Mathematical Problems in Engineering最新文献

{"title":"Developing Control Strategy for PV-Based Distributed Generator for Enhancing Frequency Regulation of Microgrid","authors":"Hoang Minh Vu Nguyen, Trong Nghia Le","doi":"10.1155/2023/7317870","DOIUrl":"https://doi.org/10.1155/2023/7317870","url":null,"abstract":"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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"20 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138509936","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}

{"title":"Soliton Solutions to the BA Model and (3 + 1)-Dimensional KP Equation Using Advanced -Expansion Scheme in Mathematical Physics","authors":"HZ Mawa, S. M. Rayhanul Islam, Md. Habibul Bashar, Md. Mamunur Roshid, Jahedul Islam, Sadia Akhter","doi":"10.1155/2023/5564509","DOIUrl":"https://doi.org/10.1155/2023/5564509","url":null,"abstract":"In this manuscript, the primary motivation is the implementation of the advanced <span><svg height=\"13.1353pt\" style=\"vertical-align:-3.429399pt\" version=\"1.1\" viewbox=\"-0.0498162 -9.7059 57.5794 13.1353\" width=\"57.5794pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,0,0)\"><use xlink:href=\"#g190-102\"></use></g><g transform=\"matrix(.013,0,0,-0.013,5.525,0)\"><use xlink:href=\"#g190-121\"></use></g><g transform=\"matrix(.013,0,0,-0.013,11.661,0)\"><use xlink:href=\"#g190-113\"></use></g><g transform=\"matrix(.013,0,0,-0.013,18.542,0)\"><use xlink:href=\"#g113-41\"></use></g><g transform=\"matrix(.013,0,0,-0.013,23.04,0)\"><use xlink:href=\"#g117-33\"></use></g><g transform=\"matrix(.013,0,0,-0.013,30.671,0)\"><use xlink:href=\"#g113-243\"></use></g><g transform=\"matrix(.013,0,0,-0.013,38.018,0)\"><use xlink:href=\"#g113-41\"></use></g><g transform=\"matrix(.013,0,0,-0.013,42.516,0)\"><use xlink:href=\"#g113-236\"></use></g><g transform=\"matrix(.013,0,0,-0.013,48.341,0)\"><use xlink:href=\"#g113-42\"></use></g><g transform=\"matrix(.013,0,0,-0.013,52.839,0)\"><use xlink:href=\"#g113-42\"></use></g></svg>-</span>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 <span><svg height=\"13.1353pt\" style=\"vertical-align:-3.429399pt\" version=\"1.1\" viewbox=\"-0.0498162 -9.7059 57.5794 13.1353\" width=\"57.5794pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,0,0)\"><use xlink:href=\"#g190-102\"></use></g><g transform=\"matrix(.013,0,0,-0.013,5.525,0)\"><use xlink:href=\"#g190-121\"></use></g><g transform=\"matrix(.013,0,0,-0.013,11.661,0)\"><use xlink:href=\"#g190-113\"></use></g><g transform=\"matrix(.013,0,0,-0.013,18.542,0)\"><use xlink:href=\"#g113-41\"></use></g><g transform=\"matrix(.013,0,0,-0.013,23.04,0)\"><use xlink:href=\"#g117-33\"></use></g><g transform=\"matrix(.013,0,0,-0.013,30.671,0)\"><use xlink:href=\"#g113-243\"></use></g><g transform=\"matrix(.013,0,0,-0.013,38.018,0)\"><use xlink:href=\"#g113-41\"></use></g><g transform=\"matrix(.013,0,0,-0.013,42.516,0)\"><use xlink:href=\"#g113-236\"></use></g><g transform=\"matrix(.013,0,0,-0.013,48.341,0)\"><use xlink:href=\"#g113-42\"></use></g><g transform=\"matrix(.013,0,0,-0.013,52.839,0)\"><use xlink:href=\"#g113-42\"></use></g></svg>-</span>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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"22 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138509934","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}

{"title":"Finite Element and Vibration Frequency Analysis of Cracked Solid Beams: A Comparison of Iron, Steel, and Titanium Materials","authors":"Rajib Karmaker, Ujjwal Kumar Deb","doi":"10.1155/2023/9911612","DOIUrl":"https://doi.org/10.1155/2023/9911612","url":null,"abstract":"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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138509935","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}

{"title":"Mathematical Analysis of the Impact of French Standardization Strategy and Electric Vehicle Development on the Breakthrough Development of EVs in China","authors":"Linfeng Wu, Junhui Liu, Peng Liu, Dan Cong","doi":"10.1155/2023/7307701","DOIUrl":"https://doi.org/10.1155/2023/7307701","url":null,"abstract":"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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"101 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134957618","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}

{"title":"Design of Single Input Dual Output DC–DC Converter for Electric Vehicle Application","authors":"Sankara Kumar S, Ramash Kumar K","doi":"10.1155/2023/3536608","DOIUrl":"https://doi.org/10.1155/2023/3536608","url":null,"abstract":"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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"10 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134991158","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}

{"title":"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","authors":"Hui Liu, Xujun Lang, Ziyang Li, Zhibing Sun, Shilong Huang","doi":"10.1155/2023/2373118","DOIUrl":"https://doi.org/10.1155/2023/2373118","url":null,"abstract":"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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"37 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134991905","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}

{"title":"Retailer-to-Individual Customer Product Supply Strategies Under a Semireal Demand Pattern","authors":"Zhiyi Zhuo, Shuhong Chen, Weihua Lin, Hong Yan, Yue He","doi":"10.1155/2023/7564316","DOIUrl":"https://doi.org/10.1155/2023/7564316","url":null,"abstract":"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.","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"35 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135589842","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}

{"title":"Retracted: Artificial Neural Network-Based Planting Arrangement of Smart City in Green Ecological Environment","authors":"Mathematical Problems in Engineering","doi":"10.1155/2023/9847354","DOIUrl":"https://doi.org/10.1155/2023/9847354","url":null,"abstract":"<jats:p />","PeriodicalId":18319,"journal":{"name":"Mathematical Problems in Engineering","volume":"21 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":"135271414","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}

{"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}

{"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}