A Probabilistic Life Model for Reliability Analysis of Power Cables Feeding Electric Traction Systems

摘要

A probabilistic life model conceived for estimating the main reliability parameters of power cables operating in distorted regime is here illustrated and applied to feeder cables for power supply systems of city subways. A first key-point of this work is that reliability parameters and functions are derived by simulating the random variability of harmonic pollution according to the probabilistic limits set in EN 50160 Standard. A second key-point is that peak, shape and rms factors, which account for the effects of distorted voltage on cable life, are all considered in the reliability analysis. The application results show that even if harmonic distortion matches EN 50160 limits (in a probabilistic sense), cable life and reliability may be reduced significantly. Furthermore, among the three voltage factors, both peak and shape factors play a non-negligible role for a thorough reliability analysis.