In view of the problem that the fault current is difficult to be detected due to the special system structure and operation mode of the micro-grid

a typical CERTS microgrid power generation system model is established and such microgridprotection scheme as the impedance amplitude variation on the busbar beforeandafterthefaultistakenasbaseforthefaultdetectionanditsphaseanglevariationasfaultlocation.The double criteria is adopted on the basis of variation of the measurement impedance of the busbar to overcome the shortcoming of traditional current protection. The model and the protection scheme proposed in this paper are simulated and analyzed on the basis of PSCAD/EMTDC platform. The Matlab software issued for data processing. It is shown by the simulation result that the scheme can distinguish clearly internalandexternalfault

detect

locate and eliminate the fault timely.