Efficient Peak Current Limit Strategy and Active Power Oscillation Reduction in a Three-Phase Grid-Interfaced PV-Battery System (GIPVBS) with Low Voltage Ride-Through Control

This research study presents a grid-interfaced photovoltaic (PV) battery-assisted system with a single-stage configuration and low-voltage ride-through (LVRT) control that adheres to the Indian grid code standards. The suggested LVRT approach ensures continuous connection of solar power to the grid, preventing system shutdown during grid disturbances and faults. The inverter ensures continuity of the connection by supplying reactive power to the grid, utilizing its capacity to effectively restore stable voltage levels at the grid connection point. A straightforward yet efficient inverter peak current limiter control is proposed, determining the maximum allowable power for various scenarios and adjusting the grid injection current accordingly. A control algorithm is also recommended to mitigate active power oscillations and address DC-link voltage fluctuations. To enhance the system’s dynamic performance post-fault, a modified drift-free Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) algorithm is implemented. The proposed approach effectively limits the maximum current to the inverter’s rated capacity while reducing active power oscillations and stabilizing the DC-link voltage. The system’s performance is validated through simulations using MATLAB/Simulink, which involves an 8.3 kW single-stage grid-connected solar PV plant subjected to both symmetrical and asymmetrical faults. The setup and control system is implemented on a real-time test bench (RTS) called OPAL-RT 4510 for practical validation. The results obtained from this real-time setup are then compared with the outcomes of the simulation, confirming the effectiveness of the LVRT control strategy.