Abstract
Failure progression of metal oxide-based surge arresters
in response to exposure to harmonics is modelled using the
accelerated failure time model. Multi-stress accelerated ageing
tests, with and without AC distorted voltage stress, are conducted
on arrester samples sourced from different suppliers to obtain
baseline and harmonic-factor logarithmic life and reliability
functions. A maximum likelihood approach is taken to estimating
the accelerated failure time model parameters based on the
failure time data. The modelled harmonic-factor reliabilities
prove MOV life acceleration and show multiplicative failure
progression of up to 41 times faster for a THD content of 8.52%
in the applied voltage stress.