A SOLVABLE ONE-DIMENSIONAL ALLOCATION DECISION MODEL OF RENEWABLE RESOURCES

In the paper, the determinate atlecation decision model and the probabilistic allocation decision model of a kind of renewable resource are separatly studied by means of dynamic programming, and the optimal allocation policy is given under some special conditions.

OPTIMAL DYNAMICAL BALANCE HARVESTING FOR A CLASS OF RENEWABLE RESOURCES SYSTEM

An optimal utilization problem for a class of renewable resources system is investigated. Firstly, a control problem was proposed by introducing a new utility function which depends on the harvesting effort and the stock of resources.Secondly, the existence of optimal solution for the problem was discussed. Then, using a maximum principle for infinite horizon problem, a nonlinear four-dimensional differential equations system was attained. After a detailed analysis of the unique positive equilibrium solution, the existence of limit cycles for the system is demonstrated. Next a reduced system on the central manifold is carefully derived, which assures the stability of limit cycles. Finally significance of the results in bioeconomics is explained.

Discussion on the Effective Use of Error Resources in Primary School Mathematics

course.With students’high thinking ability,they are faced with many problems and challenges.In this process,the teaching mode of teachers is too traditional.In class,teachers always give endless lectures,so that students have little time for independent thinking and inquiry learning.At the same time,teachers pay too much attention to the use of“correct resources”in the teaching process,but ignore the use of“wrong resources”and the use of value.The long-term continuation of this teaching mode will reduce the enthusiasm and initiative of primary school students in mathematics learning,and learning is very bad for students.Therefore,teachers should pay attention to the correct use of“wrong resources”,and make effective use of these resources for classroom teaching,in order to improve students’learning enthusiasm and the cultivation of inquiry ability.

An Overview on Advanced Grid-connected Inverters Used for Decentralized Renewable Energy Resources

并网逆变器是分散式可再生能源接入配电网的重要接口,随着分布式可再生能源渗透率的不断提高,并网逆变器在传统配电网中的地位越发突出。为了高效完成可再生能源分散式并网,并有效降低并网逆变器对电网的冲击,一些在装置上、结构上和功能上更加先进的并网逆变器成为了迫切的需求。针对现有的一些先进并网逆变器进行比较、分析和研究,从装置级、功能级和控制级的角度对现有先进并网逆变器进行综述。给出一些在结构上能更加灵活地将可再生能源分散接入配电网的硬件电路。研究一些适用于可再生能源分散接入的,使并网逆变器能虚拟同步发电机完成自治运行、电能质量治理、系统阻抗检测、网络阻抗控制等辅助控制功能。同时还对并网逆变器的并网同步算法和电流跟踪控制策略进行了探讨。最后,提出一个适合于可再生能源分散并网的先进并网逆变器框架。

Hybrid Ensemble-Learning Approach for Renewable Energy Resources Evaluation in Algeria

In order to achieve a highly accurate estimation of solar energy resource potential,a novel hybrid ensemble-learning approach,hybridizing Advanced Squirrel-Search Optimization Algorithm(ASSOA)and support vector regression,is utilized to estimate the hourly tilted solar irradiation for selected arid regions in Algeria.Long-term measured meteorological data,including mean-air temperature,relative humidity,wind speed,alongside global horizontal irradiation and extra-terrestrial horizontal irradiance,were obtained for the two cities of Tamanrasset-and-Adrar for two years.Five computational algorithms were considered and analyzed for the suitability of estimation.Further two new algorithms,namely Average Ensemble and Ensemble using support vector regression were developed using the hybridization approach.The accuracy of the developed models was analyzed in terms of five statistical error metrics,as well as theWilcoxon rank-sum and ANOVA test.Among the previously selected algorithms,K Neighbors Regressor and support vector regression exhibited good performances.However,the newly proposed ensemble algorithms exhibited even better performance.The proposed model showed relative root mean square errors lower than 1.448%and correlation coefficients higher than 0.999.This was further verified by benchmarking the new ensemble against several popular swarm intelligence algorithms.It is concluded that the proposed algorithms are far superior to the commonly adopted ones.

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.

The Construction and Application of Digital Resources in Rural Primary School English Teaching and Learning

To arouse rural primary school students’ English learning interest, broaden their horizon and promote their critical thinking, we construct a series of dig-ital education resources which include not only language points of phonetics, vocabulary, language skills of English teaching and learning but western and Chinese cultures. The results show teachers and students’ roles and discourse power changed by using the digital education resources in the process of rural primary school English teaching and learning.

Sustainability analysis of SEEA indicators for non-renewable resources

Despite the fact that the non-renewable resources industry contributes greatly to regional and national gross domestic product(GDP),it casts massive negative impacts on the environment,which fails to be deducted from economic growth.Hence,sustainable development of non-renewable resources(extraction and processing)is playing an essential role in boosting economic growth continuously.The System of Integrated Environmental and Economic Accounting(SEEA)proposed by the United Nations Statistics Division(UNSD)provides a brand-new perspective for sustainability study.This paper designs a fundamental approach of green accounting for non-renewable resources based on SEEA.Three main aspects of the accounting are extracted to explore the way of analysis for sustainability indicators,which are not touched upon by SEEA.Main analyses are as follows:(1)the analysis on the influence of the change of the discount rate in user cost(UC);(2)correlation analysis between environmental degradation and pollutants emission intensity;(3)analysis of the accounting results of green GDP and green GCF(gross capital formation).Then taking petroleum resources in Shandong Province as an example,this paper will calculate and analyze green data based on the accounting and analytical approaches discussed above.However,sustainability indicators studied in the paper are just associated with past economic activities,while investigation into the factors of the change of sustainability indicators is the one most critical point in relevant policymaking.

China puts more money in renewable energy resources

In 2010, over 300 billion yuan ($47.31 billion) are invested in renewable energy sources in China, outranking every other country. Hence, China has become one of the world’s biggest investors in renewable energy sources.

Tapping Renewable Energy Resources -with A Combined Capacity of 1236 MW as Target for the Year 2000

China began the research and development of renewable energy generation since 1970s, in particular in the Eighth Five-year Plan period, the State made closer attention to the research and development of renewable energy, therefore the technical level, application scale and economic, social benefits have seen greater progress. The combined capacity of renewable energy generation reached 100 MW at the end of 1994. And it is planned a combined capacity of 1236 MW will be targeted for the year 2000.

Evaluation and re-understanding of the global natural gas hydrate resources

Natural gas hydrate(NGH)has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973.At least 29 global estimates have been published from various studies so far,among which 24 estimates are greater than the total conventional gas resources.If drawn in chronological order,the 29 historical resource estimates show a clear downward trend,reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time.A time series of the 29 estimates was used to establish a statistical model for predict the future trend.The model produces an expected resource value of 41.46×1012 m3 at the year of 2050.The statistical trend projected future gas hydrate resource is only about 10%of total natural gas resource in conventional reservoir,consistent with estimates of global technically recoverable resources(TRR)in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches.Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources,only those on the very top of the gas hydrate resource pyramid will be added to future energy supply.It is unlikely that the NGH will be the major energy source in the future.

Communication Resources Allocation for Time Delay Reduction of Frequency Regulation Service in High Renewable Penetrated Power System

The high renewable penetrated power system has severe frequency regulation problems.Distributed resources can provide frequency regulation services but are limited by com-munication time delay.This paper proposes a communication resources allocation model to reduce communication time delay in frequency regulation service.Communication device resources and wireless spectrum resources are allocated to distributed resources when they participate in frequency regulation.We reveal impact of communication resources allocation on time delay reduction and frequency regulation performance.Besides,we study communication resources allocation solution in high renewable energy penetrated power systems.We provide a case study based on the HRP-38 system.Results show communication time delay decreases distributed resources'ability to provide frequency regulation service.On the other hand,allocating more communication resources to distributed resources'communica-tion services improves their frequency regulation performance.For power systems with renewable energy penetration above 70%,required communications resources are about five times as many as 30%renewable energy penetrated power systems to keep frequency performance the same.Index Terms-Communication resources allocation,commun-ication time delay,distributed resource,frequency regulation,high renewable energy penetrated power system.

Intelligent Fractional-Order Controller for SMES Systems in Renewable Energy-Based Microgrid

An autonomous microgrid that runs on renewable energy sources is presented in this article.It has a supercon-ducting magnetic energy storage(SMES)device,wind energy-producing devices,and an energy storage battery.However,because such microgrids are nonlinear and the energy they create varies with time,controlling and managing the energy inside them is a difficult issue.Fractional-order proportional integral(FOPI)controller is recommended for the current research to enhance a standalone microgrid’s energy management and performance.The suggested dedicated control for the SMES comprises two loops:the outer loop,which uses the FOPI to regulate the DC-link voltage,and the inner loop,responsible for regulating the SMES current,is constructed using the intelligent FOPI(iFOPI).The FOPI+iFOPI parameters are best developed using the dandelion optimizer(DO)approach to achieve the optimum performance.The suggested FOPI+iFOPI controller’s performance is contrasted with a conventional PI controller for variations in wind speed and microgrid load.The optimal FOPI+iFOPI controller manages the voltage and frequency of the load.The behavior of the microgrid as a reaction to step changes in load and wind speed was measured using the proposed controller.MATLAB simulations were used to evaluate the recommended system’s performance.The results of the simulations showed that throughout all interruptions,the recommended microgrid provided the load with AC power with a constant amplitude and frequency.In addition,the required load demand was accurately reduced.Furthermore,the microgrid functioned incredibly well despite SMES and varying wind speeds.Results obtained under identical conditions were compared with and without the best FOPI+iFOPI controller.When utilizing the optimal FOPI+iFOPI controller with SMES,it was found that the microgrid performed better than the microgrid without SMES.

Resources—Towards Sustainable Use

A resource is any physical or virtual entity of limited availability used to earn good life.Resources are divided into natural and human resources.Natural resources are derived from the environment and are classified on the basis of origin,including biotic resources like forests,animals and their products, marine organisms and minerals.Abiotic resources

Bioeconomy in the Agrarian Resources Potential System of Ukraine

The main goal of this research is to determine the importance and prospects of bioeconomy development in agriculture of Ukraine for international economic integration.Actual reason for this research is military occupation of west regions and the macroeconomic instability.Available resources form supply potential for agrarian production,renewable energy,and sustainable development.However,unemployment of labour,land,and capital determine the inflationary gap,which could be closed in two main ways:The innovative economic growth in business and households’sectors in accordance to bio-based principles and rational government state regulation with fiscal and monetary policies instruments.The external and internal effects of bioeconomy development in the agrarian resources system are determined in accordance to strengths,weaknesses,opportunities,and threats(SWOT)-analysis.European integration requires entrepreneurial initiative,environmental protection,social benefits in the satisfaction of individual needs of the population,modern principles of competition,such as mutual beneficial cooperation and new market creation for food security and human resources development.

Significance of Rare Mineral Resources to Strategic Emerging Industries

As non-renewable natural resources, rare minerals＇ are extensively used as important raw materials in strategic emerging industries. As global consumption continues to increase over recent years, international competition in the area of rare mineral minerals has been escalating. On the basis＇ of the identification of 22 rare mineral resources of six categories and analysis of their applications in strategic emerging industries, this paper has adopted a three-factor analytical framework and designed nine indicators from the three dimensions of supply risks, environmental impacts and economic impacts of restricted supply to conduct a quantitative evaluation of the strategic significance of rare mineral resources. The result indicates that the strategic significance of platinum-group metals is the highest and the strategic significance of cesium is the lowest. In order to further increase the reliability of evaluation results, this paper has employed the Monte Carlo simulation for uncertainty analysis＇. Simulation result demonstrates that after the impacts＂ of individual indicators have been taken into account, the results＇ of this paper＇s evaluation of 22 rare mineral resources remain valid. Given the growing significance of rare mineral resources to strategic emerging industries, China should formulate a national strategy on rare mineral resources＇, strive to inerease the supply security of key raw materials for strategic emerging industries and achieve the sustainable development and utilization of rare mineral resources for national security of natural resources.

Studies on the Evolutionary Laws and Maintaining Mechanism of Renewability of the Yellow River's Water Resources

The Yellow River has a vast catchment area and historically it is the mother river of the Chinese nation. Now it serves as one of the main theatres for the on-going national campaign to develop China's western hinterland.……

Environmental impact of energy imports:Natural resources income and natural gas production profitability in the Asia-Pacific Economic Cooperation Countries

Environmental degradation is a pressing global concern,with the energy sector being one of the major contributors to this issue.The environmental impact of energy imports,particularly regarding natural resources income and natural gas production profitability,cannot be ignored.Countries must assess the environmental consequences of their energy choices and take steps to minimize their impact.By transitioning to cleaner and more sustainable energy sources,countries can ensure a better future for the environment and their economies.This study examines the impact of energy imports and natural resources income on environmental degradation in the Asia-Pacific Economic Cooperation(APEC)countries from 1990 to 2020,using revenue minus the production cost of natural gas and electricity production from renewable sources as moderating variables.Long-run estimates are derived using the Generalized Method of Moments and robust least squares.Our findings elucidate that importing energy from countries specializing in renewable energy can help reduce reliance on fossil fuels.This diversification of energy sources decreases the overall carbon footprint and contributes to a cleaner environment.Natural gas production often involves infrastructure construction,such as drilling rigs and pipelines,which can disrupt natural habitats and wildlife corridors.This destruction of ecosystems can have long-term consequences on biodiversity and ecological balance.The environmental impact of energy imports,particularly related to natural resource income and natural gas production profitability,requires BRICS countries to take proactive measures.These nations can address the environmental challenges associated with their energy demands by implementing policies prioritizing sustainable resource management,carbon pricing,stringent regulation,and investment in research and development.By doing so,they can balance economic growth and environmental sustainability,ensuring a greener future for the BRICS countries.

Stochastic Security-constrained Unit Commitment Considering Electric Vehicles, Energy Storage Systems, and Flexible Loads with Renewable Energy Resources

In this paper, a new formulation for modeling the problem of stochastic security-constrained unit commitment along with optimal charging and discharging of large-scale electric vehicles, energy storage systems, and flexible loads with renewable energy resources is presented. The uncertainty of renewable energy resources is considered as a scenario-based model. In this paper, a multi-objective function which considers the reduction of operation cost, no-load and startup/shutdown costs, unserved load cost, load shifting, carbon emission, optimal charging and discharging of energy storage systems, and power curtailment of renewable energy resources is considered. The proposed formulation is a mixed-integer linear programming(MILP) model, of which the optimal global solution is guaranteed by commercial solvers. To validate the proposed formulation, several cases and networks are considered for analysis, and the results demonstrate the efficiency.

Optimal Day-ahead Dynamic Pricing of Grid-connected Residential Renewable Energy Resources Under Different Metering Mechanisms

Nowadays,grid-connected renewable energy resources have widespread applications in the electricity market.However,providing household consumers with photovoltaic(PV)systems requires bilateral interfaces to exchange energy and data.In addition,residential consumers’contribution requires guaranteed privacy and secured data exchange.Dayahead dynamic pricing is one of the incentive-based demand response methods that has substantial effects on the integration of renewable energy resources with smart grids and social welfare.Different metering mechanisms of renewable energy resources such as feed-in tariffs,net metering,and net purchase and sale are important issues in power grid operation planning.In this paper,optimal condition decomposition method is used for dayahead dynamic pricing of grid-connected residential renewable energy resources under different metering mechanisms:feed-intariffs,net metering,and net purchase and sale in conjunction with carbon emission taxes.According to the stochastic nature of consumers’load and PV system products,uncertainties are considered in a two-stage decision-making process.The results demonstrate that the net metering with the satisfaction average of 68%for consumers and 32%for the investigated electric company leads to 28%total load reduction.For the case of net purchase and sale mechanism,a satisfaction average of 15%for consumers and 85%for the electric company results in 11%total load reduction.In feed-in-tariff mechanism,in spite of increased social welfare,load reduction does not take place.