Novel low voltage ride through strategy of single-stage grid-tied photovoltaic inverter with supercapacitor coupled

Abstract

This paper proposes a control method for improving the performance of single-stage photovoltaic (PV) inverter with supercapacitor coupled. Connecting by a bidirectional DC-DC converter, supercapacitor is then indirectly coupled to the common dc-link of whole inverter. Transient maximum power point tracking (Transient MPPT) method is employed to realize fast MPP tracking without causing obvious output distortion. At the same time, the operational performance of low voltage ride through (LVRT) is improved with the assistant of fast energy storage which helps inverters recover from voltage dip fault fast. All these theoretical findings are verified by Matlab simulation and constructed laboratory prototype.