因目前多数自适应重合闸方案,均须采用故障相的线路侧电压进行瞬时性和永久性故障的区分,具有一定的局限性,于是提出了一种基于模电流双窗函数暂态能量比的判据。如果滤波器效果良好。该判据在信号平稳段的输出接近1,在信号奇异时刻附近,能量比明显增强,便于整定。为了更有效地提取高频能量,在多分辨形态学梯度变换(MMG)的基础上提出了一种新的广义多分辨形态梯度变换(GMMG)。GMMG的设计更加灵活,可以根据需要达到的效果调节结构元素的各种要素。EMTP仿真研究表明,由GMMG构成的自适应重合闸方案提高了判别的可靠性,具有实用价值。
At present, most self-adaptive auto-reclosure schemes are dependent on the voltages sampled from the transmission lines to distinguish between the instant faults and the permanent fault, therefore have some limitation in the applications. A criterion of dual-window transient energy ratio (ER) based on modal current is proposed in this paper. This ER approaches to 1 during the steady state whereas it increases greatly around the time instants at which the signal has singularity, Therefore, the setting of the criterion is easy. To effectively extract the high-frequency energy of the modal current, a novel concept of generalized multi-resolution morphological gradient (GMMG) is put forward on the basis of multi-resolution morphological gradient (MMG). The design of GMMG is more flexible and the relative factors of the structure element can be adjusted according to the desirable effects. EMTP based simulation results show that the GMMG based auto-reclosure scheme improves the reliability of discrimination and is promising to be used in the real power systems.