During the development transition period of China's ultra-high voltage(UHV)power grid

the characteristics of power grid continue to change significantly. The traditional defense technologies and measures on security and stability are difficult to adapt

thus the security prevention and control system is needed to improve. The necessity and demand of “system protection” to adapt to construct UHV AC/DC power grid is put forward based on the characteristic-changes of power grid. The design of system protection is proposed

including design ideas

overall composition and specific measures. Then the key technologies of system protection are put forward

and the requirement and framework of panoramic state perception

real-time decision-making and coordinated control as well as precision load control technology are focused on. Finally

the implementation scheme of system protection construction for State Grid Corporation of China is briefly illustrated

which provides a solution for the safe and stable operation control of large-scale UHV AC/DC power grid.