High-Voltage Ride-Through Method for Single-Stage Grid-connected Photovoltaic System Based on Model Predictive Control

Grid-connected PV inverter plays an important role in solar power applications. Since large-scale switching-off loads and grid faults may lead to voltage swell in the grid, the PV system should have high-voltage ride-through (HVRT) ability. This paper found that there are three problems lying in single-stage PV system during HVRT due to its characteristics. In this paper, the relationship between DC voltage, grid voltage and PV output power in single-stage PV system is discussed. On this basis, a calculation method of the minimum required DC voltage for single-stage PV system during grid voltage swell is proposed. Further, a HVRT method based on model predictive control is proposed to enhance steady-state and dynamic performance under grid swell condition. Through this scheme, the output current quality is improved and the ripples in the DC voltage is suppressed. Finally, experimental results according to a control hardware-in-the-loop approach are presented to validate the effectiveness of the proposed method.