With the construction of UHVAC and UHVDC hybrid power grid

power grid faults can lead to a variety of security and stability problems. In order to make dispatchers effectively respond to various kinds of power grid fault

Hunan power grid actively promotes the pilot work of online check module of fault preplan. This paper briefly introduces the main functions of the fault preplan check module based on online security analysis

and promotes fault preplan check of two maintenance plans of Hunan power grid. According to the two maintenance plans

the possible grid risks in the actual operation of the power grid are pointed out and the effective subsidiary decisions are provided. At last

the effectiveness of subsidiary decisions are proved by graphical operation. The construction of fault preplan check module based on online security analysis has great significance on safe and steady operation of power system.