Transient overvoltage is a dominating cause in damaging insulation and power plants, which possibly leads to severe power system failures and threatens safety operation of the power system. Thus, it is increasingly emphasized to equip the system with accurate measuring ability for the transient overvoltage. This paper reviews the existing technologies on measuring transient overvoltages, which are categorize by contacted and non-contacted technologies based on their principles. In details, the principles, features and application ranges are summarized over voltage divider, bushing tap, GIS sensor, field sensor, optical sensor, etc.
