Study on phase lead based islanding detection of grid-connected system

Islanding conditions and damages of PV grid-connected power system were analyzed;and then proposed basic principle and implementation procedure of phase lead anti-islanding detection method with inverter grid equivalent circuit according to islanding IEEE Std.2000-929 and UL1741.Finally the experiment was researched under the condition of islanding,the results prove: phase lead detection method can effectively detect islanding and invariable leading phase and can conduce to increasing resistance and inductance load detection time,the purpose of anti-islanding is achieved.