Voltage and current-harmonics induced ageing in electrical insulation

Health of a high voltage electrical equipment is decided by the strength of its electrical insulation. With the use of non-linear loads, penetration of renewable energy sources and islanded grid operation, the level of voltage and current harmonic pollution on the electrical equipment terminal has increased. Although there are many established diagnostic and prognostic techniques to study the condition of an electrical insulation, the effect/influence of harmonics is neglected on the life of an insulation. An attempt has been made to critically review the literature on effect of voltage and current harmonics. Finite Element model and the results of simulation study are presented to demonstrate the influence of harmonics on electrical insulation.