Reliability and sensitivity analysis of loop-designed security and stability control system in interconnected power systems

Security and stability control system(SSCS)in power systems involves collecting information and sending the decision from/to control stations at different layers;the tree structure of the SSCS requires more levels.Failure of a station or channel can cause all the execution stations(EXs)to be out of control.The randomness of the controllable capacity of the EXs increases the difficulty of the reliability evaluation of the SSCS.In this study,the loop designed SSCS and reliability analysis are examined for the interconnected systems.The uncertainty analysis of the controllable capacity based on the evidence theory for the SSCS is proposed.The bidirectional and loop channels are introduced to reduce the layers and stations of the existing SSCS with tree configuration.The reliability evaluation and sensitivity analysis are proposed to quantify the controllability and vulnerable components for the SSCS in different configurations.By aiming at the randomness of the controllable capacity of the EXs,the uncertainty analysis of the controllable capacity of the SSCS based on the evidence theory is proposed to quantify the probability of the SSCS for balancing the active power deficiency of the grid.

Emergency Control Strategy Based on Multi-agent Theory under Blackout

The multi-agent theory is introduced and applied in the way to strike the control amount of emergency control according to stability margin, based on which an emergency control strategy of the power system is presented. The multi-agent control structure which is put forward in this article has three layers: system agent, areal agent and local agents. System agent sends controlling execution signal to the load-local agent according to the position and the amount of load shedding upload from areal agent;The areal agent judges whether the power system is stable by monitoring and analyzing the maximum relative power angle. In the condition of instability, determines the position of load-shedding, and the optimal amount of load-shedding according to the stability margin based on the corrected transient energy function, upload control amount to system agent;local-generator agent is mainly used for real-time monitoring the power angle of generator sets and uploading it to the areal agency, local-loads agent control load by receiving the control signal from system agent. Simulations on IEEE39 system show that the proposed control strategy improves the system stability.

Implementing a Rainwater Sustainable Control in SaheI-Feedback from ＂Niayes＂ Zone of Dakar

Dakar area landscape is mainly characterized by the existence of the ＂niaye＂-or agricultural depressions located in the sand dunes system. In these depressions, the top-table of quaternary sand groundwater reaches or overflows the soil surface. Because of a recent groundwater level drop, some of the niayes have become runoff-gathering sites. This water ensures various economical, environmental and social services, i.e. urban agriculture, drinking water supply of Dakar and formation of ecosystems supporting biodiversity. Given that rainwater infiltration is the only natural ＂input＂, conception and implemention of rainwater management PPP （Politics, Plan and Program） must necessarily take into account this interrelationl Nowadays, two acute problems are observed in the Dakar area. On the one hand, the niayes are threatened by a hydrological drying process due to the insufficiency of rainwater refill. On the other hand, the dramatic social pressure on the environment has led to the urbanization of these bottom-lands. Furthermore, because of the pluviometry decrease, a worsening of the nuisances （floods and malaria） related to surface waters occurs. Consequently, an appropriate runoff management should integrate both the ＂risk＂ and ＂resource＂ dimensions, thus allowing the protection of natural resources and a secure living environment. According to the limits of＂classicai＂ solutions, this paper provides approach elements for building a sustainability plan focusing on emergent concerns, which would control rainwater in urbanized zones.

On-line Optimal Pre-decision Making for Stability Control

A rigorously quantitative stability assessment method is the prerequisite for optimal stability controls of modem power systems. This method should be able to identify all potentially unstable modes, recognize both dangerous and the safest reloading stratcgy and offer sensitivity information. Besides, it should be general and fast enough for on-line tracking system changes and decision searching. Possibly negative effects on transient stability are uncovered for many kinds of emergency actions, including generator tripping, load shedding and rapidly increasing excitation by using extended equal-area criterion (EEAC). An online pre-analysis-based real-time-matching frarnework using EEAC method is presented.

A novel optimization method of transient stability emergency control based on practical dynamic security region (PDSR) of power systems

This paper proposes a novel optimization method of transient stability emergency control based on a new concept of the so-called extended practical dynamic security region (EPDSR) defined in this paper and four experiential laws about the EPDSRs found from a number of studies in real power systems. In this method, the effect of a control action is represented by the displacement of EPDSRs critical hyper-plane boundary in the direction of its outer normal vector. If an unstable contingency occurs, appropriate emergency control actions are triggered so that the enlarged EPDSR can cover the current operating point. Based on these ideas, a mathematics model of emergency control strategy is developed for minimizing its total cost and guaranteeing power system transient stability. The simulation results on the 10-generator, 39-bus New-England Test System as well as other real power systems have shown the validity of this method.

Adaptive Emergency Control of Power Systems Based on Deep Belief Network

Emergency control is an essential means to help system maintain synchronism after fault clearance.Traditional“offline calculation,online matching”scheme faces significant challenges on adaptiveness and robustness problems.To address these challenges,this paper proposes a novel closed-loop framework of transient stability prediction(TSP)and emergency control based on Deep Belief Network(DBN).First,a hierarchical real-time anti-jitter TSP method using sliding time windows is adopted,which takes into account accuracy and rapidity at the same time.Next,a sensitivity regression model is established to mine the implicit relationship between power angles and sensitivity.When impending instability of the system is foreseen,optimal emergency control strategy can be determined in time.Lastly,responses after emergency control are fed back to the TSP model.If prediction result is still unstable,an additional control strategy will be implemented.Comprehensive numerical case studies are conducted on New England IEEE 39-bus system and Northeast Power Coordinated Council(NPCC)140-bus system.Results show the proposed method can detect instability of system as soon as possible and assist in maintaining reliable system synchronism.

Research on the emergency response mechanism of emergencies in student management in private colleges and universities

With the advancement of the popularization of higher education in China,the development of private higher education institutions has been rapid and dynamic.However,various unexpected events have become increasingly frequent,bringing negative impacts to schools and even threatening their survival and development.Therefore,ensuring the harmonious and stable development of private higher education institutions and improving their emergency management mechanisms for unexpected events is an urgent task.This paper analyzes the relevant issues and causes regarding the management of unexpected events in private higher education institutions from six aspects:emergency awareness,organizational structure,plan formulation,training and drills,supervision and evaluation,and post-incident handling and accountability.Based on these analyses,the paper further proposes corresponding strategies from three levels:prevention,response,and recovery,aiming to provide theoretical references of value for enhancing the governance system and capacity of private higher education institutions in managing unexpected events.

Analysis and Recommendations for the Adaptability of China’s Power System Security and Stability Relevant Standards

In developing power grids,setting standards is critical to its success.The development of China’s power industry has proposed new requirements for power systems to ensure secure and stable operations.The principal standards for the security and stability of China’s current power systems are analyzed in terms of operational control,generator-grid coordination and simulation.The shortcomings are pointed out and the directions of future development are discussed.In the end,the study highlighted the following key areas that require further research and improvement:the evaluation criteria of power system security and stability should be improved to ensure the secure and stable operation of China’s power systems;the operational control standards should be constantly enhanced to increase the reliability and flexibility of operational control strategies;generatorgrid coordination standards should be upgraded to improve the coordination between the generator control protection system and the grid;and the simulation methodology should be standardized in future power system security and stability research.

Stochastic stability analysis of networked control systems with random cryptographic protection under random zero-measurement attacks

Security issues in networked control systems（NCSs） have received increasing attention in recent years.However, security protection often requires extra energy consumption, computational overhead, and time delays,which could adversely affect the real-time and energy-limited system. In this paper, random cryptographic protection is implemented. It is less expensive with respect to computational overhead, time, and energy consumption,compared with persistent cryptographic protection. Under the consideration of weak attackers who have little system knowledge, ungenerous attacking capability and the desire for stealthiness and random zero-measurement attacks are introduced as the malicious modification of measurements into zero signals. NCS is modeled as a stochastic system with two correlated Bernoulli distributed stochastic variables for implementation of random cryptographic protection and occurrence of random zero-measurement attacks; the stochastic stability can be analyzed using a linear matrix inequality（LMI） approach. The proposed stochastic stability analysis can help determine the proper probability of running random cryptographic protection against random zero-measurement attacks with a certain probability. Finally, a simulation example is presented based on a vertical take-off and landing（VTOL） system. The results show the effectiveness, robustness, and application of the proposed method, and are helpful in choosing the proper protection mechanism taking into account the time delay and in determining the system sampling period to increase the resistance against such attacks.

继电保护远程运维系统报文合规检测及入侵阻断技术应用

继电保护远程运维中数据传输各环节存在网络入侵风险,现有安全措施未有效处理业务层风险,且存在风险阻断不及时等问题。为此,提出一种报文合规检测方法及入侵阻断技术,分析报文的对象、格式、业务逻辑和行为模式,建立报文合规规则库及不合规报文阻断策略,设计开发不合规报文阻断模块及“一键阻断”紧急控制模块。通过模拟仿真环境测试,结果表明,上述技术对不同类型异常报文进行的阻断效果与预期一致,可有效阻断非法入侵攻击,从而提高继电保护远程运维的安全性和稳定性。

外部干扰和随机DoS攻击下的网联车安全H∞队列控制

针对网联车队列系统易受到干扰和拒绝服务(Denial of service, DoS)攻击问题,提出一种外部干扰和随机DoS攻击作用下的网联车安全H∞队列控制方法.首先,采用马尔科夫随机过程,将网联车随机DoS攻击特性建模为一个随机通信拓扑切换模型,据此设计网联车安全队列控制协议.然后,采用线性矩阵不等式(Linear matrix inequality, LMI)技术计算安全队列控制器参数,并应用Lyapunov-Krasovskii稳定性理论,建立在外部扰动和随机DoS攻击下队列系统稳定性充分条件.在此基础上,分析得到该队列闭环系统的弦稳定性充分条件.最后,通过7辆车组成的队列系统对比仿真实验,验证该方法的优越性.

面向稳控系统E1通道的网络靶场实验台的设计与实现

随着智能电网和跨区稳定控制技术的发展,信息通信与电力系统的耦合更加紧密,网络攻击带来的安全风险也越来越高。稳控系统E1通道作为重要的测控通道,其安全性对稳控系统起到重要的作用,因此,开展面向稳控系统E1通道的半实物仿真和攻防演练,对发现E1通道的安全漏洞有重要意义。首先,基于半实物仿真技术设计了面向稳控系统E1通道的网络靶场实验台,介绍基于该实验台的攻防演练方案;然后,通过该实验台对一个典型的在运稳控系统E1通道开展仿真和攻击模拟实验,测试了稳控系统的安全隐患,并验证了实验台的有效性;最后,提出几种提升E1通道安全性的方法,并展望了实验台的应用前景。

区域新能源并网暂态功角稳定分析与紧急控制策略优化

随着新型电力系统发展和新能源机组不断投产,南方区域将形成多区域新能源与邻近常规电源联合集中接入系统的场景。新能源集中接入常与常规电源共用输电通道,将影响区域系统暂态稳定特性及输送通道的传输能力,使南方区域系统的安全稳定运行和风险防控面临了前所未有的挑战。为深入研究区域新能源送出的稳定特性建立了区域新能源交流集中送出的等值系统模型,分析了新能源并入对区域系统对暂态稳定特性影响的主要机理。基于等面积法则对区域送出系统暂态过程的加、减速面积进行了定量分析,提出了紧急控制切机策略的协调优化方法,实现区域送出传统机组与新能源机组紧急控制切机量及控制代价的最小化的切机策略配置。最终,基于广东区域海风火电打捆送出系统为例,对分析结果的正确性进行了验证。

基于时序卷积残差网络和鹈鹕优化算法的新能源电网安全稳定控制方法

随着“双碳”目标的推进,随机波动的新能源接入电网的规模和容量日益提升,严重影响电网的安全稳定运行。针对大干扰故障电压稳定控制问题,文章提出了一种基于时序卷积残差网络和鹈鹕优化算法的新能源电网电压安全稳定控制策略。首先,利用时序卷积信息损失少、感受野宽以及残差网络深层特征提取能力强的优势,构建基于时序卷积残差网络的电压稳定预测模型,映射出敏感节点电压时序特征和电压稳定之间的关系;其次,构建电压稳定控制模型,利用鹈鹕优化算法收敛速度快、搜索能力强的优势求解控制模型,得出最佳切机和切负荷动作措施;最后,进行了仿真验证。验证结果表明,所提方法提高了新能源电网电压安全稳定预测的准确性,通过最佳的电压稳定控制策略提高了电网故障后的安全稳定运行水平。

泥水平衡顶管下穿运营铁路施工安全影响分析

结合某电厂至呼和浩特市长输供热管网工程泥水平衡顶管施工项目,采用数值模拟的方法,对顶管穿越段京包客专、京包铁路、呼王联络线路基及呼王联络线桥梁变形进行仿真分析,揭示泥水平衡套管下穿运营铁路施工对路基及桥梁的影响。结果表明:客专线路路用便梁和管棚加固、普速线路路基采用管棚加固、桥梁基础采用注浆防护后,既有运营铁路路基及桥梁的变形值均能满足铁路运营的安全要求,根据三种不同等级的铁路,所提出的三种加固设计方案均切实有效、可行。

本质安全视域下健全平安建设长效机制的思考——以H省为研究样本

本质安全作为一种高层次的安全管理理念,强调从源头防范化解系统性风险和预防事故的发生。H省自2021年9月践行本质安全理念以来,持续致力于健全平安建设长效机制,坚持控增量、减存量、防变量的原则,在“预”字上下足功夫,在“防”字上做好文章,全力以赴打击犯罪,积极化解积案和矛盾纠纷,开展了一系列有益探索。结合多地实践来看,平安建设的长效机制构建还存在一些问题。对此,基于本质安全视角客观审视这些问题,建议从强化社会治理共同体、创新公共安全体制机制、完善社会治安防控体系、筑牢舆情风险立体化防控体系、健全应急管理体系等方面着手促进长效机制建设,为平安建设更高水平、可持续发展打造坚实的支撑。

面向直流受端新型电力系统暂态电压稳定的紧急控制策略

在直流受端新型电力系统中,新能源电源及直流的接入导致同步机开机减少,动态无功功率相对紧张,暂态电压失稳风险显著增大。为高效快速获取紧急控制策略,即直流电流控制方案,并使其适应不同的电网运行方式和故障场景,尤其是电网拓扑结构的变化,基于图卷积神经网络(GCN)对常规深度强化学习模型深度确定性决策梯度(DDPG)的网络结构进行改造,构建了GCN-DDPG融合模型。在此基础上,引入双评价网络机制和评价网络与动作网络非同步更新策略以提升算法效果。进一步地,在应用方面,基于GCN-DDPG融合模型构建紧急控制模型并将其下达至安控主站,安控主站将依据电网实际运行方式和故障等信息,对紧急控制策略进行在线量化计算,并发送至直流控保系统执行。最后,通过改造的IEEE 14节点系统验证所提方法的有效性和优越性。

提升末端区域电网供电能力的调控方案及稳控策略研究

针对内蒙古某末端区域电网供电能力受同塔双回线路N-2故障及母线故障制约问题,开展安全稳定控制系统(以下简称稳控系统)控制策略研究。首先,基于对典型故障后末端区域电网稳定特性的仿真计算与分析,结合新能源出力、火电机组开机等对切负荷定值的影响,制订预控方案与稳控系统相结合的综合调度控制方案;然后,分析电解铝行业整流变压器负荷转移特性,提出可优先实切负荷量计算方法和适用于末端电网的分档阶梯切负荷原则,对末端区域电网稳控系统的控制策略进行优化。

基于数字孪生的安全稳定控制系统试验验证展望

随着新型电力系统建设的推进,安全稳定控制系统呈现出控制对象增多、控制范围增大、耦合性增强、复杂度增高的趋势,现有工程试验验证方法无法满足未来安全稳定控制系统试验验证需求。考虑到数字孪生技术具有高保真、实时性、交互性的特点,结合数字孪生技术的内涵、模型、架构,提出了基于数字孪生的安全稳定控制系统试验验证架构。最后,对所涉及的关键技术进行了展望。

道路交通事故处置安全管控措施探讨

针对车辆交通事故类型多样、事故突发、调度力量多、救援危险性大、易引发次生灾害的5个特点,深入分析并归纳总结了造成消防救援人员伤亡的3方面原因,包括风险研判不足、阵地设置不当、安全措施不当等,并进一步提出交通事故处置过程中力量调派、人员分工、安全评估、现场警戒、救人排险、现场清理6个重点环节的安全管控措施。