电网拓扑结构日趋复杂以及系统运行方式多变，导致现有后备保护越来越难以适应电网的快速发展。在全网信息可视化的背景下，广域后备保护技术将电力系统继电保护由单一元件的局部保护功能外延到整个电力系统的全局保护，这种能够获得较大区域信息的保护方式对于解决传统后备保护协调配合、动作延时、保护误动易引起连锁跳闸等问题有着积极作用。 故障扰动波及范围有限，越靠近故障点处的信息越能准确反映故障情况。通过分析电网故障时初始行波的传输特性，提出基于行波信息的自适应故障区域识别方法。该方法利用行波时间信息能够表征距离故障点远近程度的特点，以最先检测到行波的变电站为中心形成逻辑半径为2、半径为3的疑似故障区域。通过该方法可将系统保护范围锁定在一个近故障点的较小区域内，实现故障区域的“粗定位”。 针对仅依赖单一信息源的广域后备保护算法难以完成在信息缺失或错误情况下正确识别故障元件的要求，提出了基于理想解法的广域后备保护算法。首先选取具有耐同步特性且分属不同信息来源的开关量与电气量作为评价指标，然后通过理想解法计算疑似故障元件的各项评价指标到理想解的距离，并以距离正、负理想解的贴近程度以及远离程度两个基准作为评估各元件是否故障的决策依据，最后根据综合评价指数大小实现故障元件识别。IEEE10机39节点系统验证了该算法具有较好的容错性能。 在故障元件正确识别的基础上，为减小故障切除范围、实现大规模互联电网的快速自适应跳闸，提出一种基于图论搜索技术的广域自适应跳闸策略。从图论角度出发，构建被保护元件—断路器邻接矩阵和断路器邻接矩阵，并根据断路器的运行状态修正邻接矩阵；以故障元件或失灵断路器为源点，通过Dijkstra算法得到与源点连接的断路器路径，最后确定跳闸策略。算例分析表明，所提方法能够根据电网实时拓扑结构、故障元件位置和断路器状态实现跳闸断路器在线搜索，跳闸策略可以很好的满足广域后备保护配合要求。

With the increasingly complex structure of power grid and various modes of operation of power system, the traditional backup protection is becoming more and more difficult to adapt to the rapid development of power grid. In the panorama of information under the background of wide area protection system will protect the entire global power system relay protection power system from the local to the protection function of epitaxial single element, which can obtain larger regional information protection mode to solve the traditional backup protection coordination, time delay, misoperation of protection has a positive effect caused by cascading trip problems. The range of fault disturbance is limited, and the information closer to the fault point can reflect the failure effectively. By analyzing the transmission characteristics of the initial traveling wave during component failure, an adaptive fault area recognition method based on traveling wave information is proposed. The traveling wave time information can represent the distance to the fault point, and a suspected fault area with a logical radius of 2 and a radius of 3 is formed at the center of the substation which first detected the traveling wave, By this method, the protection scope of the system can be locked in a smaller area near a fault point, so as to realize the "rough location" of the fault area. The wide area backup protection only dependent on single information source is difficult to meet the requirements of correct identification of fault components in case of incomplete information or information error, so TOPSIS-based wide area backup protection algorithm is put forward. Firstly, switching value and electrical quantity with synchronization resistance from different information sources are selected as evaluation index. Then, TOPSIS is used to calculate the distance between each evaluation index of each suspected fault components and ideal solutions, and two standards of being close to positive ideal solution and being away from negative ideal solution are taken as the criterion for evaluating various suspected fault components. Finally, fault components are identified according to the comprehensive evaluation index. This paper conducts emulation proof on IEEE 10-generator 39-bus system, which shows good fault tolerance of algorithm. In order to minimize the range of fault isolation and achieve the rapid self-adaptive trip of large-scale interconnected power grid, a wide-area self-adaptive tripping strategy based on graph theory search technology has been proposed. Starting from the graph theory perspective, the protected element-circuit breaker adjacency matrix and circuit breaker adjacency matrix are set up, and the adjacency matrix is modified based on the operation state of the circuit breaker; with fault element or failure circuit breaker as source point, circuit breaker paths connected with source point is obtained through Dijkstra algorithm. Finally, self-adaptive tripping strategy is established by the distance values and paths. According to the examples analysis, the method proposed can be used to achieve the online search of tripping circuit breaker based on the real-time topological structure of the power grid, fault element position and circuit breaker state, and the tripping strategy can be used to meet the coordination requirements of wide area backup protection.