Reactive Power and Voltage Online Optimization Control Strategy for Urban High-Voltage Power Grid with UPFCs

With the growing cableization of urban high-voltage power grids, the network’s inductive characteristics progressively transition to capacitive dominance, rendering traditional reactive power compensation-based voltage control methods inadequate for this structural shift. To address this challenge, advanced control devices such as Unified Power Flow Controllers (UPFCs) and high-voltage reactors are being widely deployed in urban power systems. This paper proposes a predictive optimization control model for reactive power and voltage regulation in UPFC-integrated urban high-voltage grids, leveraging 24-hour rolling load forecasting data. The optimization model minimizes comprehensive network losses, voltage deviations, control costs, and adjustment efforts while satisfying operational constraints, including power flow balance, nodal voltages limits, equipment capacity boundaries. The Cuckoo Search (CS) algorithm is used to solve this nonlinear optimization problem. additionally, a real-time predictive-correction control framework is developed to dynamically refine the control strategy by comparing actual and forecasted load deviations. Simulation studies on a modified IEEE 30-bus test system validate the proposed approach, demonstrating significant improvements in reactive power and voltage control performance compared to conventional methods.