资源类型

期刊论文 42

年份

2023 1

2022 1

2021 1

2020 6

2019 1

2017 4

2016 2

2015 2

2014 1

2013 2

2012 2

2011 1

2009 1

2008 5

2007 2

2006 2

2005 5

2003 1

2002 2

展开 ︾

关键词

反馈线性化 2

薄膜润滑 2

裂缝 2

RLC网络;谐振性质;振荡特性;幅频特性 1

SAC 1

Walsh循环谱 1

三维有限元 1

分析设计 1

初始刚度 1

力学性能 1

动态模量 1

医院中子照射器I型堆 1

半无限平面问题 1

单边直线感应电机 1

压力容器 1

厚板 1

参数测量 1

复合浇筑式 1

复杂网络;等效变换;非线性差分方程;等效电阻 1

展开 ︾

检索范围:

排序: 展示方式:

压力容器分析设计中基于“处理面”的等效线性化方法

尹益辉,余绍蓉

《中国工程科学》 2008年 第10卷 第10期   页码 31-35

摘要:

从球形压力容器在内压作用下的解析解出发进行分析,指出在现有著作和规范中,直接对沿壳体厚度变化的应力表达式沿壳体厚度的一条“处理线”进行一维积分求解厚壁球壳壁上的薄膜应力和弯曲应力的方法在概念上不够准确,会导致一定的额外误差。由此提出了在壳体的环形截面区域的一个“处理面”上进行二维积分来求解壳壁上的薄膜应力和弯曲应力的方法,在概念上是准确的,能够避免“处理线”法导致的额外误差。通过一个受内压厚壁球壳的弹性解析计算,说明新方法比原方法有明显的改进。

关键词: 压力容器     分析设计     应力分类     等效线性化方法    

Design of damping valve for vehicle hydro pneumatic suspension

DONG Mingming, HUANG Hua, GU Lian

《机械工程前沿(英文)》 2008年 第3卷 第1期   页码 97-100 doi: 10.1007/s11465-008-0014-5

摘要: According to the design features of a hydro pneumatic spring, the necessity of a separate damping valve is proposed. Based on a 1/4 vehicle linear suspension model, the optimum damping coefficient is worked out and the parameters of the damping valve are determined with the equivalent linearization method. A practical structure of the damping valve is proposed having a small size, high flowrate when the valve opens, and the ability of enduring high back pressure. Based on bench tests, the damping valve has been found to properly work and be suitable. The design method and damping valve structure are useful guides for hydro pneumatic suspension, especially for the design of heavy-duty vehicles.

关键词: ability     pneumatic     necessity     flowrate     equivalent linearization    

Feedback linearization based control for weak grid connected PV system under normal and abnormal conditions

Rahul SHARMA,Sathans SUHAG

《能源前沿(英文)》 2020年 第14卷 第2期   页码 400-409 doi: 10.1007/s11708-017-0459-5

摘要: This paper proposes a control strategy for interface of distributed energy sources into the weak grid system with a focus on the energy and ancillary services. A novel controller has been designed and implemented to tackle the challenges of coupling terms in the LCL filter, the transient behavior under sudden changes, and the voltage support under fault condition using the feedback linearization technique. The controller proposed has been implemented on the PV system connected with the weak grid using the LCL filter and the performance of the controller has been verified using Matlab/Simulink through simulation under different conditions. The results of the controller proposed have been compared with the conventional PI dual loop controller. The simulation results obtained demonstrate the effectiveness and simplicity of the controller design strategy.

关键词: PV system     grid interface     feedback linearization     inverter     LCL filter    

Robust nonlinear control via feedback linearization and Lyapunov theory for permanent magnet synchronous

Ridha CHEIKH, Arezki MENACER, L. CHRIFI-ALAOUI, Said DRID

《能源前沿(英文)》 2020年 第14卷 第1期   页码 180-191 doi: 10.1007/s11708-018-0537-3

摘要: In this paper, the method for the nonlinear control design of a permanent magnet synchronous generator based-wind energy conversion system (WECS) is proposed in order to obtain robustness against disturbances and harvest a maximum power from a typical stochastic wind environment. The technique overcomes both the problem of nonlinearity and the uncertainty of the parameter compared to such classical control designs based on traditional control techniques. The method is based on the differential geometric feedback linearization technique (DGT) and the Lyapunov theory. The results obtained show the effectiveness and performance of the proposed approach.

关键词: permanent magnet synchronous generator     wind energy conversion system     stochastic     differential geometric     feedback linearization     maximum power point tracking     Lyapunov     robust control    

A modified zone model for estimating equivalent room thermal capacity

Hua CHEN, Xiaolin WANG

《能源前沿(英文)》 2013年 第7卷 第3期   页码 351-357 doi: 10.1007/s11708-013-0254-x

摘要: The zone model has been widely applied in control analysis of heating, ventilation and air conditioning (HVAC) systems to achieve a high building efficiency. This paper proposed a modified zone model which is much simpler in the HVAC system simulation and has the similar accuracy to the complicated simulation model. The proposed model took into consideration the effect of envelop heat reservoir on the room indoor temperature by introducing the thermal admittance of the inner surfaces of the building enclosure. The thermal admittance for the building enclosure was developed based on the building thermal network analytical theory and transfer function method. The efficacy of the proposed model was demonstrated by comparing it with the complicated model — heat balance method (HTB2 program). The predicted results from the proposed model well agreed with those from the complicated simulation. The proposed model can then make the HVAC system dynamic simulation much faster and more acceptable for control design due to its simplicity and efficiency.

关键词: room model     thermal network analysis     transfer function     heating     ventilation and air conditioning (HVAC) system simulation    

Distribution of background equivalent static wind load on high-rise buildings

Jianguo ZHANG , Ming GU ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 241-248 doi: 10.1007/s11709-009-0036-z

摘要: In this paper, the along-wind and cross-wind fluctuating load distributions along the height of high-rise buildings and their correlations are obtained through simultaneous pressure measurements in a wind tunnel. Some typical methods proposed in some relative literatures, i.e., load-response correlation (LRC), and quasi-mean load (QML) and gust load envelope (GLE) methods, are verified in terms of their accuracy in describing the background equivalent static wind load distribution on high-rise buildings. Based on the results, formulae of the distribution of background equivalent static load on high-rise buildings with typical shapes are put forward. It is shown that these formulae are of high accuracy and practical use.

关键词: high-rise buildings     along-wind     cross-wind     background equivalent static wind load     close formulae    

China’s new problems of food security revealed by the Food Equivalent Unit

Huilong LIN,Ruichao LI,Cangyu JIN,Chong WANG,Maohong WEI,Jizhou REN

《农业科学与工程前沿(英文)》 2014年 第1卷 第1期   页码 69-76 doi: 10.15302/J-FASE-2014023

摘要: China's food security has a great influence on the world, and has always been the top priority in China. In recent years, as the concept of food security is evolving into one of nutrition security and the importance of food diversity is increasing, research based on nutrition security and broad food systems are increasingly needed in today’s China. Thus, not only grain for human consumption, but also animal foods have been integrated into the Food Equivalent, which is used to analyze China’s current agriculture system and reveal the water resource distribution. The results indicated that the average animal food consumption has risen by 78.6%, and now China’s daily supply of animal food per capita has reached about 50% of that in the USA and 80% of that in the South Korea. So there exist an obvious disparity in animal food supply between China and these two countries. It is impossible for the China’s current agricultural system to achieve the level in the USA. Under China’s current agricultural system, the consumption proportion of feed grain had surpassed the consumption of food grain, increased sharply from 33% in 1992 to 67% in 2011. However, the growth potential of total grain output is approaching an upper limit, so the continued growth of feed grain demand exerts great pressure on the China’s food supply. The discordance of the spatial distribution of water resource and virtual water revealed that China’s current agriculture system had a low efficiency in being able to achieve food and nutrition security. China’s current “grain farming” cannot meet the demand of increasing nutrition and appropriate resource utilization. The implementation of grassland agriculture appears feasible and necessary for saving feed grain, providing a large number of high-quality animal foods and appropriate water resource utilization.

关键词: food security     nutrition security     food equivalent unit     grassland agriculture     China    

Equivalent circuit and characteristic simulation of a brushless electrically excited synchronous wind

Hao WANG, Fengge ZHANG, Tao GUAN, Siyang YU

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 420-426 doi: 10.1007/s11465-017-0439-9

摘要:

A brushless electrically excited synchronous generator (BEESG) with a hybrid rotor is a novel electrically excited synchronous generator. The BEESG proposed in this paper is composed of a conventional stator with two different sets of windings with different pole numbers, and a hybrid rotor with powerful coupling capacity. The pole number of the rotor is different from those of the stator windings. Thus, an analysis method different from that applied to conventional generators should be applied to the BEESG. In view of this problem, the equivalent circuit and electromagnetic torque expression of the BEESG are derived on the basis of electromagnetic relation of the proposed generator. The generator is simulated and tested experimentally using the established equivalent circuit model. The experimental and simulation data are then analyzed and compared. Results show the validity of the equivalent circuit model.

关键词: wind power     brushless electrically excited synchronous generator     hybrid rotor     equivalent circuit    

Fault classification and reconfiguration of distribution systems using equivalent capacity margin method

K. Sathish KUMAR, T. JAYABARATHI

《能源前沿(英文)》 2012年 第6卷 第4期   页码 394-402 doi: 10.1007/s11708-012-0211-0

摘要: This paper investigates the capability of support vector machines (SVM) for prediction of fault classification and the use of the concept of equivalent capacity margin (ECM) for restoration of the power system. The SVM, as a novel type of machine learning based on statistical learning theory, achieves good generalization ability by adopting a structural risk minimization (SRM) induction principle aimed at minimizing a bound on the generalization error of a model rather than the minimization of the error on the training data only. Here, the SVM has been used as a classification. The inputs of the SVM model are power and voltage values. An equation has been developed for the prediction of the fault in the power system based on the developed SVM model. The next steps of this paper are the restoration and reconfiguration by using the ECM concept, the development of a code, and the testing of the results with various load outages, which have been executed for a 12 load system.

关键词: support vector machines (SVM)     structural risk minimization (SRM)     equivalent capacity margin (ECM)     restoration     fault classification    

医院中子照射器I型堆热中子束流孔道等效平面源的模拟计算

朱养妮,江新标,赵柱民,张良,周永茂

《中国工程科学》 2012年 第14卷 第8期   页码 56-59

摘要:

采用蒙特卡罗程序MCNP模拟计算了医院中子照射器I型堆(IHNI-1)热中子束流孔道出口处的等效平面源。对B堆芯进行了临界搜索计算,模拟计算了热中子束流孔道及出口处中子、γ的束流参数,应用等效平面源模型建立了BNCT等效中子、γ平面源。为人体头颅等效模型剂量分布的快速计算提供了较为可靠的平面源。

关键词: 医院中子照射器I型堆     热中子束流孔道     等效中子平面源     等效γ平面源    

Assessment indices for uniform and non-uniform thermal environments

ZHANG Yufeng, SUN Shufeng, ZHAO Rongyi

《能源前沿(英文)》 2008年 第2卷 第2期   页码 129-133 doi: 10.1007/s11708-008-0029-y

摘要: Different assessment indices for thermal environments were compared and selected for proper assessment of indoor thermal environments. 30 subjects reported their overall thermal sensation, thermal comfort, and thermal acceptability in uniform and non-uniform conditions. The results show that these three assessment indices provide equivalent evaluations in uniform environments. However, overall thermal sensation differs from the other two indices and cannot be used as a proper index for the evaluation of non-uniform environments. The relationship between the percentage and the mean vote for each index is established.

关键词: thermal sensation     proper assessment     relationship     equivalent     thermal acceptability    

Optimal operation of integrated energy system including power thermal and gas subsystems

《能源前沿(英文)》 2022年 第16卷 第1期   页码 105-120 doi: 10.1007/s11708-022-0814-z

摘要: As a form of hybrid multi-energy systems, the integrated energy system contains different forms of energy such as power, thermal, and gas which meet the load of various energy forms. Focusing mainly on model building and optimal operation of the integrated energy system, in this paper, the dist-flow method is applied to quickly calculate the power flow and the gas system model is built by the analogy of the power system model. In addition, the piecewise linearization method is applied to solve the quadratic Weymouth gas flow equation, and the alternating direction method of multipliers (ADMM) method is applied to narrow the optimal results of each subsystem at the coupling point. The entire system reaches its optimal operation through multiple iterations. The power-thermal-gas integrated energy system used in the case study includes an IEEE-33 bus power system, a Belgian 20 node natural gas system, and a six node thermal system. Simulation-based calculations and comparison of the results under different scenarios prove that the power-thermal-gas integrated energy system enhances the flexibility and stability of the system as well as reducing system operating costs to some extent.

关键词: integrated energy system     power-to-gas     dist-flow     piecewise linearization     alternating direction method of multipliers (ADMM)    

Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand in China

Huilong LIN, Ruichao LI, Yifan LIU, Jingrong ZHANG, Jizhou REN

《农业科学与工程前沿(英文)》 2017年 第4卷 第1期   页码 69-80 doi: 10.15302/J-FASE-2017140

摘要: To explore the distribution of food demand and the projected trend in future food demand in China, this paper analyzed the change in current (1998–2012) per-capita demand for grain, grain-consuming and herbivorous livestock products, and predicted the food demand in 2020. The results indicated that in 1998–2012, the national per-capita consumption of grain ration declined by about 36.66%, and the per-capita consumption of grain-consu-ming and herbivorous livestock products increased by about 48% and 34.09%, respectively. The grain-consu-ming livestock products have become the primary source of both calories and protein for consumers. The proportion of herbivorous livestock products in consumer diets has increased steadily and there has been huge potential in substituting beef and mutton for pork in this dynamic market. The demand for food in different provinces of China is highly variable, which is important for planning grassland agriculture development and ensuring food safety. The demand for grain, and grain-consuming and herbivorous livestock products will increase by about 3.3%, 20% and 14% respectively by 2020. Based on the food demand and trend in the development of grassland agriculture, the 31 provinces in China are divided into three priority groups for grassland agriculture development.

关键词: arable land equivalent unit (ALEU)     food equivalent unit (FEU)     food security     grassland agriculture     time trend prediction    

用二极管统一构建两个n阶电路网络 Research Article

林小燕,谭志中

《信息与电子工程前沿(英文)》 2023年 第24卷 第2期   页码 289-298 doi: 10.1631/FITEE.2200360

摘要: 本文通过二极管将两个不同的n阶拓扑电路网络连接起来,建立起一个统一的网络模型,这是一个以前没有研究解决的新问题。该网络模型不仅包含五个电阻元件,还包含二极管器件,因此该网络包含多种不同的网络类型。该问题可以通过三个主要步骤来解决:首先,将网络简化为两个不同的等效电路模型;其次,应用基尔霍夫定律建立非线性差分方程模型;最后,对结构相似的两个方程进行统一处理,并利用等效变换技术得到非线性差分方程的通解。作为应用,文章推导出几个有趣的特殊结果。网络模型的研究非常重要,可以应用于跨学科研究。

关键词: 复杂网络;等效变换;非线性差分方程;等效电阻    

单边直线感应电机等效电路参数研究

徐伟,孙广生

《中国工程科学》 2008年 第10卷 第8期   页码 76-80

摘要:

单边直线感应电机(SLIM)相对于旋转感应电机(RIM)存在气隙大、边缘效应等,若采用RIM开路和短路试验方法,会给参数测量带来较大误差。文章提出的一种适合SLIM参数测定的新型方案,只需测量电机输入端的总功率、相电压、相电流和频率4个量,即可计算出初级电阻、初级漏感、次级电阻、次级漏感、气隙电感和铁损电阻。电机的特性分析表明,该方法真实有效,具有一定的参考价值。

关键词: 单边直线感应电机     开路试验     短路试验     参数测量     等效电路    

标题 作者 时间 类型 操作

压力容器分析设计中基于“处理面”的等效线性化方法

尹益辉,余绍蓉

期刊论文

Design of damping valve for vehicle hydro pneumatic suspension

DONG Mingming, HUANG Hua, GU Lian

期刊论文

Feedback linearization based control for weak grid connected PV system under normal and abnormal conditions

Rahul SHARMA,Sathans SUHAG

期刊论文

Robust nonlinear control via feedback linearization and Lyapunov theory for permanent magnet synchronous

Ridha CHEIKH, Arezki MENACER, L. CHRIFI-ALAOUI, Said DRID

期刊论文

A modified zone model for estimating equivalent room thermal capacity

Hua CHEN, Xiaolin WANG

期刊论文

Distribution of background equivalent static wind load on high-rise buildings

Jianguo ZHANG , Ming GU ,

期刊论文

China’s new problems of food security revealed by the Food Equivalent Unit

Huilong LIN,Ruichao LI,Cangyu JIN,Chong WANG,Maohong WEI,Jizhou REN

期刊论文

Equivalent circuit and characteristic simulation of a brushless electrically excited synchronous wind

Hao WANG, Fengge ZHANG, Tao GUAN, Siyang YU

期刊论文

Fault classification and reconfiguration of distribution systems using equivalent capacity margin method

K. Sathish KUMAR, T. JAYABARATHI

期刊论文

医院中子照射器I型堆热中子束流孔道等效平面源的模拟计算

朱养妮,江新标,赵柱民,张良,周永茂

期刊论文

Assessment indices for uniform and non-uniform thermal environments

ZHANG Yufeng, SUN Shufeng, ZHAO Rongyi

期刊论文

Optimal operation of integrated energy system including power thermal and gas subsystems

期刊论文

Allocation of grassland, livestock and arable based on the spatial and temporal analysis for food demand in China

Huilong LIN, Ruichao LI, Yifan LIU, Jingrong ZHANG, Jizhou REN

期刊论文

用二极管统一构建两个n阶电路网络

林小燕,谭志中

期刊论文

单边直线感应电机等效电路参数研究

徐伟,孙广生

期刊论文