再生能源系统中太阳能电池仿真器的研究

提出了一个由直流斩波器构成的太阳能电池仿真器 ,它能模拟太阳能电池的输出特性。试验表明 ,该仿真器的输出特性非常接近实际情况 ,并且动态响应良好 ,可以用在太阳能研究系统中替代太阳能电池板。

风光水氢储一体互补的再生能源制造系统

[目的]为了早日实现国家“2030年碳达峰,2060年碳中和”的双碳目标,[方法]积极改进现时风电、光电互补单元,创新研发水能蓄水发电单元,创新引入氢能源发电单元以及超级电容并联锂、钠电池储电单元等,并以可编程控制器(工业控制专用计算机PLC)、LM358运算放大器、功率继电器及固态功率继电器等为核心将五单元元素合一,取长补短,共同组合成新再生能源制造、生产的“开放式”系统。[结果]该系统可以推广成为家喻户晓的新型普及节能节省设备,能够满足用户通用性和特殊性的全方位需求。[结论]风光水氢储一体互补的再生能源制造系统能够成为实现双碳目标的急先锋。

平流层飞艇再生能源能量平衡的关键技术分析研究

介绍了平流层飞艇再生能源系统的构成及功能,在再生能源能量平衡分析中建立了太阳电池阵列在平流层飞艇曲面铺装的模型和能源闭环模型,分析了能源消耗构成和全天24 h的能量平衡;且实现了太阳电池输出功率的可视化仿真。结果表明平流层飞艇能够在全天实现能量平衡。分析了能源系统的关键技术参数对能源系统的影响,结果显示:锂电池能量密度、太阳电池转换效率和锂电池充电效率是平流层飞艇能源系统的最关键技术参数。研究结果为平流层飞艇能量平衡分析方案论证和方案设计提供参考。

Modeling and optimization of a multi-carrier renewable energy system for zero-energy consumption buildings

For the carbon-neutral,a multi-carrier renewable energy system(MRES),driven by the wind,solar and geothermal,was considered as an effective solution to mitigate CO2emissions and reduce energy usage in the building sector.A proper sizing method was essential for achieving the desired 100%renewable energy system of resources.This paper presented a bi-objective optimization formulation for sizing the MRES using a constrained genetic algorithm(GA)coupled with the loss of power supply probability(LPSP)method to achieve the minimal cost of the system and the reliability of the system to the load real time requirement.An optimization App has been developed in MATLAB environment to offer a user-friendly interface and output the optimized design parameters when given the load demand.A case study of a swimming pool building was used to demonstrate the process of the proposed design method.Compared to the conventional distributed energy system,the MRES is feasible with a lower annual total cost(ATC).Additionally,the ATC decreases as the power supply reliability of the renewable system decreases.There is a decrease of 24%of the annual total cost when the power supply probability is equal to 8%compared to the baseline case with 0%power supply probability.

Multi-objective planning model for simultaneous reconfiguration of power distribution network and allocation of renewable energy resources and capacitors with considering uncertainties

This research develops a comprehensive method to solve a combinatorial problem consisting of distribution system reconfiguration, capacitor allocation, and renewable energy resources sizing and siting simultaneously and to improve power system's accountability and system performance parameters. Due to finding solution which is closer to realistic characteristics, load forecasting, market price errors and the uncertainties related to the variable output power of wind based DG units are put in consideration. This work employs NSGA-II accompanied by the fuzzy set theory to solve the aforementioned multi-objective problem. The proposed scheme finally leads to a solution with a minimum voltage deviation, a maximum voltage stability, lower amount of pollutant and lower cost. The cost includes the installation costs of new equipment, reconfiguration costs, power loss cost, reliability cost, cost of energy purchased from power market, upgrade costs of lines and operation and maintenance costs of DGs. Therefore, the proposed methodology improves power quality, reliability and security in lower costs besides its preserve, with the operational indices of power distribution networks in acceptable level. To validate the proposed methodology's usefulness, it was applied on the IEEE 33-bus distribution system then the outcomes were compared with initial configuration.

Design and Description of a Photovoltaic Pumping System： Application in the Site of Adrar

The Saharan areas and in particular the isolated sites are characterized by low levels of population, in dispersed cores, which suffer from serious problems of water supply for consumption and the irrigation. The photovoltaic pumping systems （PV） are an ideal solution for these problems. Despite the presence of several photovoltaic pumping systems （PVPS） projects, data acquisition system is still missing in most cases. In this work, the authors will present the PVPS installed at the unit of research in renewable energies in Saharan medium （URERMS, Algeria）. This system will enable us to better analyze the performances ofa photovoltaic pumping system in Saharan medium. The principal elements of the chain of the photovoltaic pumping system are： a photovoltaic generator, the power conditioning system, a motor-driven pump immersed group, an electric wiring, a hydraulic infrastructure which comprises a water tank.

Perspectives of China’s wind energy development

Wind energy is a kind of clean renewable energy, which is also relatively mature in technology, with largescale development conditions and prospect for the commercialization. The development of wind energy is a systematic project, involving policy, law, technology, economy, society, environment, education and other aspects. The relationship among all the aspects should be well treated and coordinated. This paper has discussed the following relationships which should be well coordinated: relationship between wind resources and wind energy development, relationship between the wind turbine generator system and the components, relationship between wind energy technology and wind energy industry, relationship between off-grid wind power and grid-connected wind power, relationship between wind farm and the power grid, relationship between onshore wind power and offshore wind power, relationship between wind energy and other energies, relationship between technology introduction and self-innovation, relationship among foreign-funded, joint ventured and domestic-funded enterprises and relationship between the government guidance and the market regulation, as well as giving out some suggestions.

Renewable Energy Sources and Pricing of Electrical Power

This report deals with some characteristics of the electric power system of Bulgaria. Emphasis is put on the benefits of joining the small photovoltaic plants in the tourist areas of the country. As an example of that the town of Pomorie is examined. Data on the quality of the consumed electric energy and the price per a four-member family are presented. The amount of the solar radiation for the town of Pomorie is audited through the PVGIS （Photovoltaic Geographical Information System）. Discussed are the types of photovoltaic panels offered on the market by manufacturers in terms of the received power efficiency. Developed is a model of creating a photovoltaic system on the roof of a house, inhabited by several families. Calculations are made on the cost of the electricity generated by the proposed system. Compared is the cost of the electricity supplied by the electricity provider EVN （Energie Verntinftig Nutzen） in the town of Pomorie to the one that will be obtained using the proposed PV-system.

Smart Grid Cyber Security： An Overview of Threats and Countermeasures

The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smart grid interconnects the flow of information via the power line, intelligent metering, renewable and distributed energy systems, and a monitoring and controlling infrastructure. For all the advantages that these components come with, they remain at risk to a spectrum of physical and digital attacks. This paper will focus on digital vulnerabilities within the smart grid and how they may be exploited to form full fledged attacks on the system. A number of countermeasures and solutions from the literature will also be reported, to give an overview of the options for dealing with such problems. This paper serves as a triggering point for future research into smart grid cyber security.

Building Sector： The Different Ways to Improve Their Energetic Efficiency

The building sector has a significant weight in the global energy consumption in almost of the countries. So, there is a high potential for increasing its energy efficiency. With the enforcement of the energetic certification, it was tried to select different solutions that presents less energy consumption and waste, as well as an effective reduction of CO2 emissions. This work fits in this perspective, since the main goal is to evaluate the contribution of passive and active solutions that can be used in buildings for the improvement of its energetic efficiency, as well as to evaluate the contribution of renewable energy sources. Contribution of solar systems for hot water heating and electric energy production has been studied, as well as cogeneration, Combined Heat and Power （CHP）. The case studied is a hotel. To improve the building performance, there were proposed several changes, with the goal of evaluating the contribution of the different solutions proposed. It was concluded that they contribute to a reduction of thermal needs of 25.2% and avoided emissions of CO2 is 30.4%. The analysis of the implementation of trigeneration, Combined Heat, Cooling and Power （CHCP） turns it executable. The payback period is less than 8 years.

Projected Long-Term Behavior of the CO2 Emission Factor in the Electricity System of Uruguay

Estimating CO2 emission factor of the electricity system is a key aspect in the calculation of the baseline emissions for projects certified as CDM （Clean Development Mechanism）, which replace energy from the grid. Currently, Uruguay is driving the expansion of the electricity system based on domestic renewable energies, in addition to replacing oil-based fuels for others with lower emission factors. This implies a substantial change of the generation park in the next decade and of the associated CO2 emissions. In this paper, a calculation methodology of the baseline emissions is adapted for its incorporation in the software SimSEE （Electric Energy Systems Simulator）, which is used for modeling the Uruguayan electric system, and therefore, allows modeling the current energy generator park and the future one. Using this tool, the CO2 emission factor＇s evolution is evaluated in the 2012-2020 period. The 2020 scenario is based on an optimal expansion of the electric system. The results indicate a strong reduction of the emission factor between 2012 and 2020, going from average values （for 100 simulations） around 0.60 tCO2/MWh to 0.15 tCO2/MWh. In this possible future scenario, CDM certification will probably not act as a strong incentive in Uruguay for the development of projects based on non-traditional renewable energies.

Research on Hybrid Renewable Energy Systems with Fault Detection Technology

Early and accurate fault detection and diagnosis for renewable energy systems can increase their safety and ensure the continuity of their service. This paper presents a comprehensive review of different fault detection and diagnosis methods for hybrid renewable energy systems consisting of a wind turbine power generator, a PV （photovoltaic） array, a PEM （polymer electrolyte membrane） fuel cell and a battery storage system. The need of batteries to store the generated power from the solar panel, wind turbine or PEM fuel cell is also emphasized. Finally, an overview of the current methods used in the diagnosing of the lead-acid battery degradation is given.

Transient Stability Analysis of Synchronous Generator in Power System with Renewable Power Sources Installed

The impact of large-scale grid-connected renewable power sources, such as wind generators and solar photovoitaic systems, on transient stability of synchronous generators is discussed in this paper. The permanent magnet synchronous generator with variable speed wind turbine is used in the simulation analysis as a wind generator model. The transient stability analysis is performed for IEEE 9-bus system model with high-penetration renewable power sources. The effect of FRT （fault ride-through） capability implemented for each power source on the transient stability is investigated.

Simulation of Multi-source Electric Production and Energy Transfers in Sailing

The exclusive use of renewable energies is today an essential nautical concern. Nowadays, the onboard energy generation comes mainly from diesel oil, which is in user mind the simplest way. Our objective is to develop a self-adaptive management system of the onboard energy in order to change the user mind. We introduce models for energy production, storage and consumption that fit with the yachting environment, which is mobile and not as predictable as the home automation case. These models are combined within a configurable simulator. This simulator can handle user＇s boat equipment, reproduce sailing conditions and so help to validate the models and to study different management strategies. This first step is necessary to develop a smart system able to manage sailing energy in order to answer the main issue： assuring safety and optimizing comfort according to user demands.

Modern Electrical Power Source on New System of Dissipation and Renewable Energies Sources

This paper presents some solutions of modem renewable energy system applied actually in dissipation energy source： wind turbine, solar panel battery charge, SSS （support set system）, and standby diesel generator cooperated in series, parallel and hybrid system with main energy system. Its solution enable obtain independent individual energy source in different work exploitations. One of problems concerned with alternative energy source is changes of output voltages and output power dependence of climatic conditions. Possible solution is application of decoupled adjustable speed generation system in renewable energy generation. The decoupled generation system consists of： alternative energy source, internal combustion engine drives permanent magnet generator and DC/AC, or AC/AC converter. Performance of single decoupled generation set is discussed supported by results of laboratory tests. To provide high quality voltage is applied an additional energy storage, made from super capacitor and bidirectional DC/DC convert. Such system performs very stiff voltage in any load condition. Integration of solar battery panels or renewable wind energy system is provided via DC link of the variable speed decoupled autonomous generation system. Results of computer simulation and laboratory experiments are presented in the paper.

Dynamic Economic Dispatch for Microgrids Including Battery Energy Storage

Microgrids integrate distributed renewable energy resources, controllable loads and energy storage in a more economic and reliable fashion. Battery energy storage units are essential for microgrid operation, which make microgird become a strong coupling system in the time domain. Hence, the traditional methods of static dispatch are no longer suitable for microgrids. This paper proposes a dynamic economic dispatch method for microgrids. Considering microgrid as a discrete time system, the dynamic economic dispatch is to find the optimal control strategy for the system in finite time period. Based on this idea, the dynamic economic dispatch model for microgrids is established, and then the corresponding dynamic programming algorithm is designed. Finally, an example of microgrid is given, and the dynamic economic dispatch results are compared with that of the static dispatch. The comparison confirms the effectiveness of the proposed dynamic dispatch method.

Total Integration of Renewable and Fossil Energy Aiming to a Clean and Sustainable Energy System

This paper presents a new concept of TIRFE （total integration of renewable and fossil energies）, represented by an octagonal structure of all sources, vectors of transmission and optimization of consumption, aiming to a clean and sustainable energy system. The main TIRFE technologies are： cogeneration of H2 and EE （electric energy） by H2-BGSCW/TEU （biomass gasification in supercritical water integrated with a thermoelectric unit）; use of H2 from biomass in oil refinery processes for production of light and clean derivatives; supply of 1-12 deficiency for methanol production from coal; carbon sequestration by a basket of technologies （exhausted petroleum and gas） wells, underground saline aquifers, forests and stockpile of cellulignin-CL-produced from forest residues）; use of H2-BGSCW/TEU as district CHP （combined heat and power） with photovoltaic panels for EE, including electric car battery recharge; optimization of energy consumption by verticalization of the cities replacing low strength materials （bricks and common cement） by high performance concrete with addition of silica from rice husk. TIRFE helps to solve key problems of H2-BGSCW/TEU, such as materials, energy recovery, plugging, corrosion, economics and energy security for the first generation of plants, and organizes the development for the second generation. TIRFE can be incrementally implanted in existent and new cities.

Counter-Rotating Type Pump-Turbine Unit Stabilizing Momentarily Fluctuating Power from Renewable Energy Resources

It is difficult for renewable energy resources to provide constant power with excellent quality for the grid system. This serial research proposes a power stabilization system with a pumped storage to guarantee power quality and capacity, while the outputs from the energy resources are at unstable and/or fluctuating conditions. The power stabilization system with a counter-rotating type pump-turbine unit was prepared and operated at the pumping and the turbine modes. The unit composed of the tandem impellers/runners connected to the inner and the outer armatures of the unique motor/generator. The experiments have verified that this type pump-turbine unit is reasonably effective to stabilize momentarily/instantaneously the fluctuating power from the renewable energy resources.

Utilisation of Geothermal Heat Pumps within Permeable Pavements for Sustainable Energy and Water Practices

Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar energy collection and heat storage capabilities as an infinite heat source/heat sink at the base of permeable pavements, which can provide excellent temperature gradients for GHP＇s. Experimental rigs were setup up at The University of Edinbttrgh for a combined permeable pavement and GHP system. At the base of a pavement structure （approximately 1 meter） below the ground＇s surface, temperatures are constant of 10℃ in the U.K all year round. The GHP performance efficiency was analysed by the coefficient of performance （COP） in a heating cycle and the energy efficiency ratio （EER） in a cooling cycle. The mean COP and EER for both systems averaged between 2-4.5 and 3-5 respectively. The combined GHP and pavement structure operated at an optimum efficiency for both heating and cooling cycles and has shown to be unaffected by higher summer or lower winter temperatures. This hybrid system is an attractive renewable energy technology and has additional environmental benefits such as urban runoff reuse and recycling.

Design and Construction of GreenWAVE Energy Converter for Shallow Waters off South Australia

Compared with more well-known renewable energy sources, such as wind and solar, the wave energy industry is relatively new. This paper describes the structural design and construction of the oscillating water column ＂greenWAVE Energy Converter＂ which was constructed during 2013 and was planned to be deployed in shallow water off the South Australian coast in 2014. Rated initially at 1 MW, the greenWAVE unit will be dedicated to electricity production, although an option is available to produce desalinated seawater. The unit base is constructed from reinforced concrete designed to international maritime codes, and the unit will be founded in approximately 10-15 m of water. The upper portion of the device extends above sea level, housing the airwave turbine and electrical control systems.