High Voltage Ride- Through Control Strategy for Two-Stage PV Grid-Connected Systems

The increased penetration of photovoltaic power generation affects the stability of the power system. To increase the fault ride-through capability and reduce the off-grid frequency of the grid-connected PV system, this paper proposes a high-voltage ride-through strategy for two-stage grid-connected PV power generation systems based on the standard requirements in the technical regulations for PV power plant access to the power system. The strategy takes into account the influence of the grid-side reactive power change on the high voltage recovery, adopts a segmented control design, and dynamically adjusts the output of the grid-connected inverter reactive power to reduce the grid-connected voltage by adjusting the current command according to the sudden rise of the grid-connected voltage on the premise of meeting the overload capacity of the inverter. Finally, the effectiveness of the proposed control strategy is verified by simulation.