A Temporary Overvoltages Mitigation Strategy for Grid-Connected Photovoltaic Systems Based on Current-Source Inverters

Temporary overvoltages (TOVs) typically caused by short-circuit faults and switching events can impose considerable damage on power system equipment. Furthermore, the penetration of distributed generations into the utility grids may intensify the problem arising from the TOVs. Despite recent research advancements, the TOV problems with current-source inverter (CSI)-based photovoltaic (PV) systems have not been investigated comprehensively. This paper proposes a combination of virtual impedance and modified switching strategy for grid-connected CSI-based PV systems. The virtual impedance-based control damps current and voltage oscillations. On the other hand, the proposed pulse width modulation strategy restricts power injection during the fault conditions. Simulation results confirm that the proposed approach effectively mitigates the TOV without controller mode switching between the standard and fault conditions.