Switching of AC filters is an important part in the operation of DC power transmission system

which affects the power transmission amount and power quality. In this paper

the configuration and AC filter automatic switching on and off logic at certain converter station is introduced; the abnormal switching circumstance of AC filter due to manual operation and discharge in the actual operation after maintenance is studied and improved;and the filter’s switching is normal after the improvement. The logic defect of low current switching off function of AC filter is analyzed and the improvement suggestion is given.