Online current limiting-based control to improve fault ride-through capability of grid-feeding inverters

Grid-feeding inverters require much better operation monitoring and improved performance for their safe and efficient integration into the power system. Specifically, these inverters must participate in grid stability enhancement under faulty conditions and without any disconnection. In this regard, a fault ride-through capability is proposed for an inductive filtered grid-feeding inverter, which is controlled in both positive and negative sequences to ensure dual current control. Grid voltage dips are tackled by injecting a reactive power according to grid codes requirements. Enhanced active power control is introduced by suppressing oscillations, which are twice the grid-frequency. In order to avoid the inverter and semi-conductor components tripping under grid faults, a new current limiting strategy is proposed. It is based on real-time active power reduction using a closedloop current magnitude controller. The effectiveness and flexibility of the proposed control strategy are verified by numerical simulations in both balanced and unbalanced grid fault cases.

Automated summary

This study proposes a fault ride-through capability control method for grid-feeding inverters, ensuring stable operation during grid faults through strategies such as dual current control and real-time active power reduction.