基于直流微电网的光伏并网功率转换装置设计与运行仿真

摘要

微电网是目前国内外应用较为广泛的一种绿色可再生能源，近几年我国微电网产业的发展十分迅速。然后，越来越多的微电网系统建立并网，微电网产生的电能受外界因素影响较大，具有一定的随机性和波动性，给并网后的电力系统稳定性带了巨大的影响。然后建立微电网厂的储能系统是改善此种情况的最好的解决办法。因此，近年来微电网场储能装置的装备、容量配置及风储联合运行控制成为了研究和应用示范的热点。

面对全球日趋严重的能源危机问题，可再生能源的开发和利用得到了人们的高度重视。其中辐射到地球太阳能资源是十分富饶的，绿色清洁的太阳能不会危害我们的生存环境，因而受到了人们的广泛利用。光伏发电作为可再生能源被广泛的应用，技术不断革新。为了提高光伏发电系统的光电转换效率，需要系统实时的进行最大功率点跟踪。

微电网是解决电力系统稳定性问题的关键所在，直流微电网相比传统交流配用电网，具有技术和经济上的优点，具有巨大的发展前景。本文主要针对直流微电网的光伏并网功率转换相关设计与运行研究。通过对微电网常用母线结构和光伏、蓄电池、逆变器不同微电网的数学模型的研究，制定与之相适应的不同的控制策略和符合实际运行方式。在Matlab/Simulink 仿真中搭建了基于光伏、储能等微电源组成的简易微电网模型，从而验证了不同微电源的运行方式和控制模式。

关键词：直流微电网，并网逆变器，光伏，功率转换

Abstract

Micro–power grid is a kind of green renewable energy which is widely used at home and abroad at present. In recent years, micro–power grid industry has developed very rapidly. Then, more and more microgrid systems are built and connected to the grid. The electric energy generated by microgrid is greatly affected by external factors and has certain randomness and volatility, which has a huge impact on the stability of the grid–connected power system. The best way to improve this situation is to build energy storage system of microgrid plant. Therefore, in recent years, the equipment, capacity configuration and combined operation control of energy storage devices in microgrid field have become a hot topic in research and application demonstration.

Facing the increasingly serious global energy crisis, the development and utilization of renewable energy has been attached great importance. Which radiation to the earth’s solar energy resources are very rich, green and clean solar energy will not harm our living environment, so it has been widely used by people. Photovoltaic power generation as a renewable energy is widely used, technology innovation. In order to improve the photoelectric conversion efficiency of photovoltaic power generation system, it is necessary to track the maximum power point in real time.

Microgrid is the key to solve the problem of power system stability. Compared with the traditional AC distribution network, DC microgrid has technical and economic advantages and has a huge development prospect. This paper mainly focuses on the design and operation of photovoltaic grid-connected power conversion in DC microgrid. Based on the study of the common bus structure of microgrid and the mathematical models of different microgrids of photovoltaic, battery and inverter, different control strategies and practical operation modes are formulated. In the Matlab/Simulink simulation, a simple micro-grid model based on photovoltaic, energy storage and other micro-power sources is built, thus verifying the operation mode and control mode of different micro-power sources.

Keywords: Dc microgrid, grid-connected inverter, photovoltaic, power conversion