基于Bezier曲线的CIGS薄膜光伏电池I-V曲线简单拟合方法

精准的光伏电池输出数学模型是研究光伏系统的必要条件,然而由于厂家提供的数据有限,铜铟镓硒(CIGS)薄膜光伏电池的输出数学模型是包含若干未知参数的非线性特性曲线.因此提出仅利用厂家提供的有限数据,对CIGS薄膜光伏电池的电流-电压输出特性曲线,即I-V曲线进行拟合.首先利用Bezier曲线选取函数控制点,对CIGS薄膜光伏电池的I-V曲线进行拟合;然后找出Bezier曲线控制点位置与CIGS薄膜光伏电池的填充因子之间的函数关系;最后,利用4种新型CIGS薄膜光伏电池对该函数关系进行验证,并对结果进行了对比分析.分析结果表明,所提方法对4种CIGS薄膜光伏电池的I-V曲线的拟合方法的平均相对误差均小于0.8％,验证了所提方法的有效性.     

ZAO特性及其在CIGS电池中的应用

透明导电氧化物薄膜(Transparent Conductive Oxides,简称TCO)用途广泛,介绍了TCO应用于光伏领域中的铜铟镓硒薄膜(CIGS)太阳电池,是CIGS太阳电池中不可缺少的一部分。简要阐述了其可见光范围内的透明性和导电性及其成因,以及作为CIGS薄膜太阳电池中窗口层的作用。将ITO和ZAO透明导电薄膜在CIGS太阳电池的应用进行相比,以掺铝的氧化锌(ZnO∶Al简称ZAO)透明导电薄膜为例,对其性能、制备方法及过程进行了简要阐述,并概括了大面积ZAO薄膜的性能。     

铜铟镓硒薄膜太阳电池的应力问题

分析了CIGS太阳电池的总应力来自于单层膜中的沉积应力及膜层界面间的相互作用.计算得出Mo薄膜与CIGS薄膜界面晶格失配度最大,表明相对于其他界面,该界面的应力值较大.而作为缓冲层的CdS薄膜有效地改善了吸收层CIGS薄膜与窗口层ZnO薄膜的界面应力.而对于柔性衬底材料的PI薄膜,如何解决因其较大的热膨胀系数造成的热应...     

CIGS薄膜太阳能电池研究进展

薄膜太阳电池以其低成本吸引越来越多的研究者。CIGS薄膜作为光伏材料,其光电转化效率高,性能稳定,CIGS薄膜太阳能电池成为各国研究的热点之一。近来研究主要关注CIGS薄膜太阳电池大面化、薄膜效率影响因素和工艺研究。本文主要介绍CIGS薄膜电池近年来的研究进展。     

柔性铜铟镓硒薄膜太阳电池

介绍了柔性铜铟镓硒薄膜太阳电池的基本结构、研究现况、关键技术,同时指出了未来面临的挑战.     

CIGS太阳电池的低成本制备工艺

目前铜铟镓硒(CIGS)太阳电池的工业化生产基本采用真空技术制备,需要很大的设备投资,生产周期长,增加了生产成本。详细介绍了几种具有潜在应用前景的低成本直接制备工艺:电沉积、丝网印刷、热解喷涂。这几种方法都使用简单、快速的非真空设备,预组装成分子级别的前驱物层,经化学或热处理形成CIGS薄膜。前驱物的选择,杂相的去除,以及后处理条件是影响非真空工艺的关键因素。     

铜铟镓硒柔性薄膜太阳电池

介绍了铜铟镓硒柔性薄膜太阳电池的性能、优点以及应用范围;阐述了柔性薄膜太阳电池的国内外研究现状、发展趋势;特别介绍了柔性薄膜太阳电池的典型结构以及柔性衬底材料的要求和选择,底电极、吸收层、缓冲层、窗口层、减反射膜、上电极等各功能层的制备工艺等,同时简要介绍了其产业化面临的困难和挑战.     

2012的新希望—薄膜太阳能电池发展趋势分析与应用展望

硅薄膜电池已经发展到第四代——非晶硅/微晶硅双结叠层电池,而这种非晶硅与微晶硅叠层的基本结构将成为未来硅薄膜电池的主流发展趋势。薄膜光伏电池是在低成本的玻璃、塑料、不锈钢等基板上沉积形成很薄的感光材料实现光电转换,主要包括硅薄膜电池(a-Si、a-Si/c-Si等)、碲化镉(CdTe)、铜铟硒(CIS、CIGS)。     

铜铟镓硒柔性薄膜太阳电池的制备及性能表征

以厚度为25～70mm的钛箔为衬底,直流磁控溅射法制备0.8～1.2mm的底电极Mo薄膜,而后以CuIn和CuGa靶交替溅射制得Cu-In-Ga金属预制膜,再以真空硒化法制得CuIn1-xGaxSe2薄膜。以化学浴沉积法制备缓冲层CdS,射频磁控溅射法制备ZnO和ZAO,直流磁控溅射法制备上电极,制得结构为衬底Ti/Mo/CIGS/CdS/ZnO/ZAO/Al,其光电转换效率达到7.3%(25℃,AM0)。     

中山大学光伏并网示范电站分析

光伏并网发电是光伏应用的主流。一方面,光伏并网发电不需要蓄电池,成本相对较低;另一方面,太阳能发电可以在白天用电高峰时给电网提供电能,缓解电力紧张。对单晶硅、多晶硅、CIGS三种类型小型光伏并网电站的年发电量,月发电量,天发电量,时段发电量和逆变器的情况进行了分析。单晶硅光伏电站每千瓦的年发电量最多,CIGS电站次之,多晶硅电站最少。在一年中的7至11月份,各类电站发电量与其它月份相比较多。9至11月份,CIGS电站发电量最多,一年的其它时间单晶硅光伏电站发电量最高。逆变器的行为符合供应商的效率说明。     

测控装置通信频繁中断故障原因分析及处理

针对一500 kV变电站长期出现的站内测控装置不定期报通信中断和五防校验超时信号,导致操作失败的现象,通过截取报文分析,发现由于存在大量的UDP心跳报文和联锁报文,造成广播网络风暴引起通信中断,通过对网络层交换机划分VLAN,隔离广播流量,成功解决了该问题。     

Size effect and statistical characteristics of dc and pulsedbreakdown of liquid helium

Breakdown time lag in liquid helium is measured over a wide range of electrode sizes and pulsed electric field strengths. The breakdown time lag and dc breakdown strength are statistically analyzed by using the Weibull distribution function and weak link theory. It is found that the time lag depends on both electrical stress and the electrode surface area stressed above a critical level. It is supposed that breakdown triggering electrons are generated by field emission phenomena at small protrusion tips on the cathode surface. In higher external electric fields, a less sharper protrusion emits initial electrons with a shorter time lag and may become responsible for liquid breakdown. A theoretical equation is proposed to predict the electrode size and electrical stress dependency of the breakdown time lag, based on Fowler and Nordheim theory. It is shown that the equation is consistent with the Weibull distribution function under multiple stress of electric field and stressing time     

Uniqueness of the asymptotic behaviour of autonomous and non-autonomous,switched and non-switched,linear and non-linear systems of dimension 2

An explicit criterion is given which guarantees that the solutions of a system of two first-order differential equations have a unique asymptotic behaviour as t'→ + ∞. the equations are allowed to be time-dependent, with isolate discontinuities (switching), and non-linear. In particular, continuously differentiable and piecewise linear systems, as far as the dependence on the state variables is concerned, are considered. the particular case of a linear system switched back and forth between two 2 × 2 matrices is treated in detail, with an outline of an algorithm to decide on the converence to zero of the solutions. The case of switching between N matrices is a straightforward generalization that is, however, not covered in this paper. It is shown that the problem of unique asymptotic behaviour of piecewise linear systems can always be treated by considering such switched linear systems. Furthermore, an example shows that even some continuously differentiable systems may be reduced to this case. Finally, the connection with the work of Brayton and Tong on the stability of differential equations, also using sets of matrices, is given.     

Effect of size and location of conventional and intermittent generation on system reliability

A method of assessing the cost-effectiveness of different generating technologies is presented, which helps the planner decide, for a given generating system and in a given year, which technology is the most effective in improving the reliability of the generating system. The method also allows the planner to rank technologies according to their cost-effectiveness. Also presented is a procedure for assessing the relative merits of centralized and decentralized generating technology. A case study is described that illustrates how the method works.     

输配电线路施工技术仿真系统的设计与实现

研究、分析和使用了面向对象的软件设计和开发方法、Browser/Server网络结构体系、基于C#语言的平台技术,结合传统的仿真数学建模,设计了一套输配电线路施工技术的仿真系统,介绍了该系统的配置、功能、构成和特点,着重阐明了该系统的设计思想和技术特色。系统是一个集计算机、通讯、多媒体技术的高新技术产物,系统采用了Browser/Serve架构,对传统上采用Client/Server架构的仿真系统来说,这一架构更符合当前的计算机和网络发展的趋势,这也是本系统的亮点。系统的设计突出了实用性、技术先进性和功能完备性,达到较高的应用水平,通过在该仿真系统上的演练,不仅有利于施工技术操作人员快速掌握输配电线路施工技术的工艺流程,积累施工技术操作经验,而且对保证输配电线路施工技术的安全进行具有重要意义。     

Principle and operation of a new type motor consisting of piezoelectric device and strain wave gearing

The authors have developed a new type of motor consisting of a piezoelectric device and strain wave gearing, and is called a piezoelectric motor. This is a first step in realizing a low-speed, small-size and lightweight motor. The principle of the motor is that the traveling wave is produced by piezoelectric devices and displacement conversion devices without mechanical resonance, and the torque to rotate the motor is generated by a mechanism of strain wave gearing (circular spline and flexspline) without using friction. The motor is operated at variable frequency and its rotational position (angle) is controlled in open-loop because it is basically a synchronous motor. In this paper, the structure and principle of the proposed motor are explained and the driving method and the mechanical characteristics of an experimental motor also are described. The results are as follows:

• 1 The realizability of the proposed piezoelectric motor is verified experimentally. The experimental motor operates at 2920 steps per revolution, and its speed range is 0 to 960 pps [or 0 to 20 (rpms)].
• 2 The torque characteristics are clarified qualitatively.
• 3 The generated torque of the experimental motor is small (less than 0.03 Nm) and therefore the improvement of the torque is an important subject hereafter.
• 4 It is possible to construct the motor with nonmetallic material. This fact is considered to facilitate obtaining a means to lighten the weight of the motor in the future.

     

Analysis and Performance Assessment of Six-Pulse Inverter-Fed Three-Phase and Six-Phase Induction Machines

This paper describes a model for a six-phase induction motor driven by an inverter operating in a six-pulse (square wave) mode. The model is implemented, and performance, in terms of torque, current, and efficiency, is compared to the performance of a three-phase motor (supplied with either a sine and six-pulse voltage). The models are verified experimentally to a degree of accuracy, and it is illustrated that the improvement in inverter efficiency when in six-pulse operating mode may improve the performance of the overall system, although the improvement is marginal in the example used. The potential of this drive configuration is demonstrated     

Design and Analysis of Fault Diagnosis and Fault-tolerant Control for a Class of MIMO Nonlinear State Systems

This paper presents a fault diagnosis and fault-tolerant control algorithm, which can be used for a class of multi-input multi-output (MIMO) nonlinear state systems. First, a state estimator is proposed, which is able to detect fault occurrence, by using a residual signal. Second, when the state is at an abnormal condition, the fault-tolerant control will be triggered to minimize the impact of the fault occurrence. This fault-tolerant control is designed by using a robust controller (original controller), and an on-line approximator to capture a nonlinear function that indicates the fault occurrence. The detailed analysis is given for the proposed fault accommodation control.     

Pruning and simulation for determination of frequency and durationindices of composite power systems

This paper introduces a method for computing the frequency and duration indices of a composite power system, using random Monte Carlo sampling selectively on those parts of the state space where failure states are more likely to occur. The implementation uses a DC flow model to represent network power flows. The method is tested using a modified form of the IEEE Reliability Test System and is shown to be significantly faster than conventional Monte Carlo simulation, while retaining the same level of accuracy     

宾馆和饭店的照明节能设计与灯具选择

建筑照明节能是技术进步的一个重要标志,也是建筑界实施可持续发展战略的一个关键环节.结合建筑照明领域相关技术的发展情况,具体论述了宾馆、饭店照明节能的实施途径.