Article’s

Keeping a power network secure against sudden equipment failures is one of the less glamorous but genuinely hard problems in grid operations. Every day, system operators must verify that losing any single line or transformer will not push surviving branches beyond their thermal ratings — a check known as the N-1 criterion. We tackled this problem for the IEEE 14-bus test system by writing a DC power flow solver and contingency loop entirely in MATLAB, bypassing toolbox dependencies. For each of the twenty possible single-branch outages, we computed post-contingency loading on every monitored branch, then ranked the scenarios using a Performance Index (PI). The worst outage — loss of the Bus 1-2 tie — produces a PI of 3.35 and overloads two branches simultaneously, while 75% of contingencies leave the network intact. Eight simulation figures, including a single-line diagram, a 20×20 loading heat map, a severity curve, and a pre-versus-post comparison dashboard, document the findings in detail.