An improved capability of LVRT in single-stage three-phase grid-linked PV systems

In non-conventional energy system, a grid-linked inverter is a crucial component. Grid disruptions, like imbalances and asymmetrical short-circuit failures, have a negative impact on the inverters’ performance. Therefore, the inverter’s functioning must be improved in such a case. For grid-connected inverters, an improved technique has been suggested in this study for minimizing imbalance current at the time of asymmetrical and symmetrical short-circuit faults. The proposed current limitation technique has three primary features: (i) reactive current injection in accordance with the necessities of the Indian grid code, (ii) removal of second-order harmonics from the instantaneous real power pumped into the grid, and (iii) always maintaining constant inverter current irrespective of the nature and severity of the fault. The proposed grid-linked PV system has been designed and tested in various platforms under both asymmetrical and symmetrical short-circuit fault scenario. The behaviour of the proposed current limiting strategy is investigated and compared with a contemporary method to confirm the efficacy of the suggested technique.