含光伏发电的电网动态无功优化方法与实证研究

发布时间：2018-04-30 07:30

本文选题：光伏发电 + 电力网络　；参考：《西安建筑科技大学》2017年硕士论文

【摘要】：光伏发电(Photovoltaics,PV)是一种清洁且环保的可再生能源发电,现今国内外电力系统常将其以分布式电源的形式并列接入到电网中。众多学者也对此进行了深入的研究,特别是在光伏发电的数学模型和对电网输出功率方面。随着经济和科学技术的不断进步,光伏发电并入电力系统的模型已经相对稳定,各行业建立了大量的光伏发电站以提升电力系统的调控和无功补偿水平。但是光伏发电与传统的火力发电相比,又具有一定的随机性。这种随机性与太阳能源受环境和气候的强相关有关,为光伏发电并入电网带来不稳定性。为了解决这种并网难题,论文重点建立了具有光伏发电随机性约束和无功补偿特性的电力系统动态无功优化模型。该模型的建立有效地调整了电力系统中无功潮流的分布,提高了网络节点电压,减少了系统的有功损耗。电力系统的无功调整方法有控制发电机端部的输出电压、调节有载调压变压器的档位及调控电容器装置的补偿能力等作用。论文首先介绍了PV系统的类别和组成,研究了光伏发电并网的不稳定性及无功输出能力。选取了经典的遗传算法,并去除了该算法收敛速度和寻求最优解方面的不足之处。将动态无功优化按照时间顺序转化为静态无功优化,用改进的遗传算法搜索各时段静态无功优化的最优解,即各时段无功补偿装置的动作次数及该时段的系统有功损耗。为了建立电力系统动态无功优化模型,在论文得到的静态模型最优解中加入了电网负荷变动曲线下电容器装置的投切损耗及光伏并网的输出功率。为了限制无功补偿装置的投切数目和减少装置因频繁动作而带来的设备损耗,采用动态规划算法制作了电容器装置的动作时间表,获得1d内最低的系统有功消耗。论文以内蒙古地区含光伏发电的电网无功优化为实证研究,应用MATLAB软件用于验证所建立的动态无功优化模型,结果显示此模型可以有效地降低网络损耗,提高节点电压,保证电压合格,为含有光伏发电并网的电力系统无功优化提供了理论依据,对内蒙古电网光伏发电的无功优化具有一定的实践价值。
[Abstract]:Photovoltaic power generation (PV) is a kind of clean and environmentally friendly renewable energy generation. Nowadays, power systems at home and abroad often connect it to the power grid in the form of distributed power generation. Many scholars have also carried on the thorough research, especially in the photovoltaic generation mathematical model and the power output to the grid. With the development of economy and science and technology, the model of photovoltaic power generation integrated into power system has been relatively stable. A large number of photovoltaic power stations have been established in various industries to improve the power system regulation and reactive power compensation level. However, compared with traditional thermal power generation, photovoltaic power generation has a certain randomness. This randomness is related to the strong correlation between solar energy and the environment and climate, which brings instability for photovoltaic power generation to be incorporated into the grid. In order to solve this problem, the dynamic reactive power optimization model of power system with stochastic constraints and reactive power compensation characteristics of photovoltaic power generation is established in this paper. The establishment of the model effectively adjusts the distribution of reactive power flow in the power system, improves the network node voltage, and reduces the active power loss of the system. The reactive power adjustment method of power system has the functions of controlling the output voltage at the end of the generator regulating the gear of the on-load regulating transformer and regulating the compensation ability of the capacitor device. In this paper, the types and components of PV system are introduced, and the instability and reactive power output ability of photovoltaic power generation are studied. The classical genetic algorithm is selected, and the shortcomings of the algorithm in convergence speed and optimal solution are removed. The dynamic reactive power optimization is transformed into the static reactive power optimization according to the time sequence. The improved genetic algorithm is used to search the optimal solution of the static reactive power optimization in each period, that is, the action times of the reactive power compensator in each period and the active power loss of the system in that period. In order to establish the dynamic reactive power optimization model of power system, the switching loss of capacitor device and the output power of photovoltaic grid are added to the optimal solution of static model obtained in this paper. In order to limit the switching number of reactive power compensator and reduce the device loss caused by frequent operation, a dynamic programming algorithm is used to make the operation schedule of capacitor device, and the lowest active power consumption in one day is obtained. Based on the research of reactive power optimization in Inner Mongolia area, the MATLAB software is used to verify the dynamic reactive power optimization model. The results show that the model can effectively reduce the network loss and improve the node voltage. It provides a theoretical basis for the reactive power optimization of the power system with photovoltaic grid connection, and has certain practical value for the reactive power optimization of photovoltaic power generation in Inner Mongolia Power Grid.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM714.3

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