Unit Commitment with Frequency‐arresting Adequacy Constraint: Modelling and Pricing Aspects

Frequency-arresting (FA) adequacy has received an increasing attention in operation of power systems with intermittent, electronically connected wind and sfolar generation. Presence of high penetration of renewable energy leads to reduced amount of inertia in the power system and the need for more sustainable market design. This paper addresses the FA adequacy by integrating Nadir and rate of change of frequency constraints in unit commitment formulation. Here, a mixed-integer linear program (MILP) is proposed for addressing the FA adequacy. The proposed MILP model of FA adequacy is non-convex and accordingly, FA adequacy pricing requires non-convex pricing techniques. The explicit and implicit uplift payment techniques are proposed and implemented for FA adequacy pricing using the authors' proposed MILP model. The primal-dual formulation is employed for implicit uplift technique. The proposed MILP model of FA adequacy along with its pricing techniques is carefully studied through an illustrative example system. For further discussions, the Nordic 44-node test network is studied.