分布式电网用有源滤波型并网逆变器控制策略的研究

发布时间：2018-07-01 08:58

本文选题：并网逆变器 + 有源滤波器　；参考：《兰州交通大学》2017年硕士论文

【摘要】：由于人类社会在近几个世纪的高速发展,电能作为当今社会的主要能源之一,日常生活生产对电能的需求量和质量的要求也在进一步提高。在当前能源危机不断深化,环境污染不断加剧的大环境下,如何有效利用新能源,尤其是电能,来改善当前能源结构,改变化石能源为主的能源消耗现状是亟待解决的一个世界性问题。正因如此,以水力发电、光伏发电及风力发电为代表的新能源发电技术受到了人类社会有史以来最高的关注。新能源发电技术大多应用于分布式发电系统中,因此如何建立坚强可靠的智能电网也是目前电力系统发展中的一个重点问题。由于技术和建设条件的制约,以新能源发电技术为基础的分布式电网不可避免的存在电能质量不高的问题。其主要原因是谐波对大电网的污染,谐波会直接导致电能传输过程中损耗增加,产生不必要的能量流失,谐波流入用电设备时会导致用电设备过热甚至损坏,也是由于这个原因,如何有效抑制电力系统中的谐波在提高电力系统电能质量中变得尤为重要。在这样的环境和背景之下,本文通过分析并网逆变器和有源滤波器结构,对比二者的异同点,以分布式电网为研究前提,研究一种结合并网逆变器和有源滤波器功能的新型逆变器,即有源滤波型并网逆变器。有源滤波型并网逆变器利用并网逆变器富余容量来实现逆变器及有源滤波器功能的结合,使得逆变器在实现逆变器对网侧供电的功能的同时,兼顾谐波抑制和无功补偿的功能。新型逆变器可有效的降低系统成本,降低运行成本,减小检修难度。本文以这种可同时实现并网逆变与谐波抑制的并网逆变器为研究对象,从理论上对这种应用于分布式电网中的逆变器的数学模型进行了分析,并采用了以直接电流控制策略为核心,以一种改进的d qi-i谐波检测算法为工具的系统统一控制策略。采用该控制策略的逆变器可在实现并网逆变器功能的同时实现有源滤波器的功能,有效的滤除网侧谐波,可有效的提高电能质量。依据理论分析,对系统进行Matlab/Simulink建模及仿真,仿真结果表明本文设计的有源滤波型并网逆变器能有效地抑制电力系统中的谐波,同时可完成并网工作,验证了本系统的可行性及实用性。
[Abstract]:With the rapid development of human society in recent centuries, electric energy, as one of the main energy sources, the demand and quality requirements of daily life production for electrical energy are also further improved. With the deepening of the current energy crisis and the worsening of environmental pollution, how to effectively use new energy sources, especially electrical energy, to improve the current energy structure, To change the current situation of fossil energy consumption is a world problem to be solved. As a result, new energy generation technologies, such as hydropower, photovoltaic power generation and wind power generation, have attracted the highest attention in the history of human society. New energy generation technologies are mostly used in distributed generation systems, so how to establish a strong and reliable smart grid is also a key issue in the development of power system. Due to the restriction of technology and construction conditions, the problem of low power quality is inevitable in the distributed grid based on the new energy generation technology. The main reason is that the harmonics pollute the large power grid, which will directly lead to the increase of the loss in the electric power transmission process and the unnecessary loss of energy. When the harmonics flow into the electric equipment, it will cause the electric equipment to overheat and even damage. For this reason, how to effectively suppress harmonics in power system becomes very important in improving power quality. In this environment and background, this paper analyzes the structure of grid-connected inverter and active power filter, compares the similarities and differences between them, and takes the distributed power grid as the premise of the research. An active filter grid-connected inverter which combines the functions of grid-connected inverter and active filter is studied. Active filter grid-connected inverter uses the surplus capacity of grid-connected inverter to realize the combination of inverter and active power filter, which makes the inverter realize the function of power supply to the grid-side of the inverter, and at the same time, the function of harmonic suppression and reactive power compensation is taken into account. The new inverter can effectively reduce system cost, operation cost and maintenance difficulty. This paper takes the grid-connected inverter which can realize grid-connected inverter and harmonic suppression simultaneously as the research object, and theoretically analyzes the mathematical model of the inverter applied in distributed power network. A unified control strategy with direct current control strategy as the core and an improved d qi-i harmonic detection algorithm as the tool is adopted. The inverter with this control strategy can realize the function of active power filter as well as realize the function of grid-connected inverter, effectively filter the harmonics on the grid side, and improve the power quality effectively. According to the theoretical analysis, the system is modeled and simulated by Matlab / Simulink. The simulation results show that the active filter grid-connected inverter designed in this paper can effectively suppress the harmonics in the power system, and can complete the grid-connected work at the same time. The feasibility and practicability of the system are verified.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

【参考文献】