【作者】 曹志怀；

【导师】 李建兵；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2012， 硕士

【摘要】 全球化石能源日益消耗,能源供给状况日趋紧张,世界各国不得不加紧寻找替代能源和大力开发节能技术。而储量丰富、清洁的太阳能,无疑是化石能源理想的可持续替代能源；光伏发电作为太阳能的主要利用途径,能够有效缓解化石能源供给紧张的的现状。光伏发电系统并入常规电网,与之共同承担发供电任务,即形成并网光伏发电系统。相对于独立光伏发电,拥有诸多优点的并网光伏发电,受到了各国极力的推崇和大力的发展。因此,并网光伏发电系统也就成为全球绿色新能源领域的研究热点。本文主要基于Matlab/Simulink仿真平台,研究两级式并网光伏发电系统的最大功率跟踪、并网控制及反孤岛效应等关键技术,并在此基础上,分析影响其电能质量的因素。首先,研究分析光伏电池的基本原理与等效模型,搭建其仿真模型,仿真分析其在不同光照强度与温度下的输出特性；对DC-DC变换电路原理及其优、缺点进行了研究分析,选择Boost升压电路实现最大功率点跟踪；对几种常用最大功率点的跟踪控制算法进行详细分析,分别利用扰动观察法、电导增量法仿真实现最大功率点跟踪,对仿真结果作对比分析,结果证明电导增量法功率跟踪性能要优于扰动观察法。其次,研究光伏并网逆变器的拓扑结构与控制策略,搭建并网逆变器输出级仿真模型,利用滞环电流比较法实现并网电流对电网电压的追踪与单位功率因数并网。再者,对孤岛效应的原理与常用的检测方法进行分析,详细分析主动频移(AFD)检测算法及正反馈主动频移法(AFDPF)的检测盲区,并利用S-Function函数编写孤岛检测程序,搭建并网光伏发电系统仿真模型,验证AFD、AFDPF以及改进的正反馈主动频移法进行孤岛检测的有效性,并对仿真结果进行对比分析,证明改进的正反馈主动频移法具有更好的检测效果。最后,在前文分析与仿真的基础上,对并网光伏发电系统的DC-DC模块、DC-AC模块以及孤岛检测各部分对系统电能质量产生影响的因素进行研究分析,给出各个参数值和控制方法对电能质量的具体影响,为系统各部分选择合理的参数值和控制方法提供依据。更多还原

【Abstract】 Global fossil energy increasingly consumption, energy supply situation increasingly nervous, all countries in the world have to step up looking for alternative energy and vigorously develop energy-saving technology. So abundant and clean solar energy undoubtedly is an ideal sustainable alternative energy of fossil energy; photovoltaic system as the main way of solar energy, can effectively relieve the fossil energy supply of nervous of the status quo. Photovoltaic system merges into conventional power grid, and undertakes the task of generate electricity, which forms a grid photovoltaic power generation system. Relative to the independent photovoltaic power generation, the grid-connected solar photovoltaic energy system with lots of advantages has got the praise highly of all countries and rapid development. Therefore, the grid-connected solar photovoltaic energy system will become a research hotspot in the field of the global green new energy.This paper mainly based on two levels of grid-connected solar photovoltaic energy system, and studies the key technologies such as maximum power tracing, grid-connected control and the contrary islanding effect, and on this basis of the above analyses, the thesis studies the factors affecting its power quality.First of all, this paper researched and analyzed the basic principle of photovoltaic cells and all kinds of equivalent model, chose one model suitable for the engineering research and analysis, used Matlab/simulink software platform, the photovoltaic cells simulation model was built, and output characteristics were simulated.The principles and its advantages and disadvantages of the DC-DC transform circuit were discussed, chose Boost booster circuit to realize the maximum power point tracking, analyzed some commonly used for maximum power point tracking control algorithm, and established DC-DC transform circuit simulation model (the power used the photovoltaic power), used incremental-conductance algorithm perturbation and observation method to implement the maximum power point tracking respectively, compared to the simulation results, the results prove conductivity incremental approach power tracking performance is superior to the disturbance of observation;Secondly, researched the topological structure and control method of the photovoltaic (pv) grid-connected inverter, and chose a suitable topology as the main circuit, build a grid inverter simulation model, and the simulation results show that, using the hysteresis current comparison method can well realize the network voltage of tracking. Furthermore, the principle and commonly used detection method of islanding effect were analyzed, analyzed the testing blind area of the active frequency shift (AFD) detection algorithm and the positive feedback active frequency shift method (AFDPF), and used S-Function function written island detection program, build the grid (pv) power system simulation model, used AFD, AFDPF and improving the positive feedback active frequency shift method for the island detection, verified the effectiveness of the algorithm, and the simulation results were compared, and showed that the improvement positive feedback initiative frequency shift method has better detection effect.Finally, based on the front analyses and simulations, researched and analyzed the factors that could affect the on the power quality among the grid (pv) power system DC-DC module, DC-AC module and the island of detecting various part, analyzed the influence of each parameter value and control methods of the on the power quality, provided basis for the reasonable selection of system parameters and the control method.更多还原