Title |
Anti-islanding Method by Harmonic Injection for Utility Interactive Inverter with Critical Load |
Authors |
Hyeong-Min Oh ; Se-Wan Choi ; Tae-Hee Kim ; Gi-Pung Lee ; Tae-Won Lee |
DOI |
10.6113/TKPE/2012.17.4.315 |
Keywords |
indirect current control; active anti-islanding; utility-interactive inverter; critical load |
Abstract |
The utility-interactive inverter with critical loads should supply continuous and stable voltage to critical loads even during the grid fault. The conventional control method which performs current control for grid-connected mode and voltage control for stand-alone mode undergoes the critical load voltage variation during grid fault. The critical load voltage may have large transient when the inverter performs mode transfer after the islanding detection. Recently, the indirect current control method which does not have the transient state during not only islanding detection but also the mode transfer has been proposed. However, since the voltage control is maintained even during the grid-connected mode it is difficult to detect the islanding. This paper proposes an active anti-islanding method suitable for the indirect current control method which does not have NDZ(Non-Detection Zone). |