多路并网光伏发电系统的设计及其有效性分析

并网光伏发电系统是光伏发电的主要实现形式,通过对多路并网光伏系统进行分析和研究,通过一个Boost DC/DC电路和同一个逆变器将所有光伏阵列进行并联,最后实现并网。通过对各元件的参数进行选取,确定控制的策略。占空比通过前级Boost斩波电路进行调节,改变光伏阵列的输出电压,对最大功率点进行跟踪。采用电压外环和电流内环的双环控制方法进行进行后级逆变电路,逆变器直流侧电容电压的稳定性受电压外环控制,并给出内环电流参考值的幅值。逆变器输出电流受电流内环控制,并将输出值作为参考值以实现并网。各路光伏阵列的最大功率点跟踪具有相互独立的优势,没有出现干扰,有效地提高了效率。最后用Matlab/Simulink进行了仿真,分析其有效性。     

基于单级式的光伏水泵控制系统研究

针对传统光伏水泵控制系统的两级结构,提出了一种简化的单级式光伏水泵控制系统及其实现方法,简化了传统光伏变频器直流变换环节,给出了单级式光伏水泵控制系统软、硬件的构成与单级式光伏水泵控制算法,为光伏水泵专用变频器开发提供了技术支持。     

单相光伏并网微型逆变器设计

设计一种适用于单个光伏组件的光伏并网微型逆变器,拓扑结构主要包括交错并联反激变换器、全桥反转电路和LC滤波电路。分析反激逆变器的工作原理和实现条件;采用数字信号控制器实现交错并联反激逆变器的软开关控制,可减小功率器件开关损耗,提高逆变器电能转换效率;改进的变步长扰动观察法,解决跟踪速度与控制精度之间的矛盾。通过样机实验验证设计的单级式光伏并网微型逆变器具有体积小、输出谐波含量低、功率密度高和电磁兼容性好等优点。     

试论双降压式光伏逆变器的电流滞环控制

随着经济的发展,社会各领域对于电力资源的需求不断增加,这也对发电系统的安全及发电系统提出了更高的要求.逆变器作为光伏发电系统的主设备之一对于光伏电力系统的安全及稳定至关重要,对于光伏发电系统来说只有保证了逆变器的使用性能才能实现电力系统的理想化运行,因而安全与稳定性能较高的双降压式光伏逆变器应运而生而且广泛投入使用.双降压式光伏逆变器最大的特点及优势便在于其使用两态调节的滞环电流控制,更大程度上保证了逆变器的安全与稳定.本文着重分析了双降式逆变器的工作原理及其电流滞环控制要点.     

基于增量电导法的光伏最大功率跟踪的仿真研究

介绍了光伏电池模型的工程数学模型,并在MATLAB/SIMULINK环境下建立了光伏电池的工程仿真模型。为了能够实现光伏电池的最大功率输出,本文介绍了最大功率跟踪的原理和方法。使用增量电导法实现最大功率点跟踪。并在MATLAB/SIMULINK环境下搭建光伏发电系统的仿真模型进行了仿真。仿真结果表明,搭建的光伏电池波形以及最大功率跟踪控制的仿真结果证明了可行性,可以用于光伏发电系统的仿真研究。     

小型光伏并网系统运行测试与分析

在国内一些大城市,小型光伏并网系统的数量快速增加,对其工作性能的研究有重要意义.在户外环境中进行实验,将小型光伏并网系统分别接入两种微型逆变器,对它们的运行情况进行测试,并分析系统整体工作性能和逆变器的效率.     

光伏与建筑一体化能量转化控制技术

以光伏与建筑一体化中的能量转化为研究对象,指出提高系统能量转化效率需要从光伏发电系统的体系结构、控制方法、运行机制等多方面综合考虑,并针对集中式结构提出了一种有效提高阴影遮挡下光伏电池输出功率的控制方法.     

北京南站太阳能光伏发电系统设计探讨

介绍了北京南站太阳能光伏建筑一体化并网发电系统(光伏组件总安装容量240 kWp,系统年输出电量为22万kW·h),对站房屋面太阳能发电材料的选择进行了详细描述(最后确定采用不透光的铜铟镓硒太阳能电池),并分别介绍了太阳能光伏电池方阵、光伏并网逆变器、汇线盒、电涌保护器、直流配电柜、交流配电柜的选用.进行了技术经济比较和环境、社会效益分析.     

浅谈分布式光伏发电经济效益

本文通过对光伏系统中电池组件、逆变器等的价格分析得出系统的铺设成本。进而得出各墙面进行分布式光伏发电收回成本所需的年限。从而推导出分布式光伏发电未来的应用前景。     

专利汇编

正1.一种智能光伏建筑门窗一体化发电装置公开(公告)号:CN106193904A本发明提供一种智能光伏建筑门窗一体化发电装置。该装置由光伏发电建筑门窗系统、光伏发电建筑门窗倾角控制系统、光伏逆变器配电系统和非光伏发电建筑门窗组成。该装置主要利用可根据太阳照射角度而调整角度的建筑门窗作为光伏发电装置的支撑结构,实现了非工程施工化且能批量化生产经营的智能光伏发电建筑门窗一体化标准产品形态,达到经济实用、规模化应用太阳     

基于PROFIBUS总线技术的变频恒压供水控制系统

针对高楼建筑行业供水的特点,采用先进的PROFIBUS总线技术和变频器,设计了变频恒压供水系统,阐述了总线系统的拓扑结构与组成,重点分析了水泵电机循环投切的设计原理、工作过程以及管压恒定的实现方法,详细讨论了变频器从站在PROFIBUS系统中的建立方法,给出了MM变频器的控制字与状态字的数据格式。该设计方法是一种先进的恒压供水设计方法,具有较大的推广价值。     

Transient analysis and selection of perturbation parameters for PV-MPPT implementation

ABSTRACT

In this article, system dynamics of a complete photovoltaic system have been studied. A small signal transient analysis model has been established to examine the effects of small change in the duty cycle of the converter as well as the time steps between each perturbation on the system dynamics. All efforts have been made to do a detailed analysis using almost all the equations involved. Sample calculations (using the simulated system model) are also shown so as to approximately analyse the perturbation effects. It is shown that the value of the step size of the duty cycle should be taken large for points far away from the maximum power point (MPP) and small for points near the MPP. Also, the time between two consecutive perturbations should be at least equal to the settling time. This article is very useful for the researchers to choose a proper delay between two consecutive perturbations and selection of the optimum value of the step size.     

Energy performance of a cooling plant system using the inverter chiller for industrial building

The purpose of this paper is to clarify energy performance of the cooling plant system in the industrial building using actual measured operating data and numerical simulation analysis. One aspect of industrial buildings is that they have large energy consumption for manufacturing and air-conditioning compared with office and commercial buildings. Some examples of high-efficiency technologies installed in this particular cooling plant system are inverter chillers, integrated cooling towers and a free-cooling system. The inverter chiller which has been put on the market recently is state-of-the-art technology. The maximum COP of the inverter chiller reaches about 18 under certain conditions and integrated cooling towers make lower temperature cooling water as the whole capacity is large. Actual operating data indicates satisfied values for chiller and system COP during the running period and the simulation results show that the cooling plant system can cut down annual electric power consumption by about 48% compared with conventional cooling system.     

Maintaining uniform hydraulic conditions with intelligent on–off regulation

An advanced control method for central heating systems is used in precise room temperature control. In this method, based on room temperature changes and user demand, the duty cycle of the control valve for each cycle was predicted and the valve was regulated according to the duty cycle to maintain room temperature at set point. However, this control method could allow all of the valves to easily open or close at the same time, resulting in large fluctuations in hydraulic conditions. In response to this issue, this article proposed a method that achieves hydraulic uniformity by staggering the control cycle of each user, which allows the number of opening users in the on/off control heating system to be uniformly distributed over time and space. The results from theoretical analysis and practical application revealed that this method was effective in solving practical problems. Furthermore, staggering the control cycles could actively manipulate the actions of valves without requiring a specific number of users as opposed to the conventional on–off adjustment mode, which achieved hydraulic uniformity primarily through the random cumulative effects of a certain number of users.     

基于模糊自适应PI控制的电梯矢量控制系统仿真研究

根据模糊自适应PID控制理论,对电梯变频调速矢量控制系统中的转速PI调节器进行优化设计。并应用电动机矢量控制系统的仿真模型进行仿真分析。仿真结果表明,采用模糊自适应PI控制器的变频调速系统具有响应时间快、超调量小等优点。     

First results on biostimulation of denitrifying activated sludge using low frequency ultrasound

Reduction of nitrate to nitrogen is critical for wastewater treatment process. The present work proposed a promising approach to improve the activity of denitrifying activated sludge by using low frequency ultrasonic treatment. Batch activity assays showed that when ultrasound was applied, denitrification performance was 2.64 higher than the control. Kinetic analysis of nitrate removal rate versus ultrasonic power and duty cycle was performed to investigate the effect of operational parameters on activated sludge activities. The best stimulating effect was observed at 40 W ultrasonic power and 40% duty cycle. The above results demonstrated that ultrasonic stimulation can be used as a technique for enhancing bacterial activities for water treatment. Studies of other parameters that also affect the denitrification under ultrasound are under way.     

单片机控制弧焊逆变器的研究

采用8031型8位单片机控制弧焊逆变器为研究对象，探讨了该单片机对TIG／MIG自动焊逆变器及设备的控制，阐述了该系统工作原理，硬件设计及软件设计，总结归纳了微机控制的弧焊逆变器能实现的功能，以期指导实践。     

1000kV避雷器动作负载试验研究

介绍了1 000 kV交流系统用避雷器的动作负载试验以及相关参数的确定.通过对1000 kV交流系统避雷器的动作负载试验验证,并对其结果分析,确定了1 000 kV交流系统用避雷器参数选择的合理性；通过试验研究,1 000kV避雷器的最大电位分布不均匀系数为1.096,小于1.15的规定值,其最大电流分布不均匀系数小于...     

计算机集散控制系统的应用

从实际出发,讨论了集散控制系统的基本结构以及集散控制系统的优越性。计算机集散控制系统算式先进、精度高、响应速度快,且兼有仪表控制系统安全可靠等优点,使用这种方式,使生产进入了计算机参与管理与控制的现代化技术的行列。用计算机集散控制系统代替了以往的仪表控制,不仅实现了数字量的自动控制,而且使生产过程长期在最佳的工作状态下运行,实现了集中管理,分散控制。     

变频器在中央空调中的应用

变频器具有明显的节能效应,变频器工作时,可根据中央空调的负荷变化调整中央空调工作电源电压和周期达到所需转矩。本文阐述了变频器在产品性能、运行周期的功率及后期正常维护的优越性。