Loss of low-frequency data in on- line frequency response analysis of transformers

Power transformers are a key component of the electricity supply grid. Monitoring and assessment of their condition has always been of great concern [1]. In critical situations, transformer failures can cause irreversible damage and considerable financial loss to the grid stakeholders or even the end-users [2], [3]. In this regard, mechanical defects are considered a major problem in distribution and power transformers [4]. Consequently various diagnostic techniques have been developed to identify transformer mechanical defects and winding deformation.