跟随样品太阳电池的光伏阵列模拟器

跟随样品太阳电池的光伏阵列模拟器，用可控的白炽灯模拟太阳光强的变化，样品电池的输出电压和电流随模拟光强而变化，经放大后驱动功率器件，使其输出跟随样品太阳电池的电压和电流，以代替实际光伏阵列进行光伏系统的各项性能测试。     

基于DSP与dsPIC的数字式太阳电池阵列模拟器设计

数字式太阳电池阵列模拟器的实现基于太阳电池的数学物理模型.系统采用低功率TMS320LF2406与dsPIC30F2020作为核心的控制电路,可以动态模拟光伏阵列在各种环境条件下的I-V特性,并记录负载运行情况,提供分析数据和历史曲线记录.     

太阳电池板的建模仿真与微扰并网电流的MPPT实现

在Matlab/Simulink仿真环境下利用S函数,开发了太阳电池板的仿真模型,其通用性较强,仿真速度快.该模型可以模拟不同太阳辐射度、环境温度、以及不同串并联连接时的光伏阵列Ⅰ-Ⅴ特性,与实际太阳电池的工作特性非常接近,在光伏系统的理论分析和工程设计中能提供很大的方便.提出了一种基于微扰并网电流的最大功率点跟踪(MPPT)控制算法,并对此MPVT算法进行了验证和测试.     

基于转速观察反馈实现MPPT的光伏水泵系统

介绍了一种基于直流无刷电机的光伏水泵系统的工作原理和采用转速观察反馈实现最大功率跟踪的控制思想及程序流程图，并给出了样机在光伏阵列模拟器上的运行结果，最后分析系统的跟踪误差、DG-DC变换的选择及系统太阳电池配置方案。‘     

CVT光伏泵水系统瞬态工作点特性分析

采用定电压跟踪器（CVT）的光伏水泵系统在不同地区已成功地投入实际应用。实地运行数据表明，CVT不能适应太阳电池阵列伏安特性的变化，使系统瞬态工作点偏离阵列输出最大功率点，导致系统功率损失。该文报道了2.5kWp，光伏水泵系统的基本构成和典型实地运行数据，并对系统瞬态工作点特性进行了分析讨论。     

光伏阵列幂函数模型及其模拟装置

以目前应用最为广泛的光伏阵列工程数学模型为基础,推导出一种新型工程数学模型——光伏阵列幂函数模型,并将其应用于光伏阵列模拟器的设计。模拟器控制环节利用IPC完成系统的数据分析处理以及实时控制,实现了模拟光伏阵列在光强、温度动态变化中的对外输出,并可以实时显示光伏阵列I-U特性曲线。测试结果表明,该模拟器可以根据负载等效阻抗的变化快速调节输出,使负载工作点迅速稳定在光伏阵列I-U特性曲线上,动态响应良好。     

基于组态优化的光伏阵列最大输出功率控制

大规模太阳能光伏阵列的输出功率不仅受入射光强和环境温度的影响,还受安装环境和安装位置的影响.随着太阳光入射角度的变化,不同位置的光伏阵列的输出变化也有明显差别.在外部环境发生变化时,对光伏阵列进行合理地重新组态,可提高光伏阵列的输出功率.文章在梯度法实现最大功率点追踪的基础上,提出了采用组态优化的方法来进一步提高输出功率.仿真结果表明,组态优化方法能有效地提高光伏阵列的输出功率.     

南极中山站30 kW光伏发电系统工作特性研究

研究南极中山站地区太阳辐照度和环境温度的联合分布情况,确定极端环境条件;建立不同辐照度和温度条件下光伏电池I-V特性分析模型,分析极端条件对电池发电特性的影响;研究确定2种30 kW光伏发电阵列方案,并对光伏阵列的发电性能进行仿真分析。研究结果:极区环境对光伏组件的发电特性有较大影响,在倾角、辐照度和环境温度等因素影响下,光伏组件的开路电压、最大功率电压能够增大16.9%,短路电流、最大功率电流增大31%,瞬间最大功率可能增大50.2%。     

局部阴影遮挡下大尺寸光伏组件的输出特性研究

以太阳电池尺寸为210 mm×105 mm、电路结构为并串结构的大尺寸光伏组件为例，首先分析单片太阳电池不同阴影遮挡比例时的情况，然后分析光伏组件6种不同阴影遮挡比例和18种典型阴影遮挡位置和形状对大尺寸光伏组件输出特性的影响。结果表明：随着单片太阳电池阴影遮挡比例不断增大，二极管始终未导通，但光伏组件的最大功率逐渐降低，最后降至初始功率的2/3；阴影遮挡比例对采用并串电路结构的大尺寸光伏组件的I-V特性的影响是非线性的。对于整块光伏组件而言，阴影遮挡比例越大，光伏组件的最大功率越小；在同一阴影遮挡比例下，集中阴影遮挡对光伏组件最大功率损失的影响更大。     

光伏并网发电系统最大功率追踪算法的稳定性研究

随着光伏发电技术及光伏产业的发展,太阳电池阵列如何在同样日照、温度的条件下输出尽可能多的电能成为人们的研究重点。然而,根据太阳电池的工作原理,当光照强度,温度等自然条件改变时,太阳电池的输出特性将随之改变,输出功率及最大工作点亦相应改变。分析了几种常见的最大功率跟踪方法（Maximum Power Point Tracking,简称MPPT）,针对扰动观测法中的误判现象进行分析,并加以改进,使系统更加平稳地输出有功功率,实现了对最大功率点的稳定追踪。     

A novel on-line MPP search algorithm for PV arrays

A novel maximum power point (MPP) search algorithm for photovoltaic (PV) array power systems is introduced. The proposed algorithm determines the maximum power point of a PV array for any temperature and solar irradiation level using an online procedure. The method needs only the online values of the PV array output voltage and current, which can be obtained easily by using just current and voltage transducers. The algorithm requires neither the measurement of temperature and solar irradiation level nor a PV array model that is mostly used in look-up table based algorithms. Satisfactory results were obtained with the proposed algorithm in a laboratory prototype implementation scheme consisting of a PV array computer emulation model, a chopper controlled permanent magnet DC motor, and a DT2827 data acquisition board with the ATLAB software drivers for interfacing     

A method for using CPV modules as temperature sensors and its application to rating procedures

A method is presented herein that allows the determination of the average temperature of solar cells in a concentrator photovoltaic (CPV) module. The module is measured systematically in a sun simulator while the average module temperature and the irradiation are varied. Two different approaches are discussed to heat a CPV module in a sun simulator. From the measurements, a function is derived that allows the derivation of the average solar cell temperature when the I-V curve of the CPV module is measured. Consequently, the module itself can be used as a temperature sensor.Outdoor I-V measurements of different CPV modules are then presented. Their temperatures are calculated by applying the newly developed method. A multi-linear regression is conducted on the data measured outdoors. In particular, the modules’ maximum powers are correlated to direct normal irradiation, the solar spectrum and the average solar cell temperature. The impact of temperature on the module’s maximum power is shown to be significantly smaller than the impact of the solar spectrum. Finally, the maximum power values for the modules are re-calculated for two different rating conditions.     

Pulse density modulation controlled converter for PV systems

This paper presents a pulse density modulation (PDM) controlled resonant converter for photo-voltaic (PV) system. Maximum power point of the PV generation system is tracked by deleting some control pulses of full bridge series resonant converter. Phase of the converter current is controlled by phase locked loop circuit and zero current switching is achieved for different irradiation conditions. Perturb and observe method is used for maximum power point tracker and designed system is experimentally tested by solar array simulator for 600 W PV power with 116 kHz PDM-MPPT controlled resonant converter.     

A comprehensive simulator for assessing the reliability of a photovoltaic panel peak power tracking system

When designing a maximum power point tracking (MPPT) algorithm, it is often difficult to correctly predict, before field testing, the behavior of this MPPT under varying solar irradiation on photovoltaic (PV) panels. A solution to this problem is to design a maximum power point trackers simulator of a PV system used to test MPPT algorithms. This simulator must have the same role as the MPPT card of the PV panel and thus will fully emulate the response of a real MPPT card of the PV panel. Therefore, it is a good substitute to help to test the peak power trackers of the PV system in the laboratory. This paper describes a simple peak power trackers simulator of the PV system which has a short response time thus, can be used to test MPPT algorithms under very rapid variation condition. The obtained results and the theoretical operation confirm the reliability and the superior performance of the proposed model.     

A Photovoltaic Array Simulator

Abstract

A system simulating the output voltage-current characteristics of a photovoltaic array is described. The simulator may be used to test the performance of PV arrays and associated power conditioning equipment necessary for the autonomous or interconnected operation of photovoltaic energy sources. The simulator's main features include simplicity of construction, wide parametric variability and low cost. It is capable of reproducing the output characteristics of commercially available arrays at varying solar irradiation levels with sufficient accuracy. The design ensures the lowest possible power dissipation and minimal thermal drift. It is estimated that the cost of the simulator is an insignificant fraction of the actual array cost in the kilowatt power range.     

New maximum power point tracker for PV arrays using fuzzy controller in close cooperation with fuzzy cognitive networks

The studies on the photovoltaic (PV) generation are extensively increasing, since it is considered as an essentially inexhaustible and broadly available energy resource. However, the output power induced in the photovoltaic modules depends on solar radiation and temperature of the solar cells. Therefore, to maximize the efficiency of the renewable energy system, it is necessary to track the maximum power point of the PV array. In this paper, a maximum power point tracker using fuzzy set theory is presented to improve energy conversion efficiency. A new method is proposed, by using a fuzzy cognitive network, which is in close cooperation with the presented fuzzy controller. The new method gives a very good maximum power operation of any PV array under different conditions such as changing insolation and temperature. The simulation studies show the effectiveness of the proposed algorithm.     

Maximum photovoltaic power tracking for the PV array using the fractional-order incremental conductance method

This paper proposes maximum photovoltaic power tracking (MPPT) for the photovoltaic (PV) array using the fractional-order incremental conductance method (FOICM). Since the PV array has low conversion efficiency, and the output power of PV array depends on the operation environments, such as various solar radiation, environment temperature, and weather conditions. Maximum charging power can be increased to a battery using a MPPT algorithm. The energy conversion of the absorbed solar light and cell temperature is directly transferred to the semiconductor, but electricity conduction has anomalous diffusion phenomena in inhomogeneous material. FOICM can provide a dynamic mathematical model to describe non-linear characteristics. The fractional-order incremental change as dynamic variable is used to adjust the PV array voltage toward the maximum power point. For a small-scale PV conversion system, the proposed method is validated by simulation with different operation environments. Compared with traditional methods, experimental results demonstrate the short tracking time and the practicality in MPPT of PV array.     

New algorithm using only one variable measurement applied to a maximum power point tracker

A novel algorithm for seeking the maximum power point of a photovoltaic (PV) array for any temperature and solar irradiation level, needing only the PV current value, is proposed. Satisfactory theoretical and experimental results are presented and were obtained when the algorithm was included on a 100 W 24 V PV buck converter prototype, using an inexpensive microcontroller. The load of the system used was a battery and a resistance. The main advantage of this new maximum power point tracking (MPPT), when is compared with others, is that it only uses the measurement of the photovoltaic current, I_PV.     

An improved maximum power point tracker using a step-up converter with current locked loop

It is well known that for a given solar radiation intensity and solar cell temperature there exists a Maximum Power Point at which the power generated from the PV panel is at its maximum. A system designer is interested in optimal matching of the load to the PV generator so that the maximum power can be obtained during operating period. A Maximum Power Point Tracker (MPPT) using a step up converter with a current locked loop is developed. Its performance is compared with the literature (the step down power converter using PWM technique), under different solar irradiance and ambient temperatures. It showed an improvement in the output power by 22.5% (average) over a wide range of solar irradiation in a day.     

Evaluation of performance of photovoltaic system with maximum power point (MPP)

Performance of the photovoltaic system is highly influenced by the weather, especially the irradiation and the temperature. To simplify the design of solar generator power, a mathematical model and its validity of the solar cell are required. In this work, the value of the parameters in the mathematical model is obtained by the measurement of the I–V curve of the module. To get an I–V curve, one of the modules in the system was radiated and loaded by a load simulator. A photovoltaic pumping system with maximum power point tracker was built and tested. The results were analyzed and evaluated by using the parameters and the photovoltaic system was shown to be well optimized.