微电网建模与仿真研究

发布时间：2018-07-28 20:31

【摘要】：在当今能源问题日趋严重的情况下，采用可再生能源的分布式发电技术成为未来能源发展的主要方向，但是由于分布式发电技术具有电压和频率不稳定的特点，易对大电网造成严重冲击，因此电网采用限制分布式发电并网的管理方式。这就造成了分布式发电商业化程度较低的结果，大大限制了该项技术的发展，阻碍了其形成规模化运行的进程。微电网技术的提出，能够大大改善分布式发电技术的现状，稳定其输出电能的频率和电压，减小对大电网的冲击；此外微电网也能在孤网运行方式下运行，在大电网故障时保证内部基本负载的电能供应，在充分利用可再生能源的同时增加供电可靠性。微电网是由分布式电源和电力负荷构成，可以在并网与孤岛两种工作模式下运行，同时具有高度可靠性和稳定性。随着电力电子接口和现代控制理论的发展，微电网将额定功率几十千瓦的发电单元作为微电源与负荷、储能装置及控制装置等结合，成为单一可控的单元，同时向用户供给电能。大规模分布式能源可以通过基于微电网结构的电网并接入中低压配电系统，是一种解决分布式能源并网的有效方案。本文借助Matlab/Simulink仿真软件，建立了各种元件的模型，仿真了微电网并网和孤网运行两种运行方式，，在孤网运行部分的仿真中，加入了电源电压跌落工况的仿真。仿真结果表明，在并网运行方式下采用电流双环控制，以及在孤网运行方式下采用U/f控制方式的策略，能够使微网运行良好，保证负载供电。
[Abstract]:Under the increasingly serious energy problem, distributed generation technology with renewable energy has become the main direction of energy development in the future. However, because of the characteristics of voltage and frequency instability, distributed power generation technology has the characteristics of voltage and frequency instability. It is easy to make a serious impact on large power grid, so the management mode of limited distributed generation and grid connection is adopted. This results in a low degree of commercialization of distributed generation, which greatly limits the development of the technology and hinders the process of large-scale operation. The development of microgrid technology can greatly improve the present situation of distributed generation technology, stabilize the frequency and voltage of power output, and reduce the impact on large power grid. The power supply of internal basic load is guaranteed when the large power network fails, and the reliability of power supply is increased while making full use of renewable energy. Microgrid is composed of distributed power generation and power load. It can be operated under two operation modes, grid-connected and islanding, and has high reliability and stability at the same time. With the development of power electronic interface and modern control theory, microgrid combines the rated power generation unit with tens of kilowatts as a micro-power source, load, energy storage device and control device, and becomes a single controllable unit. At the same time to provide electricity to the user. Large-scale distributed energy can be connected to the medium-low voltage distribution system through the micro-grid structure, which is an effective solution to the grid connection of distributed energy. In this paper, with the help of Matlab/Simulink simulation software, the models of various components are established, and the two operation modes of microgrid and isolated grid are simulated. In the simulation of the operation part of the isolated network, the simulation of the power supply voltage drop condition is added. The simulation results show that the strategy of current double loop control in grid-connected operation mode and U / F control mode in isolated network operation mode can make the microgrid run well and ensure load supply.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM743

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