Analysis and management strategies for the low voltage problems of rural power grid based on the distribution network flow calculation method

For a long time, because of the lack of investment capital and enough attentions, the overall constructions of rural power grid were far behind than the urban power grid in Chongqing Jiangbei Power Company. The low voltage problems were highlighted in the rural power grid due to the characteristics of rural power grid. Using the distribution network flow calculation method, we evaluated the low voltage problems of the rural power grid which belongs to Chongqing Jiangbei Power Company. In addition, we collected the data of distribution transformers in electricity consumption peak period. Some practical management strategies were proposed by the analysis and evaluation of potential and appeared low voltage problems.

Design of a Photovoltaic Mini-Grid System for Rural Electrification in Sub-Saharan Africa

This paper presents a detailed design of a photovoltaic (PV) system for use in the rural electrification of remote settlements that are far off from the electricity grid. Since investment in building transmission lines from the grid to these localities is not viable, a good solution is an installation in these areas of standalone photovoltaic systems. The design process comprises the choice and dimensioning of the solar panels, the battery storage, DC-AC inverter, and mini transmission grid to the different homes. The design is for a 15 kW PV system including an economic evaluation and analysis using Hybrid Optimization of Multiple Energy Resources (HOMER) software. Data on the average monthly solar radiation and temperature were obtained from various sources, including, Photovoltaic Geographical Information System (PVGIS) for Africa. From this data the study area receives a monthly average solar insolation of 6.16 kWh/m2/day with the worst month being August with 5.22 kWh/m2/day. The total daily electrical energy consumption is estimated to be about 72.525 kWh. Simulation results using HOMER software shows that the overall capital cost of the PV system components is $122,337, a replacement cost of $12,889 and an operation and maintenance cost of $29,946 over 10years. A financial analysis of the system showed that the design was both viable and sustainable with low maintenance cost.

Study on Comprehensive Efficiency Evaluation of Rural Power Grid under Rural Revitalization Strategy Considering Regional Differences

As an essential infrastructure,the rural power grid is vital in promoting agricultural and rural carbon sequestration and improving rural energy electrification.It is necessary to carry out in-depth research on its comprehensive efficiency.Based on the requirements of“double carbon”and rural revitalization strategy for the rural Power Grid,this paper focuses on the modernization and low-carbon transformation of the rural Power Grid.It constructs an input-output index system for the investment efficiency of the rural Power Grid in China under the new situation.It uses the primary data of the rural Power Grid of 30 prefecture-level cities in China from 2019 to 2021 to evaluate the investment efficiency of the rural Power Grid in China through a three-stage DEA model.The empirical results show that:considering the regional differences,the comprehensive efficiency of the rural Power Grid in backward areas is significantly improved;that is,the three-stage DEA method can more objectively evaluate the comprehensive efficiency of the rural Power Grid.In the context of the continued promotion of the rural revitalization strategy,to improve the comprehensive efficiency of the rural Power Grid,it is necessary to improve the technical level of the rural Power Grid further and appropriately expand the scale of investment in the rural Power Grid.

Improved VSVPWM Modulation Method for Three-level NPC Inverter in Rural Power Grid

With the acceleration of agricultural electrification,a lot of nonlinear and shock loads appear in the rural power grid,and the resulting harmonic and reactive currents pollute the rural power grid more and more seriously.To solve the above problem,three-level neutral point clamped(NPC)inverters have been widely used,but their development is greatly restricted by the defect of neutral point voltage imbalance.In this paper,an improved virtual space vector pulse width modulation(VSVPWM)was proposed.Firstly,the mathematical models of various space vectors were established,and the influence of various space vectors on neutral point voltage was analyzed.The sum of the vector current at the neutral point was zero and the voltage control at the neutral point was completed by.introducing the time offset into different switching times of the redundant small vector.This method was simple in design and avoided the redundant calculation of the traditional VSVPWM method and tedious switch sequence design.This balancing control strategy could greatly reduce the influence of virtual vectors on neutral point voltage and effectively control the low-frequency oscillation of neutral point voltage.The validity of the method was verified by establishing a matlab simulation model.

Research and Application of Distributed Data Mining Method for Improving Rural Power Grid Enterprises in Production and Operation Status Evaluation

With the reform of rural network enterprise system,the speed of transfer property rights in rural power enterprises is accelerated.The evaluation of the operation and development status of rural power enterprises is directly related to the future development and investment direction of rural power enterprises.At present,the evaluation of the production and operation of rural network enterprises and the development status of power network only relies on the experience of the evaluation personnel,sets the reference index,and forms the evaluation results through artificial scoring.Due to the strong subjective consciousness of the evaluation results,the practical guiding significance is weak.Therefore,distributed data mining method in rural power enterprises status evaluation was proposed which had been applied in many fields,such as food science,economy or chemical industry.The distributed mathematical model was established by using principal component analysis(PCA)and regression analysis.By screening various technical indicators and determining their relevance,the reference value of evaluation results was improved.Combined with statistical program for social sciences(SPSS)data analysis software,the operation status of rural network enterprises was evaluated,and the rationality,effectiveness and economy of the evaluation was verified through comparison with current evaluation results and calculation examples of actual grid operation data.

Some Technical Proposals on Rural Power Grid Construction and Retrofit

In consideration of high investment, large scope, longperiod and arduous tasks of rural power garid construction andretrofit, this paper analyzes the present state of China’s ruralpower grids and the difficulties on the construction and retrofit,for which some technical proposals are put forward.

Innovative Approaches to Energy Provision in Off-Grid Rural Communities—A Case of Botswana

Although renewable energy technologies applications to rural communities to improve energy access have been embraced in numerous parts of the world, sustainability of these systems is increasingly becoming critical as far as realization of long term benefits is concerned. The current manuscript proposes approaches deemed to provide appropriate match between technology and users in a select of Botswana’s rural communities. The methodology includes a participatory and inclusive approach in which the local community is engaged in the generation of their own energy. Available information indicates that available feedstock in selected communities is sufficient to generate and provide sustainable energy supply for the community.

技术治理如何影响乡村自治:基于村庄网格化治理的反思

网格化治理是推进乡村治理现代化的重要技术手段。“网格单元—网格员—网格长”这一套技术治理体系在进入乡村社会时,冲击了“村民群众—小组长—村干部”这一套既有的自治体系。合并小组与重新划定网格单元激化了小组间既有矛盾,破坏了村级自治的社会基础。从小组长中选拔网格员破坏了内生性力量的治理秩序,弱化了村级自治的中间力量。村干部担任网格长以应对上级考核,挤占了村级自治的主体资源,最终产生技术治理弱化乡村自治的后果。网格治理技术体系在下沉至村庄时要充分嵌入乡村自治体系,通过网格单元嵌入自治单元、网格队伍吸纳中间结构、降低村级网格考核压力,让技术治理为乡村自治增权赋能,推进乡村治理现代化。

考虑乡村振兴贡献度的农网项目投资决策模型

深入推进乡村振兴战略对农村电网发展提出更高要求,量化新时代农网项目贡献度,辅助农网实现精准投资成为关键。基于乡村振兴战略对现代农村电网发展提出的新要求,构建包含安全可靠、精准服务、绿色低碳、数字智能等4个维度的农网贡献度评价指标体系,采用最小交叉熵模型融合完全一致性方法(FUCOM)-变异系数法赋权系数对指标进行组合赋权,运用加权马氏距离TOPSIS法量化农网贡献度。以农网单位投资贡献度最优及财务效益最大为目标,构建农网项目投资决策模型,并基于c-DPEA算法进行求解。某县某批次20个农网项目的算例仿真结果表明,所提量化模型能科学评价农网项目贡献度,投资决策模型能为农网实现精准投资提供有效参考。

Sociodemographic characteristics, cultural biases, and environmental attitudes: An empirical application of grid-group cultural theory in Northwestern China

Natural resource-management studies have become increasingly attentive to the influences of human factors. Among these,cultural biases shape people’s responses to changes in natural resource systems. Several studies have applied grid-group cultural theory to assess the effects of multiple value biases among stakeholders on natural resource management. We developed and administered a questionnaire in the Heihe River Basin(n = 364) in northwestern China to investigate the appropriateness of applying this theory in the Chinese context of natural resource management. The results revealed various cultural biases among the respondents. In descending order of prevalence, these biases were hierarchism(46.98%), individualism(26.65%), egalitarianism(18.96%), and fatalism(2.78%), with the remaining respondents(4.67%) evidencing no obvious bias. Our empirical study revealed respondents’ worldviews and the influence of sociodemographic characteristics on cultural biases, as theoretically posited. Among the variables examined, age had a positive and significant effect across all biases except individualism. The correlation of income to all cultural biases was consistently negative. Only education had a negative and significant effect across all biases. Women were found to adhere to egalitarianism, whereas men adhered to individualism and hierarchism. Thus, grid-group cultural theory was found to be appropriate in the Chinese context, with gender, age, education, and income evidently accounting for cultural biases. Relationships between environmental attitudes and cultural biases conformed with the hypothesis advanced by grid-group cultural theory. This finding may be of value in explaining individuals’ environmental attitudes and facilitating the development and implementation of natural resource-management policies.

乡村振兴战略下农网综合效益评价模型研究

农村地区之间存在着显著的地区差异,为了指导农村电网投资,提出一种基于组合赋权和多属性边界逼近区域比较法(multi-attributive border approximation area comparison,MABAC)的差异化农网综合效益评价模型。首先,综合考虑农村地区差异及乡村振兴战略对农网发展的要求,从农网投资经济效益、供电能力、基础设施情况、地区发展带动、生产生活质量、清洁低碳发展等6个方面构建农网综合效益评价指标体系;其次,基于最小化主客观权重异质性原则构建基于图模型—熵权法的组合赋权模型,并引入MABAC方法用于解决农网综合效益评价问题;最后,通过算例分析验证了所提出模型的有效性。

考虑多能互动的农村区域电网负荷预测方法

为应对煤改电及分布式电源规模化接入导致农村区域电网负荷预测复杂性提升的问题,本文提出一种考虑多能互动的农村区域电网负荷预测方法。首先,分析多能源信息耦合关系,提出农村区域多能信息横向和纵向交互的特征;其次,建立并行长短期记忆网络的多任务学习模型,支持多能源系统之间的横向交互分析;最后,以河北雄安农村区域电网进行验证,结果表明本文所提方法能够有效提高农村区域复杂场景下的预测精度。

配电自动化技术在农村电网中的实践及应用

随着经济发展,居民用电量激增,对供电可靠性、供电质量要求越来越高,传统落后的供电网架无法满足用电需求,配电自动化的研究与应用从变电运行、配网巡查、故障分析等方面全方位的减少配电网管理成本,全面提升农村配电网的管理水平和服务水平,适应新时代农村的用电需求及电网发展。本文通过对某农村电网公司农村电网配电自动化的逐步推进与改造,深入开发研究适合农村电网的配网自动化应用模式及运转模式,解决农村电网由于电网节点多,地理位置复杂,故障诊断麻烦带来的电网运维问题,为公司节省人力物力,提高工作效率,提高供电服务水平。

新能源电动农机一源多用创新供能赋能农网农机融合发展——基于全国536份调查问卷分析

随着我国“三电”技术的快速发展,新能源电动农机也如雨后春笋般迅速崛起,一源多用的提出是解决新能源电动农机季节性闲置、利用率低、无法与农村电网(以下简称农网)新型电力系统互动融合等问题的创新发展模式,具有用能清洁环保、数智化程度高、易于组网的现代化技术特征。针对新能源电动农机一源多用的关键技术、应用场景、实施路径和商业模式等存在问题与发展前景,面向农机、农业、电力和电网等相关从业人员开展网络问卷调研,从一源多用技术发展潜力和农网农机融合认知态势等视角,基于调研结果,研究了一源多用赋能农网农机融合的农机电能替代潜力、应用场景、综合效益等,分析了一源多用的实施路径和商业模式,提出了一源多用创新供能模式赋能农网农机融合的关键技术和扶持政策建议。结果表明,新能源电动农机一源多用发展模式具有较好经济效益和环保效益,发展前景被普遍看好,对落实双碳目标与乡村振兴战略具有积极意义。未来仍需开展新能源电动农机和电网融合互动关键技术协同攻关和应用研究,探索可持续且多方共赢的良性商业模式。

农村配电网的规划策略分析

阐述农村配电网规划建设的特征、问题及原因,提出改进建议,包括合理规划农村电网结构、加快健全农村配电网规划制度与技术导则、加强实地勘测、根据用电需求进行规划设计。

碳管理体系助力宁夏地区电网能源规划和城乡建设——基于国网宁夏电力的研究

我国“双碳”目标的确立对能源规划和清洁能源使用提出新要求,对电力行业而言,既是机遇,也是挑战。电网作为电力系统的枢纽,需要制定合理的碳管理策略,促进电力市场健康、有序发展,助力国家和地方低碳社会建设。文章在总结宁夏地区供能端、输送端和需求端能源规划现状的基础上,有针对性地提出优化策略;并以国网宁夏电力有限公司为例,进一步探索电网企业碳管理体系支撑下高效的低碳发展路径,从电网企业、能源规划及城乡建设三个维度提供可借鉴的经验。研究结果有利于推动电网行业的能源规划优化,助力城乡建设,推进国家和地方碳普惠建设,有效改善人居环境,为可持续绿色城市规划和乡村振兴提供新路径。

基于改进图时间卷积网络的农村地区电动汽车充电负荷预测及其对农网的影响

在新能源汽车下乡政策的有力引导下,电动汽车在农村地区的销量快速增长,然而农村电网地域分布广、供电线路长,充电负荷相对分散且难以预测。为此,提出了基于改进图时间卷积网络的农村地区电动汽车充电负荷预测模型。首先,基于图卷积网络构建农村电网图结构矩阵,以表征用户充电特征的空间信息并降低输入数据的维度。其次,引入时间卷积网络感知充电数据的时序信息,挖掘影响负荷预测的时序特征。然后,提出基于注意力机制的改进图时间卷积网络算法进行充电需求预测,对不同特征进行权重分配,提升模型对时空信息的融合学习能力。最后,基于算例结果验证所提方法在农村地区电动汽车充电负荷预测上的有效性,并进一步分析了不同电动汽车渗透率下充电负荷对农村电网的影响。

农网台区线路异常的自适应DBSCAN-PNN诊断方法

新型电力系统建设背景下,线路异常诊断对于实现农网台区的线损管理和线路健康状态评价意义更为显著。针对当前农网台区缺少数字化线路异常诊断手段的问题,提出了一种基于自适应DBSCAN-PNN的农网台区线路异常诊断方法。首先,获取异常用户的虚拟回路阻抗计算结果;其次,采用K近邻方法自适应选取DBSCAN参数,并结合各类阻抗异常形成的专家先验知识规律,构建典型农网台区线路异常样本数据集;进一步将样本数据集按照一定的比例拆分为训练集和测试集,送入PNN分类模型中进行训练与测试,输出典型异常分类结果。最后,以某地区4类典型异常案例为基础进行案例分析,结果证明该方法异常诊断准确率能够快速实现典型农网台区线路异常诊断的快速精准识别,辅助支撑农网台区线损的精益化运维管理。

2020年京津冀1 km格网农村道路密度数据集

农村道路承担了农村农业生产和部分社会经济活动双重任务。合理配置农村道路对农业生产机械化、促进农村经济,改善农村生产生活条件意义重大。本文利用京津冀地区2020年度变更调查农村道路矢量数据,提取农村道路中心线,使用公里格网生产软件,通过格网空间计算,得到2020年京津冀1 km格网农村道路路网密度数据集。在农村道路矢量抽取、农村道路骨架线提取和公里格网农村道路密度计算等数据处理的各个阶段采取了完善的质量控制和质量检查措施,保证数据的正确性、完整性和一致性。本数据集可用于乡村规划编制、规划实施评估、耕作便利度、农田通达性计算等方面研究。