Lifetime characteristics of magnet wires under multistress conditions

The objective of this paper is to present the results of a study on the effect of multistress on the lifetime characteristics of magnet wires. The enamel coating on a magnet wire is subjected to multistress aging factors such as electrical, thermal and other environmental stresses. In order to identify the most important factors that contribute to the lifetime of the electrical insulation, the insulation must be evaluated under simulated service conditions. Lifetime analysis provides us with statistical information such as lifetime characteristics, probability of failures and lifetime percentiles. Weibull distribution was used to model lifetime characteristics. Failure data of the aging tests is used to obtain parameters of the frequency-electrical-thermal life model. Accelerated life tests are performed on AWG 40 gauge Type B magnet wires. The life model used to describe the behavior of insulation in the presence of multistress can also be used to estimate the lifetime of magnet wires at any desired stress level.