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Developing Control Strategy for PV-Based Distributed Generator for Enhancing Frequency Regulation of Microgrid 开发基于pv的分布式发电机控制策略以增强微电网的频率调节
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-27 DOI: 10.1155/2023/7317870
Hoang Minh Vu Nguyen, Trong Nghia Le
This paper presents a control strategy for a photovoltaic (PV)-based distributed generator (DG) to enhance the frequency regulation of a microgrid. A microgrid is a small-scale power system that integrates distributed energy sources and interconnected loads, which can operate independently or in parallel with the main grid. However, the high integration of DGs poses stability problems, particularly the frequency regulation under contingencies in the microgrid. For example, the shutdown of one generating unit or the reduction of system inertia owing to the high integration of converter-based DGs will increase the risk of instability of the microgrid and the main grid. Therefore, maintaining and increasing the frequency regulation capability is crucial in microgrid operation. This paper focuses on developing a controller for PV DG based on virtual inertia control combined with the conventional control method of a converter in order to regulate the microgrid frequency under contingency. The proposed control strategy for a PV-based DG is then verified through simulation of the 14-bus microgrid model using MATLAB/Simulink, showing regulation in frequency under island mode operation of the microgrid. In addition, comparisons between the original and proposed control strategy microgrid model are then carried out.
为提高微电网的频率调节能力,提出了一种基于光伏(PV)分布式发电机(DG)的控制策略。微电网是一种集成分布式能源和互联负荷的小型电力系统,可以独立运行,也可以与主电网并网运行。然而,分布式电网的高集成度带来了稳定性问题,特别是微电网在突发事件下的频率调节问题。例如,由于基于变流器的dg的高度集成化,一个发电机组的关闭或系统惯性的减少将增加微电网和主电网不稳定的风险。因此,保持和提高微电网的调频能力对微电网的运行至关重要。本文重点研究了基于虚拟惯性控制与变流器常规控制方法相结合的光伏发电DG控制器,以实现微网频率在突发情况下的调节。然后,通过MATLAB/Simulink对14总线微电网模型进行仿真,验证了所提出的基于pv的DG控制策略,显示了微电网孤岛模式运行下的频率调节。此外,还对原控制策略和提出的微网模型进行了比较。
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引用次数: 0
Soliton Solutions to the BA Model and (3 + 1)-Dimensional KP Equation Using Advanced -Expansion Scheme in Mathematical Physics 数学物理中BA模型和(3 + 1)维KP方程的高级展开格式的孤子解
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-21 DOI: 10.1155/2023/5564509
HZ Mawa, S. M. Rayhanul Islam, Md. Habibul Bashar, Md. Mamunur Roshid, Jahedul Islam, Sadia Akhter
In this manuscript, the primary motivation is the implementation of the advanced -expansion method to construct the soliton solution, which contains some controlling parameters of two distinct equations via the Biswas–Arshed model and the (3 + 1)-dimensional Kadomtsev–Petviashvili equation. Here, the solutions’ behaviors are presented graphically under some conditions on those parameters. The height of the wave, wave direction, and angle of the obtained wave is formed by substituting the particular values of the considerations over showing figures with the control plot. With the collaboration of the advanced -expansion method, we construct entirely the solitary wave results as well as rogue type soliton, combined singular soliton, kink, singular kink, bright and dark soliton, periodic shape, double periodic shape soliton, etc.
在本文中,主要的动机是通过Biswas-Arshed模型和(3 + 1)维Kadomtsev-Petviashvili方程实现高级展开方法来构造包含两个不同方程的一些控制参数的孤子解。文中用图形表示了这些参数在一定条件下解的行为。波浪的高度、波浪的方向和所获得的波浪的角度是通过用控制图代替显示图形时考虑的特定值而形成的。在先进的-展开方法的配合下,我们完整地构造了孤波结果,以及流氓型孤子、组合奇异孤子、扭结、奇异扭结、亮暗孤子、周期形孤子、双周期形孤子等。因此,值得注意的是,先进的-展开技术是一种简单,可行的数值实体装置,用于澄清其他非直等效的谨慎结果。
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引用次数: 0
Finite Element and Vibration Frequency Analysis of Cracked Solid Beams: A Comparison of Iron, Steel, and Titanium Materials 裂纹实体梁的有限元和振动频率分析:铁、钢和钛材料的比较
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-21 DOI: 10.1155/2023/9911612
Rajib Karmaker, Ujjwal Kumar Deb
Different solid materials are widely used in various constructions due to their availability and low cost. However, cracks or conversions in the structures can affect their stiffness and vibration signatures. This research aims to evaluate the load distribution, deformation, and the effects of the cracks on the natural frequencies and deformations of iron, steel, and titanium beams. A finite element-based model and COMSOL Multiphysics software were employed to measure and compare the frequencies and strengths of the beams. The results showed that the frequencies increased with the load, and titanium beams had the highest frequencies and deflections, while steel beams had the highest stress resistance. This frequency analysis can help to detect very small cracks (less than 0.05 mm) in the beams. The study concluded that steel is the most suitable material for construction due to its elasticity, availability, and low cost.
不同的固体材料由于其可获得性和低成本而广泛应用于各种建筑中。然而,结构中的裂缝或变形会影响它们的刚度和振动特征。本研究旨在评估铁、钢和钛梁的荷载分布、变形以及裂纹对其固有频率和变形的影响。采用有限元模型和COMSOL Multiphysics软件对光束的频率和强度进行了测量和比较。结果表明,频率随荷载的增加而增加,钛梁的频率和挠度最高,钢梁的抗应力能力最高。这种频率分析可以帮助检测梁中非常小的裂缝(小于0.05毫米)。该研究得出的结论是,由于钢铁的弹性、可用性和低成本,它是最合适的建筑材料。
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引用次数: 0
Mathematical Analysis of the Impact of French Standardization Strategy and Electric Vehicle Development on the Breakthrough Development of EVs in China 法国标准化战略与电动汽车发展对中国电动汽车突破性发展影响的数学分析
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-14 DOI: 10.1155/2023/7307701
Linfeng Wu, Junhui Liu, Peng Liu, Dan Cong
The problems of operating range and costs are the two most critical bottlenecks restricting the extensive application of electric vehicles (EVs) in China and some other countries. There are also some prominent problems in China’s EVs, which lead to poor competitiveness of EVs compared with traditional internal combustion engine vehicles. This paper analyzes the key mathematical factors restricting the development and popularization of EVs in China from the aspects of strategic policy, sales situation, and self-problems. For the best-selling family cars in China, select the representative models with the same body structure, and make statistics on various parameters most concerned by consumers, establish a database through data statistics and analysis software. Through summarizing France’s standardization development strategy and relevant issues reflected by the development data of its EVs, this paper puts forward the hypothesis leading the development of EVs through standardization to enhance their competitiveness, gives the specific suggestions, and briefly analyzes the feasibility from the aspects of product situation. The research content of this paper provides a certain basis and ideas for the future research work.
续航里程和成本问题是制约电动汽车在中国和一些国家广泛应用的两个最关键的瓶颈。中国的电动汽车也存在一些突出的问题,导致电动汽车与传统内燃机汽车相比竞争力较差。本文从战略政策、销售形势和自身问题三个方面分析了制约电动汽车在中国发展和普及的关键数学因素。针对国内最畅销的家用汽车,选取具有代表性的车型,采用相同的车身结构,对消费者最关心的各种参数进行统计,通过数据统计分析软件建立数据库。本文通过总结法国的标准化发展战略及其电动汽车发展数据所反映的相关问题,提出了通过标准化引领电动汽车发展以提升竞争力的假设,并给出了具体建议,并从产品现状方面简要分析了可行性。本文的研究内容为今后的研究工作提供了一定的依据和思路。
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引用次数: 0
Design of Single Input Dual Output DC–DC Converter for Electric Vehicle Application 电动汽车单输入双输出DC-DC变换器设计
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-14 DOI: 10.1155/2023/3536608
Sankara Kumar S, Ramash Kumar K
DC–DC converters are playing a vital in the electric vehicles (EVs) application. In current EVs, a separate DC–DC converter is used to charge both in the low voltage and the high-voltage batteries. These factors have resulted in higher output voltage ripples, higher switching and device conduction losses, all of which can have an impact on EV performance. In addition, the previous mulitport converters have more number of energy storage elements and switching devices for EV application. To address these issues, this article proposes a multiport DC–DC converter charging circuit for EVs. The proposed circuit has a single-input dual-output (SIDO) structure that consists of a positive output boost converter (POBC) with integration of buck converter (POBCIBC). Here, the POBC is used to stepping-up the voltage, while the buck converter is used to step-down the voltage. The POBC is a fundamental topology composed of Cascaded Boost Super Lift Luo Converters. The designed POBCIBC has several advantages such as reduced output voltage ripples, high-voltage transfer gain, proficient efficiency, lower switching and conduction losses, less number of storage components, and a compact structure over the existing multiport converters. The performance of the POBCIBC is tested at different operating conditions by constructing the MATLAB/Simulink and prototype models. The proposed converter has produced different output voltage levels based on their duty cycles variations. The results are presented to show the proficient POBCIBC for the EV application.
DC-DC变换器在电动汽车的应用中起着至关重要的作用。在目前的电动汽车中,使用一个单独的DC-DC转换器为低压和高压电池充电。这些因素导致更高的输出电压波纹,更高的开关和器件传导损耗,所有这些都会影响EV性能。此外,以前的多端口变换器有更多的储能元件和开关器件用于电动汽车应用。为了解决这些问题,本文提出了一种用于电动汽车的多端口DC-DC转换器充电电路。该电路具有单输入双输出(SIDO)结构,由正输出升压变换器(POBC)和集成降压变换器(POBCIBC)组成。在这里,POBC用于升压,而降压转换器用于降压。POBC是由级联升压超级升力罗转换器组成的基本拓扑结构。与现有的多端口转换器相比,所设计的POBCIBC具有输出电压波动小、电压转移增益高、效率高、开关和传导损耗低、存储元件数量少、结构紧凑等优点。通过构建MATLAB/Simulink和原型模型,对POBCIBC在不同工况下的性能进行了测试。所提出的变换器根据其占空比变化产生不同的输出电压水平。结果表明,POBCIBC可以很好地应用于EV。
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引用次数: 0
Influences of Wind Deviation on the Ground Resultant Electric Field under Parallel Operation of 750-kV Ultra-High-Voltage Alternating Current and ±800-kV Extra-High-Voltage Direct Current Transmission Lines Passing through Residential Areas in a High-Altitude Area 高海拔地区750-kV特高压交流电与±800-kV特高压直流输电线路并联运行时风偏对穿越居民区地面合成电场的影响
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-14 DOI: 10.1155/2023/2373118
Hui Liu, Xujun Lang, Ziyang Li, Zhibing Sun, Shilong Huang
The formation mechanism of the resultant electric field is complex under parallel operation of extra-high-voltage alternating current (AC)/direct current (DC) transmission lines. However, existing methods are computationally expensive and fail to guarantee the stability and convergency of results. To solve this problem, a calculation method with nonuniform grids and varying time steps was proposed on the basis of the finite-volume and finite-element method for calculating the ground resultant electric field of parallel AC/DC transmission lines. The selection of the initial value of space charges and the setting of the surface charge density of conductors were also improved, which greatly enhanced the computational stability and efficiency. Then, the improved method was adopted to calculate the ground resultant electric field under parallel operation of a 750-kV AC transmission line and a ±800-kV DC transmission line when considering and not considering wind deviation. Results show that, when ignoring wind deviation, the normalized values of the ground resultant electric field within 6 m from the side-phase conductor of the AC line are always less than 1 under conditions of the minimum clearances to earth of the AC and DC lines passing through a residential area stipulated in the national standards, which meets codified requirements. When considering wind deviation, instead of an increase, the calculated ground resultant electric field of parallel AC/DC lines is significantly reduced, and the weighted value is much less than the limiting value.
在特高压交流/直流输电线路并联运行时,产生的电场形成机制是复杂的。然而,现有的方法计算量大,不能保证结果的稳定性和收敛性。针对这一问题,在有限体积有限元法的基础上,提出了一种非均匀网格变时间步长的交直流并联输电线路接地合成电场计算方法。改进了空间电荷初值的选择和导体表面电荷密度的设置,大大提高了计算的稳定性和效率。然后,采用改进的方法计算了750 kv交流输电线路与±800 kv直流输电线路并联运行时考虑风偏和不考虑风偏情况下的接地合成电场。结果表明,在不考虑风偏的情况下,在国家标准规定的通过住宅小区的交直流线路对地最小间隙条件下,距离交流线路侧相导体6 m范围内的接地综合电场归一化值均小于1,符合法规要求。在考虑风偏的情况下,交直流并联线路的计算地合成电场不但没有增加,反而显著减小,且加权值远小于极限值。
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引用次数: 0
Retailer-to-Individual Customer Product Supply Strategies Under a Semireal Demand Pattern 半真实需求模式下零售商对个人客户的产品供应策略
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-06 DOI: 10.1155/2023/7564316
Zhiyi Zhuo, Shuhong Chen, Weihua Lin, Hong Yan, Yue He
In the consumer goods supply chain, there are three different modes of demand: real, false, and semireal. It is an interesting topic to discuss the optimal profit of enterprises according to these three demand patterns. This paper develops three mathematical models that can be used to investigate the factors that affect retailers with respect to the design of product supply strategies for individual customers under a semireal demand pattern and thereby addresses the problem of retailers’ maximum profitability. The results of the present study show that these models may effectively help retailers develop appropriate supply strategies for individual customers under a semireal demand pattern; in turn, this may help retailers improve operational performance. The main contribution of the current study lies in the construction of mathematical models of product supply strategies for the individual customer in the off-invoice mode, the scan-back mode, and the unsold-item processing mode under the semireal demand pattern. The effectiveness of the models has been verified through numerical calculations. In concrete management practice, the mathematical model given in this paper can be used to effectively adjust the quantity of goods purchased, correct retail prices, and optimize sales discounts to maximize profits.
在消费品供应链中,有三种不同的需求模式:真实的、虚假的和半真实的。根据这三种需求模式来探讨企业的最优利润是一个有趣的话题。本文建立了三个数学模型,用于研究半真实需求模式下影响零售商个体顾客产品供应策略设计的因素,从而解决零售商盈利能力最大化的问题。研究结果表明,这些模型可以有效地帮助零售商在半真实需求模式下为个体顾客制定合适的供应策略;反过来,这可能有助于零售商提高运营绩效。本研究的主要贡献在于构建了半真实需求模式下个人客户在开票模式、扫货模式和未售出商品加工模式下的产品供应策略数学模型。通过数值计算验证了模型的有效性。在具体的管理实践中,本文给出的数学模型可以有效地调整进货数量,修正零售价格,优化销售折扣,实现利润最大化。
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引用次数: 0
Retracted: Artificial Neural Network-Based Planting Arrangement of Smart City in Green Ecological Environment 撤稿:基于人工神经网络的绿色生态环境下智慧城市种植布置
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-01 DOI: 10.1155/2023/9847354
Mathematical Problems in Engineering
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引用次数: 0
Retracted: Dynamic Mathematical Models’ System and Synchronization 撤下:动态数学模型的系统与同步
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-01 DOI: 10.1155/2023/9796803
Mathematical Problems in Engineering
{"title":"Retracted: Dynamic Mathematical Models’ System and Synchronization","authors":"Mathematical Problems in Engineering","doi":"10.1155/2023/9796803","DOIUrl":"https://doi.org/10.1155/2023/9796803","url":null,"abstract":"<jats:p />","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135271423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Retracted: Diagnosis of Melanoma Using Deep Learning 撤回:使用深度学习诊断黑色素瘤
4区 工程技术 Q1 Mathematics Pub Date : 2023-11-01 DOI: 10.1155/2023/9785184
Mathematical Problems in Engineering
{"title":"Retracted: Diagnosis of Melanoma Using Deep Learning","authors":"Mathematical Problems in Engineering","doi":"10.1155/2023/9785184","DOIUrl":"https://doi.org/10.1155/2023/9785184","url":null,"abstract":"<jats:p />","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"50 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135271136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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Mathematical Problems in Engineering
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