光储微电网运行控制策略的研究

发布时间：2018-12-27 13:54

【摘要】：摘要：随着人类对能源需求量的日益增加,同时煤、石油、天然气等一次性能源的日益锐减,人们已意识到开发可再生能源的重要性。利用可再生能源的关键技术是如何将可再生能源并入大电网,微电网技术恰好可以解决这个难题。将分布式电源和负荷作为一个整体,形成可控的、既可孤岛运行又可并网运行的小电网称之为微电网。微电网包括直流微电网、交流微电网、交直流微电网三类,其中交流微电网采用交流母线与大电网相连,符合交流用电情况,交流用电负荷不需专门的逆变装置。微电网有并网和孤岛两种工作状态,两种工作状态间的平滑切换问题,即微电网的“即插即用”,是微电网研究中的重点。本文的研究对象为由光伏电池、蓄电池及负荷组成的交流微电网,结合微电网的结构和控制目标,分别设计了系统在并网和孤岛状态下的控制策略。并网状态下,由大电网来维持微电网的电压和频率,光伏电池工作在最大功率跟踪模式,蓄电池工作在P/Q控制模式；当大电网异常断电时,系统能够快速检测到孤岛发生并自动脱离电网孤岛运行；本文通过分析微电网功率匹配、过剩及缺额三种不同情况,分别提出了在并离网切换时不同的控制策略。孤岛状态下,光伏电池可能工作在最大功率跟踪模式或恒功率模式,蓄电池工作在V/f控制模式；当系统接收到并网信号准备并网时,启动同步并网控制器使系统的电压、相位和频率与大电网保持同步,之后再合上并网开关,实现带负荷并网。搭建了光储交流微电网的仿真模型和实验平台,通过增减负荷、闭合或断开并网开关来检测系统的稳定性和可靠性。仿真和实验结果表明提出的控制策略实现了工作状态间的平滑切换,满足了系统的设计要求。设计了基于LabVIEW的上位机监控系统,用于模拟系统各部分的操作控制与运行结果展示。
[Abstract]:Absrtact: with the increasing demand for energy and the decrease of disposable energy such as coal, oil and natural gas, people have realized the importance of developing renewable energy. The key technology of utilizing renewable energy is how to integrate renewable energy into large power grid. Microgrid technology can solve this problem. The distributed power generation and load are taken as a whole to form a controllable small grid which can be operated on both island and grid. Microgrid includes DC micro-grid and AC / DC micro-grid. Ac microgrid is connected with large power grid by AC bus, which accords with AC power consumption, and AC power load does not need special inverter device. There are two working states in microgrid, one is grid-connected and the other is islanding. The smooth switching problem between the two working states, that is, "plug and play" of micro-grid, is the key point in the research of micro-grid. The research object of this paper is the AC microgrid composed of photovoltaic cell, battery and load. Combined with the structure and control goal of the microgrid, the control strategy of the system under the condition of grid-connected and isolated island is designed respectively. In grid-connected state, the voltage and frequency of microgrid are maintained by large power grid, photovoltaic cells work in maximum power tracking mode, and batteries work in P / Q control mode. When the power supply of large power grid is abnormal, the system can detect the occurrence of isolated island and operate automatically from the isolated island of power network. In this paper, by analyzing three different situations of power matching, surplus and deficit in microgrid, different control strategies are proposed for parallel and off-grid switching. In isolated island state, photovoltaic cells may work in maximum power tracking mode or constant power mode, and batteries may work in V / F control mode. When the system receives the grid-connected signal and prepares to be connected to the grid, the synchronous grid-connected controller is activated to keep the voltage, phase and frequency of the system in sync with the large power grid, and then close the grid-connected switch to realize grid-connected with load. The simulation model and experimental platform of optical storage AC microgrid are built to detect the stability and reliability of the system by adding or decreasing load closing or disconnecting the grid-connected switch. Simulation and experimental results show that the proposed control strategy realizes smooth switching between working states and meets the design requirements of the system. A computer monitoring system based on LabVIEW is designed, which is used to simulate the operation control and operation result of each part of the system.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM732

【共引文献】