Due to the large number of sub-equipment and special equipment performance

the series compensation（SC）overhaul has caused problems such as large workload

long time-consuming and low efficiency.In order to solve these problems

this paper combines the characteristics of China’ s first 750 kV Riyueshan-Haixi-Caidamu transmission line SC project

and proposes a 750 kV SC key equipment state self-assessment system design scheme.The daily operation and maintenance data gives the status evaluation conclusions of key equipment such as capacitor banks

MOV

GAP

and damping devices.Therefore

a more accurate and efficient overhaul work plan can be formulated based on this status evaluation system.This solution has great reference value for achieving fine control of SC overhaul and maintenance work

reducing costs and increasing efficiency.