多环复杂电网方向保护全网最优配合的研究：第2部分 确定全 …

引入相关顺序组的概念,从数学上准确地描述了大规模多环复杂网络方向保护全网最优配合问题,提出了利用系统最小断点集和主／后备保护函数依赖关系形成全网最优配合顺序的新方法。     

基于配合关系计算复杂环网保护最优配合顺序的新方法

基于保护主后备配合关系,引入并定义了保护配合主依赖度和后备依赖度的概念来描述保护之间的配合依赖关系,提出了通过动态调整保护主依赖度和后备依赖度逐步计算复杂环网最小断点集和确定全网最优配合顺序的新方法,根据保护后备依赖度最大的原则选择候选断点和主依赖度为0的原则确定保护配合顺序,同时给出了详细的算法流程和算例分析.该方法简单直观,计算量小,只需利用基本的配合关系,完全不需要形成全网所有有向回路,有效解决了多环复杂网络中方向保护全网最优配合问题.     

基于配合依赖关系图计算环网方向保护最优配合顺序的新方法

提出了基于保护主后备配合关系,利用保护配合依赖关系有向图节点邻接矩阵计算环网方向保护最优配合顺序的新方法。根据节点入度最大的原则逐步选择断点,根据节点出度为0的原则确定保护配合顺序,通过对节点邻接矩阵简单的行列化简运算逐步计算大规模复杂环网最小断点集和确定全网保护最优配合顺序。该方法简单直观,大大降低了问题的复杂度和计算量。     

多环复杂电网方向保护全网最优配合的研究——第1部分 确定所有有向基本回路矩阵

提出了大规模多环复杂电网方向保护全网最优配合的系统方法,能统一处理辐射线路、终端线、多邻接Ｔ形接线和环网中方向保护的最优配合问题,利用方向保护之间的主／后备配合依赖关系和深度优先搜索／回溯技术,建立了搜索所有有向基本回路的新方法,降低了问题的计算复杂性,弥补了现有指数复杂性方法的不足。     

多环复杂电网方向保护全网最优配合的研究 第1部分 确定所有有向基本回路矩阵

提出了大规模多环复杂电网方向保护全网最优配合的系统方法,能统一处理辐射线路、终端线、多邻接T形 接线和环网中方向保护的最优配合问题,利用方向保护之间的主/后备配合依赖关系和深度优先搜索/回溯技 术,建立了搜索所有有向基本回路的新方法,降低了问题的计算复杂性,弥补了现有指数复杂性方法的不 足。     

多环复杂电网方向保护全网最优配合的研究：第1部分 确定所有？…

提出了大规模多环复杂电网方向保护全网最优配合的系统方法,能统一处理辐射线路,终端线,多邻接Ｔ形接线和环网中方向保护的最优配合问题,利用方向保护之间的主／后备配合依赖关系和深度优先搜索／回溯技术,建立了搜索所有有向基本回路的新方法,降低了问题的计算性,弥补了现有指数复杂性方法的不足。     

基于网络化简和配合关系的最小断点集计算方法

基于保护主后备配合依赖关系有向图,提出了通过有向图化简计算保护配合最小断点集（MBPS）的新方法。定义了配合依赖关系有向图化简操作的顺序和原则,按照优先级顺序将保护分类,根据保护后备依赖度最大原则从具有较高优先级的类中选择候选断点,将化简过程中得到的自环顶点选为断点。所述方法适用于环网全网配合和同段配合中MBPS的计算。     

全网最优无功潮流及无功补偿设备调度管理权限的划分

全网只有按最优无功潮流方式运行，才会有最好的电压质量和最低的线损指标，这是人们长期追求的目标。介绍了全网最优无功潮流、全网最优无功潮流调节方法、无功分层控制及其调度管理权限的划分。现阶段基本具备了实现全网最优无功潮流运行的条件，任务是因势利导，促进全网最优无功潮流运行方式的实现。     

一种求解复杂环网保护配合最优断点集的新方法

为确定复杂环网保护配合中的最优断点集,引入了4个指标作为最优断点寻找的评判依据,建立了寻找最优断点集的数学模型。基于细菌群体趋药性算法的基本原理,提出了计算最优断点集的新方法。较已有的计算断点集方法,所述方法可以快速地找出最优的最小断点集。算例分析证明了该方法的有效性和实用性。     

考虑保护重要度计算环网方向保护配合最小断点集

在对复杂环网方向保护进行整定计算时,确定其最优配合顺序的核心步骤就是求解最小断点集(MBPS)。根据保护主后备的依赖关系,建立了计算MBPS的数学模型,将整定过程用一系列矩阵运算表示,并加入到约束条件。将保护重要度引入到目标函数中,利用人工蜂群算法对模型进行求解,得到最优MBPS。通过算例验证算法及模型的有效性。     

Time coordination method for power system protection byevolutionary algorithm

A typical industrial power network may consist of hundreds of pieces of equipment and even more protection relays to protect the system are required. Each protection relay in the power network needs to be coordinated with the relays protecting the adjacent equipment. The overall protection coordination is, thus, very complicated. A new concept of protection coordination by time is introduced in this paper to formulate all the system relays and system equipment operation into a set of optimization equations and constraints. Its purpose is to search for an optimal protection setting to minimize the system disturbance time as well as the time of interruption of the power supply. An evolutionary algorithm is applied as a constraint satisfaction optimization tool to search for the optimal relay setting. This method can find the best protection relay coordination, which cannot be achieved by traditional methods. This is the most significant achievement of the paper     

A new approach for optimal coordination of distance and directional over-current relays using multiple embedded crossover PSO

Proper coordination between distance relays and Directional Over-Current Relays (DOCRs) in power systems is one of the important conditions for the system security. The coordination problem in interconnected systems, because of complexity of the system, is complicated and a powerful optimization program must be used in order to do the best and optimal relay coordination.In this paper at first, a new problem formulation for optimal coordination of distance relays in presence of DOCRs, as the backup relays, is proposed. Then to deal with this complex problem, as another contribution, a new Multiple Embedded Crossover PSO (MECPSO) is proposed. In the presented MECPSO by updating velocity vector, diversity of the swarm is enhanced and exploration and global search capabilities of the PSO is improved as well. In the proposed approach, with considering the effect of in-feed or out-feed currents, the optimal second zone timing of distance relays and optimal settings of DOCRs are computed. The proposed method is tested on two case studies and encouraging optimal results are obtained.     

Algorithmic-knowledge-based adaptive coordination in transmission protection

Changes in power system operating conditions can affect both the reach point of distance relays and the coordination of distance and overcurrent relays. To improve the performance of the protection system, an adaptive scheme of relay settings is proposed. That is possible since the protection relays became digital . This paper describes a system for online adaptive setting and coordination of protection relays in meshed networks where the backup protection is achieved in remote form. After changes in the state of the network, an expert system (ES) performs the detection and proposes the correction of erroneous settings of protection zones and miscoordinations between relays at different stations; through an algorithm based on a fast determination of a nonminimal set of "break-points" (BPs) relays , new time characteristics for the coordination are found. The results of the application of the developed system to a test network of 34 nodes, 55 branches, and 110 relays are shown.     

Computer aided coordination of directional relays: determination ofbreak points

The directional overcurrent and distance relays of a multiloop network must be set in a sequence to ensure coordination. The starting points of the sequence are called break points. An algorithm to determine the minimum number of break points is presented. It can be readily implemented on a computer and forms a basic component of a computer-aided-design package for a protective system     

Optimal coordination of directional over-current relays using Teaching Learning-Based Optimization (TLBO) algorithm

Relay Coordination in a big distribution system with multiple meshes and bidirectional power feed becomes very Complex for protection engineers. Manual and graph theory based approaches were applied successfully in small power system. In a big distribution system linear and non-linear programming based optimizing techniques are applied for relay coordination. Presently, artificial intelligence techniques are applied for optimal co-ordination of directional overcurrent relays. This paper discusses the application of Teaching Learning Based Optimization (TLBO) algorithm for optimal coordination of DOCR relays in a looped power system. Combination of primary and backup relay is chosen by using Far vector of LINKNET structure, to avoid mis-coordination of relays. Coordination of DOCR is tested for IEEE 3, 4 and 6 bus systems using the TLBO. Also, the objective function is modified to optimize the operating time between backup and primary relays. The results are compared with the optimized values of Time dial setting and Plug setting values obtained from modified differential evolution algorithm. The proposed algorithm TLBO gives optimal coordination margin between 0.3 and 0.8 s and no miscoordination between primary and backup pairs. Results are also verified using Digsilient power factory simulation software.     

基于蚁群算法的环网方向保护配合最小断点集计算

利用复杂环网方向保护最优配合中最小断点集（MBPS）的启发性知识,将MBPS的计算问题等价为0-1整数规划问题。基于蚁群优化算法基本原理,构造了适用于MBPS问题的启发信息计算公式,改进了更新信息素浓度的计算方法,提出了计算MBPS的新方法。相对于其他计算MBPS的算法,所述算法所需迭代次数较少,通过一次计算即可同时获得多组最优解。     

A Novel Multi-Objective Protection Coordination Scheme for a Microgrid with Optimal Deployment of Dual-Setting ROCOV Based Relays

Relay coordination is crucial in electrical power systems to protect against malfunctions and damage caused by unexpected events like short circuits. To address the challenge associated with the reverse direction of fault current, dual-setting (DS) directional over-current relays have evolved but failed to provide proper coordination during changes of load, generation, and network. In the meantime, with the increasing number of DS relays, the total relay operating time tends to saturate. Therefore, this paper proposes a protection scheme based on the optimal deployment of conventional and dual-setting rate of change of voltage (DS-ROCOV) relays in distribution systems. This holds true for varying network topologies and is unaffected by variations in load and generation. The objective of the proposed scheme is to ensure reliable and efficient protection against faults in distribution systems by minimizing the overall operating time with the optimal number of DS-ROCOV relays. The proposed protection scheme''s performance is evaluated for different coordination time interval values as well as in different microgrid scenarios. This paper outlines the design and implementation of the proposed protection scheme which is validated on the modified IEEE 14-bus system using simulations in Matlab/Simulink.     

多环电网方向保护整定计算中形成有向简单回路的新方法

在高压或超高压电网的距离保护和零序保护的整定计算过程中，首先要确定全网的最小断点集(MBPS)，然后在断点集的保护安装处打开断点，使得全网变为辐射网络。其中，多环复杂电网中有向简单回路的确定是求解最小断点集的关键，也是其必要步骤之一。为了最大限度地减少多环复杂电网中有向简单回路的计算复杂性，该文提出了一种保护依赖度和主／后备保护依赖集的新概念：将所有有向简单回路的形成过程归结为环网中所有保护依赖度大小的比较和保护依赖集的不完全深度优先搜寻过程。通过比较保护依赖度的大小来确定每次方向回路搜索的起始点，并通过对保护依赖集的深度优先搜索来确定所有有向简单回路。该方法能统一处理环网中的‘T’形接线、辐射线路等保护的配合问题。算例表明该方法简单有效，显著地降低了计算的复杂性，可方便地应用于高压或超高压电网的距离保护和零序保护的整定计算。