【作者】 赵洋；

【导师】 肖湘宁；

【作者基本信息】 华北电力大学（北京） ， 电力系统及其自动化， 2009， 博士

【摘要】 静止同步串联补偿器(Static Synchronous Series Compensator,SSSC或S~3C)是一种基于电压源型逆变器(Voltage Source Converter,VSC)的串联型系统特性参数调节装置。它对于提高线路输电容量,优化网络潮流以及增强系统稳定性均具有重要的作用。本文给出了SSSC包括上层系统级,中层装置级和底层器件级在内的分层控制结构,并针对各级别的特点给出了具体控制内容。主要针对SSSC上层系统级和中层装置级两个部分的数学模型和控制策略等关键技术问题进行深入研究。其中,SSSC的中层装置级控制策略是系统级与器件级控制策略之间的重要的衔接环节。本文详细说明了SSSC三种装置级运行模式,并得到了dq坐标系下的状态空间模型,给出了交流输出电压与直流电容电压动态过程之间相互耦合的原因。采用了交叉解耦方法和较为直接的精确反馈线性化方法实现了两个控制过程之间的解耦。针对系统级控制,本文详细地描述了带有SSSC的单机无穷大系统和多机系统的Phillips-Heffron模型的求解过程。分析了当SSSC装置级运行于不同模式时对于该模型所可能造成的影响。在此基础上,研究了利用小信号方法设计SSSC阻尼低频振荡控制器的思路与方法,以及对于发电机阻尼力矩的作用。为了克服小信号方法带来的误差,在系统级控制中应用了微分几何方法,实现了精确线性化,大大增强了SSSC增强系统阻尼的作用和性能。基于所建立的Phillips-Heffron模型,针对SSSC与励磁之间所可能造成的影响进行了分析,进而将精确线性化与扩张观测器结合并应用于了SSSC与励磁之间的协调控制。对于扩张观测器当中非线性函数的系数确定方法也进行了讨论。鉴于SSSC快速的响应特性以及对于SSR的免疫能力,使其成为一种用于抑制SSR的理想装置。将SSSC代替部分固定串联电容器的容量,从而形成混合串联补偿(Hybrid Series Compensation,HSC)系统,在保证固定串联电容器补偿容量的基础上,具备了对于线路潮流的灵活控制能力,同时可以抑制由于固定串联电容器而引起的SSR。本文采用复数转矩系数和时域仿真相结合的方法研究了HSC对于SSR的抑制效果和影响。最后,基于实时数字仿真技术搭建了数字-物理闭环控制实验平台,提出了一种简单实用的大型电力系统的实时数字仿真器建模方法;以国内首个利用SVC抑制SSR的实际工程为背景,首次在此测试平台上开展了SVC抑制SSR的研究。对于SSR的抑制效果以及抑制过程当中所可能对交流系统造成的影响进行了深入分析。并对应用SVC和HSC抑制SSR抑制效果进行了对比分析。更多还原

【Abstract】 Static Synchronous Series Compensator(SSSC or S~3C)is a series FACTS device based on Voltage Source Converter(VSC),which is applied to control power system characteristic parameters.It can improve transmission line capacity,optimize network power flow and enhance power system stability.In this paper,the control course of SSSC was divided into 3 levels which were composed of top system level,middle device level and bottom switch level.And then according to characteristic of each level,the control object was specified.As the main conteng,the math model and control strategy of both device and system level were anlyzed thoroughly in this paper.As the important connection between top level and bottom level,device level control has three operation modes which were analyzed in detailr.The state space math model and reason of coupling between output AC voltage and DC capacitor voltage dynamic process were obtained.Two methods were applied to realize the decoupling between two control approach.For the system level control,the sovling of Phillips-Heffron model of single machine infinite bus system and multimachine system including SSSC was described in detail.Based on this model,the small signal idea of design method for damping low frequency oscillation by SSSC,difference of Phillips-Heffron model when SSSC device level operate at different mode and the damping torque provide by SSSC were analysed. For overcoming the error caused by small singnal approach,the differential geometry approach was applied to solving system level control which can improve system stability greatly.Based on the Phillips-Heffron model,the mutual affection between SSSC and excitor was analysed in this paper and then Extend State Observer(ESO)and EFL were combined to obtain coordinate control.The design of parameters of nonlinear function in ESO was also discussed.The fast response characteristic and immunity for SSR of SSSC make it an ideal device to surppress SSR.When SSSC operate in intead of part of capacity,this hybrid compensation system can not only remain series compensation capacity but also have the flexible capability of control the power flow.Besides,the SSR that is excited by fixed capacitor compensation can be damped by SSSC efficiently.The complex torque coefficient method and time domain simulation method were used to analyse the effection of hybrid series compensation on the SSR and the control approach.Finally, Real Time Digital Simulator is used for establishing a digital-physical closed loop control test platform,and a simple and practical method of establishing simulation model of large power system was proposed;based on the first project in which SVC is used for damping SSR which is excited by Fixed Series Compensation in China,the damping performance and the impact to the power system during the SSR damping process were analysed in the platform for the first time.The performance difference of SSR mitigation between SSSC and SVC was studied.更多还原