光伏扬水与照明综合系统的能量管理策略

“国家光明工程“计划已在西部无电乡村建立了若干个光伏发电站,其负荷以扬水与照明为最基本负荷。为了高效、可靠地运行这些光伏电站,客观上需要采用能量管理器进行能量优化分配与管理。本文从能量分配的角度,叙述了太阳能扬水与照明综合系统的能量管理策略,包括光伏电力的分配方案、蓄电池的充放电管理、最大功率跟踪,以及基于16位微控制器的控制电路的构成。运行情况表明,有效合理地分配与管理太阳能光伏系统所发电能,对提高光伏应用效率,提高蓄电池的使用寿命具有重要意义。     

分布式太阳能最大功率跟踪系统的研究

传统的集中式最大功率跟踪虽然可以使太阳能阵列的电量保持最大值,但是在实际应用中系统会有失配的问题,可能导致系统有多个最大功率点,存在次优的最大功率点,传统的最大功率跟踪方式解决不了这个问题。文中的分布式最大功率跟踪方法可以使这种失配对系统造成的影响降到最小,文章分析了这种方法的优点和运行原理,然后通过计算机仿真模拟验证方法的可行性。     

低速电动汽车太阳能充电装置的设计与实现

为了满足低速电动汽车中增加太阳能电池充电装置,并实现最大功率点跟踪(MPPT)的需求,设计并实现一套专用的太阳能电池充电控制系统。首先介绍该行业的应用背景和设计需求,然后从系统结构、电源拓扑、升压电路和功率检测等方面详细阐述系统的硬件设计方案,并着重从高效数据采集方案和MPPT跟踪算法等方面介绍软件设计思路,最后给出了效率测试和MPPT效果测试方案。实际应用证明,该设计方案跟踪效率高,性价比高,长期运行稳定可靠。     

基于变步长电导增量法的光伏最大功率跟踪控制

太阳能光伏发电的最大功率跟踪控制是小型太阳能发电系统中的核心控制之一.针对光伏电池功率曲线的特点,本文在分析最大功率跟踪原理的基础上,提出了基于变步长电导增量法,实现光伏电池最大功率跟踪的优化控制,最大程度的提高光伏电池效率.并通过与定步长算法的仿真对比实验,验证了该算法跟踪迅速,控制精度高和稳定无振荡的特点.     

嵌入式太阳能充电系统的设计

给出了采用嵌入式芯片来对太阳进行角度跟踪和太阳能电池板最大功率点跟踪,从而实现用太阳能对用电电路进行充电的太阳能充电系统的设计方法。利用该方法可以对太阳能进行充分利用．以使太阳能电池保持最大的输出功率。     

太阳能电池综合管理自动控制器

现有小型独立太阳能系统普遍存在的效率低、蓄电池寿命短、运行不稳定等问题,采用一种新型全自动控制器,可以实现太阳能电池最大功率点跟踪和蓄电池充电精确控制,满足小型独立太阳能系统在不同工作状态下的稳定运行。试验结果表明,应用此自动控制器的太阳能系统效率高、运行稳定,蓄电池寿命可延长1～2年。控制器实现了基于单片机PIC16F676的MPPT工作状态控制和蓄电池充放电智能管理。     

具有最大功率跟踪控制的太阳能LED路灯智能控制系统

针对太阳能路灯系统中太阳能光伏电池的输出效率不高的问题,提出把固定电压法、变步长与扰动观察法相结合得到的一种改进的最大功率点跟踪(Maxi Power Point Tracking,MPPT)算法,设计和实现了太阳能LED路灯智能控制系统。该系统不仅能进行太阳能最大功率的跟踪,并且还能根据时间、环境的光强等参数来智能控制LED路灯的亮度。实验结果表明,该系统能有效提高光伏电池的使用效率,实现节能。     

太阳能最大功率点跟踪优化算法研究

太阳能作为人类已经使用的一种重要的可再生能源,在很多领域得到了广泛的应用,其无污染、取之不尽用之不竭等特点,有着极其重要的能源作用。在对太阳能系统应用的研究中,通过最大功率点的跟踪技术,可以提高太阳能的利用率,提高光伏发电系统功能,使之形成为离散采样-控制,适应外界环境变化。本研究对传统文波控制算法进行了改进,结果表明在测试环境中,当系统的转变区间为1000W/cm2到200W/cm2时,此种算法追踪最新的太阳能系统最大功率点仅需0.1s,因此仿真算法可以快速准确跟踪太阳能系统中的最大功率点。     

基于GSM的太阳能路灯联网监控系统研究

通过对太阳能光伏电池板特性及光伏电源最大功率点跟踪原理的分析,提出了基于CUK电路的光伏电源最大功率点跟踪方法,通过对太阳能路灯工作机理的分析,引进了一种新的太阳能路灯联网监控系统,介绍了太阳能路灯控制器的整体设计思路,并重点阐述了从机与主机间的通信连接以及主机与监控中心之间的无线通信连接等。该系统具有控制能力强、可靠性高和应用灵活等特点,具有很高的实际应用价值。     

小功率光伏并网逆变系统的研制

本文介绍小功率光伏并网逆变系统，该系统应用SPWM技术将光伏电池电压逆变成标准的正弦单相220V、50Hz交流电压。改进的固定频率电流跟踪控制方法使电流跟踪误差明显减小，并且系统实现了最大功率点的跟踪。本文阐述了该变换器的硬件设计及软件流程，实验证明本装置运行稳定、性能优良。     

单级三相式光伏并网逆变器仿真研究

本文在MATLAB/SIMULINK下搭建了整个单级三相式光伏并网逆变器的仿真模型,包括电池及最大功率跟踪(MPPT)模块。并采用同步PI电流控制技术,实现无功电流和有功电流的独立控制,具有较好的动态和稳态特性。     

3C strategy for inverters in parallel operation achieving an equalcurrent distribution

A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper. In the proposed inverter system, all the modules have the same circuit configuration, and each module includes an inner current loop and an outer voltage loop control. A proportional-integral controller is adopted as the inner current loop controller to expedite the dynamic response, while an H^∞ robust controller is adopted to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters. With the 3C strategy, the modules are in circular chain connection and each module has an inner current loop control to track the inductor current of its previous module, achieving an equal current distribution. Simulation results of two-module and a three-module inverter systems with different kinds of loads and with modular discrepancy have demonstrated the feasibility of the proposed control scheme. Hardware measurements are also presented to verify the theoretical discussion     

On the testing,characterization, and evaluation of PV inverters and dynamic MPPT performance under real varying operating conditions

The increasing number of photovoltaic inverters that are coming on to the PV market stresses the need to carry out a dynamic characterization of these elements and their maximum power point tracking (MPPT) algorithms under real operating conditions. In order to make these conditions repeatable at the laboratory, PV array simulators are used. However, actual simulators, including the commercial simulators, recreate only a single or small set of PV array characteristic curves in which quite commonly theoretical calculations are included in order to simulate irradiance and temperature artificial variations. This is far from being a recreation of the real and long dynamic behavior of a PV array or generator. The testing and evaluation of the performance of PV inverters and MPPT algorithms has to be carried out when the PV system moves dynamically according to real operating conditions, including processes such as rapidly changing atmospheric conditions, partial shadows, dawn, and nightfall. This paper tries to contribute to the analysis of this problem by means of an electronic system that both measures the real evolution of the characteristic curves of PV arrays at outdoor operation and then recreates them at the laboratory to test PV inverters. This way the equipment can highlight the different performances of PV inverters and MPPT techniques when they operate under real operating conditions. As an example, two commercial inverters are tested and analyzed under the recreated behavior of a PV generator during 2 singular days that include processes of partial shading and fast irradiance variations. Copyright © 2007 John Wiley & Sons, Ltd.     

Current Weighting Distribution Control Strategy for Multi-Inverter Systems to Achieve Current Sharing

A current-weighting-distribution-control (CWDC) strategy for multi-inverter systems to achieve current sharing is presented in this paper. With a CWDC strategy, the inverters connected in parallel are allowed to have different power ratings and can achieve a weighted output current distribution by adding only simple circuits to each inverter. In such systems, each inverter has an outer voltage loop controller to govern system stability, an inner current loop controller to expedite dynamic response, and a weighting current controller to achieve current distribution and to reduce possible interactive effects among inverters. Experimental results from a two-inverter system and a three-inverter system have demonstrated the feasibility of the proposed strategy in weighting current distribution and fast regulation during a step-load change or hot-swap operation     

A novel communication strategy for decentralized control of paralleled multi-inverter systems

A new communication strategy for decentralized control of paralleled multi-inverter systems is introduced in this paper. The proposed strategy utilizes the common mode signal's circuit in the paralleled system as a channel of communication between individual inverters. Source voltage synchronization for paralleled inverters is presented to demonstrate its effectiveness. One inverter module acts as a source and a synchronized signal is sent by means of frequency modulation in this channel to all other modules via the common mode current. Each module will then receive and transform the signal to be used as a synchronized voltage command for individual inverters. The approach enables synchronization in the paralleled multi-inverter system and the method is not affected by external factors such as load change, output voltage variation, and different types of loads. The principle of operation, performance of the proposed strategy, as well as the experimental evaluation with three single-phase paralleled inverters are discussed and presented in this paper.     

单相光伏并网逆变器控制策略研究与设计

针对光伏并网逆变器并网后其本质上为电流源的特点,采用STM32F103VET6型ARM芯片作为系统的控制核心,制造了一台5 kW单相光伏并网型逆变器。采用了固定开关频率的电流瞬时值控制技术来实现对并网电流的控制,在控制策略中加入了电压前馈来抑制电网电压对逆变器输出电流的影响,使用二阶电流预估来抵消SPWM波形延时对系统控制的影响。并且优化了最大功率点跟踪（MPPT）。实验证明,该逆变器样机性能完全达到设计要求。     

Fuzzy-tuning current-vector control of a three-phase PWM inverterfor high-performance AC drives

This paper proposes a new discrete fuzzy-tuning current-vector control (FTC) scheme for three-phase pulsewidth modulation (PWM) inverters. The proposed current control scheme can achieve fast transient responses and, at the same time, have very low total harmonic distortion in output current during steady-state operation. The proposed FTC scheme generates quasi-optimum PWM patterns by using a closed-loop control technique with instantaneous current feedback. The proposed FTC scheme has been realized using a single-chip digital signal processor (TMS320C14) from Texas Instruments. Experimental results are given to verify the proposed fuzzy-tuning current control strategy for three-phase PWM inverters     

Partial shadowing,MPPT performance and inverter configurations: observations at tracking PV plants

When analysing the influence of shade on photovoltaic (PV) systems, the intuitive assumption is that conversion architectures with more inverters, such as string‐ and module‐inverters, will have lower energy losses associated with partial shading of the generators. However, other phenomena which can affect a system's response to shade, for example, the way in which the inverter performs the maximum power point tracking (MPPT), mean that modular configurations are not always the least susceptible to shade effects. We present a case in which the general tendency of many of the currently available commercial inverters to remain in local power maxima results in a string‐inverter configuration behaving worse in response to shade than a central‐inverter configuration. Experimental data were collected throughout 2005 and 2006 from PV plants in Arguedas and Sesma (Spain). We interpret our observations with theoretical analysis based on the results of simulation experiments. Copyright © 2008 John Wiley & Sons, Ltd.     

光伏系统中最大功率点跟踪的研究

最大功率点跟踪是光伏发电研究的一个重要方向。本文介绍了光伏电池组件的特性以及光伏电池阵列最大功率点跟踪的原理,阐述了传统的跟踪光伏电池最大功率点的方法——扰动观察法,在此基础上提出了基于变换器输出电流控制的最大功率点跟踪法,该方法继承了扰动观察法的优点,并且降低了系统的成本,减轻了系统的运算负担。本研究在光伏系统的开发和应用中具有重要的科学研究意义和现实意义。     

Interleaving Quasi-Sliding-Mode Control of Parallel-Connected Buck-Based Inverters

An interleaving fixed-switching-frequency quasi-sliding control algorithm based on the zero average dynamics approach is reported and applied to the design of a modular system of parallel-connected single-phase inverters. This approach is used in a laboratory prototype of three inverters with field-programmable gate array control-based implementation embedding this algorithm, as well as a power management strategy for handling the number of active inverters. Experimental results are provided to illustrate the design features in terms of ac output voltage regulation, balanced current sharing among mismatched modules, interleaved fixed-switching-frequency operation and robustness with respect to load variations, and inverter activation during system operation.