A Dual Timescales Reactive Power Optimization Control Strategy Considering Voltage Security In Doubly-Fed Wind Farm

The increasing scale of grid integration for wind power has led to significant voltage security challenges faced by wind farms. In this paper, a dual timescales reactive power control (RPC) strategy considering voltage security in doubly-fed wind farm is proposed. The mathematical model for reactive power optimization control (RPOC) under dual timescales is established, taking into account the varying reflection speeds of different RPC methods in the wind farm. The objective function includes system node voltage deviation and reactive power reserve margin capacity. In the long timescale, slow adjustments are made to the on-load tap changer (OLTC) transformer and capacitor banks (CBs), while in the short timescale, rapid adjustments are made by fully utilizing the flexibility of doubly-fed wind turbines (DFIG) and static var generators (SVG). Simulation examples comparing different RPC methods verify that the proposed approach effectively reduces internal voltage and point of common coupling (PCC) voltage limitations within the wind farm, ensuring safe operation of the grid-connected wind power system.