A first step towards predicting the life of HVDC cables subjected to load cycles and voltage polarity reversal

This paper is a first step towards the evaluation of the life and reliability of HVDC cable systems in the presence of voltage polarity reversals. It combines a physical-phenomenological life model for HVDC cables subjected to voltage polarity with a recently-developed life model for HVDC cables subjected to load cycles. Under some meaningful approximations, a quite powerful model that accounts both for load cycles and voltage polarity reversal is eventually attained. Such model can be applied in order to predict the life of HVDC cables subjected to voltage polarity reversal tests with load cycles superimposed, performed in line with CIGRÉ Recommendations after Electra 189, 2000. By doing so, results in agreement with the experience gained by Terna (the Italian TSO) in testing HVDC cables - in particular MIND cables - are attained.