【作者】 周丽霞；

【导师】 肖湘宁； 尹忠东；

【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】 远距离、大容量输电的需求带动了特高压输电技术的研究,基于可控电抗器的超、特高压无功补偿装置的研究和应用是我国当前电力系统需要解决的重大关键技术课题。本文针对大容量输电长线的特点,确定了采用可控电抗器的并联补偿方案,对磁阀式可控电抗器的结构、特性、损耗等进行了全面分析,研究了其在补偿大容量输电长线的充电功率时的容量调节问题,同时,配合一定的中性点小电抗实现了潜供电弧的抑制。通过引入可控硅关断角改进了可控电抗器基于状态变量的数学模型,更加精确地描述了可控电抗器随可控硅开关状态变化的不同运行模式,基于MATLAB建立了较为精确的磁阀式可控电抗器仿真模型,重点研究了可控电抗器的谐波特性,基于谐波移相抵偿的基本思想,首次提出了一种抑制可控电抗器谐波的方法,有效降低可控电抗器并网时向系统注入的谐波;同时,采用提高控制电压和充电电容器放电的方法,实现了可控电抗器的快速励磁。基于ANSYS建立了可控电抗器的电磁场分析模型以及场路耦合模型,并在此基础上对可控电抗器的小截面设计及损耗分析进行了初步研究,为大容量、高电压等级可控电抗器的优化设计提供了理论依据。引入了信号的相关性分析技术,定义了相位相似度函数、频率相似度函数和波形相似度函数,更好地描述了电压和电流之间的功率关系。在此基础上,提出了一种基于相似理论的无功功率检测方法,该方法实现简单,比较适合工程应用,为进一步提高采样频率和补偿精度打下基础。同时,完善了可控电抗器的无功容量定义,设计了可控电抗器功率控制的闭环系统,对大容量输电长线的充电功率进行了补偿研究,可以有效地控制可控电抗器的补偿容量,保持系统电压在允许范围之内。针对特高压线路潜供电弧难以熄灭,影响单相重合闸成功率的问题,采取并联可控高抗配合中性点小电抗的方式进行了抑制研究,基于分布参数的特高压长线建立了潜供电弧的动态模型,对不同影响因素下潜供电流的变化特性进行了定量的计算分析,得到了不同补偿度下,并联高抗与中性点小电抗的协调控制关系,为工程应用提供参考;设计了可控电抗器的物理实验样机,搭建了输电长线的实验平台,对理论分析结果进行了验证。更多还原

【Abstract】 For the requirement of long-distance and large transmission capacity,ultra-high voltage(UHV) transmission technology becomes more and more significant.The research and application of extra/ultra-high voltage reactive power compensation device based on controllable reactor are the great key topic of current power system in our country.According to the characteristics of the large capacity long transmission line,the shunt compensation scheme by adopting controllable reactor is introduced in this paper. And the structure,characteristics and loss of the controllable are analyzed completely. Then the capacity adjustment for the compensation of large capacity long transmission line is studied.Meanwhile,the suppression of secondary arc is also achieved through the coordinate control between shunt reactors and the neutral small reactor.The thyristor turn-off angle is introduced in this paper for improving the state variables based mathematic model of controllable reactor,which describes the different operation modes of controllable reactor accurately.Furthermore,simulation model is established in MATLAB,and the harmonic characteristics are studied deeply.According to the phase-shifting harmonic compensation theory,a circuit topology of controllable reactor harmonic suppression is put forward,which can effectively reduce the harmonics injected to the system by controllable reactor itself.Quantitative calculations which have guiding significance in engineering are gained.Furthermore,the Electromagnetic field analytical model and field-circuit coupled model of controllable reactor are established in ANSYS.The magnetic circuit system and loss are analyzed through finite element analysis method.All these provide basic theory for the optimization design of large capacity and high voltage controllable reactor.The correlation analysis technology is introduced,and the phase similar degree function,frequency similar degree function and waveform similar degree function are established for the first time.Thus,the relationship between voltage and current is described from a different point of view,from which the definition of reactive power is derived and a new detection method of reactive power is proposed.The closed-loop system of power control for the controllable is built to achieve the reactive power compensation of the large capacity long transmission ling,which can effectively control the compensation capacity of the controllable reactor and keep the system voltage within the scope of permit. For the difficult extinguish of secondary arc in ultra-high voltage system,the controllable shunt reactors with small neutral reactor is used widely to suppress such phenomenon.The dynamic model of secondary arc based on distributed parameter on UHV long line is established.Quantitative analysis of variation characteristics of the secondary arc current under different influence is studied.The coordinative control relationship between shunt reactor and the neutral reactor under different compensation degree is gained,which provide reference for project application.A group of experimental device of controllable reactor is designed,and theoretical analysis results are verified via the corresponding experiments.更多还原