Research of remote backup protection functioning at the software and hardware complex RTDS

Remote backup protection is installed at the ends of the power line of 35–220 kV and provides detection of short-circuit on the low-voltage side of branch transformers. To support remote protection on 110 kV lines and above with two or multi-way power feed, it is mandatory to implement a three-stage remote protection from interphase short-circuit (phase-to-phase fault). To implement line protection with remote protection on a substation (in case of protection equipment operation failure, breaker failure on high voltage side and signal transfer device failure) seems to be more difficult comparing to a line short-circuit. It is related to limited possibilities of line protection sensitivity and, in many cases, operation parameters of a loaded line that define relay protection stage protection significantly exceed nominal power of the branch transformer.