【作者】 钱军；

【导师】 李欣然；

【作者基本信息】 湖南大学 ， 电气工程， 2010， 博士

【摘要】 紧密结合国家大力开发可再生洁净能源分布式发电技术与装备的科技发展战略,综合运用电力系统分析、系统辨识、计算机技术、统计数学等科学原理与方法,将总体测辨法、仿真实验等电力系统负荷建模理论与方法有机结合,围绕考虑风力发电(Wind Power Generation,WG)、光伏电池(Photovoltaic,PV)、燃料电池(Fuel Cell,FC)、微型燃气轮机(Microturbine,MT)等典型分布式发电装置影响的配电网广义综合负荷建模开展了一系列的研究,具体工作和贡献有如下几个方面:1、针对电力系统传统感应电动机综合负荷模型存在的结构缺陷,从总体测辨的角度,提出了一种“配电网集结等效的综合感应电动机模型”。模型将配电网络用集总线路-变压器组集结等效,并计及了变压器有载调整分接头的影响;在静态负荷中考虑负荷暂态无功功率的补偿调整作用。推导出了模型的完整解析描述;提出了模型参数的“递推辨识策略”。模型实现了220kV变电站综合负荷物理环境—模型辨识环境—仿真计算环境的统一,更加符合电网的综合负荷实际结构。基于现场实测数据的建模实例表明,该模型在参数稳定性、泛化能力等综合性能上,较传统感应电动机模型有了一定的提高,为考虑分布式发电影响的配电网综合负荷建模提供了有效的广义综合负荷模型结构体系基础。2、基于MATLAB仿真工具并运用总体测辨负荷建模方法,研究了考虑WG的配电网综合负荷模型结构。提出把WG看作一个功率消耗为负的广义动态负荷,用异步发电机来等效描述;进而提出了一种任意动静比例的异步电机并联静态负荷的配电网广义综合负荷模型来描述含WG的配电网综合负荷特性。3种典型运行方式的建模研究,检验了该模型对不同WG容量和负荷水平的配电网综合负荷特性的综合适应性能力。3、在构建IEEE 14节点典型配电系统的基础上,研究了容量比例、地理位置和接入方式(集中或分散)等影响因素下WG接入对配电网综合负荷特性的影响。研究表明,容量比例的影响要明显大于地理位置的影响,占主导作用;且WG分散接入的影响要明显小于WG集中接入。在此基础上,利用上面的研究数据,进一步验证了所提出的任意动静比例的异步电机并联静态负荷的广义综合负荷模型的有效性;进而结合第1部分的研究成果对该模型进行了扩展,提出“任意动静比例的配电网集结等效的异步电机广义综合负荷模型”,比较分析验证了该模型的优越性。4、为研究考虑PV和FC等直流分布式电源影响的配电网综合负荷建模,在构建PV和FC发电系统的基础上,详细阐述了各功能模块的模型和并网控制策略;提出把直流分布式电源看作一个功率消耗为负的广义静态负荷,用恒功率模型来等效描述;进而提出了一种等效静态负荷并联感应电动机的广义综合负荷模型来等效描述含直流分布式电源的配电网综合负荷特性;针对三种不同接入容量比例的直流分布式电源,进行了总体测辨建模研究,通过模型自描述能力、泛化能力和影响其综合负荷特性的关键参数(动静比例和ZIP静态负荷系数)的变化规律分析,验证了该模型的有效性。5、为研究考虑MT的配电网综合负荷建模,在构建MT发电系统的基础上,详细阐述了各功能模块的模型和控制策略;提出把微型燃气轮机看作一个功率消耗为负的广义动态负荷,用一阶微分方程模型来等效描述;进而提出了一种微型燃气轮机和感应电动机组成的等效动态负荷并联静态负荷的广义综合负荷模型来等效描述含MT的配电网综合负荷特性;针对MT接入容量的不同,对三个样本进行了总体测辨建模研究,验证了该模型的有效性。更多还原

【Abstract】 With the fast development of renewable and clean energy generation, there will be a series of new theory and practical problems to be solved. One of them is the modeling of power systems. Based on the background stated above, this dissertation studies the composite load modeling of distribution power network considering distributed generation. The main work and contributions are as below:1. Aiming at the disadvantages of the structure of traditional induction motor load model, a novel“synthesis induction-motor model considering distribution network”is established. In this model, the distribution network is equivalent to a line connecting to a terminal transformer, which can describe the influence of OLTC (on-load tap changer) and reactive power compensation. The model achieves the unity of the physics environment, parameters identification environment and simulation applying environment of composite load at the power substation. The results of modeling test based on simulation measured data shows that the“synthesis induction-motor model considering distribution network”has excellent identifiability, generalization, and the composite describing capability. Its integral performance is better than traditional induction motor model. This model provides the basis and effective structure for research on load modeling of distribution network considering distributed generation.2. The composite load model of distribution network including wind power generation (WG) is studied with MATLAB Simulation toolbox and theory of measurement-based method. The research proves that the WG could be considered as generalized dynamic load which consumes negative power, and could be described by asynchronous generator. In order to describe the synthetic load characteristic of distribution network including WG, the author proposes a kind of generalized composite load model that is constituted by asynchronous machine in parallel with static load. In the model, the ratio of dynamic load can be any real numerical value. The validity of this composite load model with any ratio of dynamic load is testified by modeling of three typical operation modes under different capacity of wind power generation.3. Using the typical IEEE 14 node distribution network as simulation environment, the author systematically studied the impact of WG on composite load characteristics, which consider some impotent influential elements such as capacity ratio, location, and the connecting mode to the distribution network and so on. It has been proved that the influence of capacity is apparently greater than that of location, and the effect of dispersed WG is smaller than that of the centralized, hence the dispersed connection one have advantage to the safe and stable operation of power system. Using the measured data from simulation, the validity of generalized composite load model is tested through fitting result, average error and identification parameters. At the same time, the generalized composite load model of asynchronous machine with any ratio of dynamic load is proposed, and its superiority is also tested.4. For the sake of studying on the composite load modeling of distribution network with photovoltaic (PV) and fuel cell (FC), the PV and FC grid-connected power system is established and the model of each function module and control strategy are expounded. It is pointed out that the PV and FC could be considered as generalized static load which consumes negative power, and could be described by constant power model. Based on this, the generalized composite load model of equivalent static load in parallel with induction motor is proposed to describe the synthetic load characteristic of distribution network including PV and FC. The validity of this generalized composite load model is testified by modeling of three typical modes under different capacity of PV and FC.5. In order to study the composite load modeling of distribution network with microturbine (MT), the model of each function module and control strategy are expounded with establishing of the MT generation system. It is pointed out that the MT could be considered as generalized dynamic load which consumes negative power, and could be described by a first-order differential state equation. And the generalized composite load model of equivalent dynamic load consisted of MT and induction motor in parallel with static load is proposed to describe the synthetic load characteristic of distribution network including MT. The validity of the composite load model is testified by modeling to three different typical capacity of MT.更多还原