The fault ride-through capability of the unified power flow controller（UPFC） is limited because of weak insulation capacity of electronic equipment.In this study

the fast fault isolation technique for UPFC series side was employed to propose a restarting strategy of UPFC control protection system combining with power grid protection for improving its fault ride-through capability.When a fault affecting UPFC operation happens

the characteristic variables are used to distinguish the fault area and type.If the AC power grid is distinguished to be abnormal

the operation state of the power grid and the running capacity of UPFC are detected according to the fault characteristics

and the strategy of fault ride-through or UPFC automatic restarting after short-time locking is performed.The discrimination principle and implementation method of the strategy are described.This strategy was applied to the system commissioning and operation of the Western Nanjing 220 kV Power Grid UPFC Project and the Southern Suzhou 500 kV Power Grid UPFC Project

and the results showed that the strategy has good application feasibility and adaptability to power grid

and it can further improve UPFC fault ride-through capability.