Participation of Load Resources in Day-Ahead Market to Provide Primary-Frequency Response Reserve

Abstract

With integration of more and more renewable energy resources, it is becoming increasingly difficult to maintain adequate primary frequency control (PFC) capability for a future power grid, especially under low system inertia conditions. Load resources (LRs) equipped with under-frequency relays can participate in PFC supplementing to the governor responses from synchronous units. In this paper, we propose an energy, inertia and frequency response reserve (FRR) co-optimization formulation in the day-ahead market where both primary frequency reserve (PFR) from synchronous generators and fast frequency response reserve (FFR) from LRs are procured in a cooperative way to meet the desired FRR need tied to the system inertia condition. Since FFR is more effective than PFR in arresting the frequency decline, the proposed approach will yield different marginal prices for FFR and its PFR counterpart to award the speed of response. As the formulation proposed involves bilinear terms in optimization problem, a linear reformulation techniques with big M is proposed to transform the problem into a mixed integer linear programming which can be solved by the commercial solver CPLEX. The case study shows the effectiveness of the proposed approach and the correctness of the quantities and prices of the cleared reserve.