Evaluation of Multifunctional PV Inverters Operation During Faults

This paper studies the performance of a multifunctional inverter (MI) connected to a distribution grid in faulty operating conditions. The MI includes a conventional power generation from a photovoltaic source, an active filter for harmonics, power factor correction and phase balancing for non-linear and unbalanced loads connected at the same point of common coupling. A model of the MI is proposed, and the analysis in a CIGRE low voltage test grid is performed for fault conditions. The inverter operation is analyzed according to IEEE Std 1574:18. Therefore, the MI must be disconnected very fast for faults that produce severe voltage sags, to avoid damage. On the other hand, for faults that produce more shallow voltage sags, the MI must operate safely, complying with the fault ride-through standards.