基于电流控制的光伏太阳能充电器系统研究

提出一种基于电流控制的最大功率点跟踪方法用于光伏太阳能充电器,以DC/DC变换器中的Boost电路作为开关充电器,系统由一个光伏电池模块、一个基于Boost变换器开关电池充电器和电池组成.采用光伏电池输出电流控制实现系统的最大功率点跟踪,调整占空比,从而使太阳电池阵列输出功率最大,以输出稳定的电压对蓄电池进行充电,可以提高蓄电池使用寿命,有效地提高独立光伏系统的综合效率,降低整个系统的成本.     

一种基于Boost电路的光伏最大功率跟踪方法

最大功率跟踪(MPPT)是太阳能光伏发电的重要组成部分,依靠最大功率跟踪可使光伏电池工作在最大功率点(MPP)附近,提高太阳能的利用率.在分析光伏电池的数学模型的基础上,选用Boost电路作为DC/DC变换来搭建仿真模型;针对传统的定步长扰动观测法存在的震荡和误判现象,提出一种改进的扰动观测法,并在Matlab/Simulink环境下进行了仿真.与定步长的扰动观测法的仿真结果进行对比,表明该算法的响应速度更加迅速;在外界环境发生变化时,该算法能够快速做出判断,准确地跟踪到光伏电池的最大功率点.     

一种数字PID控制的扰动观察法光伏电池MPPT仿真

光伏电池的最大功率点(MPP)随着光照强度和环境温度的变化而变化,因此最大功率点跟踪(MPPT)成为光伏系统中的重要研究内容。本文选用PSIM仿真软件,搭建Boost电路,采用数字PID控制的扰动观察法来实现光伏电池最大功率点的跟踪,并进行了仿真验证。     

一种单相光伏系统并网策略研究

提出了一种单相光伏并网系统控制策略,通DC/DC电路对变流器母线稳压,在并网端变流器中采用瞬时电流控制和以输出电流最大为目标的扰动观测改进算法。该控制策略避免了传统变流器电压外环调节速度慢的不足,同时对于最大功率点跟踪不依赖光伏电池输出特性检测。本策略具有MPPT跟踪速率快,成本低,并网电流畸变小等特点,通过实验结果验证了该方案的可行性和正确性。     

基于双并联Boost电路的光伏系统最大功率点跟踪控制方法

光伏电池的输出功率取决于外界环境（温度和光照条件）和负载状况,需采用最大功率点跟踪（MPPT）电路,才能使光伏电池始终输出最大功率,从而充分发挥光伏器件的光电转换效能.在比较了常用光伏发电系统控制的优缺点后,依据MPPT控制算法的基本工作原理,主电路采用双并联Boost电路,具有电压提升功能,并且能够提高DC-DC环节的额定功率和减小直流母线电压的纹波.针对传统扰动观察法存在的振荡和误判问题,提出了一种新型的基于双并联Boost电路的改进扰动观察法最大功率跟踪策略.在Matlab/Simulink下进行了建模与仿真,仿真结果表明,当外界环境发生变化时,系统能快速准确跟踪此变化,避免算法误判现象的发生,通过改变当前的负载阻抗,使之与光伏电池的输出阻抗等值相匹配采满足最大功率输出的要求,使系统始终工作在最大功率点处,并且在最大功率点处具有很好的稳态性能.最后通过实验验证了该算法的有效性.     

光伏发电系统中最大功率跟踪的研究

讨论了并网太阳能光伏发电系统最大功率跟踪问题-提出了实现最大功率跟踪的方法,并且比较了四种方法优缺点。在分析光伏电池伏安特性的基础上,提出扰动观察法的实现算法,通过比较前后两次功率的大小来决定光伏电池电压扰动的方向,使光伏电池最终达到最大功率点。文章利用Matlab的S-函数构建了光伏电池的仿真模型,实验结果表明,该算法可有效跟踪光伏电池最大功率点,适用于光伏并网逆变系统。     

应用于光伏发电系统的最大功率点跟踪控制器设计

为了提高光伏发电系统的效率和稳定性,从而有力促进可再生能源的推广,提出一种应用于光伏电池系统的最大功率点跟踪控制器。首先,对光伏电池系统进行Matlab/Simulink建模和仿真,并完成输出特性分析;然后,采用动态步长对最大功率点跟踪算法中的传统扰动观察法进行优化,以减少误判;最后,基于DSP TMS320F2812设计了控制器的硬件电路。实验结果显示,提出的最大功率点跟踪控制器具有更高的稳定性,有效地提高了太阳能的利用率。     

基于模糊理论的光伏发电最大功率点跟踪控制策略研究

介绍了光伏电池的特性,最大功率点跟踪原理和Boost变换电路,提出了一种基于模糊逻辑控制的最大功率点控制策略,即将光伏电池和Boost电路作为一个整体,通过检测负载功率的变化,来调整控制开关占空比,简化了系统。仿真结果表明,当外部环境发生变化的时候,系统能够迅速跟踪此变化,使系统始终工作在最大功率点附近,并具有较好的稳定性。     

基于模糊PID控制MPPT在光伏系统中的仿真研究

由于光伏电池在外界条件发生变化时,其输出特性也随之变化.为了提高光伏系统的效率,需要对其进行最大功率跟踪.针对光伏系统为非线性被控对象,以及存在不确定未知扰动的特性,采用模糊控制器实时调整PID控制器参数的模糊PID控制方法,将其运用到光伏系统中,以满足光伏系统的快速响应,有效消除光伏电池输出功率在最大功率点的振荡,减少能量损失.仿真结果证明,该控制器能快速、准确的跟踪光伏电池的最大功率点,减少稳态时振荡,提高光伏电池工作效率.     

基于模糊控制算法的光伏电池MPPT设计

介绍了光伏电池的特性,分析了光伏电池最大功率点跟踪（MPPT）的原理,针对光伏电池具有非线性和时滞性的特点,提出了一种模糊控制算法来跟踪光伏电池的最大功率点。仿真结果显示,系统具有良好的控制性能。     

Development of a microcontroller-based, photovoltaic maximum powerpoint tracking control system

Maximum power point tracking (MPPT) is used in photovoltaic (PV) systems to maximize the photovoltaic array output power, irrespective of the temperature and irradiation conditions and of the load electrical characteristics. A new MPPT system has been developed, consisting of a buck-type DC/DC converter, which is controlled by a microcontroller-based unit. The main difference between the method used in the proposed MPPT system and other techniques used in the past is that the PV array output power is used to directly control the DC/DC converter, thus reducing the complexity of the system. The resulting system has high-efficiency, lower-cost and can be easily modified to handle more energy sources (e.g., wind-generators). The experimental results show that the use of the proposed MPPT control increases the PV output power by as much as 15% compared to the case where the DC/DC converter duty cycle is set such that the PV array produces the maximum power at 1 kW/m² and 25°C     

基于ATmega128的光伏并网发电系统设计

光伏并网发电已成为目前发展最快、应用面最广的光伏能源应用技术。在光伏系统中,由于电池光电转换效率过低,导致其不能以最大功率输出,最大功率点跟踪（MPTT）是光伏并网发电系统中的核心技术。系统采用单片机ATmega128作为核心芯片输出SPWM信号,实现最大功率点跟踪功能、频率相位跟踪功能、输入欠压保护功能以及输出过流保...     

基于BOOST电路的光伏阵列最大功率点跟踪仿真研究

太阳能电池作为光伏逆变系统最重要的器件之一,其光电转换效率的高低直接影响整个系统的性能以及成本。光伏电池的输出特性受光照强度及其工作环境影响很大,具有明显的非线性特点,因此需要对其最大输出功率点进行跟踪（MPPT）。基于光伏电池的直流物理模型,在MATLAB7．6的simulink平台下建立光伏模块模型,并基于Boost电路利用该模型对常见的三种MPPT控制方案进行仿真研究,仿真结果证明了这些方案的有效性及其优缺点。     

A Technique for Improving P&O MPPT Performances of Double-Stage Grid-Connected Photovoltaic Systems

In double-stage grid-connected photovoltaic (PV) inverters, the dynamic interactions among the DC/DC and DC/AC stages and the maximum power point tracking (MPPT) controller may reduce the system performances. In this paper, the detrimental effects, particularly in terms of system efficiency and MPPT performances, of the oscillations of the PV array voltage, taking place at the second harmonic of the grid frequency are evidenced. The use of a proper compensation network acting on the error signal between a reference signal provided by the MPPT controller and a signal that is proportional to the PV array voltage is proposed. The guidelines for the proper joint design of the compensation network (which is able to cancel out the PV voltage oscillations) and of the main MPPT parameters are provided in this paper. Simulation results and experimental measurements confirm the effectiveness of the proposed approach.     

基于SG/Simulink的一种改进MPPT算法

针对传统MPPT算法响应速度慢和追踪精度不够理想的特点,分析了光伏电池在不同环境下的输出特性,提出一种改进的变步长扰动观测法,即采用新的自适应步长公式 作为扰动步长,使光伏电池以较大步长快速接近最大功率点,然后以较小步长稳定于最大功率点。在SG/Simulink混合建模仿真平台下进行了仿真,所得结果表明算法可显著提高最大功率点追踪速度与精度。     

Generation control circuit for photovoltaic modules

Photovoltaic modules must generally be connected in series in order to produce the voltage required to efficiently drive an inverter. However, if even a very small part of photovoltaic module (PV module) is prevented from receiving light, the generation power of the PV module is decreased disproportionately. This greater than expected decrease occurs because PV modules which do not receive adequate light cannot operate on the normal operating point, but rather operate as loads. As a result, the total power from the PV modules is decreased if even only a small part of the PV modules are shaded. In the present paper, a novel circuit, referred to as the generation control circuit (GCC), which enables maximum power to be obtained from all of the PV modules even if some of the modules are prevented from receiving light. The proposed circuit enables the individual PV modules to operate effectively at the maximum power point tracking, irrespective of the series connected PV module system. In addition, the total generated power is shown experimentally to increase for the experimental set-up used in the present study     

Microcontroller‐based simple maximum power point tracking controller for single‐stage solar stand‐alone water pumping system

A simple microcontroller‐based maximum power point tracking controller is proposed for a single‐stage solar stand‐alone water pumping system for remote, isolated, and nonelectrified population, where less maintenance, low cost, and an efficient system is of prime interest. It consists of a photovoltaic (PV) module, a DC–AC converter utilizing space‐vector pulse‐width modulation, an induction motor coupled with a water pump, a voltage sensor, and a current sensor. A space‐vector pulse‐width modulation‐controlled DC–AC converter aided by a fast‐acting on–off supervisory controller with a modified perturb‐and‐observe algorithm performs both the functions of converting PV output voltage to a variable voltage, variable frequency output, as well as extracting the maximum power. A limited variable step size is preferred during transient state, and a steady frequency, which is calculated on the basis of steady‐state oscillation, is set during steady state. A fast‐acting on–off supervisory controller regulates DC link voltage during steady state and enables maximum power point tracking algorithm only during transient state to draw a new voltage reference. In the event of low voltage, the controller switches off the motor but continuously scans for an available PV voltage. The system is not protected against an overcurrent because the maximum current is equal to its short circuit current. The 16‐bit microcontroller dsPIC6010A (Microchip Technology, Inc., Chandler, AZ, USA) is used to implement the control functions. The proposed controller is verified through simulation as well as tested in the laboratory prototype model. The simulation and experimental results show good correlation. Copyright © 2011 John Wiley & Sons, Ltd.