Real Power Restoration Based LVRT Control Strategy for Weak Grid-Tied VSC System

The increasing adoption of renewable energy sources in recent years and beyond has led to the retirement of fossil fuel-based power generation units. These renewable energy sources are connected to the power grid using power electronic converters. Typically, these converters comply with grid code regulations (GCR) to ensure they can effectively handle low voltage conditions and provide reactive power support. Maintaining the connection between the DC source and the grid while providing grid support is crucial during a voltage sag event in the grid. This research paper introduces a control strategy for low-voltage ride-through (LVRT) events that can successfully ride through voltage sags caused by faults while strictly adhering to the ramp rate limits for restoring real power, as specified by the grid code. The effectiveness of this LVRT control strategy is demonstrated through simulations using MATLAB2019b/Simulink.