【作者】 柏祎山；

【导师】 吴麟章； 吴铁洲；

【作者基本信息】 湖北工业大学 ， 电力电子与电力传动， 2009， 硕士

【摘要】 太阳能发电在世界能源危机的背景下飞速发展,已成为新能源的主流之一。逆变器作为主要的能量变换装置器件,其性能的好坏对整个光伏系统的效率造成很大的影响。本文采用电压外环、电流内环的双环控制策略,保证了系统的动态响应速度快,稳态误差小。为此,论文主要对系统的电路拓扑结构、数学模型、控制方法以及基于FPGA的软件实现方法等技术进行了分析研究。本文首先通过对几种常见的数学模型分析方法的比较,选择适合本文的数学建模方法。文中给出了逆变器的拓扑结构,详细论述了其工作原理,对该逆变器不同工作状态下的等效电路进行分析,并利用状态空间平均法建立了逆变器数学模型,确定主要元件的参数。随后对当前比较流行的几种逆变电路的控制方法进行了对比分析。本文采用的基于SPWM控制的电压电流双环控制的算法,具有开关频率固定、物理意义清晰、实现方便的优点,保证系统的稳态误差小,动态响应速度快。通过分析几种最大功率跟踪算法各自的优缺点,最后给出了改进的最大功率跟踪算法,保证系统输出最大功率。最后用FPGA实现了系统控制方案的设计。整机测试结果表明:该逆变器的性能指标基本达到了设计要求,验证了数学模型和控制策略的有效性和理论分析的正确性和可行性。更多还原

【Abstract】 With the increasingly aggravated energy crisis in the world, solar "photovoltaic" power has been greatly developed and become one of the cleanest and most effective renewable energy. The inverter, as the major power converter in the PV generator system, its performance will directly influence the efficiency of the solar power. This paper focuses on the control method of virtual value outer loop and instantaneous value inner loop, which can eliminate the static error, as well as make the output wave function normally, therefore, this paper analyzed the topology of the system, the mathematical model, control strategy and the key technology of realization based on FPGA.First of all, this paper chooses the suitable method of mathematical modeling by comparing it with several other relative methods. Then this paper gives the structure of the inverter and makes a detailed analysis on the operation principle, equivalent circuit under the different states. The mathematical model is based on the state-space average method and it deduce the input-output characters of the system so as to ensure the parameters of the main components.Several relatively popular control methods of inverter are simply introduced by using block diagram. Voltage and current dual-loop control algorithm based on SPWM has some advantages, such as invariable switching frequency, simplified signification and easy realization. In order to enable the maximum power output of solar cells, the dissertation introduces some usually maximum power point tracking (MPPT) methods and analyzes respective advantages, disadvantages and appropriateness of using the occasion.Finally, the author designs the system control plan by implementing FPGA technology. The experimental results show that the performance indicators can satisfy the design requirements, which can be used in verifing the correctness and feasibility of mathematical modeling and SPWM control method.更多还原