【作者】 金辉；

【导师】 信赢； 朱晓辉；

【作者基本信息】 天津大学 ， 电气工程， 2020， 硕士

【摘要】 近年来,随着化石能源的枯竭与环境的恶化,越来越多的国家开始重视可再生能源的发展。而在众多可再生能源中,风电技术相对成熟,且具有更高的成本效益和资源有效性,成为近年来世界上增长最快的二次能源之一。随着风力技术的不断发展,风电机组的单机容量日益增大,大型风电场内需要越来越多的输电线路用于传输风电,输电线路回数的增多不仅会增加风电的损耗,也会提升风电场的建造成本。而超导电缆作为一种日趋成熟的新型输电载体,同等截面积下其电能输送能力是传统线路的3-5倍,直流传输损耗不及传统线路的十分之一,交流传输损耗也只有传统线路的二分之一,因此若将超导电缆应用于风力发电并网具有一定的潜在经济性。然而,若要分析超导电缆在风电并网领域的可行性不仅需考虑其经济性,还需考虑其安全性与可靠性。当电网或风电场发生短路故障,强大的故障电流可能会使超导电缆全线失超,从而对风电场与电网造成严重影响。因此,若要将超导电缆应用于风电发电并网,需详细分析超导电缆在应对风电场暂态工况时的暂态特性,以判定超导电缆用于大型风电场并网的可行性。本论文首先介绍了风力发电的技术分类以及发展趋势,详细叙述了大型风电场的电气主接线结构,提出了将超导电缆应用于风力发电并网的方案,分析比较了永磁直驱风电系统多种拓扑结构优缺点,阐述了风电系统机侧、网侧以及卸荷电路的控制策略。然后介绍了超导电缆、电阻型和饱和铁心型超导限流器的内部结构与工作原理,通过分析电阻型、饱和铁心型超导限流器的工作原理得出两者的性能对比,并针对所选的超导限流器及超导电缆物理、数学模型进行详细推导与说明。最后利用PSCAD/EMTDC与MATLAB搭建仿真平台,详细分析了超导电缆在具备、不具备低电压穿越能力的永磁直驱风电场中应对不同位置、程度的暂态工况时的暂态特性,以及暂态工况过后超导电缆能否满足风电场要求即较快时间内恢复至满功率输电状态,进而判定超导电缆用于风力发电并网的可行性。研究结果表明,超导电缆应用于风力发电并网领域具有一定的优越性和可行性。更多还原

【Abstract】 In recent years,with the exhaustion of fossil energy and the deterioration of the environment,more and more countries begin to attach importance to the development of renewable energy.Among renewable energy sources,wind power technology is relatively mature and has higher cost efficiency and resource efficiency,making it one of the fastest growing secondary energy sources in the world now.With the continuous development of wind power technology,the capacity of single wind turbine is increasing day by day,and more and more transmission lines are needed to transmit wind power in large wind farms.The increase of transmission lines will not only increase the loss of power,but also increase the construction cost of wind farms.However,as a new and increasingly mature power transmission technology,superconducting cables have a power transmission capacity of 3-5 times of that of traditional lines under the same cross-sectional area.For DC power transmission,the transmission loss is less than one tenth of that of traditional lines and for AC power transmission,the transmission loss is only half of that of traditional lines.Therefore,it has certain potential economic merit if superconducting cables are applied to wind power integration.However,in order to analyze the feasibility of superconducting cable in the field of wind power integration,it is necessary to consider not only its economy,but also its safety and reliability.When the power grid or the wind farm has a short circuit fault,the strong fault current may cause the whole superconducting cable to quench,thus causing a serious impact on the wind farm and the power grid.For applying superconducting cables to wind power integration,the transient characteristics of the superconducting cable in response to the transient conditions of the wind farm should be analyzed in detail,so as to determine the feasibility of the superconducting cable for wind power integration.This thesis introduces the classification and development trend of wind power generation technology,describes the main electrical wiring structure of large wind farm in detail,puts forward the scheme of grid-connected wind farms with application of superconducting cables,analyzes and compares the advantages and disadvantages of the topological structures of the permanent magnet direct-drive wind power system,expounds the control strategy of machine side,grid side and unloading circuits.Furthermore,this thesis introduces the internal structure and working principle of superconducting cables and the internal structure and working principle of resistive and saturated iron-core superconducting fault current limiters.By means of performance comparison of these two kinds of fault current limiters,the detailed physical and mathematical models of the selected one are derived and explained.Finally,this thesis uses PSCAD/EMTDC and MATLAB to build the simulation platform,analyze the transient characteristics of superconducting cables in response to the transient conditions of the wind farm,discuss whether superconducting cable can recover full power transmission state after some transient conditions.The results indicate that the application of superconducting devices in wind power networks has some advantages with certain feasibility.更多还原