光伏发电系统MPPT技术研究

发布时间：2018-05-07 14:50

本文选题：光伏阵列 + 部分阴影遮挡　；参考：《北京交通大学》2014年硕士论文

【摘要】：本文主要针对部分阴影遮挡条件下光伏发电系统的MPPT技术进行研究,以光伏组件的输出特性分析与研究为基础,通过搭建光伏阵列的模型,对部分阴影遮挡条件下光伏阵列的输出特性进行了理论研究与机理分析。为了从根本上解决由部分阴影遮挡所导致的阵列输出功率大幅下降及多峰特性等问题,对比研究了集中式、组串式和组件式三种光伏发电系统的拓扑结构、MPPT控制策略及功率输出特性,得出了组件式光伏发电系统MPPT具有明显优势的结论。在组件式系统的MPPT技术方面,主要研究了双向Buck-Boost变换器和Sepic变换器。在对这两种拓扑的小信号模型分析的基础上,分别进行了电压电流双闭环的MPPT控制环路设计,提出了一种改进型滞环比较MPPT算法；针对双向Buck-Boost变换器,还提出了一种双载波的调制控制方法。利用Matlab及Psim搭建系统的模型,实现了任意外界条件下光伏阵列的最大功率输出,验证了双闭环MPPT控制策略及改进型滞环比较MPPT算法的有效性；最后在器件参数选择、调制方法、控制复杂程度及工作效率等方面对这两种组件式拓扑进行了对比分析。本文的主要创新点包含以下几点： ①基于对数学模型及简化模型的对比分析,提出了一种精确工程模型,它以数学模型为基准,对简化模型的补偿参数进行拟合修正,同时兼顾了精确度与复杂程度； ②提出了一种改进型滞环比较MPPT算法,不仅能有效解决振荡和误判问题,同时还能兼顾速度与精度,达到高效、准确实现最大功率点追踪的目的； ③提出了一种双载波的双向Buck-Boost变换器调制方法,能自适应地实现工作模式的切换,保证了任意外界条件下组件的最大功率输出； ④针对组件式MPPT的控制,提出了一种电压电流双闭环的控制策略,实现了状态变量的解耦控制,具有较好的鲁棒性、快速响应特性及较高的可靠性。
[Abstract]:In this paper, the MPPT technology of photovoltaic power generation system under partial shadow occlusion is studied. Based on the analysis and research of the output characteristics of photovoltaic module, the model of photovoltaic array is built. The output characteristics of photovoltaic arrays under partial shadow occlusion are studied theoretically and the mechanism is analyzed. In order to solve the problems of decreasing output power and multi-peak characteristics caused by partial shadow occlusion, the centralized method is compared and studied. The topology structure and power output characteristics of three kinds of PV power generation systems are discussed. It is concluded that MPPT has obvious advantages. In the MPPT technology of component system, the bidirectional Buck-Boost converter and Sepic converter are studied. Based on the analysis of the small signal model of these two topologies, the MPPT control loop with double closed loops of voltage and current is designed, and an improved hysteresis comparison MPPT algorithm is proposed. A dual carrier modulation control method is also proposed. Using Matlab and Psim to build the system model, the maximum power output of photovoltaic array under arbitrary external conditions is realized, and the effectiveness of double closed loop MPPT control strategy and improved hysteretic comparison MPPT algorithm is verified. The control complexity and working efficiency of these two component topologies are compared and analyzed. The main innovations of this article include the following: 1. Based on the comparative analysis of mathematical model and simplified model, an accurate engineering model is proposed, which is based on mathematical model and modifies the compensation parameters of simplified model, taking into account the accuracy and complexity. (2) an improved hysteretic loop comparison (MPPT) algorithm is proposed, which not only can effectively solve the problem of oscillation and misjudgment, but also can give consideration to speed and accuracy, and achieve the purpose of high efficiency and accurate maximum power point tracing. (3) A dual-carrier bi-directional Buck-Boost converter modulation method is proposed, which can adaptively realize the switching of the working mode and ensure the maximum power output of the module under arbitrary external conditions. 4 aiming at the control of component MPPT, a voltage and current double closed loop control strategy is proposed. The decoupling control of state variables is realized, which has good robustness, fast response and high reliability.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM615

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