Scope: Primary circuit of the 345 kV grounded shunt reactor: 52RX, CT-RXH, reactor winding, CT-RXN, CT-RXG to ground.. The drawing is a protection scheme for a single reactor bay; the only power path is this series chain.
Boundary: Source = 345 kV Bus, sink = H0 neutral ground.. The bus is the supply boundary of the bay and the grounded neutral terminates the reactor circuit.
Can fail: breaker, ct, other. Series primary equipment (breaker, bushing/neutral CTs, reactor winding) can fail and remove the reactor from service; the 345 kV bus is the boundary supply and the ground is an ideal reference, so they are treated as perfect.
Success: any_path. The reactor is in service if a closed conducting path exists from the 345 kV bus through the reactor to ground.
Not modelled:
- Protection relays 67Q, 67N, 50G and directional-control links: They are secondary/protection functions, not in the primary power path; misoperation modes are outside a connectivity model.
- VT on the 345 kV bus: Shunt-connected for measurement only; not in series with the reactor path.
- Figure (b) as a separate circuit: It shows the same primary circuit as figure (a) with different relay options, so it is modelled once.