摘要
The increasing scale and complexity of power systems require high performance and high reliability of power system protection.Protective relaying based on directional comparison with power line carrier or microwave channels is the most suitable protection scheme for long distance EHV transmission lines and is widely used in power systems.The key element of such protection is a directional relay used to discriminate the fault direction.In order to overcome the disadvantages of conventional directional relays,the authors of this paper put forward the directional comparison carrier protection based on the artificial neural network(ANN).The protection is extensively tested using electromagnetic transient program (EMTP) under various electric power system operating and fault conditions.It is proved that the directional comparison carrier protection based on ANN,which can recognize various fault patterns of the protected transmission line(such as fault direction,fault phases etc.)correctly in any kind of operating and fault conditions and the whole process,is satisfactory for EHV transmission line protection.
利用载波或微波通道实现的方向保护最适用于远距离超高压输电线路，在电力系统中得到广泛应用，这种保护的关键元件是用于判别故障方向的方向继电器．为了克服传统方向元件的缺点，提出基于人工神经网络的方向高频保护，通过电磁暂态仿真程序（ＥＭＴＰ）的广泛测试，证明基于人工神经网络的方向高频保护在任何运行状态和故障条件下都能正确识别被保护输电线路的各种故障模式（如故障方向和相别），完全满足超高压输电线路对保护的要求．
