Operation Control Method of Relay Protection in Flexible DC Distribution Network Compatible with Distributed Power Supply

A novel operation control method for relay protection in flexible DC distribution networks with distributed power supply is proposed to address the issue of inaccurate fault location during relay protection,leading to poor performance.The method combines a fault-tolerant fault location method based on long-term and short-term memory networks to accurately locate the fault section.Then,an operation control method for relay protection based on adaptive weight and whale optimization algorithm(WOA)is used to construct an objective function considering the shortest relay protection action time and the smallest impulse current.The adaptive weight and WOA are employed to obtain the optimal strategy for relay protection operation control,reducing the action time and impulse current.Experimental results demonstrate the effectiveness of the proposed method in accurately locating faults and improving relay protection performance.The longest operation time is reduced by 4.7023 s,and the maximum impulse current is limited to 0.3 A,effectively controlling the impact of large impulse currents and enhancing control efficiency.

Impacts of Large-scale Wind Power Grid Integration on Relay Protection and Countermeasures

Several large-scale wind turbine tripping accidents occurred in Jiuquan wind power base in 2011.According to the on-site survey and analysis of these accidents related to relay protection,causes were found to be the collection system defects and low correct operation rate of small current grounded line selectors of the unearthed neutral point collection system.By referring to both the characteristics of Jiuquan wind power base and arrangement of relay protection,the short-circuit features of wind power and its impacts on relay protection are analyzed.The collection system and the retrofit of the small current grounded line selector are improved by specific countermeasures.Finally,further research subjects are put forward.

Research on the Process Layer and Substation Layer Relay Protection in Smart Substation Relay Protection

The intelligent substation relay protection facility is a fundamental element in construction of modern power system,based on the principles of flexibility,security and accuracy,and it can be divided into process layer and substation layer according to specific equipment.The former is suitable for individual sampling of disposable equipment,can be separated from the base station synchronization sampling,with the help of synchronous digital system and ping-pong algorithm to achieve synchronization of the overall sampling,that is to take the distribution protection components,through the separate transmission medium to realize the information transmission;the latter is for variable power plant components centralized backup protection,taking online real-time tuning technique.

The Automated System of Unified Templates as an Element of Trainability of Microprocessor Relay Protection Devices

The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.

Serial Failure Diagnosis of a Transmission Line Protection Relaying System by Petri Nets

With the development of large-scale complicated modern power systems, the requirement for the associated protection scheme tends to be more stringent and its combination more complex. However, it is very difficult to figure out the factors of failure of such systems. This paper proposes a Petri net model of a transmission line protection relaying system, including three types of relays as well as an automatic reclosing device, and shows how to diagnose serial failure of the system by analyzing invariant sets of the model. Furthermore, it gives four basic types of failure sequences and its execution is much more intuitive and effective than the traditional method.

The Principle and Practice of the Deviation of Power Frequency Component Relay on High Voltage Transmission Line

The research and development of ultra high speed protective relay of transmission line has got great interest and attention of protective relay engineer over the world. Several versions and schemes of ultra high speed relay have been studied and designed in recent twenty years. But only a few of them have got actual apiication in the power system. The relay based on the deviation of power frequency component (DPFC) can get very high reliability with ultra high speed so it has got wide application in Chinese power system. Thousands relay sets have been applied and its operation experience verifies their excellent performance. This paper summarizes the course of the development of the uItra high speed protective relay and compares the merits and defects of the main schemes which have been developed. The principle and successful pratice of the ultra high speed protection based on DPFC reIay are introduced.

Present State and Development Planning ofEast China Power System

This paper presents the existing state anddevelopment planning of East China PowerSystem, which refers to load, power source,power network, system protection, dispatchautomation and system communication.

Comprehensive Automation of Microprocessor Protection Relay Terminals Operated on AC Railways

The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.

A Complete Analytic Model for Fault Diagnosis of Power Systems

现代大规模互联电网提高了电力系统运行的稳定性和经济性,同时也给电网的故障诊断增加了难度。对电网保护配置和断路器动作规则进行深入分析,提出一种新的电网故障诊断模型——完全解析模型,并为基于此模型的故障诊断提出一种实用有效的求解方法。在完全解析模型中,故障假说（即可疑故障设备的故障情况）与保护、断路器的动作情况及拒动和误动情况一同表示成逻辑变量,而保护配置和断路器动作规则以逻辑方程组形式进行充分表达,逻辑方程组的每个解析解对应一个故障模式（设备故障状态和保护动作、断路器跳闸状态及拒动/误动情况）,是对故障情形的完整解释。本模型对故障诊断规则和保护、断路器的动作逻辑进行完全解析,并完整保留了故障设备、保护动作和断路器跳闸之间的耦合关系,克服了已有解析模型的缺陷。算例表明,保留完整耦合关系的完全解析模型可有效提高故障诊断的准确性和容错能力。

Reliable Remote Relay Protection in Smart Grid

As the false trips of remote protection relays are among the main reasons behind cascading blackouts, it is critical to design reliable relay protection. Even though common protection schemes on traditional power systems have been investigated for a few decades, cascading failures in recent years indicate more research needed in this area. Consequently, researchers have proposed agent-based methods on the Smart Grid （SG） to address this issue. However, these existing agent-based methods simply use TCP protocol without considering real-time communication requirements （such as bandwidth and delay）. To deal with this issue, several methods for efficient network resource management are proposed. Furthermore, these existing methods do not consider the potential issues in practical communication networks, which may result in delay violation and trigger relay false trips. We have discussed simple backup solutions in the previous work. In this paper, in addition to network efficiency, we focus on improving the system reliability by exploring known power system information and minimizing the chances of false trips of important remote relays, e.g., defining power line priorities based on their importance. Moreover, to further improve the. system reliability, we also in- vestigate the peer-to-peer protection approaches to address the single point of failure of centralized control center.

基于ARM架构柔性直流控制保护系统的低链路延时优化设计

基于进阶精简指令集机器(ARM)架构多核处理器芯片设计了柔性直流控制保护系统新一代平台,提出适用于柔性直流输电的4层控制系统通用架构,给出新平台控制保护主机配置方案及功能配置原则。建立换流器高频阻抗简化模型,推导得到负阻尼频率与控制链路延时的数学关系。分析柔性直流控制系统的链路延时构成,提出一种链路复用的在线延时测试方法;基于多核架构与高速接口,研究控制系统的低延时优化方案。最后,在基于实际工程参数的实时仿真系统中,对ARM架构新平台开展了功能和性能测试,并验证了低延时优化方案的有效性。

基于任务驱动法的继电保护综合实训在电气工程毕业实习中的应用

主要研究继电保护综合实训在电气工程及自动化专业毕业实习中的教学创新与实践。首先介绍了继电保护综合实训的背景和意义,详细描述了实施该实训教学的步骤和措施,包括实验设备的配置和连接,实验操作的流程等;其次,提出创新分解式任务驱动法,该方法将继电保护综合实训融入实习环节,使学生深入学习继电保护装置的工作原理和应用技术,提高其实际操作能力、问题解决能力;最后,论述了教学评价标准和实训报告要求。该综合实训教学创新对学生的素质提升和职业发展具有积极影响,对于电气工程及自动化专业毕业实习的改进和发展具有重要参考价值。

面向主动探测式保护的变流器正交控制策略

为避免主动探测式保护的变流器附加控制策略与原有基础控制策略之间相互干扰,提出了一种正交控制的方法。首先分析了新型电力系统中变流器的基础控制策略,针对空间矢量脉宽调制采用正序分量计算空间矢量的特点,设计了基于负序分量的附加控制策略,保证基础控制系统、附加控制系统相互解耦。其次利用基础和附加控制策略处理后的不同信号频带,引入前置滤波环节,给出了常规应用场景下的正交控制策略;然后研究了脉冲信号的生成方式,分析了附加控制策略的适用场景;最后分析了探测信号生成对一次系统和传统保护的影响。

大规模新能源接入的交流电网继电保护整定计算研究

新型电力系统高速发展,新能源大量投产,现有忽略新能源电源属性的继电保护传统整定计算方法难以适应。鉴于此,结合新能源的物理特性和整定计算特点,提出了新能源的整定计算实用化模型。讨论了计及大范围新能源接入的短路计算方法,给出了恒流源和受控源接入的短路计算算法,提出了大范围新能源接入后的新能源影响域评价指标,在保证整定计算准确度的前提下提高了整定计算的效率。在前述研究的基础上,详细分析了计及新能源的参数收资、方式设置、保护配置、整定计算原则、重合闸、边界保护管理等内容。所做工作为面向新型电力系统的整定计算业务提供了解决思路,对继电保护整定人员具有借鉴与参考意义。

经柔性高压直流输电并网的海上风电送出线路拟功率和、差波形比较式纵联保护

经柔性高压直流输电并网的海上风电送出线路在故障情况下呈现出的两端电流存在较大相角差等故障特性导致传统纵联保护面临不能正确动作的风险。根据电路中的拟功率定理,分别利用线路两端故障前后电压、电流瞬时值列写拟功率表达式,并对两表达式进行求和与作差运算,得到拟功率和与拟功率差。分析表明,发生区内故障时,两者波形相似性高,波形接近完全重合;发生区外故障时,两者含有成分不同,相似性较差,据此形成拟功率和、差波形比较式纵联保护的保护判据。利用EMTP-RV软件搭建经柔性高压直流输电并网的海上风电场模型,对不同故障类型、过渡电阻、噪声、数据窗长、控制方式、同步误差进行仿真验证,理论分析与仿真结果表明所提保护方法具有较强的适应性。

基于储能参与的电网连锁跳闸主动防控方法

新型电力系统中系统惯性降低及触发连锁跳闸风险因素的增多,使得防范连锁跳闸的重要性愈发凸显。针对这一问题,提出一种融合储能的电网连锁跳闸抑制方法。利用储能的快速响应特性,在潮流转移初期即投入储能调控电网潮流,可快速抑制导线温升,为后续水火电机组及其他慢速响应的备用电源参与调控赢得时间。文中提出了基于网络动态最大电气介数、风险扫描和需量计算的“三要素法”储能配置决策方法,包括构建反映网络薄弱环节和时变风险的连锁跳闸防控预案,解决了连锁跳闸抑制的储能资源时空选择问题;基于输电线路动态热特性,提出了储能与水火电协同调控时的储能功率和容量计算方法,确定了防范连锁跳闸所需要的储能资源规模。针对IEEE 30节点网络给出了N-1和N-2故障计算案例,验证了所提方法的有效性。

应对变电站二次直流失电的超高压输电线路相间保护方案

变电站二次直流失电会导致本站继电保护装置等设备失去供电电源而无法动作,本站出线发生故障时需要依靠上级变电站的远后备保护进行切除。针对变电站二次直流失电情况下超高压输电线路发生相间短路故障时保护远后备灵敏度不足的问题,提出了一种应对变电站二次直流失电的超高压输电线路相间保护方案。首先,根据超高压电网相间故障时负序电流的自然分布特性,探讨了反时限负序过流保护的远后备应用可行性和相间距离保护的补充特性,确定了相间故障远后备保护的构成思路。接着,研究了助增系数和负序电流对反时限负序过流保护整定时间定值的影响,讨论了临界助增系数的确定方法和反时限负序过流保护的时间定值整定方法。然后,提出了反时限负序过流保护为主、相间距离保护为辅的应对变电站二次直流失电的超高压输电线路相间保护方案。最后,以IEEE 39节点系统和某实际500 kV电网作为仿真算例,对所提方案的有效性进行验证。

基于区间证据理论的多源融合广域后备保护

针对传统保护方案在光伏接入系统时存在的可靠性不足问题,该文提出了一种基于区间证据理论的多源融合广域后备保护方案。首先,将光伏输出电流对保护的影响解耦分析,提出了保护方案的基本概率分配函数,将传统保护结果的0,1值转化为描述故障概率的区间值,定量考虑了光伏接入对配网保护的影响。其次,利用改进的区间证据理论对多种保护的判别结果进行融合,得到每条线路的综合故障概率区间,进而识别故障线路。该方法将光伏接入对保护判别的影响定量化,利用了多个保护综合判断,提高了广域后备保护的可靠性。同时,改进的区间证据理论消除了冲突证据的影响,在保护存在数据缺失及错误时仍能可靠识别故障线路。最后仿真验证了该文方法的可靠性。

分布式光伏电站接入配电网继电保护整定优化

为了缓解配电网的供电压力,越来越多的分布式光伏电站接入其中,导致配电网结构发生了改变,因此需要重新整定继电保护的定值,否则,当配电网发生故障时,继电器很难有效发挥其保护作用。提出一种分布式光伏电站接入配电网的继电保护整定优化方法。以继电器协同动作时间总和最小值为优化目标,设置4个约束条件,利用微分进化算法求取目标函数的最优解,得出继电器启动电流和时间整定系数的最优整定值。实验结果表明:在接入分布式光伏电站的两相短路故障时,所提整定优化方法的继电器保护总体动作时间更短,验证了该算法的保护整定效果更好,更有利于继电器迅速排除配电网故障,保护配电网安全。