Based on the double angle vector and grid systems islanding protection method

The present invention discloses a method of a photovoltaic power generation islanding protection system, which is based on active islanding protection technologies double angle vector, and before the perturbation technique uses the two voltage vector angle disturbance, disturbance extract components therein, Sandia islanding protection and integration technology; this method not only improves the performance of a photovoltaic system islanding protection, but also overcomes the shortcomings of conventional phase active power fluctuations caused perturbation algorithm to improve the performance of the output power of the inverter during normal operation.