Impact of Time Delays on the Performance of a Wide-Area Damping Controller Under Reduced Inertia Scenarios

Communication delays in a wide-area damping controller (WADC) can have negative effects on the dynamic stability of a power system. Furthermore, the increasing integration of converter interfaced generation changes the dynamic properties of the grid since the inertia is reduced. Therefore, this paper aims to investigate the effect of communication delays on a WADC operating under low inertia scenarios. For this purpose, the effect of communication delays in a WADC for damping inter-area oscillations were analysed and evaluated first in a Control Hardware in the loop (CHIL) setup. Simulations were carried out with this setup considering several delays as well as different inertia constants for the involved machines. Then, to get a more practical insight of these effects under more realistic conditions, a scaled power system-based dynamic hardware emulator was used. The results in both setups show that with increasing delays the WADC performance degrades, affecting significantly its ability to damp inter-area oscillations. Furthermore, it becomes clear that with reduced inertia the margin regarding communication delays also reduces and thus the stability of the system might be potentially endangered by the WADC response.