利用有限相量测量单元的故障识别与广域后备保护策略

Fault Identification and Wide-Area Backup Protection Strategy Based on Limited Phasor Measurement Units

针对传统后备保护整定困难、动作延时长、配合关系复杂等问题,提出了一种利用有限相量测量单元的故障识别与广域后备保护策略。首先,根据相量测量单元的安装位置划分后备保护区域;在发生故障时,利用电气量信息确定故障设备所在的后备保护区域,以期快速缩小可疑故障设备范围。其次,提出一种基于解析模型的故障识别方法和广域后备保护策略。当主保护未能成功切除故障时,这种解析模型可综合利用主保护动作警报、断路器动作警报、后备保护启动信息和功率方向继电器指向信息,利用禁忌算法(tabu search,TS)求解最优故障假说,并通过解析保护和断路器的动作逻辑判断拒动装置。之后,根据不同的拒动情况提出相应的后备保护策略以防止故障扩大。最后,以IEEE 39节点系统为例,对所提出的方法做了验证。仿真结果表明,所提出的方法是可行的,具有较强的容错能力。

The traditional backup protection has some drawbacks, including difficult protection setting, long time delay and complicated coordination. Given this background, this paper proposes a fault identification and wide-area backup protection strategy based on limited phasor measurement units （PMUs）. Firstly, the whole power network is divided into several backup protection zones （BPZs） based on the placement of PMUs. Once a fault occurs, the electrical quantities are utilized to identify the faulted BPZ, so as to quickly narrow down the scope of suspected fault sections. Then, we present fault identification method and wide-area backup protection strategy based on the analytical model. When the main protection fails to clear the fault, this analytical model can comprehensively use the alarm information of main protection, circuit breaker action alarm, backup protection startup information and power direction relays to point to the information, adopt tabu search （TS） algorithm to seek the optimal fault hypothesis, and determine the malfunction devices through analyzing the action logics of protection and circuit breaker. Based on the identified malfunctions, the corresponding backup protection strategy is initiated to prevent the fault from spreading. The simulation results show that the proposed method is feasible and has strong fault tolerance ability.