International Journal of Rotating Machinery最新文献_第10页

Influence of End Structure on Electromagnetic Forces on End Winding of a 1550 MW Nuclear Generator 1550mw核电机组端面结构对端面绕组电磁力的影响

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International Journal of Rotating Machinery Pub Date : 2017-10-29 DOI: 10.1155/2017/9545238

C. Zeng, Song-bo Huang, Y. Yongming, Guang-hou Zhou

引用次数: 4

Overvoltage and Insulation Coordination of Overhead Lines in Multiple-Terminal MMC-HVDC Link for Wind Power Delivery 风电多端MMC-HVDC线路过电压与绝缘协调

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International Journal of Rotating Machinery Pub Date : 2017-10-25 DOI: 10.1155/2017/4849262

He Huiwen, Lei Wang, Peihong Zhou, Y. Fei

{"title":"Overvoltage and Insulation Coordination of Overhead Lines in Multiple-Terminal MMC-HVDC Link for Wind Power Delivery","authors":"He Huiwen, Lei Wang, Peihong Zhou, Y. Fei","doi":"10.1155/2017/4849262","DOIUrl":"https://doi.org/10.1155/2017/4849262","url":null,"abstract":"The voltage-sourced converter-based HVDC link, including the modular multilevel converter (MMC) configuration, is suitable for wind power, photovoltaic energy, and other kinds of new energy delivery and grid-connection. Current studies are focused on the MMC principles and controls and few studies have been done on the overvoltage of transmission line for the MMC-HVDC link. The main reason is that environmental factors have little effect on DC cables and the single-phase/pole fault rate is low. But if the cables were replaced by the overhead lines, although the construction cost of the project would be greatly reduced, the single-pole ground fault rate would be much higher. This paper analyzed the main overvoltage types in multiple-terminal MMC-HVDC network which transmit electric power by overhead lines. Based on ±500 kV multiple-terminal MMC-HVDC for wind power delivery project, the transient simulation model was built and the overvoltage types mentioned above were studied. The results showed that the most serious overvoltage was on the healthy adjacent line of the faulty line caused by the fault clearing of DC breaker. Then the insulation coordination for overhead lines was conducted according to the overvoltage level. The recommended clearance values were given.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":"1-7"},"PeriodicalIF":0.9,"publicationDate":"2017-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/4849262","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45422482","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

Influence of Varnish on Bearing Performance and Vibration of Rotating Machinery 清漆对旋转机械轴承性能和振动的影响

IF 0.9

International Journal of Rotating Machinery Pub Date : 2017-10-19 DOI: 10.1155/2017/9131275

Chu Zhang, Jiangang Yang, Shi Liu, Q. Gao, Yi Yang

{"title":"Influence of Varnish on Bearing Performance and Vibration of Rotating Machinery","authors":"Chu Zhang, Jiangang Yang, Shi Liu, Q. Gao, Yi Yang","doi":"10.1155/2017/9131275","DOIUrl":"https://doi.org/10.1155/2017/9131275","url":null,"abstract":"Varnish is a kind of fouling adhered on bearing inner face near the load zone. The model to analyze its influence on bearing performance and rotor vibration was set up. Pressure and temperature distribution were solved on the basis of the Reynolds equation by the iteration method simultaneously. It is found that bearing performance is changed by the step flow effect at the leading edge of the varnish. Its influence is more obvious when the rotating speed is low. Bearing varnish results in a large decrease of minimum clearance and an increase in the oil film temperature and pressure. Loading capacity of bearing is also decreased. It is harmful to the bearing. With the varnish, the minimum oil film thickness decreases. This leads to an increase of bearing stiffness and damping coefficients. Its influence is larger in the horizontal direction than that in the vertical direction. The trend of unbalance response to rotating speed is similar. There is little influence of the varnish on the modal frequency. However, system stability is improved due to the increased bearing damping coefficients.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":"1-10"},"PeriodicalIF":0.9,"publicationDate":"2017-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/9131275","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43811314","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: 4

Failure Diagnosis for Demagnetization in Interior Permanent Magnet Synchronous Motors 车用永磁同步电动机退磁故障诊断

IF 0.9

International Journal of Rotating Machinery Pub Date : 2017-10-16 DOI: 10.1155/2017/2716814

T. Ishikawa, Naoto Igarashi, N. Kurita

{"title":"Failure Diagnosis for Demagnetization in Interior Permanent Magnet Synchronous Motors","authors":"T. Ishikawa, Naoto Igarashi, N. Kurita","doi":"10.1155/2017/2716814","DOIUrl":"https://doi.org/10.1155/2017/2716814","url":null,"abstract":"Since a high degree of reliability is necessary for permanent magnet synchronous motors, the detection of a precursor for the demagnetization of permanent magnets is very important. This paper investigates the diagnosis of very slight PM demagnetization. The permanent magnet volume is altered so as to mimic the effect of demagnetization. This paper investigates the influence of demagnetization by using several methods: the 3D finite element analysis (FEA) of the motor, the measurement of high-frequency impedance, and the measurement and FEA of the stator voltage and current under vector control. We have obtained the following results. The back-EMF is proportional to permanent magnet volume, and there is no difference in the demagnetization in the radial direction and in the axial direction. Even harmonics and subharmonics of flux density at the teeth tip could be useful for diagnosis if a search coil is installed there. The relatively low frequency resistance at the -axis position is useful for diagnosis. Under vector control, the stator voltage is useful except in an intermediate torque range, and the intermediate torque is expressed by a simple equation.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":"2017 1","pages":"1-13"},"PeriodicalIF":0.9,"publicationDate":"2017-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/2716814","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43098624","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: 8

Rolling Element Bearing Performance Degradation Assessment Using Variational Mode Decomposition and Gath-Geva Clustering Time Series Segmentation 基于变分模态分解和聚类时间序列分割的滚动轴承性能退化评估

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International Journal of Rotating Machinery Pub Date : 2017-10-12 DOI: 10.1155/2017/2598169

Yaolong Li, Hong-ru Li, Bing Wang, Hongqiang Gu

{"title":"Rolling Element Bearing Performance Degradation Assessment Using Variational Mode Decomposition and Gath-Geva Clustering Time Series Segmentation","authors":"Yaolong Li, Hong-ru Li, Bing Wang, Hongqiang Gu","doi":"10.1155/2017/2598169","DOIUrl":"https://doi.org/10.1155/2017/2598169","url":null,"abstract":"By focusing on the issue of rolling element bearing (REB) performance degradation assessment (PDA), a solution based on variational mode decomposition (VMD) and Gath-Geva clustering time series segmentation (GGCTSS) has been proposed. VMD is a new decomposition method. Since it is different from the recursive decomposition method, for example, empirical mode decomposition (EMD), local mean decomposition (LMD), and local characteristic-scale decomposition (LCD), VMD needs a priori parameters. In this paper, we will propose a method to optimize the parameters in VMD, namely, the number of decomposition modes and moderate bandwidth constraint, based on genetic algorithm. Executing VMD with the acquired parameters, the BLIMFs are obtained. By taking the envelope of the BLIMFs, the sensitive BLIMFs are selected. And then we take the amplitude of the defect frequency (ADF) as a degradative feature. To get the performance degradation assessment, we are going to use the method called Gath-Geva clustering time series segmentation. Afterwards, the method is carried out by two pieces of run-to-failure data. The results indicate that the extracted feature could depict the process of degradation precisely.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":"1-12"},"PeriodicalIF":0.9,"publicationDate":"2017-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/2598169","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43075408","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: 7

Numerical Simulation of Wind Turbine Rotors Autorotation by Using the Modified LS-STAG Immersed Boundary Method 基于改进LS-STAG浸入边界法的风力机转子自旋数值模拟

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International Journal of Rotating Machinery Pub Date : 2017-10-11 DOI: 10.1155/2017/6418108

I. Marchevsky, V. Puzikova

引用次数: 6

Aerodynamic Optimization Design of a Multistage Centrifugal Steam Turbine and Its Off-Design Performance Analysis 多级离心汽轮机气动优化设计及其非设计性能分析

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International Journal of Rotating Machinery Pub Date : 2017-09-27 DOI: 10.1155/2017/4690590

Hui Li, Diangui Huang

{"title":"Aerodynamic Optimization Design of a Multistage Centrifugal Steam Turbine and Its Off-Design Performance Analysis","authors":"Hui Li, Diangui Huang","doi":"10.1155/2017/4690590","DOIUrl":"https://doi.org/10.1155/2017/4690590","url":null,"abstract":"Centrifugal turbine which has less land occupation, simple structure, and high aerodynamic efficiency is suitable to be used as small to medium size steam turbines or waste heat recovery plant. In this paper, one-dimensional design of a multistage centrifugal steam turbine was performed by using in-house one-dimensional aerodynamic design program. In addition, three-dimensional numerical simulation was also performed in order to analyze design and off-design aerodynamic performance of the proposed centrifugal steam turbine. The results exhibit reasonable flow field and smooth streamline; the aerodynamic performance of the designed turbine meets our initial expectations. These results indicate that the one-dimensional aerodynamic design program is reliable and effective. The off-design aerodynamic performance of centrifugal steam turbine was analyzed, and the results show that the mass flow increases with the decrease of the pressure ratio at a constant speed, until the critical mass flow is reached. The efficiency curve with the pressure ratio has an optimum efficiency point. And the pressure ratio of the optimum efficiency agrees well with that of the one-dimensional design. The shaft power decreases as the pressure ratio increases at a constant speed. Overall, the centrifugal turbine has a wide range and good off-design aerodynamic performance.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":"1-11"},"PeriodicalIF":0.9,"publicationDate":"2017-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/4690590","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42538232","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: 5

Optimal Sizing for Wind/PV/Battery System Using Fuzzy -Means Clustering with Self-Adapted Cluster Number 基于自适应聚类数的模糊均值聚类优化风/光伏/电池系统的规模

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International Journal of Rotating Machinery Pub Date : 2017-09-26 DOI: 10.1155/2017/5142825

Xin Liu, Hongkun Chen, Bing Huang, Yubo Tao

{"title":"Optimal Sizing for Wind/PV/Battery System Using Fuzzy -Means Clustering with Self-Adapted Cluster Number","authors":"Xin Liu, Hongkun Chen, Bing Huang, Yubo Tao","doi":"10.1155/2017/5142825","DOIUrl":"https://doi.org/10.1155/2017/5142825","url":null,"abstract":"Integrating wind generation, photovoltaic power, and battery storage to form hybrid power systems has been recognized to be promising in renewable energy development. However, considering the system complexity and uncertainty of renewable energies, such as wind and solar types, it is difficult to obtain practical solutions for these systems. In this paper, optimal sizing for a wind/PV/battery system is realized by trade-offs between technical and economic factors. Firstly, the fuzzy -means clustering algorithm was modified with self-adapted parameters to extract useful information from historical data. Furthermore, the Markov model is combined to determine the chronological system states of natural resources and load. Finally, a power balance strategy is introduced to guide the optimization process with the genetic algorithm to establish the optimal configuration with minimized cost while guaranteeing reliability and environmental factors. A case of island hybrid power system is analyzed, and the simulation results are compared with the general FCM method and chronological method to validate the effectiveness of the mentioned method.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":"1-9"},"PeriodicalIF":0.9,"publicationDate":"2017-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/5142825","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45254935","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: 10

Observations of the Growth and Decay of Stall Cells during Stall and Surge in an Axial Compressor 轴流压气机失速和喘振过程中失速细胞生长和衰减的观察

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International Journal of Rotating Machinery Pub Date : 2017-09-13 DOI: 10.1155/2017/6329382

Adam R. Hickman, S. Morris

{"title":"Observations of the Growth and Decay of Stall Cells during Stall and Surge in an Axial Compressor","authors":"Adam R. Hickman, S. Morris","doi":"10.1155/2017/6329382","DOIUrl":"https://doi.org/10.1155/2017/6329382","url":null,"abstract":"This research investigated unsteady events such as stall inception, stall-cell development, and surge. Stall is characterized by a decrease in overall pressure rise and nonaxisymmetric throughflow. Compressor stall can lead to surge which is characterized by quasi-axisymmetric fluctuations in mass flow and pressure. Unsteady measurements of the flow field around the compressor rotor are examined. During the stall inception process, initial disturbances were found within the rotor passage near the tip region. As the stall cell develops, blade lift and pressure ratio decrease within the stall cell and increase ahead of the stall cell. The stall inception event, stall-cell development, and stall recovery event were found to be nearly identical for stable rotating stall and surge cases. As the stall cell grows, the leading edge of the cell will rotate at a higher rate than the trailing edge in the rotor frame. The opposite occurs during stall recovery. The trailing edge of the stall cell will rotate at the approximate speed as the fully developed stall cell, while the leading edge decreases in rotational speed in the rotor frame.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":"1-11"},"PeriodicalIF":0.9,"publicationDate":"2017-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/6329382","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45834151","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: 1

Bubble Flow Analysis of High Speed Cylindrical Roller Bearing under Fluid-Solid Thermal Coupling 流固耦合下高速圆柱滚子轴承的气泡流动分析

IF 0.9

International Journal of Rotating Machinery Pub Date : 2017-09-13 DOI: 10.1155/2017/8372176

L. Cui, Wenxia Wang, Zhang Yan-lei

{"title":"Bubble Flow Analysis of High Speed Cylindrical Roller Bearing under Fluid-Solid Thermal Coupling","authors":"L. Cui, Wenxia Wang, Zhang Yan-lei","doi":"10.1155/2017/8372176","DOIUrl":"https://doi.org/10.1155/2017/8372176","url":null,"abstract":"Heat generation model of high speed cylindrical roller bearing is constructed by calculating the local friction in the bearing. Bubble flow calculation model of roller bearing considering fluid-solid thermal coupling is constructed based on two-body fluid model and turbulent model, in which diameter and size of bubbles, breakup, and coalescence model of bubbles are considered. Using dynamic mesh method, a new method for evaluating bearing temperature is set up treating the rolling elements as moving heat sources. Based on these models and finite element method, bubble flow of a high speed roller bearing is studied based on FLUENT software. The numerical study reveals the relationship between velocity of bearing, air volume fraction, and velocity and pressure of oil-air flow. An increase of air content in the oil produces a lower pressure at the bearing outlet while the exit fluid velocity increases. When fluid-solid thermal coupling effect is considered, velocity and pressure at outlet of the bearing both become larger, while temperature of bearing is lower than that without coupling. In comparison, the coupling effects on flow pressure and temperature are obvious. For a given rotating speed, there is an optimal value for air volume fraction, such that temperature rise of the bearing reaches the lowest value. Experiments verify the outcomes of the method presented in this paper.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":"2017 1","pages":"1-11"},"PeriodicalIF":0.9,"publicationDate":"2017-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/8372176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41434904","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: 4