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1.
Optimal power flow with generation reallocation is a suitable method for better utilization of the existing system. In recent years, Flexible AC Transmission System (FACTS) devices, have led to the development of controllers that provide controllability and flexibility for power transmission. Out of the FACTS devices unified power flow controller (UPFC) is a versatile device, capable of controlling the power system parameters like voltage magnitude, phase angle and line impedance individually or simultaneously. The main aim of this paper is to minimize real power losses in a power system using BAT search algorithm without and with the presence of UPFC. Minimization of real power losses is done by considering the power generated by generator buses, voltage magnitudes at generator buses and reactive power injection from reactive power compensators. The proposed BAT algorithm based Optimal Power Flow (OPF) has been tested on a 5 bus test system and modified IEEE 30 bus system without and with UPFC. The results of the system with and without UPFC are compared in terms of active power losses in the transmission line using BAT algorithm. The obtained results are also compared with Genetic algorithm (GA).  相似文献   
2.
为提升安全约束最优潮流调度的经济性与安全性,提出一种基于直流潮流的考虑柔性交流输电系统(FACTS)设备控制的校正型安全约束最优潮流模型。在线路故障发生后,通过FACTS设备校正措施,将线路潮流控制在其容许范围内。由于所提模型为大规模的非凸、非线性优化问题,难以直接求解,因此先采用大M法,将原非线性优化模型转换为混合整数线性规化模型,并采用Benders分解算法将转换后的模型分解为基态最优潮流主问题与N-1故障校验子问题。通过固定整数变量的方法,将非凸的混合整数优化子问题转换为线性规划子问题,从而能向主问题返回对应的Benders割。6节点系统与IEEE RTS-79节点系统算例验证了所提模型与算法的有效性。结果表明,考虑FACTS设备校正控制的安全约束最优潮流能有效提升调度运行的经济性。  相似文献   
3.
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.  相似文献   
4.
In the modern world, only conventional energy resources cannot fulfil the growing energy demand. Electricity is a fundamental building block of a technological revolution. Today, most of the electricity demand is met by the burning of fossil fuels but at the cost of adverse environmental impact. In order to bridge the gap between electricity demand and supply, nonconventional and eco-friendly means of energy generation are considered. Renewable energy systems (RESs) offer an adequate solution to mitigate the challenges originated due to greenhouse gasses (GHG). However, they have an unpredictable power generation with specific site requirements. Grid integration of RESs may lead to new challenges related to power quality, reliability, power system stability, harmonics, subsynchronous oscillations (SSOs), power quality, and reactive power compensation. The integration with energy storage systems (ESSs) can reduce these complexities that arise due to the intermittent nature of RESs. In this paper, a comprehensive review of renewable energy sources has been presented. Application of ESSs in RESs and their development phase has been discussed. Role of ESSs in increasing lifetime, efficiency, and energy density of power system having RESs has been reviewed. Moreover, different techniques to solve the critical issues like low efficiency, harmonics, and inertia reduction in photovoltaic (PV) systems have been presented. Unlike most of the available review papers, this article also investigates the impact of FACTS technology in RESs-based power system using multitype flexible AC transmission system (FACTS) controllers. Three simulation models have been developed in MATLAB/Simulink. The results show that FACTS devices help to maintain the stability of RESs integrated power system. This review paper is believed to be of potential benefit for researchers from both the industry and academia to develop better understanding of challenges and solution techniques for REs-based power systems and future research dimensions in this area.  相似文献   
5.
6.
随着非线性科学理论研究的发展,分叉理论作为研究非线性系统的新方法被引入电压稳定研究中。简要介绍了分叉的基本概念和主要分叉点类型,然后以基于Matlab的分叉分析软件包Matcont为工具,应用分叉理论,对典型的不含FACTS装置和含FACTS装置进行电压稳定的分析。最后重点对Matcont得出的数据进行了详细的分析,研究发现,通过添加FACTS装置,可以有效减少分叉点数量,增加负荷极限,从而提高了系统电压稳定性。  相似文献   
7.
电力系统稳定器对次同步振荡的影响及其机制研究   总被引:2,自引:0,他引:2  
采用测试信号法,在普通交流系统、含静止无功补偿(static var compensator,SVC)的系统、含可控串联补偿(thyristor controlled series capacitor,TCSC)的系统中,研究速度反馈型(以△ω为输入)和功率反馈型(以-△Pe为输入)电力系统稳定器(power system stabilizer,PSS)对次同步振荡阻尼特性的影响规律,得到速度反馈型PSS对次同步振荡影响较大,而功率反馈型PSS对次同步振荡几乎没有影响的结论;从PSS输入信号、相位补偿特性及PSS增益3个角度研究PSS对次同步振荡产生影响的机制:引入“次同步振荡响应比”的概念分析△ω和△Pe的动态响应,并通过频域分析研究相位补偿环节的补偿特性及放大增益的影响。结果表明,速度反馈信号中次同步分量较大以及超前环节对次同步频率信号的放大作用是导致速度反馈型PSS对次同步振荡影响较大的主要原因。  相似文献   
8.
越来越多的柔性交流输电系统(FACTS)装置应用于电网,成为可能的次同步振荡激发源,严重的次同步振荡将直接导致大型汽轮发电机组转子轴系的严重破坏,危及电力系统的安全运行。为了有效抑制次同步振荡,文中设计了基于测量阻抗提升系数(本地测量信号)的可控串联补偿(TCSC)控制次同步振荡方法,并通过建立包含火电机组的TCSC系...  相似文献   
9.
Wind energy is a growing renewable energy because of its several advantages; this has changed dramatically with more wind energy penetrating the conventional power network. The influence of wind generators on the power quality is becoming an important issue; non-uniform power production causes variations in system voltage and frequency, therefore, a wind farm requires high reactive power compensation. The advances in high power semiconductor devices have led to the development of Flexible AC Transmission System (FACTS). This paper presents the impact of wind energy integration on voltage stability and the goal of FACTS devices such as Static Var Compensator (SVC), which is a power electronic switch, to control the reactive power injection according to the thyristor firing angle, introduced as a state variable in power flow and combined with the nodal voltage magnitudes and angles of the power network for iterative solutions, thereby regulating the bus voltages.  相似文献   
10.
This paper is a critical review and summary of the analytical procedures currently used by operating water utilities to control ozone treatment processes, considering disinfection as well as the many oxidative applications of ozone in water treatment applications. The role of common interferences in the various methods is described.

In operating U S., Canadian, European, and Japanese water treatment plants currently employing ozone as a primary disinfectant, ozone nearly always is followed by the addition of small quantities of chlorine, chlorine dioxide, or chloramine to provide the residual in the distribution system and to act as a secondary disinfectant. Clearly, the analytical procedures used must distinguish between the various species. This review critically presents these various factors and their implication with respect to “true values” of ozone determined under widely varying conditions.  相似文献   

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