The philosophy, design, and evaluation of a wide area back-up differential protection scheme are described in this paper. In the absence of a commercially available relay capable of servicing the back-up function the back-up relay is "emulated" on a DSP in a real time digital simulator and coordinates with commercially available primary protection relays interfaced to the power system simulation running on the simulator. The scheme is evaluated on a small closely coupled power distribution system.
J. Tang, M. Sloderbeck, D. Ouellette, P. Forsyth, J. Langston and P. McLaren, "In System Emulation (ISE) of a New Current Differentiall Back-Up Protection Relay," 2008 IET 9th International Conference on Developments in Power System Protection (DPSP 2008), Glasgow, 2008, pp. 400-405.
KEYWORDS: differential protection, emulated relay, RTDS