光伏功率扰动下的水电机组海鸥优化模糊PID控制研究

光伏发电机组输出功率的随机性和波动性影响着供电系统的安全稳定运行。为了提高水光供电系统的频率稳定能力,根据水轮机调速系统的数学模型,结合海鸥算法的寻优能力和模糊控制的推理能力,提出基于海鸥优化模糊PID（SOAFPID）控制的水电机组控制策略,使其能够快速调节光伏和负荷波动引起的系统频率偏差。通过搭建Simulink仿真模型,分析其在不同扰动工况下的频率稳定能力。仿真结果表明：与传统PID控制方法相比,采用SOAFPID控制的水电机组在光伏和负荷功率扰动下具有更小的超调量和更快的稳定速度,在水光供电系统中表现出了优越的动态调节性能。     

光伏快速充电站配电变压器端电能质量综合控制研究

针对光伏快速充电站将光伏发电与电动汽车快速充电站有机结合,在充分发挥清洁能源优势和大量提升充电效率的同时所带来的电能质量扰动类型复杂、变化快速等问题,提出了一种基于串并联组合配电网柔性交流输电(distribution flexible AC transmission system, DFACTS)的新型电能质量补偿器的电能质量综合控制方法。深入研究了新型电能质量补偿器主电路拓扑,建立起了动态工作模型。详细分析了新型电能质量补偿器线性自抗扰控制方法的工作原理,设计出线性自抗扰控制器。并针对各DFACTS控制器间的交互影响,提出多DFACTS控制器的协调控制策略。最后搭建仿真模型,进行仿真验证。仿真结果表明,所提出的新型电能质量补偿器采用线性自抗扰控制方法相比传统PI控制方法,提高了电能质量扰动快速变化时的综合补偿能力和动态响应能力。并且验证了该协调控制能有效提高系统电压稳定能力,具有良好的可行性和有效性。     

带谐波补偿的T型三电平并网逆变器控制研究

为了提高光伏逆变器并网电流质量,鉴于有源滤波器的控制算法,提出了一种新型的带谐波补偿的T型三电平并网逆变器控制策略。首先,采用锁相环分析电网电压矢量相位角,并根据光伏阵列输出的功率计算光伏并网逆变器的基波输出电流。然后,通过自校正滤波器技术提取网侧负载谐波电流。最后,根据基波输出电流与负载谐波电流确定T型三电平光伏并网逆变器的开关导通序列。为验证该控制策略,搭建了基于Matlab/Simulink的仿真模型。仿真试验结果表明:该控制策略可有效改善网侧谐波电流,提高并网电流质量,在不增加设备的前提下实现光伏并网与有源滤波双重功能。该研究对于T型三电平逆变器在光伏并网及电能质量治理领域的推广应用具有重要价值。     

太阳能-空气光伏/光热一体化热泵热水系统实验特性

本文研究了一种新型光伏/光热一体化(PV/T)复合热源热泵热水系统,将多孔扁盒式PV/T集热板与空气源热泵相结合,根据不同控制方式组合成双热源并联、单太阳能和单空气能三种不同运行模式。在室外环境温度28.5℃下,将200 L 30℃热水加热到55℃,研究了加热时间、热水温度、COP等性能的变化规律,结果表明双热源并联运行模式下分别比单太阳能模式和单空气能模式的加热时间缩短了42%和54%,COP分别提高了32.78%和47.64%;同时实验研究了在夏季工况下将200 L水从9∶00循环加热到17∶00过程中系统热性能,探讨了太阳辐射强度、PV/T集热板温度对光电/光热效率的影响,通过实验对比可以得出在热电模式下系统的光电效率η_(pv)比单一光电模式平均高25.8%.     

Photoelectric properties of the photoconducting film composites based on ferrocenyl‐ and carbazolyl‐containing oligomer doped with polymethine dye

New photosensitive polymeric film composites based on oligomer containing ferrocenyl and carbazolyl fragments doped with symmetric polymethine dye are synthesized. Their photoelectric properties are investigated. Photovoltaic properties of these composites are detected. The mechanisms and peculiarities of the photovoltaic and photodielectric effects are discussed.     

Is floating photovoltaic better than conventional photovoltaic? Assessing environmental impacts

Photovoltaic (PV) solar energy installations are growing all over the world as a promising renewable alternative to generate electricity. However, many studies have highlighted some drawbacks associated with the installation and operation of conventional solar energy power plants. Thus, floating photovoltaic (FPV) systems have been emerging as a new concept in solar energy to lessen negative environmental impacts caused by allocation of conventional PV facilities. This paper is an overview of the potential negative and positive environmental impacts caused by photovoltaic systems with particular interest on large-scale conventional and floating photovoltaic. This study addresses and compares the impacts at all phases of project implementation, which covers planning, construction, and operation and decommissioning, focusing on ambient located in the tropics. The overall impacts associated with project allocation such as deforestation (for the project implementation and site accessing), bird mortality, erosion, runoff, and change in microclimate are expected to have higher magnitudes for the implementation of conventional PV facilities. The results highlight advantages of FPV over conventional PV during the operational and decommissioning phases as well. Though, further studies are required to assess both qualitative and quantitative aspects of installations in similar areas.     

Recent Advances in Rolling 2D TMDs Nanosheets into 1D TMDs Nanotubes/Nanoscrolls

Transition metal dichalcogenides (TMDs) van der Waals (vdW) 1D heterostructures are recently synthesized from 2D nanosheets, which open up new opportunities for potential applications in electronic and optoelectronic devices. The most recent and promising strategies in regards to forming 1D TMDs nanotubes (NTs) or nanoscrolls (NSs) in this review article as well as their heterostructures that are produced from 2D TMDs are summarized. In order to improve the functionality of ultrathin 1D TMDs that are coaxially combined with boron nitride nanotubes and single-walled carbon nanotubes. 1D heterostructured devices perform better than 2D TMD nanosheets when the two devices are compared. The photovoltaic effect in WS₂ or MoS₂ NTs without a junction may exceed the Shockley–Queisser limit for the above-band-gap photovoltage generation. Photoelectrochemical hydrogen evolution is accelerated when monolayer WS₂ or MoS₂ NSs are incorporated into a heterojunction. In addition, the photovoltaic performance of the WSe₂/MoS₂ NSs junction is superior to that of the performance of MoS₂ NSs. The summary of the current research about 1D TMDs can be used in a variety of ways, which assists in the development of new types of nanoscale optoelectronic devices. Finally, it also summarizes the current challenges and prospects.     

基于Matlab的光伏阵列数学模型的研究

通过对单体光伏电池的物理模型的研究,给出了易于求解、便于仿真的光伏阵列的数学模型,该模型可以计算在任一环境温度、太阳辐射强度下光伏电池的I-V特性;以该模型为基础,在工程误差允许的范围内,给出了可行的最大功率点的计算公式。Matlab仿真结果表明,光伏阵列的输出特性随温度和光强的变化而变化,并且光伏阵列I-V和P-V特性呈非线性;在不同光强和温度下,光伏阵列最大功率点不同,它能较好地反应光伏阵列的实际特性。     

三相光伏并网电流型PWM逆变器的研究

基于三相电流型PWM逆变器装置,将直接电流控制方法应用于该逆变器中,设计了一套1kW实验装置。通过仿真分析和实验验证表明,该方法不仅实现了逆变器网侧电流正弦化并与网侧电压同相位,而且实现了直流侧电压宽范围调节,提高了系统动态性能,更适合于光伏并网。     

基于PLC的太阳能电池板自动跟踪系统的研究

研究了基于可编程逻辑控制器(PLC)的太阳能电池板自动跟踪系统。该系统有效地提高了太阳能的利用率和光伏发电系统的效率,降低了光伏并网发电的成本,具有理论研究意义和应用推广价值。