Short-term voltage stability constrained ORPF for real-time voltage control

Abstract

In power systems with high renewable energy penetration, short-term voltage stability (STVS) has become an increasingly critical issue. In future real-time automatic voltage control (AVC), sufficient STVS margins need to be incorporated into the optimization process. However, the strong coupling between the STVS and steady-state features makes it challenging to formulate suitable constraints for real-time optimization. This paper proposes a short-term voltage stability constrained optimal reactive power flow (STVSC-ORPF) model for real-time AVC. First, a short-term voltage stability index is employed, and it is mapped into device-level reactive power-related features and system-level aggregated features to approximate transient voltage responses within the state space. Then, a partitioned constraint construction method is proposed to achieve dimension reduction. Finally, feature coefficients are estimated from offline datasets via the least squares method. The constraints are embedded into the ORPF model and solved efficiently with gradient-based optimization algorithms. Case studies on the CSEE-VS 66-bus system demonstrate that the proposed strategy effectively enhances STVS while ensuring real-time computational efficiency.