摘要
针对相差保护虽具有不受系统振荡影响的优点,但由于其对通道要求高,保护动作时间长的问题,该文提出一种利用小波变换提取非工频故障电流相位进行比较的保护新方法:基于故障产生的暂态电流分量在线路上的流向进行保护。它具有快速比相的能力,提高了相差保护在高阻接地和两相运行下的保护性能。新方法能够有效地加快保护速度,提高保护在大负荷电流下的抗过渡电阻的能力,改善保护在缺相运行时的保护特性等。对保护两端同步采样的要求较低,因而很容易实施。大量EMTP仿真试验验证了新方法的快速性和可靠性。该方法如应用于实际中,可提高运行部门的旧有相差保护性能和经济效益。
Phase comparison based current differential protection has advantages such as immune to oscillation. But it needs longer operation time, which will greatly affect the performance of the protection set. This paper proposes a new current differential protection that is based on non-power current component, and it can overcome the disadvantages of the conventional protection. Phase of fourth harmonic current of each end of the transmission line has been extracted by utilizing complex wavelet transformation and then compared with each other for detecting fault direction. The new scheme can greatly improve performances of differential protection under conditions of higher fault resistances and two-phase operation system. A lot of simulation results have verified effective of the proposed technology.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2005年第11期12-16,共5页
Proceedings of the CSEE
基金
国家自然科学基金项目(51017007)
上海高校优秀青年教师后备人选科技基金项目。~~
