【作者】 唐林；

【导师】 郭世明；

【作者基本信息】 西南交通大学 ， 电力电子与电力传动， 2013， 硕士

【摘要】 为解决能源短缺和环境污染两大难题,太阳能光伏发电近年来受到世界各国广泛关注,其中并网逆变器控制技术作为光伏发电系统的关键环节,成为目前研究的热点。本文选择带LCL滤波器的三相桥式并网逆变器为研究对象,分析了LCL滤波器谐振峰产生的原理及抑制的措施,重点讨论了并网逆变器的控制技术,分别从并网电流和输入功率两方面入手研究了三种控制方法,通过仿真分析验证了三种方法的控制性能。首先,对光伏并网发电系统中并网逆变器的拓扑结构进行介绍,在此基础上选择三相桥式逆变器作为本文的研究重点；对LCL滤波器进行参数设计；分析了当前应用比较广泛的并网逆变器控制技术。其次,采用了基于准比例谐振(QPR)控制器的电流双闭环并网控制技术,利用电容电流内环的反馈控制作为有源阻尼来抑制LCL滤波器的谐振峰；在QPR电流双闭环控制技术的基础上,利用谐振环节对特定频率增益无限大的特点,分析了具有抑制特定次谐波能力的谐波补偿器。再次,分析了基于滞环功率控制的并网控制技术,由于该控制方法采用滞环控制,使得开关频率不固定,增大系统的滤波难度,在滞环功率控制的基础上研究了一种基于滤波电感在线估算的定频直接功率控制方法,解决了滞环控制中开关频率不固定的缺点,同时兼具滞环控制的响应速度快,鲁棒性好等优点,最后对两种直接功率控制方法进行比较分析。最后,分析光伏并网逆变器和有源滤波器的工作特点,找出其统一控制的结合点,实现一机多用,降低应用成本,提高系统利用效率。采用基于准比例谐振(QPR)的电流双环控制技术,重点分析了统一控制条件下的三种工作模式。更多还原

【Abstract】 To solve the two problems of energy shortage and environmental pollution, solar photovoltaic power generation had received extensively attention all over the world in recent years, grid-connected inverter as the key part of the photovoltaic power generation system, which had become the focus of current research. In this paper, three-phase bridge grid-connected inverter with LCL filter was selected as an research subject, the principles of LCL filter’s resonance peak and the restraining measures had been analyzed, focused on the control technology for grid-connected inverter, this paper studies the three control methods from two aspects of the grid-connected current and the input power, and verified the control performance of the three methods by simulation analysis.First, introduced the topological structure about the grid-connected inverter of the grid-connected photovoltaic system and chosen the three-phase bridge type as the research focus in this paper, designed the parameters of the LCL filter and analyzed the grid-connected control technology which is used wildly in the current.Secondly, adopted the grid-connected control technology which based on the quasi proportion resonant (QPR) controller of current double closed-loop, the use of capacitive current inner loop feedback control as the active damping to suppress LCL filter resonance peaks; on the base of the QPR current dual closed-loop control technology, take advantage of the resonator infinitely large part of the specific frequency gain characteristics to analyse the ability for inhibiting specific sub-harmonic of the harmonic compensator.Thirdly, analyzed a grid-connected control technology which based on the hysteresis loop power control, as adopting the hysteresis control method that leaded to no fixed switching frequency and increased the difficulty of filtering for the system, a method of fixed-frequency direct power control method of the filter inductor online estimate, whicn could solve the shortcomings of the no fixed switching frequency of the hysteresis control, this method had both the advantages of fast response and good robustness of the hysteresis control, finally, had a comparative analysis of the two direct power control methods.Finally, analyzed the working characteristics of photovoltaic grid inverters and active filter to identify the combining site of the unified control, which could achieve multi-usage, decrease the cost of application and improve the utilization efficiency of the system, adopted the control technology which based on the quasi proportion resonant (QPR) controller of current double closed-loop, focused on analysis of three modes which under the conditions of the unified control.更多还原