The grid-connection strategy of double fed VSCF wind power generator without voltage sensors

The traditional grid-connection strategies of doubly fed VSCF wind power generator need to detect the grid voltage for vector orientation. This paper presented one novel strategy which doesn´t need voltage measurement. It designed a kind of grid virtual flux (GVF) observer without voltage sensors, which realized the initial flux estimation by the cooperation of grid side converter (GSC) when it start to work, and constructed the grid-connection strategy based on the GVF oriented vector control technology. The experimental research demonstrated the strategy´s effectiveness in connecting the generators to the grid quickly and safely at variable speed.