Optimizing Renewable Energy Integration: Real-Time Current Limiting for Grid-Feeding Inverter During LVRT Operation

The present study delves into the complexities surrounding the integration of renewable energy sources, particularly grid-feeding inverters, into the power system. These inverters are tasked with bolstering grid stability during faulty conditions while maintaining connectivity. A modified fault ridethrough (FRT) methodology is proposed for a grid-linked inverter featuring an inductive filter. This method emphasizes both positive and negative sequence controls to ensure dual current regulation. Adhering to grid code stipulations, the suggested approach involves injecting reactive power during voltage dips and curtailing active power and oscillations at twice the grid frequency. Furthermore, a fresh real-time current limiting approach is introduced, which curbs active power via a closed-loop current magnitude controller to avert inverter tripping. The efficacy of the suggested approach is verified through numerical simulations encompassing various balanced and unbalanced grid fault scenarios. This study makes a substantial contribution to enhancing the dependability and stability of renewable energy systems assimilated into the power grid.