一种改进的变步长电导增量光伏电源MPPT控制方法

光伏系统的最大功率点跟踪方法可以最大限度地利用光伏电池所能产生的电能,因此成为提高光伏发电系统运行效率、降低光伏电能成本的研究热点。针对目前常用的扰动观察法速度较慢、电导增量法在最大功率点附近有较大振荡的问题,提出一种改进变步长电导增量的最大功率点跟踪控制方法,该方法既具有电导增量法快速跟踪的优点,又能准确、稳定地跟踪到最大功率点,因此更适于提高光伏电源的能源利用率。对所提方法进行了仿真分析,并比较了几种MPPT算法的跟踪效果,结果表明,所提方法具有快速性、稳定性和有效性。     

基于电压闭环滑模控制的变步长电导增量法MPPT策略

光伏发电最大功率点跟踪技术具有广泛的应用需求。文章设计了一种基于电压闭环滑模控制的变步长电导增量法,该方法的外环采用变步长电导增量法来实现最大功率点的准确跟踪;该方法的内环采用滑模算法来实现电压的控制,并通过改进的指数趋近律来改善电压控制的动态品质。分析结果表明,相比于电压闭环PI控制方法,基于电压闭环滑模控制的变步长电导增量法具有更优的动态和稳态性能。     

基于改进电导增量法的光伏MPPT控制

为了提高光伏发电效率及系统稳定性,需要对光伏阵列进行最大功率点跟踪(MPPT)控制.针对传统扰动观测法存在的系统振荡及误判问题,提出一种改进的电导增量法,通过计算系统当前时刻电导与电导变化率的差值,利用积分器进行调节,消除其差值,最终实现对系统最大功率点的稳定跟踪.为验证所提算法的有效性,将改进电导增量法与传统扰动观测...     

改进的电导增量法在光伏系统MPPT中的应用

分析了太阳能光伏阵列的输出特性和传统最大功率跟踪方法的优缺点,并在此基础上提出了一种改进的电导增量法.用Matlab/Simulink对Boost DC/DC变换器系统进行了建模与仿真,将改进的方法和传统的电导增量法分别应用于控制该系统.仿真结果表明,在外界环境变化的情况下,改进的方法在保证系统稳定性的前提下,使得光伏...     

一种变步长阻抗匹配的光伏MPPT控制

针对光伏系统最大功率点跟踪难以同时获得响应速度和稳态跟踪精度的问题,提出了一种基于变步长阻抗匹配的光伏发电系统最大功率点跟踪技术。利用光伏系统拓扑结构的阻抗匹配原理实现光伏系统最大功率点跟踪,在此基础上,引进了变步长控制方法,改善了系统的动态响应速度和稳态跟踪精度。仿真结果证明了该算法的有效性。     

基于Z源逆变器的粒子群和模糊变步长电导增量MPPT算法

针对局部阴影环境及环境辐照度阶跃的问题,提出一种基于Z源逆变器的粒子群和模糊变步长电导增量MPPT算法。粒子群通过少量迭代搜索至最大功率点附近,再切换至模糊变步长电导增量法,不仅使得最大功率点跟踪过程用时短,还可保证最大功率点追踪的稳态精度。同时此算法针对辐照度阶跃变化的情况设置重启环节,以便在功率阶跃后能迅速跟踪至新的最大功率点。通过建立的仿真模型和搭建的试验平台验证算法的可行性和优越性。     

基于模型预测控制的MPPT控制策略

提出一种新的基于模型预测控制(MPC)的最大功率点跟踪(MPPT)优化算法。该目标控制算法把基于电流的改进型电导增量法与模型预测控制算法相结合,完成对光伏阵列最大输出功率的快速跟踪。在算法执行过程中,通过建立系统性能指标函数,评价与估算出未来控制变量的动作,从而决定P-U曲线的跟踪方向。仿真结果表明:该控制策略有效地解决了传统电导增量法在外界环境激烈变化时所产生的误判现象,在提高系统稳定性的同时,大大地减少了最大功率点跟踪时间和系统的能量损耗。     

改进功率预测变步长扰动法在光伏MPPT中的研究

针对最大功率点跟踪技术在光伏发电系统中的应用和研究现状,提出一种改进功率预测变步长扰动法.首先分析光照强度在一个采样周期内非线性变化时功率预测法会因功率预估值偏差较大而产生误判这一现象,为减少功率振荡损失,基于牛顿插值法建立三点采样函数模型以减少预测功率值与实际功率值的偏差.其次在确定变步长的过程中纳入光照强度变化这一...     

一种改进的变步长扰动观察光伏发电MPPT控制方法

针对常规固定步长扰动观察法步长难以确定和以光伏电池P-U曲线的斜率dP/dV作为变步长具有波动性大而导致震荡的缺点,提出了以dP/P作为步长变化控制量的改进变步长扰动观察法。仿真结果表明,改进变步长方法很好地解决了固定步长动态性能和稳定性能不能兼顾和以dP/dV作为变步长的方法存在功率震荡的问题,提高了光伏发电的转换效率。     

基于跃变探索式电导增量法的光伏阵列全局最大功率点跟踪控制研究

实现光伏阵列最大功率点跟踪(Maximum power point tracking, MPPT)的传统算法已经较为成熟,但是在局部阴影出现后会发生寻优失效,难以实现全局最大功率跟踪(Global maximum power tracking, GMPPT)。为解决该问题,研究人员提出将粒子群(Particle swarm optimization, PSO)等群搜索算法应用在MPPT控制过程中,虽然能够控制工作点稳定在全局最大功率点处,但由于该算法收敛能力依赖于核心参数,在应用过程中有一定概率会导致系统振荡。针对以上问题,在电导增量法(Incremental conductance, INC)的基础上提出跃变探索式电导增量法(Jump explore incremental conductance, JEINC),相较于传统电导增量法而言,具有较强的探索能力,能够在局部阴影下实现全局最大功率点跟踪控制,同时所提算法具有较好的收敛能力,在工作点位于最大功率点附近能够快速稳定。在三种光照环境下进行Matlab仿真,从稳定时间、暂态过程能量损耗率和振荡幅值三个方面验证了所提算法相较于电导增...     

基于电导增量法与改进粒子群算法混合控制的最大功率点跟踪策略

利用传统电导增量法跟踪最大功率点时,若跟踪步长较大,则跟踪速度较快,但跟踪精度较差;反之,则跟踪精度较好,但跟踪速度较慢。当外界环境发生变化时,利用传统电导增量法得到的功率变化曲线振荡幅度较大,功率损失较多。改进粒子群算法能够对外界环境的突变迅速作出响应,利用该方法得到的功率变化曲线振荡幅度较小,但是很难精确地定位到最大功率点(MPP)。因此,文章提出一种混合控制的最大功率点跟踪(MPPT)策略,先利用改进粒子群算法快速跟踪到MPP附近,然后利用小步长电导增量法对MPP进行精细搜索。仿真结果表明,该跟踪策略在一定程度上能够增加跟踪系统的响应速度、跟踪精度,减小功率变化曲线的振荡幅度。     

基于变结构模糊控制的MPPT控制策略

为了充分提高光伏发电系统的效率,针对光伏电池成本高、转化效率低的问题,基于电导增量法和模糊控制技术,提出了一种最大功率点跟踪方法。该方法采用了非对称的输出隶属度函数和具有PID功能的变结构模糊控制,能快速响应外界环境变化,准确跟踪到光伏电池的最大功率点,且有效地减小了最大功率点处的输出波动。     

A novel two-mode MPPT control algorithm based on comparative study of existing algorithms

In this paper, the effectiveness of these three different control algorithms is thoroughly investigated via simulation and a proposed efficiency evaluation method of experimentation. Both the steady-state and transient characteristics of each control algorithms along with its measured efficiency are analyzed. Finally, a novel two-mode maximum power point tracking (MPPT) control algorithm combining the modified constant voltage control and IncCond method is proposed to improve the efficiency of the 3 kW PV power generation system at different insolation conditions. Finally, a novel two-mode MPPT control algorithm combining the modified constant voltage control and IncCond method is proposed to improve the efficiency of the 3 kW PV power generation system at different insolation conditions. Experimental results show that the proposed two-mode MPPT control provides excellent performance at less than 30% insolation intensity, covering the whole insolation area without additional hardware circuitry.     

基于滞环比较的自寻优扰动观察MPPT控制策略

文章对于光伏发电系统最大功率点跟踪过程中定步长扰动观察法跟踪速度与跟踪精度之间的矛盾,分析了光伏电池的输出特性,并提出了一种基于滞环比较的自寻优扰动观察法。该算法首先以自寻优的方式来确定扰动步长,然后通过滞环比较环节来判断扰动的添加方向,这样能够保证控制系统的跟踪速度与跟踪精度满足要求,并有效地避免了最大功率点处的振荡问题和系统的误判问题。文章利用Simulink软件搭建了光伏发电系统模型。仿真结果表明,基于滞环比较的自寻优扰动观察法能够快速、准确地跟踪到最大功率点,从而提高了光伏发电系统的能量利用率。     

Whale optimization algorithm based MPPT control of a fuel cell system

Renewable energy sources have provided a great contribution to global energy demand; However, their intermittent characteristics can cause sustainability and efficiency problems. To handle these, alternative systems are utilized. Among these, proton exchange membrane fuel cells (PEMFCs) stand out with their longer lifecycle, efficient, and cost-effective features. However, their performance depends on operating conditions such as temperature, gas pressure, and membrane water content. These nonlinear features require instant and proper control for maximizing efficiency and longer working life. In this study, a whale optimization algorithm (WOA) based maximum power point tracking (MPPT) controller is utilized for a PEMFC system. To validate the proposed controller, the PEMFC system has been analyzed under changing conditions in the MATLAB/Simulink environment. The proposed method has been compared with the other MPPT methods. The results indicate that the proposed controller can provide accurate and fast MPPT performance, less power fluctuations, and higher production efficiency.     

Analysis and enhancement of PV efficiency with incremental conductance MPPT technique under non-linear loading conditions

This paper presents experimental evaluations for variation in the efficiency of energy extracted from a photovoltaic (PV) module (under non-linear loading) incorporated with an incremental conductance(IC) maximum power point tracking (MPPT) algorithm. The focus is on the evaluation of the PV panel under non-linear loading conditions using the experimental installation of a 100W_p photovoltaic array connected to a DC–DC converter and a KVA inverter feeding a non-linear load. Under the conditions of non-linear loading, both the simulation and experiment show that the MPPT technique fails to attain maximum power point due to the presence of ripples in the current leading eventually to a reduction in efficiency. In this paper, panel current is taken as a function of load impedance in the MPPT algorithm to eradicate power variation, as load impedance varies with supply voltage under non-linear conditions. The system is simulated for different non-linear loads using MATLAB-Simulink. A TMDSSOLAREXPKIT was used for MPPT control. In case 2, the inverter is connected to a single phase grid. When a voltage swell occurs in the grid, PV power drops. This power loss is reduced using the proposed MPPT method. The results of simulations and experimental measurements and cost efficiency calculations are presented.     

Input output feedback linearization control and variable step size MPPT algorithm of a grid-connected photovoltaic inverter

In this paper, the power factor of a grid-connected photovoltaic inverter is controlled using the input output Feedback Linearization Control (FLC) technique. This technique transforms the nonlinear state model of the inverter in the d–q reference frame into two equivalent linear subsystems, and then applies a pole placement linear control loops on this subsystem in order to separately control the grid power factor and the dc link voltage of the inverter. Maximum Power Point Tracker (MPPT) that allows extraction of maximum available power from the photovoltaic (PV) array has been included. This MPPT is based on variable step size incremental conductance method. Compared with conventional fixed step size method, the variable step MPPT improves the speed and the accuracy of the tracking.