【作者】 王亮；

【导师】 赵彤；

【作者基本信息】 山东大学 ， 电气工程（专业学位）， 2017， 硕士

【摘要】 直流输电接入交流电网,为大区电网输送提高了输电效率、稳定性的同时,交直流混联系统的分析、控制也变得复杂。目前现有的电力系统极限切除时间的评估方法对大系统的适应性不强,需要提出更好的方法对电力系统暂态稳定进行定量评估。本文在了解国内外关于交直流混联系统暂态稳定研究现状的基础上,分析交流系统发生故障后,对系统暂态稳定的影响机理,分析交直流混联系统暂态稳定特征的影响因素,提出交直流混联系统暂态稳定定量评估方法。针对电力系统暂态稳定分析方法进行分析阐述,基于隐式梯形法分析电力系统时域仿真的计算原理,基于扩展等面积法则分析多机电力系统暂态稳定影响因素及评价指标。结合Matlab工具箱电力系统分析工具PSAT,采用时域仿真法与扩展等面积法则相结合对交直流混联系统进行暂态稳定分析。研究PSAT中的HVDC数学模型,研究同步发电机与风力发电机的数学模型,基于PSAT搭建交直流混联系统.mdl仿真模型。分析电力系统暂态稳定定量评价指标及暂态稳定特征影响因素,包括HVDC接入前后对系统暂态稳定的影响、HVDC接入位置对系统暂态稳定的影响、同步机转动惯量对系统暂态稳定的影响。提出了提高系统暂态稳定的转动惯量增加最优位置选取方法。研究了交直流混联系统暂态稳定影响因素,研究了 BP神经网络的基本原理。基于BP神经网络建立暂态稳定定量评价数学模型,并通过西北电网桥湾地区仿真算例验证本文方法的有效性。更多还原

【Abstract】 The DC transmission is connected to the AC power grid,which improves the efficiency and stability of the transmission of the large area power grid.At present,the evaluation method of the limit time of power system is not suitable for large system,so it is necessary to put forward a better method to evaluate the transient stability of power system.Based on the understanding of home and abroad on the transient stability of AC/DC hybrid system based on the present research,analysis of AC fault,influence mechanism on system transient stability,influence factor analysis of AC/DC hybrid system transient stability characteristics of the proposed AC/DC hybrid system transient stability evaluation method.According to the power system transient stability analysis method analysis,calculation principle analysis of power system time domain simulation implicit trapezoid method based on extended equal area criterion factors and evaluation index of transient stability of multi machine power system based on impact.Combined with Matlab toolbox power system analysis tool PSAT,the transient stability analysis of AC/DC hybrid system is carried out by using the time domain simulation method and the extended equal area criterion.The mathematical model of PSAT is studied,and the mathematical model of synchronous generator and wind turbine is studied.Based on PSAT,the.Mdl simulation model of AC/DC hybrid system is built based on HVDC.Factor analysis of quantitative evaluation index of power system transient stability and transient stability characteristics,including the effects of HVDC access,before and after the system transient stability HVDC location influence of inertia on system transient stability influence on system transient stability of synchronous machine.In this paper,the method of improving the moment of inertia of the system is proposed.The influence factors of transient stability of AC/DC hybrid system are studied,and the basic principle of BP neural network is studied.Based on the BP neural network,the mathematical model of transient stability quantitative evaluation is established,and the effectiveness of the method is verified by the simulation example of the Northwest Power grid.更多还原