The active control ability of the electric vehicle(EV)load is studied for the parked EV in a specific area. Firstly

according to the status parameters of parked EVs

the status matrix of EVs is established. Secondly

all the parked EVs are divided into two status

i. e.

controllable status and uncontrollable status

and the charging behaviors of EVs with controllable status are controlled. Finally

the controllable EVs' load margin boundary is got by using recursion

and the corresponding control strategy for specific control objectives is proposed. In the premise of the reliable two-way communication system

the upper dispatch department can monitor the real-time using margin of EVs based on the EV load margin boundary

so as to achieve the goal of load balance with EVs for the specific area. This work is supported by National Natural Science Foundation of China(No. 51261130473

No. 51477116).