Dielectric response analysis,performed in time domain and frequency domain is one of the interesting methods used for condition assessment of high voltage equipment.In this article,the degradation of epoxy-mica compos...Dielectric response analysis,performed in time domain and frequency domain is one of the interesting methods used for condition assessment of high voltage equipment.In this article,the degradation of epoxy-mica composite insulation which is widely used in rotating machines has been investigated through frequency domain spectroscopy measurements.Artificial ageing of the carefully prepared stator bar insulation sample was performed through simultaneous application of high temperature and electric field in a designated environmental chamber for specific durations.To study the effect of temperature,the measurements were performed at temperatures ranging from 20 to 60°C at different ageing status.Following experimental work,the measurement results were modelled using Havriliak–Negami model and ageing sensitive parameters were extracted.To study the effect of temperature,the measurements were performed at temperatures ranging from 20 to 60°C.The modelled results matched well with the experimental measurements and certain model parameters sensitive to the ageing condition were identified.The numerical relationships between the insulation status of the stator bar and the aforementioned parameters were identified.It was observed that the nature of the numerical relationship remains identical in the investigated temperature range,although the coefficients vary to some extent.展开更多
基金the DST,Government of India(Grant no EMR/2016/005246)the FIST grant of DST,Government of India(Grant no SR/FST/ETI-362/2014).
文摘Dielectric response analysis,performed in time domain and frequency domain is one of the interesting methods used for condition assessment of high voltage equipment.In this article,the degradation of epoxy-mica composite insulation which is widely used in rotating machines has been investigated through frequency domain spectroscopy measurements.Artificial ageing of the carefully prepared stator bar insulation sample was performed through simultaneous application of high temperature and electric field in a designated environmental chamber for specific durations.To study the effect of temperature,the measurements were performed at temperatures ranging from 20 to 60°C at different ageing status.Following experimental work,the measurement results were modelled using Havriliak–Negami model and ageing sensitive parameters were extracted.To study the effect of temperature,the measurements were performed at temperatures ranging from 20 to 60°C.The modelled results matched well with the experimental measurements and certain model parameters sensitive to the ageing condition were identified.The numerical relationships between the insulation status of the stator bar and the aforementioned parameters were identified.It was observed that the nature of the numerical relationship remains identical in the investigated temperature range,although the coefficients vary to some extent.
