Experimental investigation on a parabolic trough solar collector for thermal power generation

Developing solar thermal power technology in an effective manner is a great challenge in China.In this paper an experiment platform of a parabolic trough solar collector system(PTCS) was developed for thermal power generation,and the performance of the PTCS was experimentally investigated with synthetic oil as the circulate heat transfer fluid(HTF).The solar collector's efficiency with the variation of the solar flux and the flow rate of the HTF was identified.The collector efficiency of the PTCS can be in ...     

浅析标准厂房的开发与设计

改革开放以来,中国的经济社会发展突飞猛进,中小企业在市场中寻找到商机之后,需要在最短的时间内以投资最省的方式使产品批量生产,投放市场,以在市场的竞争中立于不败之地。基于此,标准厂房的诞生有了它的市场基础。20世纪80年代末期,全国掀起了工业园区开发的第一次浪潮,标准厂房的建设和土地批租一起成为工业区招商引资的重要手段。文章基于作者多年从事标准厂房设计的工作经验,介绍标准厂房的一种开发设计思路,供同行参考借鉴。     

A novel and simple model for estimating the hourly global solar radiation

This letter proposes a novel and simple method for estimating solar radiation, named the ‘three‐point method’. The three points used to form the model are sunrise, sunset, and the maximum radiation point. The issue of obtaining maximum radiation is performed with the weighting evaluation of the HOTTEL and ASHRAE models. The feasibility and effectiveness of the proposed model is shown by simulation results. This model is equally applicable in any part of the world with a reassessment of the weighting factors for the maximum radiation. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

台湾质子交换膜燃料电池的研发

燃料电池由于直接将化学能转换成电能,能源转换效率高于一般传统能源技术,同时由于环保无污染的特色,所以也几乎不需任何后处理。简单介绍了6种不同类型的燃料电池,虽然到目前为止燃料电池仍未能完全大量商业化应用,不过质子交换膜燃料电池近期商业化潜力相当大,而2002年6月台湾燃料电池伙伴联盟正式成立,主要目的即为提倡燃料电池技术应用。针对质子交换膜燃料电池的研发工作已展开,主要集中在系统的开发与应用,并已成功开发出千瓦级纯氢定置型发电系统。虽然燃料电池具有许多优于传统能源技术的特点,但是诸如氢气供应、价格等许多商业化的障碍仍然有待克服;长期而言,再生能源与燃料电池结合可能在能源供应方面扮演相当重要的角色。     

太阳能电池输出特性与光伏阵列MPPT仿真研究

基于Matlab／Simulink仿真平台,根据太阳能电池的数学表达式。建立了一种太阳能电池的仿真模型。通过Maflab／Simulink仿真平台,给出了光照强度和温度对太阳能电池输出特性的影响。在太阳能电池模型的基础上,根据扰动观察法的原理,建立了扰动光伏阵列的MPPT仿真模型,给出了仿真结果。     

基于太阳能输出电压的跟踪方法研究

研究一种车载太阳能的自动跟踪方法。该方法以太阳能输出电压为细跟踪参数,以光敏管组成的比较电路输出电平为粗跟踪参数,并针对太阳能最大输出电压随车载电器负荷变化及天气状态变化的问题,对给定目标值采取了实时调节策略。由于跟踪参数直接取自于太阳能输出电压,因而较好地反映出了太阳能的实际跟踪状态。实验表明,即使车载电器负荷变化及天气状态变化,上述方法均能较好地满足太阳能的动态跟踪要求。     

Electric double‐layer capacitor module with series‐parallel reconfigurable cell voltage equalizers

When electric double‐layer capacitors (EDLCs) are connected in series, a cell voltage imbalance occurs due to nonuniform cell properties. Cell voltage imbalance should be minimized to prolong cycle lives and maximize the available energy of cells. In this study, we propose a series‐parallel reconfigurable cell voltage equalizer that is considered suitable for energy storage systems using EDLCs instead of traditional secondary batteries as the main energy storage sources. The proposed equalizer requires only EDLCs and switches as its main circuit elements, and it utilizes EDLCs not only for energy storage but also for equalization. An equivalent circuit model using equivalent resistors that can be regarded as an index of equalization speed is developed. Current distribution and cell voltage imbalancing during operation are quantitatively generalized. Experimental charge–discharge tests were performed on the EDLC modules to demonstrate the performance of the cell voltage equalizer. All the cells in the modules could be charged/discharged uniformly even when a degradation‐mimicking cell was intentionally included in the module. The resultant cell voltage imbalances and current distributions were in good agreement with those predicted by mathematical analyses. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(4): 38–50, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21287     

Active device‐less voltage equalization charger using capacitors,diodes, and an AC power source

Conventional cell/module voltage equalizers or equalization chargers based on traditional DC‐DC converters require numerous switches or transformers as the number of series connections increases; therefore, their cost and complexity tend to increase and their reliability decreases as the number of connections increases. This paper proposes a novel voltage equalization charger that consists only of passive components such as capacitors, diodes, and a transformer. The fundamental operating principle, major features, and derivation of equivalent DC circuits are presented. A symmetrical configuration is also proposed to mitigate the RMS current flowing through energy storage cells in the charging process. Simulations and experimental charging and cycle tests were performed on series‐connected electric double‐layer capacitor modules to demonstrate the equalization performance. The experimental and simulation results were in good agreement, and the voltage imbalances were gradually eliminated as time elapsed even during charge‐discharge cycling. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 181(3): 39‐48, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21288     

日本家用燃料电池热电联供系统在中国应用的经济性分析

分析日本家用燃料电池热电联供系统（ENE-FARM）的技术原理及推广应用情况,针对影响ENE-FARM经济性的因素较为复杂的特点,建立考虑设备价格、家庭年用电量、电力及燃气价格等因素的ENE-FARM经济性分析一般模型,引入盈亏平衡电价曲线分析ENE-FARM在日本和中国应用的经济性差异,并分别对2020年和2030年场景进行测算。分析表明：现阶段ENE-FARM在日本已具备应用经济性,但在中国尚不具备大规模推广应用的条件,可在海岛等偏远地区以及自然灾害频发地区试点应用;2030年,在设备造价逐步降低,居民电力及燃气价格体系逐步理顺的前提下,ENE-FARM系统在中国居民家庭中的应用将实现盈亏平衡。     

Maximum oscillation frequencies and ft sensitivities of two groups of single-VFOA active-RC oscillators

Two groups of three active-RC oscillators that use a single voltage feedback op amp (VFOA) are compared. Linear analysis using a first-order VFOA model shows that all six oscillators have the same maximum oscillation frequency (OF) of 16.67% of the op amp gain-bandwidth product (GBP), despite the fact that based on an ideal VFOA the gain required in the oscillator amplifier section is 3 for one group and 1.5 for the other.Sensitivity of OF to op amp GBP is found to be the same for both groups. Simulation results using a nonlinear VFOA macromodel give good agreement with linear analysis.