Planning and operation of distribution networks become increasingly challenging with the large-scale grid connection of electric vehicles （EVs）. Studying the orderly control and unified scheduling of EV charging and discharging can facilitate peak load regulation assisted by the load of substantial EVs. In response to the distribution network overload caused by the extensive grid-connection of EVs， a potential evaluation method for electric vehicle aggregation considering subjective and objective response capabilities of the grid side and the user side is proposed. Then， EVs are classified by the k-means clustering algorithm and contour coefficient method， which improves the efficiency of the model solving when massive EVs are connected to the grid under the premise of sufficient operational fluidity of EVs. Finally， the weight set is obtained by the comprehensive weighting method combining the analytic hierarchy process and entropy weight method， and the aggregation potential evaluation result of electric vehicle demand response is obtained by the rank-sum ratio（RSR） comprehensive evaluation method. The simulation results validate the effectiveness and superiority of the proposed evaluation method， providing a new approach for the unified scheduling of EVs， and having engineering value for ensuring the safe and stable operation of the power grid.
