Enhanced Active Power Control and Low-Voltage Ride-Through for Offshore PMSG Wind Turbines Using Model Predictive Control

Abstract

This paper presents a comprehensive analysis and design of an enhanced control framework for offshore wind turbine generators (WTGs) equipped with permanent-magnet synchronous generators (PMSGs) and full-scale power converters. The proposed strategy integrates Model Predictive Control (MPC) for maximum power point tracking (MPPT) on the machine-side converter (MSC) with a coordinated reactive-current injection scheme on the grid-side converter (GSC) to satisfy Low-Voltage Ride-Through (LVRT) requirements stipulated by modern grid codes. Furthermore, a synthetic-inertia emulation loop is embedded within the GSC controller to provide primary frequency support to the hosting network. Analytical derivations of the machine model, energy-extraction criterion, and DC-link energy buffer constraints are provided. Simulation results demonstrate that the proposed MPC-MPPT scheme achieves a tip-speed ratio (TSR) tracking error below 1.5% across the entire operating wind-speed range, while the LVRT module maintains continuous grid connection during symmetrical voltage dips of up to 100% depth lasting 150 ms, fully conforming to the EN 50549-2 standard. The synthetic-inertia contribution raises the effective system inertia constant by approximately 2.0 s, reducing the frequency nadir by 18 mHz following a 5% generation-loss event.