光伏发电逆变器及控制策略的研究

发布时间：2018-05-01 23:21

本文选题：光伏发电 + 最大功率跟踪　；参考：《武汉科技大学》2014年硕士论文

【摘要】：在能源消费日益增长和可持续发展要求越来越高的今天，太阳能光伏发电作为清洁可再生的能源，已经逐步成为新能源开发中的主要形式。逆变器是太阳能光伏发电系统的核心部分，本文以光伏发电逆变系统为研究对象，以逆变器及其控制策略为重点，在PSCAD4.5Schematic环境中设计了由光伏电池，双向Buck-Boost逆变器组成的双级光伏逆变系统，仿真结果表明系统能够达到设计要求。针对光伏发电系统的特点，逆变器要有较大的直流输入电压范围。本文选择了一种新型的双向Buck-Boost DC/AC电压源逆变电路，由两组双向Buck-Boost斩波电路输入并联、输出反向串联组成，，该拓扑能够实现单级升-降压逆变。本文采用的是PWM控制技术对脉冲的宽度进行调制，进而控制开关管的占空比。为了改善多环PI控制方法中存在的纹波干扰较大的问题，本文展开了对电感电流、负载电压、负载电流的归一化控制方法的研究，将电流内环控制与电压外环控制统一起来，在一定程度上改善了输出电压的纹波问题，提高了系统的稳定速度。为了验证该逆变系统对光伏发电的适用性，本文对光伏电池及基于Boost电路的MPPT控制进行了仿真建模，通过对比各种MPPT控制算法后，选择了适合本系统的电导增量法，能够较好地跟踪到光伏电池的最大功率点。最后将光伏电池模块与逆变器组成光伏发电逆变系统进行了仿真联调，分析了光照，温度以及MPPT控制等各种影响因素，并对系统的输出特性进行了详细的仿真测试与研究，结果表明光伏电池能工作在最大功率点，逆变器的输出达到了设计指标。
[Abstract]:With the increasing of energy consumption and the increasing requirement of sustainable development, solar photovoltaic power generation, as a clean and renewable energy, has gradually become the main form of new energy development. Inverter is the core part of solar photovoltaic system. In this paper, a photovoltaic cell is designed in the PSCAD4.5Schematic environment, focusing on the inverter and its control strategy, taking the photovoltaic inverter system as the research object, and focusing on the inverter and its control strategy. The simulation results show that the two-stage photovoltaic inverter system composed of bidirectional Buck-Boost inverter can meet the design requirements. According to the characteristics of photovoltaic system, the inverter should have a large DC input voltage range. In this paper, a new type of bidirectional Buck-Boost DC/AC voltage source inverter is selected, which consists of two sets of bidirectional Buck-Boost chopping circuits in parallel input and output in series. This topology can realize single-stage rise-down inverter. In this paper, the PWM control technique is used to modulate the pulse width and then control the duty cycle of the switch tube. In order to improve the problem of large ripple interference in the multi-loop Pi control method, the normalization control method of inductance current, load voltage and load current is studied in this paper, which unifies the current inner loop control with the voltage outer loop control. To some extent, the ripple problem of output voltage is improved, and the stable speed of the system is improved. In order to verify the applicability of the inverter system to photovoltaic power generation, the photovoltaic cell and MPPT control based on Boost circuit are simulated and modeled in this paper. After comparing various MPPT control algorithms, the conductance increment method suitable for the system is selected. It can track the maximum power point of photovoltaic cell well. Finally, the photovoltaic inverter system composed of PV cell module and inverter is simulated and adjusted, and various influencing factors such as illumination, temperature and MPPT control are analyzed, and the output characteristics of the system are tested and studied in detail. The results show that the photovoltaic cell can work at the maximum power point and the output of the inverter reaches the design target.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM615

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