Designing a backup system of relay protection for multi-end overhead lines

摘要

One of the numerous elements of modern distribution electric networks with a voltage of 6-110 kV in Russia are multi-ended overhead lines with branch substations with transformers rated at 2.5-25 MVA. Designing a backup protection system for these substations is difficult due to the comparability of short-circuit currents on the side of lower voltage with the current flowing between the supply substations in the normal regime. The authors proposes a backup system, the algorithms of which are based on multiparameter monitoring of signals from both the substation sides: same side and monitoring the parameters of the information signs of signals from other substations using device associated with signaling system for transmitting alarm signals and commands.