Secure states By adjusting the output of G1 and G2 before the outage occurs,avoiding the overloading when outage occurs---the meaning of security! ■ The analysis tool for taking measures to avoid overloading after outages is SCOPF Due to some large blackout in interconnected power network,the priority in operation is defined: Power is reliably delivered In the range of reliability,try to make the system as economic as possible No power system is 100%secure,simply because it is not economic! 电力拿镜广城洲量写控制四川省童点实验蜜 家电网电力系统广域测量与控制四川省重点实验室 Secure states  By adjusting the output of G1 and G2 before the outage occurs, avoiding the overloading when outage occurs---the meaning of security!  The analysis tool for taking measures to avoid overloading after outages is SCOPF  Due to some large blackout in interconnected power network, the priority in operation is defined:  Power is reliably delivered  In the range of reliability, try to make the system as economic as possible  No power system is 100％ secure, simply because it is not economic!