【作者】 张文波；

【导师】 王玉斌；

【作者基本信息】 山东大学 ， 电力电子与电力传动， 2011， 硕士

【摘要】 由于超高压、集中式、远距离的大电网供电模式在电能质量、可靠性、经济性、安全性及灵活性方面存在问题,使可再生能源为主的分布式发电技术得以发展。随着传统主要能源的日益减少,太阳能、风能、热能等清洁、环保的可再生能源的开发和利用越来越受到重视。利用这些新能源转化为电能与电网并网发电技术是目前研究的关键。将微源与负荷连接在一块,形成可控的、能并网运行和孤岛运行的小电网称为微电网。微电网代表着电力系统新的发展方向,正在成为当前的研究热点。本文首先介绍了微电网的研究背景及意义,微电网的技术概念和国内外微电网的发展状况。接着分析了微电网的运行要求和控制策略,分别介绍了微电网的PQ控制法、下垂控制和倒下垂控制,分析了他们各自控制的优缺点,并在此基础上采用了一种新的控制方法即基于虚拟同步发电机思想的控制策略,最后对微电源逆变器进行了主电路设计。而后建立了虚拟同步发电机模型,重点设计了功频控制器和电压控制器。通过MATLAB/Simulink仿真实验表明,采用虚拟同步发电机机电暂态算法和调节系统建立的虚拟同步发电机能够模拟实际的同步发电机的输出特性,具有良好的稳态,动态调节性能,能很好的适应微电网的运行要求。最后设计了虚拟同步发电机微电源系统的电路结构和控制系统,选用了TMS320F2808芯片作为该系统的主控制器,给出了微电源系统的控制框架,对控制系统进行了硬件电路和软件设计本文主要研究了微电网逆变电源的控制策略,利用基于虚拟同步发电机思想提出了一种新型微电网逆变电源,即虚拟同步发电机逆变电源。分析并建立了虚拟同步发电机逆变器的模型,通过仿真试验,结果表明由该逆变电源组成的微电网既能连接大电网运行,又能实现孤岛运行时频率的无差控制。更多还原

【Abstract】 Due to many issues such as power quality, reliability, economy, security, flexibility, in a large power grid with ultra-high voltage, centralized, long-distance transmission, the distributed generation technology with renewable energy begins to develop. With the decrease of traditional primary energy, the energy sources such as solar, wind, geothermal and other clean, environmentally renewable energy are becoming more and more attractive, then how to develop and use them are taken more and more attention. How to convert these new energies into electrical energy and the grid-connected power generation technology are current study key point. A small grid that connecting micro-sources and loads, is known as microgrid, which is controllable and can operate in both grid-connecting and islanding mode, is becoming current research emphasis, and represents a new developing trend.The research background, concept, domestic and overseas developments of microgrid are introduced first in this paper, then the microgrid operation requirements and control strategy are analyzed. Some controlling methods, such as microgrid PQ control, droop-control and reverse droop-control, are introduced respectively and analyzed according to their own advantages and disadvantages. A new control method, which is based on the idea of virtual synchronous generator control strategy, is applied consequently, and then a virtual synchronous generator model is established, which focus on the power/frequency controller and voltage controller designs. MATLAB/Simulink simulation results show that the established virtual synchronous generator, which is based on virtual synchronous generator electromechanical transient algorithms and control system, can simulate the actual output characteristics of synchronous generator, have a good steady-state and dynamic-state regulation performance, then can easily adapt to microgrid operation requirements. A virtual micro-source synchronous generator, consisting of main circuit and control system, is designed finally, in which the DSP TMS320F2808 chip is used as the main controller. The control framework of micro-source, hardware circuit and software for the control system are also designed. The microgrid inverter control strategy is mainly studied in this paper, and a new-type microgrid inverter, i.e. a virtual synchronous generator inverter, is proposed based on virtual synchronous generator. The model of this new-type microgrid inverter is studied and established. The simulation results show that the microgrid formed by this new-type inverters can both operates in grid-connected mode and achieves zero-error control of frequency in islanding operation mode.更多还原