Power transmission of high voltage

large capacity and long distance

adverse meteorological environment

AC/DC fault coupling propagation

a large number of application of power electronic equipments and other factors have brought new challenges to power system protection and security control. Firstly

the causes and the types of transmission and trans-formation equipment faults

as well as the difference in fault consequences are analyzed in this paper

and the technical system of pro-active protection and control(PPC)of power equipment is proposed. Then

the concepts of security region

dynamic security margin and tolerance time for safety of power transmission and transformation equipment are proposed to describe the safety of equipment as the main features. The technical architecture of pro-active protection and control is further proposed cored on the prediction of security region and security parameters of equipments. Finally

main technical directions of the pro-active protection and control are analyzed in this paper

and feasibility of the corresponding key technology

and prospect of the pro-active protection and control are discussed.