Performance evaluation of protection functions for IEC 61850-9-2 process bus using real-time hardware-in-the-loop simulation approach

With the evolution of Process Bus (IEC 61850-9-2), there is a need to assess the performance of protection schemes using process bus against those where traditional copper wires are implemented. Differential protection is the fundamental and most commonly used protection for transformers, motors and generators. In this paper a power system is modelled in SimPowerSystems and is executed in real-time using Opal-RT´s eMEGAsim real-time simulator. Hardware-in-the loop validation of a process bus implementation for differential protection for a two winding transformer is done by using the differential protection feature in ABB´s RED-670 relay. The event reports generated by the ABB relay during Hardware-in-the-Loop testing are compared for three different scenarios i.e. complete process bus, hybrid process bus and complete traditional topology.