Control strategy to maximize the power capability of PV-based industrial microgrids during voltage sags

Abstract

In industrial microgrids with medium power rating photovoltaic systems, the low-voltage ride-through capability should be incorporated to help keep power system stability. The goal of this paper is to present a control strategy that allows taking advantage of the maximum capability of the inverters to support the most dropped phase in a photovoltaic-based industrial microgrid during voltage sags. Depending on the grid code requirements, the rated current value could be injected by the local inverters during these disturbances. The currents can be injected through the positive and negative sequences depending on the sag characteristics and the power rating of the local inverters. Also, to prevent overcurrent, the controller can apply active power curtailment. Lastly, selected simulation results are presented to validate the performance of the control scheme.