交错并联反激微逆变器的研究与设计

发布时间：2018-02-22 21:52

本文关键词： 交错并联反激微逆变器非互补式有源钳位电路控制策略优化　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：全球经济的快速发展,引发了严重的能源危机和环境问题,太阳能光伏发电以其清洁环保、资源广泛的优点成为研究热点。传统集中式光伏并网发电系统中,光伏模块通过串并联形式获得足够大的电压和功率,其最大功率点跟踪针对的是整个光伏组串,从而导致单个光伏模块与光伏逆变器之间存在能量不匹配问题,并造成了较大的电能损耗。为克服上述不足,国内外专家提出了微逆变器方案,微逆变器与单个光伏模块相连,能够实现单模块级的MPPT,有效减小电能损耗,成为光伏发电的一个研究方向及热点。微逆变器是连接光伏模块与电网的枢纽,既要保证光伏模块以最大功率输出电能,又要保证向电网输出高品质电能,同时要求并网电流的功率因数、电流谐波满足光伏并网标准,因此,选择高效的拓扑结构及控制系统至关重要。本文设计采用两级拓扑结构,前级为交错并联反激电路,反激电路具有结构简单、稳定性好、效率高等优点,交错并联结构可以提高功率等级并减小电流纹波;后级全桥逆变为工频逆变,可以有效减小开关损耗。本文在分析了交错并联反激微逆变器的工作原理的基础上,详细设计了主功率电路和非互补式有源钳位电路,并完成相关电路参数设计及器件选型;然后根据功能需求和拓扑结构,研究设计了相应的控制系统,主要包括系统控制流程、并网电流控制算法和均流控制算法等,并通过仿真验证了控制算法的可行性;最后设计了一款250W的微逆变器样机,并完成相关实验测试。为了进一步减小损耗、提高微逆变器的效率,本文对交错并联反激微逆变器的控制策略进行了优化研究。为了减小有源钳位电路的损耗,本文研究设计了基于反激主开关管电压的优化控制策略;为了减小半载及轻载时微逆变器的损耗,本文研究设计了基于输出有功功率的优化控制策略;为了减小全负载范围内微逆变器的损耗,本文研究设计了基于瞬时输出功率的优化控制策略。并通过仿真验证了优化控制策略的可行性。
[Abstract]:The rapid development of global economy has caused serious energy crisis and environmental problems. Solar photovoltaic power generation with its advantages of clean, environmental protection and extensive resources has become a research hotspot. The photovoltaic module obtains enough voltage and power by series-parallel connection, and its maximum power point tracking is aimed at the whole photovoltaic cluster, which leads to the problem of energy mismatch between a single photovoltaic module and a photovoltaic inverter. In order to overcome the above shortcomings, experts at home and abroad put forward a micro-inverter scheme, which is connected to a single photovoltaic module, and can achieve single-module MPPTT, which can effectively reduce the power loss. Microinverters are the key link between photovoltaic module and power grid. It is not only to ensure the photovoltaic module to output electricity with maximum power, but also to ensure the output of high quality power to the power grid. At the same time, the power factor and current harmonic of grid-connected current are required to meet the standard of photovoltaic grid-connected. Therefore, it is very important to select efficient topology and control system. In this paper, the two-stage topology structure is adopted, and the front stage is staggered parallel flyback circuit. The flyback circuit has the advantages of simple structure, good stability and high efficiency. The staggered parallel structure can improve the power level and reduce the current ripple. Based on the analysis of the working principle of the interleaved parallel flyback micro-inverter, the main power circuit and the non-complementary active clamp circuit are designed in detail, and the related circuit parameter design and device selection are completed. Then according to the functional requirements and topology, the corresponding control system is designed, including system control flow, grid-connected current control algorithm and current sharing control algorithm, and the feasibility of the control algorithm is verified by simulation. Finally, a 250W micro-inverter prototype is designed, and the related experiments are completed. In order to further reduce the loss and improve the efficiency of the micro-inverter, In order to reduce the loss of the active clamping circuit, the optimal control strategy based on the flyback main switch voltage is designed in this paper, in order to reduce the loss of the active clamp circuit, the control strategy of the interleaved parallel flyback micro-inverter is optimized. In order to reduce the loss of the micro-inverter under half load and light load, the optimal control strategy based on the output active power is designed in this paper, and the loss of the micro-inverter in the full load range is reduced. In this paper, the optimal control strategy based on instantaneous output power is designed, and the feasibility of the optimal control strategy is verified by simulation.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

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