A new wide area damping controller design method considering signal transmission delay to damp interarea oscillations in power system

Wide area damping controller(WADC) is usually utilized to damp interarea low frequency oscillation in power system. However, conventional WADC design method neglects the influence of signal transmission delay and damping performance of WADC designed by the conventional method may deteriorate or even has no effect when signal transmission delay is beyond delay margin, an index that denotes delay endurance degree of power system. Therefore, a new design method for WADC under the condition of expected damping factor and required signal transmission delay is presented in this work. An improved delay margin with less conservatism is derived by adopting a new Lyapunov-Krasovskii function and more compact bounding technique on the derivative of Lyapunov-Krasovskii functional. The improved delay margin, which constructs the correlation of damping factor and signal transmission delay, can be used to design WADC. WADC designed by the proposed method can ensure that power system satisfies expected damping factor when WADC input signal is delayed within delay margin. Satisfactory test results demonstrate the effectiveness of the proposed method.

Advancement in Wide Area Monitoring Protection and Control Using PMU’s Model in MATLAB/SIMULINK

A big step forward to improve power system monitoring and performance, continued load growth without a corresponding increase in transmission resources has resulted in reduced operational margins for many power systems worldwide and has led to operation of power systems closer to their stability limits and to power exchange in new patterns. These issues, as well as the on-going worldwide trend towards deregulation of the entire industry on the one hand and the increased need for accurate and better network monitoring on the other hand, force power utilities exposed to this pressure to demand new solutions for wide area monitoring, protection and control. Wide-area monitoring, protection, and control require communicating the specific-node information to a remote station but all information should be time synchronized so that to neutralize the time difference between information. It gives a complete simultaneous snap shot of the power system. The conventional system is not able to satisfy the time-synchronized requirement of power system. Phasor Measurement Unit (PMU) is enabler of time-synchronized measurement, it communicate the synchronized local information to remote station.

A Delay-dependent Dynamic Wide Area Damping Controller for Renewable Energy Integrated Power System Resilient to Communication Failure

Integration of renewable energy sources(RES)with a conventional power system has a detrimental effect on interarea oscillation.Most popular RESs are solar photovoltaic(PV)and wind energy conversion systems(WECS).Both solar PV power generation and WECS are integrated with power systems using a power electronic converter.Increasing the amount of RES generation lead towards reduction of system damping,which leads towards inter-area oscillation.Also,the intermittent behavior of a RES reduces the effectiveness of damping controllers.A dynamic controller based wide area damping controller(WADC)is proposed in this paper to increase small signal stability of a RES integrated power system.The WADC is designed for contemplating delay in a communication channel,communication failure and saturation.An anti-windup compensator is developed to overcome the effect of actuator saturation.However,the gain of the anti-windup compensator is calculated using LyapunovKrasovskii functional(LKF)in terms of linear matrix inequality(LMI).The actuator considered in this paper is a unified power flow controller(UPFC).Efficacy of PV and wind power integration on power system is also observed.The efficacy of the developed dynamic controller is verified using IEEE 39 bus and 68 bus power system.

Comparison and Performance Analysis of FACTs Controller in System Stability

In large inter connected power systems, inter-area oscillations are turned to be a severe problem. Hence inter-area oscillations cause severe problems like damage to generators, reduce the power transfer capability of transmission lines, increase wear and tear on network components, increase line losses etc. This paper is to maintain the stability of system by damping inter-area oscillations. Implementation of new equipment consists of high power electronics based technologies such as FACTs and proper controller design has become an essential to provide better damping performance than Power System Stabilizer (PSS). With development of Wide Area Measurement System (WAMS), remote signals have become as feedback signals to design Wide Area Damping Controller (WADC) for FACTs devices. In this work, POD is applied to both SVC and SSSC. Simulation studies are carried out in Power System Analysis Toolbox (PSAT) environment to evaluate the effectiveness of the FACTs controller in a large area power system. Results show that extensive analysis of FACTs controller for improving stability of system.

多断面多通道互联电网广域失步解列控制系统设计及实施

总结分析了多断面多通道区域互联电网失步振荡时可能存在的多断面失步存在选择性、同一断面不同通道失步不同时以及同一断面上部分通道失步特性不明显等特性,针对现有就地失步解列方案不适应上述特性的问题,采用基于就地装置动作允许命令,利用远方通信构建的广域失步解列系统方法,根据考虑解决现有就地失步解列方案问题、与现有就地失步解列功能的配合、系统防误设计以及异常情况下控制策略处理逻辑等主要设计原则,设计并实施了南方电网广域失步解列控制系统。RTDS仿真试验结果表明,该系统能够正确响应,有选择、快速、可靠地采取既定措施同时解列相关断面,有效解决现有就地失步解列方案的局限性,满足实际系统运行需要。

全并联AT供电方式下供电臂保护的适应性研究

广域保护测控系统的供电臂保护元件在越来越多的干线铁路投入运营。结合供电臂保护原理,深入分析了现场一起实际故障,研究了供电臂保护动作过程,分析了出口原因,为提高供电臂保护的健壮性、适应性提供了参考。

大电网广域安全稳定控制系统远传测试技术研究

为应对电力系统数字化、复杂化导致的安全稳定控制系统可靠性降低的问题,研究了一种大电网广域安全稳定控制系统远传测试技术,通过对关键技术的研究应用,构建大电网广域安控系统远传测试系统,实现对安控系统的系统级功能逻辑及动作可靠性检测。最后基于该技术搭建测试系统并进行验证,结果表明:该测试系统能够方便快捷地实现异地安控系统联合测试,具有较高的应用价值。

A robust composite wide area control of a DFIG wind energy system for damping inter-area oscillations

This paper presents a novel composite wide area control of a DFIG wind energy system which combines the Robust Exact Differentiator(RED)and Discontinuous Integral(DI)control to damp out inter-area oscillations.RED generates the real-time differentiation of a relative speed signal in a noisy environment while DI control,an extension to a twisting algorithm and PID control,develops a continuous control signal and hence reduces chattering.The proposed control is robust to disturbances and can enhance the overall stability of the system.The proposed composite sliding mode control is evaluated using a modified benchmark two-area power system model with wind energy integration.Simulation results under various operating scenarios show the efficacy of the proposed approach.

内埋式光电搜索瞄准指示系统的广域扫描控制技术

研制了一款适用于隐身机载平台的内埋式光电搜索瞄准指示系统,该系统具备广域侦察、凝视监视、激光测距、激光照射等功能。推导并验证了地理稳定结合快调反射镜光学像移补偿的广域扫描控制技术,基于样机在实验室和外场开展算法验证。试验结果表明,该系统在成像清晰前提下实现了二维无缝广域扫描搜索功能,能够对扫描视频图像进行实时拼接和显示,满足信息化战争对目标侦察、监视和指示的功能要求。

含广域混合储能互联电力系统的负荷频率控制

为解决电力系统调频存在的灵活性资源不足和调节特性欠佳问题,针对抽水蓄能和电池储能广域接入情况下的互联电力系统,提出一种基于分布式模型预测控制的负荷频率协调优化控制方法。首先,根据互联电力系统中各主要元件的频率响应特性,建立互联电力系统频率响应的状态空间模型;然后,充分考虑系统受到的各种约束,确定优化控制目标,分别对各区域的控制器进行设计;最后,对所提负荷频率协调优化控制方法的可行性和有效性进行仿真验证。结果显示该方法不仅对广域混合储能互联电力系统的频率响应特性有很好的改善,而且当系统频率发生变化时,能够使不同储能形式进行合理的响应。

新型配电系统分布式源网荷储资源广域电压自趋优管控方法

不同于单纯电能分配的传统配电网,新型配电系统逐步展现出源-网-荷-储等众多资源的强耦合强关联复杂大系统形态,其各类资源呈现出“点多、面广、量少”的广域分布特征。挖掘可再生能源发电、分布式储能及柔性负荷等分布式资源的广域电压调控潜力对构建源网荷储高度融合的新型配电系统具有重要意义。文中提出了一种基于数据驱动的新型配电系统分布式源网荷储资源广域电压自趋优管控方法,通过可再生能源发电、储能及柔性负荷等分布式资源的综合协同控制,在保证储能后备容量和降低网损的同时能够提高配电网广域电压质量。最后,以某城市配电网为例验证了所提方法的有效性和先进性,比传统调压方法更加契合新型配电系统的电压调控需求。

智能牵引供电系统网络化广域保护通信通道

以数字化、智能化为特征的智能高铁,系统内各要素之间信息充分流通,实现信息空间和物理空间内数据实时共享、交互。数据信息的流通离不开通信技术的支撑和通信通道的建设。智能牵引供电系统是智能高铁的重要组成部分,文章以供电系统中的广域保护测控系统对通信通道的需求为出发点,分析其技术要求和组网方案,并结合现场实例说明了通信通道的重要性。

配电网继电保护的创新路径研究

继电保护作为配电网的重要组成部分,不仅可以促进配电网的稳定运行,还有助于减少突发事件对配电网所产生的影响。但随着配电网建设规模的逐渐扩大,传统的继电保护已无法满足需求。文章基于配电网继电保护的概念和原理,分析了配电网继电保护创新的必要性,并提出了具体的创新措施,以期保障电力系统的安全稳定运行,助力于我国电力行业的进一步发展。

关于广域测量系统及广域控制保护系统的评述

评述广域测量系统及广域控制保护系统的构成、关键技术及应用领域,提出广域测量预警控制系统的概念。分别讨论了基于纯相量测量单元(PMU)数据的应用功能,以及结合PMU数据与模型仿真结果的应用功能。在此基础上指出广域测量预警控制系统理论和应用的瓶颈及可能的解决途径。

考虑时滞影响的电力系统稳定分析和广域控制研究进展

计算机技术、网络技术和通信技术的快速发展及其在电力系统中的广泛应用,使得电力系统的监测、分析和控制方式向着广域化、网络化和智能化方向发展。在此发展过程中,一个不容忽视的问题就是信号传输和处理过程中时滞的影响。文中首先对广域测量系统的时滞特性进行了分析,接着对国内外考虑时滞影响的电力系统建模、稳定分析和广域控制3个方面的最新研究成果进行了综述,指出常规电力系统稳定分析方法与考虑时滞的状态估计方法相结合具有工程实践价值,并认为在电力系统时滞特性的定量分析、信息和电力网络综合建模、考虑时滞的状态估计以及基于时滞电力系统动力模型的稳定控制方面仍需进一步深入研究。最后展望了时滞电力系统稳定分析和广域控制可能的研究方向。

计及反馈信号时滞影响的广域FACTS阻尼控制

随着同步相量测量单元(PMU)在电力系统中的广泛应用,开展基于广域测量系统(WAMS)的广域控制的研究具有重要的理论和实际意义。由于远方反馈信号的时滞影响,基于广域信号的闭环电力系统将是一个典型时滞微分动力系统。针对这种时滞微分动力系统,该文提出了一套基于线性矩阵不等式(LMI)理论的广域FACTS阻尼控制器的设计方法。对于高维、时滞电力系统,首先应用Schur降阶算法进行降阶处理,然后在降阶系统上应用LMI理论和遗传算法设计了具有最大允许时滞的广域FACTS控制器,以提高互联电力系统对反馈信号时滞的不敏感性。并将所提出的方法应用于广域SVC控制器的设计。时域仿真结果表明:当考虑反馈输出信号的时滞后,所设计的广域FACTS控制器仍能有效地阻尼10机39节点新英格兰测试系统中的低频振荡。

安全稳定控制系统在新疆南部电网的应用

新疆南部电网安全稳定控制系统由安装在30个厂站的稳定控制装置组成,覆盖巴州、阿克苏、喀什、和田地区。当新疆南部区域电网联络线或主力机组发生故障时,采取解列、切负荷措施,防止大面积停电,保证新疆南部电网的安全稳定运行。文中通过对新疆南部电网安全稳定控制系统的研究,提出了适合于该类型电网的稳定控制系统结构、实现方式、新原理、新判据。该系统多次在电网故障中正确动作,确保了电网的稳定运行。

广域闭环控制系统时延的测量及建模(二):闭环时延

由2篇论文组成的系列论文旨在研究广域闭环控制系统(wide-area closed-loop control system,WACS)中时延的特性。在系列论文第1篇的研究基础上,首先提出估计实际WACS中闭环时延的方法,综合考虑通信时延与操作时延,提出正态分布模型以估计实际系统中的闭环时延分布,并给出确定正态分布模型参数的方法。然后介绍在实际WACS中实测闭环时延的时标对比法。最后,在专用通道与非专用通道的条件下,实测贵州电网WACS中的闭环时延,并将实测结果与使用正态分布模型的估计结果进行对比分析,验证了所提出的正态分布估计模型。该文对时延的分析及测试结果对广域闭环控制的研究及应用具有参考价值。

交直流互联系统鲁棒自适应直流功率调制

设计了应用于交直流互联电力系统的直流功率调制的非线性鲁棒自适应控制器。该控制器基于驱动各互联区域电网的惯量中心至统一平衡点的设计思想,采用广域测量系统的全局信号,用以阻尼交直流互联系统的区域间功率振荡。采用反步法设计的自适应鲁棒控制规律使控制器对未知参数具有自适应性,对模型误差、扰动和平衡点变化具有较强的鲁棒性。仿真结果表明,与传统的线性直流功率调制控制器相比,该控制器对联络线的功率振荡具有优良的阻尼性能,可显著提高输电极限,而且能很好地适应运行点的变化。

FACTS协调控制研究进展及展望

概述了灵活交流输电系统(FACTS)交互影响的实例和主要分析方法。总结分析近年来国内外研究所提出的多种FACTS协调控制方法,并将其分为线性控制方法、非线性控制方法和智能控制方法三大类,简要评述了其优点和不足。介绍了广域测量系统(WAMS)技术在协调控制中的应用情况,并归纳广域测量中信号时滞的处理方法。最后,总结目前FACTS协调控制研究存在的问题和未来有待进一步开展的工作,指出开展基于WAMS的FACTS协调控制研究是未来我国FACTS发展的主要方向之一。