As for insufficiency of adjustable capacity in the system operation due to active output predictionerror of new energy

the reactive power adjustable capacity of new energy is defined by the introduction oflimit theory. In view of randomness and uncertainty of active output of new energy

the active power outputof new energy is classified into different scene with unit of day in accordance with scene analysis methodand is the occurrence probability for each scene is defined as per historical data. The scene reactive poweroptimization model is established and the influence of new energy output to distribution grid is analyzed bythe improved particle swarm optimization algorithm solving model and by the use of improved IEEE 33 node system.