Optimization of dielectric strength test for the selection of insulating compounds for underground powercables

The selection of new compounds for the manufacture of underground power cables, involves a lot of qualification and acceptance testing according to the standards applicable to such cables. All these tests have been performed on samples or complete cable, which implies that the time and production costs of these tests are too large, some having reached up to one year to obtain preliminary results . In the present work an analysis of existing global models proposes a testing methodology based on the different types of failure that are evaluated in the power lines, making an adjustment to perform all required high voltage tests on a full cable model, this will be done on more economic samples and in a short time, in order to have a complete idea of the quality of materials and their behavior. For the optimization model, we used simulation finite element techniques, in order to get the best geometry, which allows us to make the assessment according to test requirements, together with the optimization of the high voltage electrodes to be employed for the characterization of different materials. In order to validate the model results impulse tests, industrial frequency tests and ageing tests were performed on the models manufactured. The results obtained were compared and validated with a similar test on full underground power cable samples using Weibull Distribution, favorable results were obtained and the test and models were validated. Results and considerations with proper interpretation of both are given and validated against full cable samples tests.