A Review of Methods and Associated Models used in Return Voltage Measurement

The measurement of dielectric properties of high voltage equipment insulations gives the basic information of the condition of the insulation. This helps in determine the aging process in the insulation. The diagnosis of the dielectric properties of the insulation materials can be performed either in time or frequency domain. In the time domain, measurement of voltage return was introduced by Endre Németh in the mid of 1960's to study the slow dielectric polarization process. This technique then gave birth to new techniques Return Voltage Measurement and Voltage Response method. Due to the non-destructive nature of the techniques, they gain the attention of the researchers for the study of the insulation diagnosis. Since their birth the methods have been used by many researchers to study the aging and dielectric relaxation processes in the insulations with the introduction of different dielectric models such as Debye and Maxwell models. In this research work some recent research work done in the measurement of return voltage technique is studied with suggesting some potential areas of the implementation of the technique.