Grid-connected PV-APF system with anti-islanding protection

SUMMARY A multi-string grid-connected two-stage photovoltaic system acting as an active power filter with anti-islanding and fault protection is presented. The inverter is current controlled for harmonic compensation. Harmonics in the load current are detected by a time-domain technique. A time-domain technique based anti-islanding method is proposed. Moreover, our time-domain technique is also utilized to detect faults in the dc bus of the inverter. The simulations were performed in PSCAD/EMTDC, and experimental results are provided to validate the concept. Copyright © 2012 John Wiley & Sons, Ltd.