A Hierarchical Adaptive Protection Scheme for Short Lines in Low and Medium Voltage Active Distribution Network

This paper aims to use the excellent ability of information interaction in active distribution network. The protection system of active distribution network is mainly divided into three layers: the terminal layer, the regional layer and the main station layer. The connection between different hierarchies of the system and the inner connection are realized through the layered, distributed and open network system. Finally, the hierarchical adaptive protection scheme for short lines is presented by using the method of the horizontal coordination in one layer and the vertical coordination between different layers. The two sets of adaptive protection schemes for horizontal and vertical coordination implement autonomous working and do not affect each other. In this way ,they give full play to their respective advantages in different power distribution scenarios, effectively solve the problem that the protection of active distribution network cannot be reliable tripping due to the close short circuit level and the variable operation mode.