Now

China has built many AC/DC hybrid systems. The disturbance in operation which causes voltage security problem has been highly concerned. Due to the limits of control ability and responding time

the traditional voltage correction control cannot deal with all the disturbance. Thus

regulation ability of DC system is used to correct over-limited voltage. Firstly

this paper sets up voltage security region optimization model of multi-scale AC/DC system

as the base of voltage correction control according to the different action modes and the characteristics of disturbances. Then

aiming at different scales of security region

this paper sets up voltage correction control optimization model to maintain the voltage within the security region under both normal condition and N-1 contingency. Finally

the feasibility and effectiveness of the method are proved by simulating a real system model.