微网系统潮流计算与运行特性的分析

发布时间：2018-01-09 09:42

本文关键词：微网系统潮流计算与运行特性的分析　出处：《河北工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着全球工业和经济的快速发展，能源急剧消耗和环境危机所造成的问题已经越来越突出；同时超大规模电力系统带来的电网脆弱性也已暴露。为了解决上述问题，基于可再生能源的分布式发电技术得以迅速发展。作为智能电网的一个重要组成部分，微网应运而生。微网能够协调分布式发电与大电网的矛盾，提高电力系统的供电可靠性。潮流计算是研究电力系统运行情况的一种基本电气计算，由于分布式电源以及负荷的随机性，确定性潮流计算方法已难以满足需求。而随机潮流计算可以考虑随机性的影响，因此对随机潮流计算进行研究是十分必要的。本文主要对微网系统的随机潮流计算及运行特性进行研究分析。首先，从随机潮流计算常用的三种方法出发，分析比较其基本原理以及各自的优缺点；并且研究了随机潮流计算的数学基础，包括概率密度函数和累积分布函数、数学期望、方差、中心矩、半不变量、Gram-Charlier级数；建立了储能元件、负荷、风力发电机和燃料电池的随机模型，，为微网随机潮流计算奠定基础。其次，针对随机潮流计算常用三种方法的不足，提出了基于蒙特卡罗模拟的半不变量法的改进方法。该方法对注入功率分布函数服从正态分布或离散分布采用常规数值方法计算其半不变量；对注入功率分布函数未知或其他分布采用蒙特卡罗抽样的方法计算其半不变量。该方法解决了传统半不变量法在注入功率未知分布函数的情况下难以求解半不变量的问题，同时保持了其准确性和快速性。编写该方法的程序，通过具体实例进行计算，并将Matlab上的计算结果与蒙特卡罗模拟法的结果进行比较，验证了该方法的准确性、可靠性和快速性。最后，建立微网系统模型，结合本文所提算法，对微网系统潮流的运行特性进行分析，主要分析相同容量不同微电源对微网系统电压的影响。Matlab的仿真结果表明相同容量不同微电源对微网系统电压的影响与其随机性成正比，同时储能元件的接入可以减小微网系统的电压波动，对电能质量有一定的改善作用。
[Abstract]:With the rapid development of global industry and economy, the problems caused by rapid energy consumption and environmental crisis have become more and more prominent. In order to solve the above problems, distributed generation technology based on renewable energy has been developed rapidly. It is an important part of smart grid. Micro-grid emerges as the times require. Microgrid can coordinate the contradiction between distributed generation and large power grid, and improve the power supply reliability of power system. Power flow calculation is a basic electrical calculation to study the operation of power system. Due to the randomness of distributed power generation and load, the deterministic power flow calculation method is difficult to meet the demand, but stochastic power flow calculation can consider the influence of randomness. Therefore, it is necessary to study the stochastic power flow calculation. In this paper, the stochastic power flow calculation and operation characteristics of micro-grid system are studied and analyzed. Firstly, the basic principle, advantages and disadvantages of the three methods used in random power flow calculation are analyzed and compared. The mathematical basis of stochastic power flow calculation is studied, including probability density function and cumulative distribution function, mathematical expectation, variance, central moment, semi-invariant Gram-Charlier series. The stochastic model of energy storage element, load, wind turbine and fuel cell is established, which lays the foundation for stochastic power flow calculation of microgrid. Secondly, aiming at the deficiency of three common methods of stochastic power flow calculation. An improved method of semi-invariant method based on Monte Carlo simulation is proposed, in which the semi-invariant of injection power distribution function is calculated from normal distribution or discrete distribution by conventional numerical method. Monte-Carlo sampling method is used to calculate the semi-invariant of injection power distribution function or other distributions. This method solves the problem that the traditional semi-invariant method is difficult to solve the semi-invariant problem when the injection power distribution function is unknown. The question of quantity. At the same time, the accuracy and rapidity of the method are maintained. The program of this method is written, and the calculation results on Matlab are compared with the results of Monte Carlo simulation. The accuracy, reliability and rapidity of the method are verified. Finally, the micro-grid system model is established, and the operation characteristics of the micro-grid system power flow are analyzed in combination with the algorithm proposed in this paper. The simulation results of Matlab show that the effect of different micro-power supply of the same capacity on the voltage of micro-grid system is proportional to its randomness. At the same time, the access of energy storage elements can reduce the voltage fluctuation of the microgrid system, and improve the power quality to a certain extent.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM744

【参考文献】