D26.8 - A Novel Low-Voltage Ride-Through Control for Bidirectional Megawatt Charging System with Grid Support Capability

The rapid deployment of megawatt charging systems (MCS) for heavy-duty electric vehicles (HDEVs) poses challenges to grid stability, especially during voltage sags. Conventional chargers operate at fixed power factor and disconnect when the point of connection voltage drops below 0.7 pu [1], causing abrupt load withdrawal that worsens instability and disrupts protection. This paper proposes a low-voltage ride-through (LVRT) control strategy for bidirectional megawatt-scale chargers with reactive power support. The method coordinates front-end and back-end converters to reduce active power and inject reactive current during voltage sag conditions, accelerating voltage recovery and enhancing AC-side protection. The proposed control strategy is implemented and tested on the IEEE 13-bus feeder in MATLAB/Simulink under both charger-induced sags and grid faults. Results show that the proposed controller sustains charger operation and enables megawatt-scale stations to act as stabilizing resources, strengthening grid resiliency during disturbances.