交错并联反激式光伏微型逆变器控制策略研究

发布时间：2018-04-20 22:04

本文选题：微型逆变器 + 全数字控制　；参考：《杭州电子科技大学》2015年硕士论文

【摘要】：随着全球经济高速发展,当前不可再生能源消耗日趋严重。为了缓解这一问题,如何合理开发利用可再生能源一直是各国政府和科研人员关注的重点。太阳能作为一种清洁的可再生能源,利用光电转换的基本原理实现光伏并网发电已成为解决未来能源危机的一种有效手段。当前国内外光伏产业发展迅速,作为适用于分布式发电领域的光伏微型并网逆变器,以其高效率、小体积以及高可靠性已被广泛应用于中小功率的分布式发电场合。本论文首先对当前光伏发电的发展做了简要介绍,并对光伏并网微型逆变器展开探讨。指出了目前国内外生产厂商,专家学者在这一领域的研究方向和研究重点,并且确定了本课题的研究对象为有源箝位交错并联反激式光伏微型逆变器。本文重点讨论了有源箝位交错并联反激式光伏微型逆变器的控制策略。首先比较了反激式微型逆变器工作在电流连续模式(Continue Conduction Mode,简称CCM)、临界连续模式(Boundary Conduction Mode,简称BCM)以及断续模式(Discontinue Conduction Mode,简称DCM)三种工作状态下的优劣情况。进而,提出基于全数字控制的BCM/DCM混合模式脉冲控制策略。微型逆变器的开关脉冲随并网输出功率而变化,使其在较宽的功率变化范围内都具有较高的效率表现。本文分析了功率电路工作的基本原理,并着重讨论了控制策略实现的核心想。同时,为了进一步优化微型逆变器的设计成本,本文应用了一种基于无电流传感器的最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)控制策略。本课题设计并制作了200W有源箝位交错并联反激式微型逆变器的实验样机。对功率电路的重要参数,和控制电路的具体实现都给出了详细的分析和说明。通过对微型逆变器样机的仿真,验证了全数字脉冲控制策略和无电流传感器最大功率点跟踪策略的可行性。并且,理论计算了微型逆变器系统的功率损耗,证明采用上述方法具有较高的工作效率。通过设计和调试200W的光伏并网反激式微型逆变器实验样机,应用了本文分析和论述的相关控制策略。实验测得的微型逆变器工作效率和并网电流波形,验证了本课题设计思路的正确性。
[Abstract]:With the rapid development of global economy, non-renewable energy consumption is becoming more and more serious. In order to alleviate this problem, how to develop and utilize renewable energy rationally has been the focus of governments and researchers all over the world. Solar energy as a clean renewable energy, using the basic principle of photovoltaic conversion to achieve grid-connected photovoltaic power generation has become an effective means to solve the future energy crisis. At present, photovoltaic industry is developing rapidly at home and abroad. As a miniature grid-connected photovoltaic inverter suitable for distributed generation, it has been widely used in distributed power generation for its high efficiency, small volume and high reliability. In this paper, the development of photovoltaic power generation is briefly introduced, and the photovoltaic grid-connected miniature inverter is discussed. The research direction and emphasis of domestic and foreign manufacturers, experts and scholars in this field are pointed out, and the research object of this paper is the active clamped interleaved flyback photovoltaic miniature inverter. This paper mainly discusses the control strategy of active clamped parallel flyback photovoltaic miniature inverter. In this paper, the advantages and disadvantages of flyback micro inverter working in the current continuous mode continuous Conduction mode, the critical continuous mode boundary Conduction mode and the discontinuous Conduction mode are compared. Furthermore, the BCM/DCM hybrid mode pulse control strategy based on full digital control is proposed. The switching pulse of the miniature inverter varies with the grid-connected output power, which makes it more efficient in a wide range of power variations. In this paper, the basic principle of power circuit is analyzed, and the core of control strategy is discussed. At the same time, in order to optimize the design cost of miniature inverter, a maximum Power Point tracking control strategy based on current sensorless is proposed in this paper. In this paper, a 200 W active clamp parallel flyback miniature inverter is designed and fabricated. The important parameters of power circuit and the realization of control circuit are analyzed and explained in detail. Through the simulation of the miniature inverter prototype, the feasibility of the full digital pulse control strategy and the maximum power point tracking strategy without current sensor is verified. Furthermore, the power loss of the micro inverter system is calculated theoretically, which proves that the proposed method has high efficiency. By designing and debugging 200W photovoltaic grid-connected flyback miniature inverter experimental prototype, the related control strategies analyzed and discussed in this paper are applied. The working efficiency and grid-connected current waveform of the miniature inverter are measured experimentally, which verifies the correctness of the design idea.
【学位授予单位】：杭州电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM464;TM615

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