Improved High Voltage Ride-Through Control Strategy for Single-Stage PV System Based on Dynamic Reactive Power Support

Operating at unity power factor in the maximum power point tracking (MPPT) mode is the most common control scheme for single-stage photovoltaic (PV) systems. However, with rising grid voltage, the PV inverter may experience overmodulation and subsequently lose control. Therefore, an improved high voltage ride-through (HVRT) control strategy, incorporating a variable DC-link voltage reference and dynamic reactive power support, is proposed. Initially, the model of a single-stage PV system is introduced. Subsequently, the fault characteristics of this system under high voltage conditions are analyzed. Subsequently, the improved control strategy, incorporating dynamic reactive power control, is integrated into the traditional dual-loop control scheme. Finally, simulation cases validate that the proposed control can prevent over-modulation and provide dynamic reactive power support.