Security region of renewable energy integration: Characterization and flexibility

Abstract

Facing uncertainties related to large-scale renewable energy generation, power systems are confronted with immense challenges in the security operation. To capture the capability of renewable energy integration more accurately on a short timescale, this paper proposes a security region evaluation method obtaining every feasible point rather than the only maximum output point of renewable generators. This evaluation method is based on multi-parametric programming considering network operational constraints, including N−1 security constraints and variable limits. In the obtained security region, each feasible point can map the values of the objective function and optimal variables of the OPF model, which is beneficial for the real-time dispatch. Furthermore, the flexible spaces including the deep peak regulation of generators and the emergency transmission rates of lines are considered to extend the security region of renewable energy integration. The security regions of renewable generator outputs and the transmission power of tie lines, which reflect the range of renewable energy self-accommodation and outside-accommodation, are quantified considering these flexible spaces. The proposed method is tested on the IEEE 39-bus and IEEE 118-bus systems.