首页 > 最新文献

Bulletin of NTU "KhPI". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice最新文献

英文 中文
Numerical-field analysis of the magnetic conductivity of the slot dispersion of the stator winding of induction motors 感应电机定子绕组槽分散磁导率的数值场分析
Volodymyr Milykh
Introduction. The magnetic fields and the corresponding magnetic conductivities of the slot dispersion of the stator winding of three-phase induction motors (IM) are studied. Such studies are relevant in their design and are one of the bases for calculating a number of energy parameters and characteristics of motors. In the classical design of an IM, which is still valid, the specified magnetic conductivities are determined analytically according to the simplified slot dispersion model, therefore they may not always provide sufficient accuracy due to a number of assumptions and conventions. Goal. Further development of the IM design system by means of a numerical-field calculation analysis of the magnetic conductivity of the slot dispersion of their stator winding, as well as a comparative check of the relevant analytical formulas from various methods of classical design. Results. The slot dispersion of IM is determined by numerical calculations using the FEMM program within the stator tooth steps. For the research, four variants of the shapes of the stator slots, which are common in modern IMs of small and medium power, are accepted. In the calculations, calculation models with strongly saturated and unsaturated in the magnetic relation with the stator core teeth are considered. The numerical-field method shows that the classical design method can give both sufficiently accurate results and unacceptable errors in determining the magnetic conductivities of slot dispersion of IM. Discussion and prospects for further development. The provided numerical-field analysis method and the obtained results of the calculation of slot dispersion of IM windings are recommended as a basis for improving the system of their design.
简介对三相异步电机(IM)定子绕组槽散的磁场和相应的磁导率进行了研究。这些研究与电机设计相关,是计算电机一系列能量参数和特性的基础之一。在目前仍然有效的传统异步电机设计中,指定的磁导率是根据简化的槽分散模型通过分析确定的,因此,由于一些假设和约定俗成的原因,这些磁导率并不总能提供足够的准确性。目标通过对定子绕组槽散磁的磁导率进行数值场计算分析,以及对各种经典设计方法的相关分析公式进行比较检查,进一步开发 IM 设计系统。结果IM 的槽散是通过定子齿步内的 FEMM 程序进行数值计算确定的。研究采用了现代中小功率 IM 中常见的四种定子槽形状。在计算中,考虑了与定子铁芯齿之间的磁力关系为强饱和和非饱和的计算模型。数值-场方法表明,经典设计方法既能给出足够精确的结果,也能在确定 IM 槽散磁导率时给出不可接受的误差。讨论和进一步发展前景。建议将所提供的数值-场分析方法和所获得的 IM 绕组槽分散计算结果作为改进其设计系统的基础。
{"title":"Numerical-field analysis of the magnetic conductivity of the slot dispersion of the stator winding of induction motors","authors":"Volodymyr Milykh","doi":"10.20998/2079-3944.2023.2.03","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.2.03","url":null,"abstract":"Introduction. The magnetic fields and the corresponding magnetic conductivities of the slot dispersion of the stator winding of three-phase induction motors (IM) are studied. Such studies are relevant in their design and are one of the bases for calculating a number of energy parameters and characteristics of motors. In the classical design of an IM, which is still valid, the specified magnetic conductivities are determined analytically according to the simplified slot dispersion model, therefore they may not always provide sufficient accuracy due to a number of assumptions and conventions. Goal. Further development of the IM design system by means of a numerical-field calculation analysis of the magnetic conductivity of the slot dispersion of their stator winding, as well as a comparative check of the relevant analytical formulas from various methods of classical design. Results. The slot dispersion of IM is determined by numerical calculations using the FEMM program within the stator tooth steps. For the research, four variants of the shapes of the stator slots, which are common in modern IMs of small and medium power, are accepted. In the calculations, calculation models with strongly saturated and unsaturated in the magnetic relation with the stator core teeth are considered. The numerical-field method shows that the classical design method can give both sufficiently accurate results and unacceptable errors in determining the magnetic conductivities of slot dispersion of IM. Discussion and prospects for further development. The provided numerical-field analysis method and the obtained results of the calculation of slot dispersion of IM windings are recommended as a basis for improving the system of their design.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"23 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138966147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The mechanical strength of which in operation directly of the introduction into highly filled halogen-free plastics production 在高填充无卤素塑料生产中直接引入的机械强度
Yuri Antonets, A. Shurupova, L. Shchebeniuk, Oksana Holyk
With the introduction into highly filled halogen-free plastics production, the mechanical strength of which in operation directly depends on the flame retardant content and application technology, it becomes important to control the cable sheath mechanical characteristics in a fireproof design. Polymeric materials and their compositions are viscoelastic materials for which the mechanical properties depend on the technological process of extrusion. The results of estimating the elongation at break of samples from the uniaxial stretching.  It is shown that the inner and outer layers of the halogen-free plastic cable sheath have significantly different values of the plasticity normative parameter: differences evidence in the polymer structure in the inner and outer layers of the sheath due to the forced deformation process during extrusion, which is forced polymer structure orientation. It is shown that the inner and outer layers of the halogen-free plastic cable sheath have significantly different values of the relative change in specific mass of polymer samples. Analysis of the statistical covariance of the relative elongation at break and of the relative change in specific mass of polymer samples different in structure similar filled halogen-free polymers. With the introduction into highly filled halogen-free plastics application technology, it becomes important to control the cable sheath mechanical characteristics in fireproof design for the inner and outer layers
随着高填充无卤塑料生产的引入,其运行时的机械强度直接取决于阻燃剂含量和应用技术,因此在防火设计中控制电缆护套的机械特性变得非常重要。聚合材料及其成分属于粘弹性材料,其机械性能取决于挤压技术工艺。通过单轴拉伸估算样品的断裂伸长率。 结果表明,无卤塑料电缆护套的内层和外层具有明显不同的塑性规范参数值:护套内层和外层的聚合物结构差异是由于挤压过程中的强制变形过程(即强制聚合物结构取向)造成的。结果表明,无卤塑料电缆护套的内层和外层聚合物样品比质量的相对变化值存在显著差异。分析了结构相似的不同填充无卤聚合物样品的相对断裂伸长率和相对比质量变化的统计协方差。随着高填充无卤塑料应用技术的引入,在防火设计中控制内外层电缆护套的机械特性变得非常重要。
{"title":"The mechanical strength of which in operation directly of the introduction into highly filled halogen-free plastics production","authors":"Yuri Antonets, A. Shurupova, L. Shchebeniuk, Oksana Holyk","doi":"10.20998/2079-3944.2023.2.08","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.2.08","url":null,"abstract":"With the introduction into highly filled halogen-free plastics production, the mechanical strength of which in operation directly depends on the flame retardant content and application technology, it becomes important to control the cable sheath mechanical characteristics in a fireproof design. Polymeric materials and their compositions are viscoelastic materials for which the mechanical properties depend on the technological process of extrusion. The results of estimating the elongation at break of samples from the uniaxial stretching.  It is shown that the inner and outer layers of the halogen-free plastic cable sheath have significantly different values of the plasticity normative parameter: differences evidence in the polymer structure in the inner and outer layers of the sheath due to the forced deformation process during extrusion, which is forced polymer structure orientation. It is shown that the inner and outer layers of the halogen-free plastic cable sheath have significantly different values of the relative change in specific mass of polymer samples. Analysis of the statistical covariance of the relative elongation at break and of the relative change in specific mass of polymer samples different in structure similar filled halogen-free polymers. With the introduction into highly filled halogen-free plastics application technology, it becomes important to control the cable sheath mechanical characteristics in fireproof design for the inner and outer layers","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"29 1‐2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138966942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Application of hybrid excitation in a DC motor for drive of transport rolls in metallurgical industry 混合励磁在冶金工业输送辊直流电机驱动中的应用
V. Shaida, O. Yurieva
Purpose. To determine the effectiveness of the application of hybrid excitation for DC motors of medium power. Estimate the influence of the location of the permanent magnet of the main pole core on the magnitude of the magnetic flux created by it. Methodology. The classical theory of electric machines, the calculation of the magnetic field by the finite element method and analytical comparison were used to conduct the research. Results. The feasibility of using hybrid excitation for DC motors of medium power has been confirmed. The use of hybrid excitation in an experimental direct current motor made it possible to increase the excitation magnetic flux by 11%. This will make it possible to reduce the current load of the excitation winding, increase the reliability of the motor and reduce electrical losses on the excitation. The optimal location of the permanent magnet, according to the criterion of the maximum magnetic excitation flux, is its location at the main pole shoe along the air gap. Originality. The difference between the conducted research and others is that the condition of the research was to keep the dimensions of its motor, the excitation winding and the interpoles winding unchanged. Practical value. The obtained results will allow the designers of dc motors with hybrid excitation to avoid wrong decisions during further research and development of these motors.
目的。确定混合励磁在中功率直流电动机中的应用效果。估计主极磁芯永磁体的位置对其产生的磁通量大小的影响。方法。利用经典电机理论、有限元法计算磁场和解析比较等方法进行了研究。结果。验证了中功率直流电机采用混合励磁的可行性。在实验直流电机中采用混合励磁可以使励磁磁通提高11%。这将有可能减少励磁绕组的电流负载,增加电机的可靠性,并减少励磁上的电损耗。根据最大磁激励通量的准则,永磁体的最佳位置为沿气隙方向的主极靴处。创意。与其他研究的不同之处在于,研究的条件是保持其电机、励磁绕组和间极绕组的尺寸不变。实用价值。所得结果将使混合励磁直流电机的设计者在进一步的研究和开发中避免错误的决策。
{"title":"Application of hybrid excitation in a DC motor for drive of transport rolls in metallurgical industry","authors":"V. Shaida, O. Yurieva","doi":"10.20998/2079-3944.2023.1.08","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.08","url":null,"abstract":"Purpose. To determine the effectiveness of the application of hybrid excitation for DC motors of medium power. Estimate the influence of the location of the permanent magnet of the main pole core on the magnitude of the magnetic flux created by it. Methodology. The classical theory of electric machines, the calculation of the magnetic field by the finite element method and analytical comparison were used to conduct the research. Results. The feasibility of using hybrid excitation for DC motors of medium power has been confirmed. The use of hybrid excitation in an experimental direct current motor made it possible to increase the excitation magnetic flux by 11%. This will make it possible to reduce the current load of the excitation winding, increase the reliability of the motor and reduce electrical losses on the excitation. The optimal location of the permanent magnet, according to the criterion of the maximum magnetic excitation flux, is its location at the main pole shoe along the air gap. Originality. The difference between the conducted research and others is that the condition of the research was to keep the dimensions of its motor, the excitation winding and the interpoles winding unchanged. Practical value. The obtained results will allow the designers of dc motors with hybrid excitation to avoid wrong decisions during further research and development of these motors.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130133118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Method of measurement of partial capacitances for tested objects with three electrodes 用三电极测量被测物体部分电容的方法
Ivan Kostjukov, Borys Kubryk
The article is devoted to the development of a method of measuring partial capacitances between the electrically conductive structural elements of a capacitive tested object with three electrodes. The developed method involves the applying of resistive-capacitive grounding of the investigated insulation layer with subsequent gradual adjustment of the value of the auxiliary resistor, through which the investigated insulation layer is grounded, to the value at which the phase shift between the voltage on the investigated insulation layer and the auxiliary capacity will be equal to 0º. The results of the calculations showed that in this case the voltage between the electrodes depends only on the capacitive elements of the circuit, and does not depend on the electrical resistance caused by dielectric losses. After measuring the voltages on the elements of the substitution scheme followed by similar re-adjustment of the value of the auxiliary resistor, for a different value of the capacity of the auxiliary capacitor, it is possible to form a system of equations, the solution of which allows you to determine the unknown values of the partial capacities of the insulation layers. The developed method can be used to determine each partial capacitance of the object of control with three electrodes and does not require the use of 3-terminal immittance meters and the use of application-based cumulative measurement survey techniques
本文致力于开发一种测量三电极电容性被测对象的导电结构元件之间部分电容的方法。所开发的方法涉及对所研究的绝缘层进行电阻-电容接地,随后逐渐调整所研究的绝缘层通过的辅助电阻的值,使所研究的绝缘层上的电压与辅助容量之间的相移等于0º。计算结果表明,在这种情况下,电极之间的电压仅取决于电路的电容元件,而不取决于介电损耗引起的电阻。在测量替代方案的元件上的电压之后,对辅助电阻器的值进行类似的重新调整,对于辅助电容器的容量的不同值,可以形成一个方程组,其解可以让您确定绝缘层部分容量的未知值。所开发的方法可以用三个电极来确定被控对象的每个部分电容,而不需要使用3端阻抗计和使用基于应用的累积测量调查技术
{"title":"Method of measurement of partial capacitances for tested objects with three electrodes","authors":"Ivan Kostjukov, Borys Kubryk","doi":"10.20998/2079-3944.2023.1.11","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.11","url":null,"abstract":"The article is devoted to the development of a method of measuring partial capacitances between the electrically conductive structural elements of a capacitive tested object with three electrodes. The developed method involves the applying of resistive-capacitive grounding of the investigated insulation layer with subsequent gradual adjustment of the value of the auxiliary resistor, through which the investigated insulation layer is grounded, to the value at which the phase shift between the voltage on the investigated insulation layer and the auxiliary capacity will be equal to 0º. The results of the calculations showed that in this case the voltage between the electrodes depends only on the capacitive elements of the circuit, and does not depend on the electrical resistance caused by dielectric losses. After measuring the voltages on the elements of the substitution scheme followed by similar re-adjustment of the value of the auxiliary resistor, for a different value of the capacity of the auxiliary capacitor, it is possible to form a system of equations, the solution of which allows you to determine the unknown values of the partial capacities of the insulation layers. The developed method can be used to determine each partial capacitance of the object of control with three electrodes and does not require the use of 3-terminal immittance meters and the use of application-based cumulative measurement survey techniques","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134133349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Generalized model of adaptive forecasting of electricity consumption modes of production facilities 生产设施用电方式自适应预测的广义模型
V. Kalinchyk, Aleksandr Meita, V. Pobigaylo, V. Kalinchyk, O. Borychenko, Olexandr Kopchikov
The article examines the methods of forecasting the electrical load of production facilities. It is shown that it is best to focus on the methods of power consumption management, which are based on the study of forecast estimates, which are the initial information for making management decisions. It is shown that the main requirements for forecasting models are fairly high accuracy of forecasting and simplicity of algorithms. It is shown that in automated power consumption management systems, due to the lack of study of the nature of the forecasted process, insufficient reliability of the source information, the most appropriate is an adaptive approach to the construction of forecasting models. Adaptive forecasting methods and, first of all, the method of exponential smoothing should be put first in terms of ease of implementation and calculation time. In the work, a generalized model of operational forecasting of electricity consumption was obtained, which is easily transformed into an exponential smoothing model and can be extended to use other (except polynomial) functions. It is shown that in relation to processes with deterministic polynomial bases, the generalized model of operational forecasting gives the same result as exponential smoothing.
本文探讨了生产设备电力负荷的预测方法。研究结果表明,功耗管理的方法是基于预测估计的研究,这是管理决策的初始信息。研究表明,对预测模型的主要要求是具有较高的预测精度和简单的算法。研究表明,在自动化用电管理系统中,由于缺乏对预测过程性质的研究,源信息的可靠性不足,最合适的是采用自适应的方法来构建预测模型。自适应预测方法,首先是指数平滑方法,在易于实现和计算时间方面应优先考虑。本文建立了电力消费运行预测的广义模型,该模型易于转化为指数平滑模型,并可推广到除多项式函数外的其他函数。结果表明,对于具有确定多项式基的过程,广义的运行预测模型与指数平滑的结果相同。
{"title":"Generalized model of adaptive forecasting of electricity consumption modes of production facilities","authors":"V. Kalinchyk, Aleksandr Meita, V. Pobigaylo, V. Kalinchyk, O. Borychenko, Olexandr Kopchikov","doi":"10.20998/2079-3944.2023.1.09","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.09","url":null,"abstract":"The article examines the methods of forecasting the electrical load of production facilities. It is shown that it is best to focus on the methods of power consumption management, which are based on the study of forecast estimates, which are the initial information for making management decisions. It is shown that the main requirements for forecasting models are fairly high accuracy of forecasting and simplicity of algorithms. It is shown that in automated power consumption management systems, due to the lack of study of the nature of the forecasted process, insufficient reliability of the source information, the most appropriate is an adaptive approach to the construction of forecasting models. Adaptive forecasting methods and, first of all, the method of exponential smoothing should be put first in terms of ease of implementation and calculation time. In the work, a generalized model of operational forecasting of electricity consumption was obtained, which is easily transformed into an exponential smoothing model and can be extended to use other (except polynomial) functions. It is shown that in relation to processes with deterministic polynomial bases, the generalized model of operational forecasting gives the same result as exponential smoothing.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123116921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Electromagnetic compatibility of technical objects and systems: overview of the system and standardization bodies of the European Union and the Federal Republic of Germany 技术对象和系统的电磁兼容性:欧盟和德意志联邦共和国的系统和标准化机构概述
Mykhailo Panteliat, Pavlo Miasoedov
Since June 2022, Ukraine has the status of a candidate country for joining the European Union (EU). On the way to the EU, Ukraine needs to carry out a number of reforms and fully adapt national legislation in accordance with European criteria. This also applies to the regulatory framework regarding electromagnetic compatibility. In this regard, the work presents the features, structure and main functions of the modern general system and standardization bodies on electromagnetic compatibility of technical objects and systems operating in the European Union at both the international (pan-European) and national levels. With regard to a specific EU member state, the paper considers the example of the Federal Republic of Germany.
自2022年6月起,乌克兰获得了加入欧盟候选国的地位。在加入欧盟的道路上,乌克兰需要进行一系列改革,并根据欧洲标准全面调整国家立法。这也适用于有关电磁兼容性的监管框架。在这方面,该工作介绍了欧洲联盟在国际(泛欧)和国家一级运行的技术对象和系统的电磁兼容性的现代一般系统和标准化机构的特点、结构和主要功能。对于一个具体的欧盟成员国,本文考虑了德意志联邦共和国的例子。
{"title":"Electromagnetic compatibility of technical objects and systems: overview of the system and standardization bodies of the European Union and the Federal Republic of Germany","authors":"Mykhailo Panteliat, Pavlo Miasoedov","doi":"10.20998/2079-3944.2023.1.04","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.04","url":null,"abstract":"Since June 2022, Ukraine has the status of a candidate country for joining the European Union (EU). On the way to the EU, Ukraine needs to carry out a number of reforms and fully adapt national legislation in accordance with European criteria. This also applies to the regulatory framework regarding electromagnetic compatibility. In this regard, the work presents the features, structure and main functions of the modern general system and standardization bodies on electromagnetic compatibility of technical objects and systems operating in the European Union at both the international (pan-European) and national levels. With regard to a specific EU member state, the paper considers the example of the Federal Republic of Germany.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115527046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Experimental study of a universal high-speed ac collector motor 通用高速交流集电极电机的实验研究
V. Chumak, M. Kovalenko, I. Kovalenko, I. Tkachuk
AC collector motors with power from tens to hundreds of watts are widely used in electric drives of flexible production systems, industrial robots, automation systems and vehicles. The most common is the use of universal alternating current collector electric motors. They are called universal because they can work from both an alternating current and a direct current network. They have the ability to smoothly change the speed of rotation of the drive - its shaft, which sets the executive mechanism in motion. An actual direction is conducting experimental studies of universal alternating current collector motors, which are used as a drive for hand-held power tools. This is done through the use of a specially developed experimental stand that takes into account the peculiarities of the operation of such electric motors. The purpose of the work is an experimental study of a universal AC collector motor to evaluate its parameters and characteristics. To evaluate the parameters and characteristics of such a motor for the drive of a hand-held electric tool, an experimental stand was developed, which takes into account the high speed of rotation of the output shaft of the device and allows smoothly changing the load to obtain operating characteristics. The hand-held electric tool of the world-famous manufacturer Makita, model GA5030, is used as the research object. Structurally, the drive motor is a collector machine of variable voltage with series excitation. The speed of rotation of such motors is regulated by changing the power supply voltage supplied to the motor. The structure of the experimental stand for the study of high-speed universal collector machines was developed, all components were selected and the stand was correctly assembled, according to the developed basic electrical and assembly diagram. Using the developed stand, the operating characteristics of the engine under study P1, Ia, η, cosϕ, n, M= f(P2) were recorded. The engine under study meets the stated characteristics. The value of the nominal efficiency is within 36% with a rather large value of the power factor cosϕ≈0.98.
功率从几十瓦到几百瓦的交流集电极电机广泛应用于柔性生产系统、工业机器人、自动化系统和车辆的电驱动中。最常见的是采用通用交流集电极电动机。它们被称为通用型,因为它们既可以在交流电中工作,也可以在直流电中工作。他们有能力平稳地改变驱动器的旋转速度-它的轴,它设置执行机构的运动。一个实际的方向是进行通用交流集电极电机的实验研究,它被用作手持式电动工具的驱动器。这是通过使用一个专门开发的试验台来完成的,该试验台考虑到这种电动机的操作特点。本文的目的是对一种通用交流集电极电机进行实验研究,以评估其参数和特性。为了评估这种驱动手持式电动工具的电机的参数和特性,开发了一个实验台,该实验台考虑了装置输出轴的高速旋转,并允许平稳地改变负载以获得操作特性。以世界知名制造商牧田公司的GA5030型手持式电动工具为研究对象。在结构上,驱动电机是一种串联励磁的变电压集电极。这种电动机的转速是通过改变供给电动机的电源电压来调节的。根据制定的基本电气原理图和装配图,设计了高速通用集热器试验台的结构,对各部件进行了选择,并对试验台进行了正确的组装。利用研制的台架,记录了所研究发动机P1、Ia、η、cosφ、n、M= f(P2)的工作特性。所研究的发动机符合规定的特性。标称效率值在36%以内,功率因数cosφ≈0.98的值相当大。
{"title":"Experimental study of a universal high-speed ac collector motor","authors":"V. Chumak, M. Kovalenko, I. Kovalenko, I. Tkachuk","doi":"10.20998/2079-3944.2023.1.06","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.06","url":null,"abstract":"AC collector motors with power from tens to hundreds of watts are widely used in electric drives of flexible production systems, industrial robots, automation systems and vehicles. The most common is the use of universal alternating current collector electric motors. They are called universal because they can work from both an alternating current and a direct current network. They have the ability to smoothly change the speed of rotation of the drive - its shaft, which sets the executive mechanism in motion. An actual direction is conducting experimental studies of universal alternating current collector motors, which are used as a drive for hand-held power tools. This is done through the use of a specially developed experimental stand that takes into account the peculiarities of the operation of such electric motors. The purpose of the work is an experimental study of a universal AC collector motor to evaluate its parameters and characteristics. To evaluate the parameters and characteristics of such a motor for the drive of a hand-held electric tool, an experimental stand was developed, which takes into account the high speed of rotation of the output shaft of the device and allows smoothly changing the load to obtain operating characteristics. The hand-held electric tool of the world-famous manufacturer Makita, model GA5030, is used as the research object. Structurally, the drive motor is a collector machine of variable voltage with series excitation. The speed of rotation of such motors is regulated by changing the power supply voltage supplied to the motor. The structure of the experimental stand for the study of high-speed universal collector machines was developed, all components were selected and the stand was correctly assembled, according to the developed basic electrical and assembly diagram. Using the developed stand, the operating characteristics of the engine under study P1, Ia, η, cosϕ, n, M= f(P2) were recorded. The engine under study meets the stated characteristics. The value of the nominal efficiency is within 36% with a rather large value of the power factor cosϕ≈0.98.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124019722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Improvement of microprocessor voltage control relay operation algorithms for single-phase household consumers 单相家庭用户微处理器电压控制继电器操作算法的改进
Y. Zorin, Oleksandr Chepelіuk
This paper pays attention to a single-phase voltage control relays work algorithms that are used for protection of the household consumers of electrical energy from unacceptable voltage deviations within power supply network. An overview, analysis and description of operation algorithms, voltage measurements and thresholds of current voltage control relays, based on microprocessors and microcontrollers have been carried out. The conducted overview and analysis systematizes information on the technical and functional features of the operational design, work algorithms, circuits and components of the mentioned relays and demonstrates the prospects for development of voltage relay operational algorithms and protective characteristics according to existing International standards. The protective characteristics and standards of power quality have been outlined and illustrated by the authors in detail. The voltage measuring and digital signal processing (signal filtering) algorithms in modified voltage relay are described as well. Also represented a novel approach in design of operation algorithms taking into account of positive sides in existing voltage control relays and new sintesed algorithms including concept of voltage measurement and decision making algorithms for a new single-phase voltage control relays for household consumers. A generalization and conclusion are made concerning the improved operation algorithm in the voltage control relay for protection of household consumers.
本文研究了一种单相电压控制继电器的工作算法,该算法用于保护家庭电能消费者免受供电网络中不可接受的电压偏差的影响。对基于微处理器和微控制器的电流电压控制继电器的操作算法、电压测量和阈值进行了概述、分析和描述。所进行的概述和分析对上述继电器的操作设计、工作算法、电路和部件的技术和功能特点进行了系统的介绍,并根据现有的国际标准展示了电压继电器操作算法和保护特性的发展前景。作者对电能质量的保护特性和标准进行了详细的概述和说明。介绍了改进型电压继电器的电压测量和数字信号处理(信号滤波)算法。同时提出了一种考虑到现有电压控制继电器的正极的操作算法设计的新方法,以及一种新的用于家庭消费者的单相电压控制继电器的电压测量和决策算法的新算法。对保护家庭用户的电压控制继电器的改进操作算法进行了归纳和总结。
{"title":"Improvement of microprocessor voltage control relay operation algorithms for single-phase household consumers","authors":"Y. Zorin, Oleksandr Chepelіuk","doi":"10.20998/2079-3944.2023.1.02","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.02","url":null,"abstract":"This paper pays attention to a single-phase voltage control relays work algorithms that are used for protection of the household consumers of electrical energy from unacceptable voltage deviations within power supply network. An overview, analysis and description of operation algorithms, voltage measurements and thresholds of current voltage control relays, based on microprocessors and microcontrollers have been carried out. The conducted overview and analysis systematizes information on the technical and functional features of the operational design, work algorithms, circuits and components of the mentioned relays and demonstrates the prospects for development of voltage relay operational algorithms and protective characteristics according to existing International standards. The protective characteristics and standards of power quality have been outlined and illustrated by the authors in detail. The voltage measuring and digital signal processing (signal filtering) algorithms in modified voltage relay are described as well. Also represented a novel approach in design of operation algorithms taking into account of positive sides in existing voltage control relays and new sintesed algorithms including concept of voltage measurement and decision making algorithms for a new single-phase voltage control relays for household consumers. A generalization and conclusion are made concerning the improved operation algorithm in the voltage control relay for protection of household consumers.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126025549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comparison of methods for monitoring icing of high-voltage power lines and an overview of measuring equipment used to diagnose such lines 高压电力线结冰监测方法的比较和用于诊断高压电力线的测量设备的概述
Nataliya Kriukova, Vladyslav Markov, Ye. Honcharov, I. Polyakov
The low structural reliability of overhead lines, due to continuous climatic influence, becomes the cause of electrical network accidents and unreliable power supply. Ensuring the trouble-free operation of overhead lines is a complex task, the solution of which is of the utmost importance for the normal functioning of the entire infrastructure. In the autumn-winter period, difficult weather conditions almost completely exclude the quick completion of repair works. A fairly large share of accidents occurs during the formation of icy deposits on wires and lightning protection cables. Today, visual inspections of high-voltage power lines remain the main way of diagnosing icy deposits. In practice, it is necessary to equip overhead lines with ice load telemetry devices, which will allow monitoring the formation of ice deposits on wires in real time. The following diagnostic methods are used in modern ice monitoring devices: strainometric, fiber-optic, aerodynamic, locational, and instrumental-parametric. The tensiometric method of diagnosis is implemented by means of direct measurement of the icy load on the wire with subsequent comparison of the measured values with predetermined values of the threshold loads. To implement this diagnostic method, magnetoelastic force measuring sensors are used. Such a sensor is connected between the traverse of the U-shaped support and the upper end of the corresponding garland of insulators with a phase wire. Ice, wind and ice-wind loads are measured separately. This method has a limited scope of application, namely for diagnosing the formation of ice on the phase wires of intermediate spans of single-circuit lines with two-post U-shaped resistances. The fiber-optic method of strain gauge measurements is implemented in object control systems under difficult operating conditions, at nuclear power plants. The mechanical effort sensor (fiber-optic strain sensor) implements the fiber-optic method of strain measurement. Fiber-optic strain sensors are characterized by high accuracy due to resistance to interference and complexity of execution.
由于持续的气候影响,架空线路结构可靠性低,成为造成电网事故和供电不稳定的原因。确保架空线路的无故障运行是一项复杂的任务,其解决对整个基础设施的正常运行至关重要。在秋冬季节,恶劣的天气条件几乎完全排除了快速完成维修工作的可能性。相当大一部分事故发生在电线和防雷电缆结冰形成的过程中。今天,对高压电线的目测检查仍然是诊断冰沉积的主要方法。在实践中,有必要为架空线路配备冰负荷遥测设备,这将允许实时监测电线上冰沉积的形成。在现代冰监测装置中使用的诊断方法有:应变法、光纤法、气动法、定位法和仪器参数法。张力测量诊断方法是通过直接测量导线上的冰载荷,然后将测量值与预定的阈值载荷进行比较来实现的。为了实现这种诊断方法,使用了磁弹性力测量传感器。该传感器用相线连接在u形支架的导线与相应绝缘子花环的上端之间。冰荷载、风荷载和冰-风荷载分别测量。该方法适用范围有限,即用于诊断双柱u型电阻单线中间跨相线结冰情况。光纤应变计测量方法是在核电站困难操作条件下的目标控制系统中实施的。机械力传感器(光纤应变传感器)实现了光纤应变测量方法。光纤应变传感器具有高精度由于抵抗干扰和执行的复杂性。
{"title":"Comparison of methods for monitoring icing of high-voltage power lines and an overview of measuring equipment used to diagnose such lines","authors":"Nataliya Kriukova, Vladyslav Markov, Ye. Honcharov, I. Polyakov","doi":"10.20998/2079-3944.2023.1.10","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.10","url":null,"abstract":"The low structural reliability of overhead lines, due to continuous climatic influence, becomes the cause of electrical network accidents and unreliable power supply. Ensuring the trouble-free operation of overhead lines is a complex task, the solution of which is of the utmost importance for the normal functioning of the entire infrastructure. In the autumn-winter period, difficult weather conditions almost completely exclude the quick completion of repair works. A fairly large share of accidents occurs during the formation of icy deposits on wires and lightning protection cables. Today, visual inspections of high-voltage power lines remain the main way of diagnosing icy deposits. In practice, it is necessary to equip overhead lines with ice load telemetry devices, which will allow monitoring the formation of ice deposits on wires in real time. The following diagnostic methods are used in modern ice monitoring devices: strainometric, fiber-optic, aerodynamic, locational, and instrumental-parametric. The tensiometric method of diagnosis is implemented by means of direct measurement of the icy load on the wire with subsequent comparison of the measured values with predetermined values of the threshold loads. To implement this diagnostic method, magnetoelastic force measuring sensors are used. Such a sensor is connected between the traverse of the U-shaped support and the upper end of the corresponding garland of insulators with a phase wire. Ice, wind and ice-wind loads are measured separately. This method has a limited scope of application, namely for diagnosing the formation of ice on the phase wires of intermediate spans of single-circuit lines with two-post U-shaped resistances. The fiber-optic method of strain gauge measurements is implemented in object control systems under difficult operating conditions, at nuclear power plants. The mechanical effort sensor (fiber-optic strain sensor) implements the fiber-optic method of strain measurement. Fiber-optic strain sensors are characterized by high accuracy due to resistance to interference and complexity of execution.","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126772466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Mathematical modeling of a hybrid magnetic gear for an autonomous low-power wind turbine 自主小功率风力机混合磁齿轮数学建模
V. Chumak, M. Kovalenko, I. Kovalenko, I. Tkachuk
In traditional wind turbines, a mechanical gearbox is used to transmit the torque. This device converts the low rotation speed of the wind turbine blades into the high rotation speed of the generator shaft. Mechanical gearboxes are characterized by low reliability. They consist of rotating gears, all the torque between which is transmitted through the contact of the teeth at one point, which is accompanied by friction. Magnetic multipliers are more efficient than gear reducers. They contain no wearing parts and have a relatively high torque density. The modulator transforms the magnetic field between the inner and outer rotor, due to which the speed of rotation changes. This device has a number of advantages over a mechanical gearbox - the interaction between rotating elements (torque transmission) occurs over their entire area, while the gears of mechanical gearboxes perceive all the transmitted force at one point of contact between them. Research of autonomous wind turbines built on the basis of magnetic gearboxes is a relevant direction. This will reduce operating costs, increase the efficiency of converting wind energy into electricity, and increase the reliability of the wind turbine as a whole. The purpose of the work is the development of a two-dimensional field mathematical model of a hybrid magnetic gearbox for the evaluation of its parameters and characteristics and the optimization of its geometric dimensions. A generator with a built-in magnetic multiplier is the object of this study. The magnetic multiplier during operation creates a rotating magnetic field that can be used to induce emf in the generator winding. Such a generator is more compact than a gear drive, so this option was chosen as a prototype in this study. Geometrical models of a hybrid generator with a magnetic gearbox were developed and numerical field mathematical models were developed for the analysis of its parameters and characteristics. An analysis of the electromagnetic field and characteristics of the basic generator was carried out in the COMSOL Multiphysics software complex, on the basis of which optimization of its geometric dimensions was carried out to optimize mass and dimensional indicators
在传统的风力涡轮机中,使用机械齿轮箱来传递扭矩。该装置将风力发电机叶片的低转速转化为发电机轴的高转速。机械齿轮箱的特点是可靠性低。它们由旋转的齿轮组成,它们之间的所有扭矩都是通过齿在一点上的接触传递的,这伴随着摩擦。磁乘法器比齿轮减速器更有效。它们不含易损件,具有相对较高的扭矩密度。调制器改变内外转子之间的磁场,从而使旋转速度发生变化。与机械齿轮箱相比,这种装置有许多优点——旋转元件之间的相互作用(扭矩传递)发生在它们的整个区域,而机械齿轮箱的齿轮在它们之间的一个接触点上感知所有传递的力。基于磁齿轮箱的自主风力发电机组的研究是一个相关的研究方向。这将降低运营成本,提高将风能转化为电能的效率,并提高风力涡轮机整体的可靠性。本文的目的是建立混合磁齿轮箱的二维磁场数学模型,以评估其参数和特性并优化其几何尺寸。一种内置磁乘法器的发电机是本研究的对象。磁倍增器在工作时产生旋转磁场,可用于在发电机绕组中感应电动势。这样的发电机比齿轮传动更紧凑,所以在本研究中选择这个选项作为原型。建立了带磁齿轮箱的混合式发电机的几何模型,并建立了数值场数学模型,对其参数和特性进行了分析。在COMSOL Multiphysics软件综合体中对基本发生器的电磁场和特性进行了分析,在此基础上对其几何尺寸进行了优化,优化了质量和尺寸指标
{"title":"Mathematical modeling of a hybrid magnetic gear for an autonomous low-power wind turbine","authors":"V. Chumak, M. Kovalenko, I. Kovalenko, I. Tkachuk","doi":"10.20998/2079-3944.2023.1.07","DOIUrl":"https://doi.org/10.20998/2079-3944.2023.1.07","url":null,"abstract":"In traditional wind turbines, a mechanical gearbox is used to transmit the torque. This device converts the low rotation speed of the wind turbine blades into the high rotation speed of the generator shaft. Mechanical gearboxes are characterized by low reliability. They consist of rotating gears, all the torque between which is transmitted through the contact of the teeth at one point, which is accompanied by friction. Magnetic multipliers are more efficient than gear reducers. They contain no wearing parts and have a relatively high torque density. The modulator transforms the magnetic field between the inner and outer rotor, due to which the speed of rotation changes. This device has a number of advantages over a mechanical gearbox - the interaction between rotating elements (torque transmission) occurs over their entire area, while the gears of mechanical gearboxes perceive all the transmitted force at one point of contact between them. Research of autonomous wind turbines built on the basis of magnetic gearboxes is a relevant direction. This will reduce operating costs, increase the efficiency of converting wind energy into electricity, and increase the reliability of the wind turbine as a whole. The purpose of the work is the development of a two-dimensional field mathematical model of a hybrid magnetic gearbox for the evaluation of its parameters and characteristics and the optimization of its geometric dimensions. A generator with a built-in magnetic multiplier is the object of this study. The magnetic multiplier during operation creates a rotating magnetic field that can be used to induce emf in the generator winding. Such a generator is more compact than a gear drive, so this option was chosen as a prototype in this study. Geometrical models of a hybrid generator with a magnetic gearbox were developed and numerical field mathematical models were developed for the analysis of its parameters and characteristics. An analysis of the electromagnetic field and characteristics of the basic generator was carried out in the COMSOL Multiphysics software complex, on the basis of which optimization of its geometric dimensions was carried out to optimize mass and dimensional indicators","PeriodicalId":385206,"journal":{"name":"Bulletin of NTU \"KhPI\". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116705681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
Bulletin of NTU "KhPI". Series: Problems of Electrical Machines and Apparatus Perfection. The Theory and Practice
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1