基于交交变频器的风电接入系统对电网稳态及动态特性影响

项目名称： 基于交交变频器的风电接入系统对电网稳态及动态特性影响

项目编号： No.51307136

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 电工技术

项目作者： 宁联辉

作者单位： 西安交通大学

项目金额： 24万元

中文摘要： 分频风电系统利用交交变频器将风机发出的低频电能并入工频电网，为提高风电利用效率、减小风电随机性对电网的扰动提供了新的解决途径。交交变频器作为其关键设备引入输电系统，对电网稳态控制策略及故障模式的影响是迫切需要解决的问题。本课题将基于交交变频器拓扑结构、控制策略及自身的运行特点建立适用于仿真研究的变频器数字模型及适用于电力系统计算的准稳态模型，并利用物理模型验证两模型的准确性，以使分频风电系统的仿真分析更符合实际运行工况。在此基础上，首先对该系统变频运行时谐波、无功变化规律进行研究；然后，分析交交变频器故障模式、系统故障的传递机理；最后，对含有分频输电的大型电力系统稳态、动态性能等方面进行深入的研究。项目的研究成果，将为分频风电系统的滤波器、无功补偿装置的设计提供决策依据；同时为现有继电保护对分频风电系统的适应性提供评估手段，进一步完善分频输风电系统的基本理论。

中文关键词： 分频风电；交交变频器；准稳态模型；谢波分析；故障模式

英文摘要： Fractional frequency transmission system(FFTS) is to use lower frequency , e.g. 50/3 Hz, to improve the utilization of wind power and reduce the disturbances generated by wind power randomness. The key equipment of FFTS is cycloconverter. Its impact on grid stability and fault identification is an urgent problem to study. The first task of this research is to establish cycloconverter 's mathematical model for simulation study and quasi-steady-state model for power system computation, which based on cycloconverter's topological structure, control strategy and operating characteristics. In order to ensure the models' accuracy, the verification, which based on cycloconverter's physical model, would be done. On the basis of the practical models, the rest of the work would firstly study the harmonics and reactive power variation, during the changing of system frequency. Then, the failure mode of cycloconverter and mechanism of fault transfer would be analyzed. Lastly, the characteristics of steady and dynamic state response of large-scale power system, which contains FFTS, would be deeply studied. The results of the research will provide decision basis for the design of filter and reactive power compensation device in FFTS. In addition, it provides the design index for relay protection in FFTS.In the long run, the re

英文关键词： fractional frequency wind power system；cycloconverter；quasi-steay mode；harmonic analysis；fault mode