In　recent　years,　the　installed　capacity　of　photovoltaic　(PV)　power　keeps　increasing　rapidly.　However,　the　typical　control　objective　of　the　PV　system　is　to　provide　as　much　active　power　to　the　system　as　possible,　ignoring　the　reactive　operating　characteristics　of　PV　inverters.　On　this　basis,　an　active　and　reactive　power　coordinated　control　method　of　PV　system　suitable　for　electromechanical　transient　stability　analysis　is　proposed　in　this　paper.　Firstly,　the　mathematical　model　for　PV　inverters　is　established.　Then,　a　novel　active　and　reactive　power　coordinated　control　method　based　on　an　improved　double-loop　control　scheme　is　proposed,　according　to　the　steady-state　active　and　reactive　power　operating　limits　of　PV　inverters.　The　voltage　control　loop　is　to　get　active　and　reactive　current　component　references,　combining　the　maximum　active　power　point　tracking　under　present　solar　irradiation　and　reactive　power　controlling　under　system　voltage　requirements;　the　current　loop　realizes　the　active　power　and　reactive　power　coordinated　control.　Finally,　the　effectiveness　of　the　proposed　control　method　on　power　system　transient　stability　is　tested,　based　on　the　IEEE　standard　test　system.　Simulation　results　show　that　the　proposed　coordinated　control　method　for　photovoltaic　inverters　is　helpful　in　improving　the　angle　stability　and　voltage　stability　of　power　systems.