a promising event detection and classification accuracy, collectively resulting in enhanced online situational awareness in modern power grids.

Producción Científica, The widespread use of devices based on power electronics and other nonlinear loads has led to an increase in harmonic distortion that affects the quality of power systems. Therefore, the correct measurement of harmonic and interharmonic content is necessary. The International Electrotechnical Commission (IEC) standards define the concepts of spectral and time grouping required for such measurements. This paper demonstrates that the procedures defined in the IEC standards are not sufficiently accurate when several close interharmonic tones interact due to the lack of stability of the values that the Discrete Fourier Transform obtains in each sampling window, and to the inaccuracy in the measurement of interharmonic groups and rates when using the Hanning window. This paper proposes novel solutions based on time aggregation and the use of other groupings and alternative windows. The results obtained are compared with the results produced by applying the rectangular window indicated in the standards, using sensitivity analysis varying one of the tones and using experimental results measuring the output signals of frequency inverters driving induction motors. The proposed method achieves greater accuracy and stability in the measurement of spectral groupings and their related distortion rates in signals with abundant and dispersed interharmonic content.

Resumen: Las celdas de combustible microbianas son una tecnología emergente que pretende tratar de manera biológica diferentes efluentes residuales mientras que simultáneamente se genera energía eléctrica, por tanto, el presente documento tiene como principal objetivo formular una propuesta de celdas de combustible microbianas a escala laboratorio para la generación de energía eléctrica y tratamiento biológico del suero lácteo producto de la elaboración de queso campesino. Para ello, se construyeron dos configuraciones de celdas de doble cámara interconectadas mediante membranas de intercambio protónico, las cuales varían en su volumen, además del tamaño de los electrodos. Posteriormente, se realizaron ensayos de laboratorio fisicoquímicos del suero lácteo, pre y postratamiento, así como microbiológicos y de energía eléctrica por medio de un multímetro y un conversor análogo digital, con el fin de evaluar el desempeño de las mismas por medio de los modelos estadísticos de correlación de Pearson y Spearman, los cuales permitieron medir la covarianza entre la reducción de materia orgánica y la energía eléctrica generada. A partir de ello, se evidenció una reducción significativa de DBO y DQO alcanzando valores de 75,36% y 76,7% respectivamente, de manera análoga, se registró un máximo valor de voltaje de 0,93V, siendo el diseño experimental de mayor volumen, tamaño de puente de intercambio y electrodo correspondiente a la celda N°2 el más eficiente. Abstract: Microbial fuel cells are an emerging technology that aims to biologically treat different waste effluents while simultaneously generating electricity. Therefore, the main objective of this paper is to formulate a proposal of microbial fuel cells at laboratory scale for the generation of electricity and biological treatment of whey from the production of farmer's cheese. For this purpose, two configurations of double chamber cells interconnected by means of proton exchange membranes, which vary in their volume, as well as in the size of the electrodes, were built. Subsequently, physical-chemical laboratory tests were carried out on the whey pre- and post-treatment, as well as microbiological and electrical energy tests by means of a multimeter and a digital analogue converter in order to evaluate their performance by means of the Pearson and Spearman correlation statistical models, which allowed measuring the covariance between the reduction of organic matter and the electrical energy generated. From this, a significant reduction of BOD and COD was evidenced, reaching values of 75.36% and 76.7%, respectively. Similarly, a maximum voltage value of 0.93V was recorded, being the experimental design with the largest volume, size of the exchange bridge and electrode corresponding to cell N°2 the most efficient. Ingeniero Ambiental Pregrado

This paper presents a comprehensive literature review with focus on the difficulties electric vehicles (EVs) face to charge the battery while on a trip, and proposes a solution without the need of an expensive change in infrastructure. The proposed method charges EVs while en route from another vehicle, which will be referred to as vehicle-to-vehicle recharging (VVR). The aim of this system is to bring an innovative way for EVs to charge their battery without getting off route on a highway. The electric vehicle can request such a service from a designated charger vehicle on demand and receive electric power wirelessly while en route. The vehicles that provide energy (charger vehicles) through wireless power transfer (WPT) only need to be semi-autonomous in order to engage/disengage during a trip. The state-of-the-art is divided into three subsections relevant to the proposed system and where most of the innovations to reduce the burden of charging EVs can be found: (1) infrastructure changes, (2) device level innovations, and (3) autonomous vehicles. The infrastructure changes highlight some of the proposed systems that aim to help EVs become a convenient solution to the public. Device level innovations covers some of the literature on technology that addresses EVs in terms of WPT. And finally, the autonomous vehicle subsection covers the importance of such technology in terms of safety and reliability, that could be implemented on the VVR system. Furthermore, modeling, analysis, and simulation is presented to validate the feasibility of the proposed system.

Integrated power systems (IPSs) are popular in the shipbuilding industry. DC shipboard microgrids (dc-SMGs) have many advantages compared with ac ones in terms of system efficiency, operation flexibility, component size, and fault protection performance. Being in the exploring stage, dc-SMGs have several potential configurations with different system architectures and voltage levels. In a dc-SMG, functional blocks integrated include power generation modules (PGMs), propulsion system, high power loads, and pulse loads specifically in naval ships. In modern ships, the PGMs include not only generators and fuel cells (FCs) but also energy storage systems (ESSs), which cooperate with generators to improve the overall efficiency and reliability. High power electric converters are vital interfaces between the functional blocks and the dc distribution system. Rectifiers for generators take the tasks of dc bus voltage regulation and power sharing. Inverters for propulsion motors are responsible for the motor drive in different operating conditions. Bidirectional dc/dc converters for ESSs are used to provide supply-demand balance and voltage fluctuation mitigation. This paper makes a comprehensive review of power architecture, functional blocks including electrical machines and energy storage, as well as power converters in dc shipboard power systems.

The recent seismic events that occurred in South Korea have increased the interest in the re-evaluation of the seismic capacity of nuclear power plant (NPP) equipment, which is often conservatively estimated. To date, various approaches—including the Bayesian method proposed by the United States (US) Electric Power Research Institute —have been developed to quantify the seismic capacity of NPP equipment. Among these, the Bayesian approach has advantages in accounting for both prior knowledge and new information to update the probabilistic distribution of seismic capacity. However, data availability and region-specific issues exist in applying this Bayesian approach to Korean NPP equipment. Therefore, this paper proposes to construct an earthquake experience database by combining available earthquake records at Korean NPP sites and the general location of equipment within NPPs. Also, for the better representation of the seismic demand of Korean earthquake datasets, which have distinct seismic characteristics from those of the US at a high-frequency range, a broadband frequency range optimization is suggested. The proposed data construction and seismic demand optimization method for seismic capacity re-evaluation are demonstrated and tested on a 480 V motor control center of a South Korea NPP.

Spacecraft operation in ultra-low Earth orbits (150–250 km) can provide advantages for carrying out traditional tasks. At the same time, the long-term maintenance of spacecraft in such orbits requires the delivery of a propellant supply from the Earth to compensate the aerodynamic drag. An increase in the lifetime can be achieved with air-breathing electric propulsion (ABEP) using outboard atmospheric gases as a propellant. To ensure ABEP operation, it is necessary to provide the required electric power supply and density of ionized gas. At the same time, lowering the orbit altitude or extension of solar arrays is accompanied by a rise in aerodynamic drag, the required thrust to compensate it and, therefore, the required power supply. In this paper the problem of integrated optimization of the trajectories and layout parameters of spacecraft by the criterion of the ABEP power consumption at the fixed spacecraft volume is considered. Variations in the density and composition of the atmosphere and the periods of shading of the spacecraft are taken into account. An analytical solution is obtained depending on generalized parameters that combine such characteristics as the specific power of solar arrays, total thruster efficiency and aerodynamic drag coefficient. The dependencies of the orbit characteristics enabling the long-term maintenance of spacecraft with ABEP on the generalized parameters are determined.

Probabilistic wind power forecasting is an important input in the decision-making process in future electric power grids with large penetrations of renewable generation. Traditional probabilistic wind power forecasting models are trained offline and are then used to make predictions online. However, this strategy cannot make full use of the most recent information during the prediction process. In addition, ensemble learning is recognized as an effective approach for further improving forecasting performance by combining multiple forecasting models. This paper studies an online ensemble approach for probabilistic wind power forecasting by taking full advantage of the most recent information and leveraging the strengths of multiple forecasting models. The online ensemble approach is first formulated as an online convex optimization model. On this basis, a quantile passive-aggressive regression model is proposed to solve the online convex optimization model. Case studies and comparisons with other online learning methods are conducted on an open wind power data set from Belgium. Results show that the proposed method outperforms competing methods in terms of pinball loss and Winkler score with high reliability.

Series-connected multi-pulse rectifiers (MPRs) are used to provide high quality electric power for high-voltage and high-power occasions. Due to conventional MPRs have limited harmonic reduction ability that cannot fulfill the related harmonic standard, some effective DC side harmonic reduction methods have been proposed to further improve power quality of the MPRs. This paper gives a comprehensive review on DC link harmonic reduction methods of series-connected MPRs. Passive and active harmonic reduction mechanisms are respectively analyzed based on two typical topologies, which are theoretical foundations for understanding and constructing novel harmonic reduction circuits (HRCs). Some useful DC side HRCs are presented and compared from aspects of their performances, complexity of overall structure, magnetic device capacity and power losses, etc. The necessary simulation results are given to verify and compare the effectiveness of some involved harmonic reduction methods. Based on these topologies, the advantages, drawbacks and future trends of the passive or active methods are concluded; besides, the hybrid harmonic reduction methods are also considered. This article aims to provide useful guidance for the researches of harmonic elimination and multi-pulse rectification technology.

CubeSats have been popular for space research due to lower cost, faster development, and easier deployment. The electrical power system (EPS) is one of the significant subsystem for the CubeSat since it handles power generation, energy storage, and power distribution to all other subsystems. Therefore, the design of EPS becomes crucial for successful CubeSat mission, wherein the first step is the selection of EPS architecture. The main objective of this paper is to present an extensive review of all the conventional and emerging EPS architectures of CubeSats. A total of seventeen categories of CubeSat EPS architectures have been identified, classified, and the operational aspects of these architectures are presented in addition to a qualitative comparison. This study is expected to provide a useful reference guide for all the researchers and developers working in the area of CubeSats EPS. Also, some of the potential research topics are provided to further exploration and innovation for the CubeSat EPS.

Hydrogen has shown great potential in the renewable power integration and urban mobility decarbonization like the hydrogen fuel cell vehicles (HFCVs). The HFCV refueling as an essential hydrogen load is of great flexibility. Considering the HFCV demand response, this paper studies the integrated electric power and hydrogen system (IPHS) operation. First, the HFCV refueling load model is formulated with its routing on the transportation network considered. Second, the optimal IPHS operation model is developed in which the electric power operation, tube-trailer based hydrogen delivery and HFCV refueling are coordinated. Third, a Lagrangian Relaxation (LR) based method is developed to solve the proposed model efficiently, which corresponds to a price-based demand response mechanism for HFCVs. Compared with existing works on IPHS, the influence of transportation networks is delicately analyzed on both HFCV refueling and hydrogen delivery. The case studies have proven the effectiveness of the proposed method and demonstrated that the overall operation cost is decreased via the proper guidance of HFCV refueling. The HFCV demand response shows great potential in exploring the synergy of energy and transportation systems.