逆系统方法在TCSC稳定控制中的应用

简单介绍了基于坐标变换和反馈控制理论的一种反馈线性化方法－逆系统方法。运用逆系统方法将含可控串联补偿电容器（TCSC）的非线性电力系统线性化,并且对该线性化的系统运用具有二次型性能指标的线性最优控制方法设计了TCSC的稳定控制器,将其与用微分几何法和用直接大范围线性化法设计的控制器进行了比较,结果表明它们具有相同的控制效果,即均能提高电力系统的暂态稳定性。     

FACTS装设地点的定量评估及优化

利用EEAC对电力系统暂态稳定性严格量化的能力,可以精确地评估各种连续或离散的变化对 稳定程度的影响。如果要快速地评估FACTS对暂态稳定性的影响,优化其装设地点,则还可 以简单地用稳定裕度对FACTS设备主回路参数的灵敏度系数来量化紧急控制效果。取可控串 联补偿和可控移相器为例,通过对华中网的数值仿真验证了上述方法的有效性。     

基于TLS-ESPRIT算法的附加励磁阻尼控制抑制次同步振荡

基于TLS-ESPRIT算法进行次同步振荡研究,将发电机机械阻尼系数取为0,以时域仿真的角速度偏差信号构成的数据矩阵为基础,用TLS-ESPRIT算法高精度地辨识出次同步振荡中各模态的频率及其对应的衰减系数,并与现场测得的模态阻尼相比较,判断次同步振荡的稳定性.该方法在难以获得弹簧-质量块模型阻尼系数的情况下依然可以判断次同步振荡稳定性,并且适用于多机系统分析.进一步提出了基于TLS-ESPRIT算法的附加励磁阻尼控制(SEDC)设计策略,以IEEE第二标准模型SYS-2为研究对象,设计了SEDC的具体参数.仿真结果表明,所设计的SEDC能有效抑制次同步振荡.     

Mitigation of the impact of transformer inrush current on voltage sag by TCSC

Thyristor Controlled Series Capacitor (TCSC) as a dynamic system, besides its capability in increasing power transfer in transmission lines, can be used to enhance different power system issues. In this paper, the effect of TCSC on voltage sag following transformer inrush current is investigated. It is shown that excessive transient inrush current occurring during transformer energizing can be mitigated by TCSC. Hence, voltage sag as one of the key components of the power quality is alleviated for the sensitive loads that are connected to the same bus which the power transformer is energized from. During a fault, TCSC can improve the voltage sag by limiting the current and help to keep the voltage as high as possible. Moreover, the inrush currents and the associated voltage sags that usually occur after clearing heavy single- or multistage faults are mitigated by the presence of TCSC. The model used for simulating inrush current is based on the characteristics of the major hysteresis loop out of which the internal trajectories are defined using the translation principal and a linear compensation to generate closed loops. An arctangent relation between the flux and the exciting current is defined. The expression parameters are deduced by curve fitting empirical data defining the major loop or the single-valued saturation characteristic.     

多可控串补自适应协调控制设计

采用多可控串联补偿器（thyristor controlled series compensation,TCSC）联合运行可提高线路功率传输能力,但多TCSC联合运行时所存在的交互影响可能导致系统暂态稳定性下降。设计一种新的自适应控制方案,动态自适应调整多个TCSC联合运行时的参数,以规避多TCSC的负交互影响。利用能量函数分析多TCSC协调控制规律,然后通过微分观测器引入微分信号,再将专家控制和神经网络引入自适应控制,动态调整PID（proportion integral differential）参数。通过在一个装设2台TCSC的4机2区域系统的仿真验证,并和PI控制、BP-PI控制进行对比,结果表明,所设计的自适应控制器在提高系统暂态稳定性方面,具有一定的优越性。     

含TCSC的电力系统最优潮流控制

电力系统最优潮流问题(OPF)对保证系统的电压质量、安全性和经济性都是十分重要的。针对含有柔性交流输电系统的最优潮流问题,根据可控串联补偿器(TCSC)的功率注入模型,建立适于潮流和最优潮流计算的数学模型,在常规最优潮流问题的基础上,充分考虑TCSC元件对系统潮流的影响,从而建立起TCSC运行情况下的非线性最优潮流模型,并应用了一种有效的求解上述模型的方法——路径跟踪内点法。仿真表明该方法能有效解决含TCSC的电力系统最优潮流问题。     

TCSC与SSSC的特性仿真分析

对基于晶闸管控制的可控串联补偿电容器和基于可关断器件GTO控制的静止同步串联补偿器在模块结构、伏安特性、功角特性及等值阻抗特性等方面进行了详细地分析比较,得出结论并进行了仿真验证。     

TCSC次同步频率阻抗特性及其抑制SSR的参数设计

正确分析TCSC次同步频率阻抗特性是研究TCSC抑制次同步谐振（SSR）能力以及进行TCSC参数设计的重要基础。基于对TCSC次同步频率阻抗模型的研究,绘制了三维频率阻抗图,分析了TCSC次同步频率阻抗特性,特别提出了次同步谐振导通角的概念。基于内蒙古上都电厂串补输电线路模型,在满足工频基波阻抗调节特性的前提下,根据次同步频率阻抗特性研究了考虑TCSC自然抑制SSR时其主电路参数的设计原则。通过对上述系统各模态频率阻抗特性的综合分析,讨论了TCSC控制参数的选择方法。仿真结果证实了次同步频率阻抗特性分析结果的正确性。     

Reduced order H∞ TCSC controller & PSO optimized fuzzy PSS design in mitigating small signal oscillations in a wide range

This paper proposes hybrid control schemes for compensation of parametric and non-parametric uncertainties arising in modern power systems. The robust loop shaping design procedure considering non-parametric uncertainty term is used to design H_∞ TCSC. To further enhance steady state stability, and consider the effect of parametric uncertainties occurring due to variation in loading conditions, robust TCSC is supplemented with three types of PSS i.e. PSO-PID PSS, PSO Mamdani FPSS and PSO TS FPSS. PSO is used to optimize the parameters of PID based and Fuzzy type PSS. The proposed hybrid control schemes are found to compensate uncertainty well by stabilizing the power system over whole parametric uncertainty range. However, the proposed hybrid controller involving robust TCSC and PSO-Takagi–Sugeno FPSS shows best performance with enhanced steady state stability among all schemes. Also the T–S FPSS performs better as compared to Mamdani FPSS.     

SEDC与TCSC联合抑制次同步振荡的研究

可控串联补偿(TCSC)工作在调节模式时,可以连续调节线路串补度,从而改变次同步振荡的条件;此外,TCSC所产生的谐波频带非常宽,足以使次同步频率的信号通过,在某些情况下可能激发次同步振荡。因此,当系统中包含TCSC时,次同步振荡问题的研究尤为复杂。本文提出使用附加励磁阻尼控制器(SEDC)与TCSC联合运行抑制次同步振荡,分析了TCSC不同运行状态对次同步振荡产生的影响,针对TCSC的运行特性,分段设计了两组SEDC参数,并模拟实现了SEDC参数间的切换。结果表明:通过切换控制参数,SEDC获得了更好的鲁棒性,TCSC的安全运行范围大大增加。