Abstract: A method and apparatus for tertiary control with over-current protection. In one embodiment, the method comprises calculating at least one unconstrained optimal net intertie target for an area of a power network; calculating, for each resource within the area, optimal scheduled current to achieve the at least one unconstrained optimal net intertie target; calculating, using the optimal scheduled currents and a plurality of stress coefficients, net scheduled current for each power line segment within the area; comparing the net scheduled currents to corresponding stress thresholds to identify any stress violations; reducing, when the comparing step identifies one or more stress violations, the optimal scheduled current for one or more resources contributing to the one or more stress violations; and calculating, when the comparing step identifies the one or more stress violations, updated optimal scheduled current for one or more resources not contributing to the one or more stress violations.