A dynamic thermal based reliability model of cast-resin dry-type transformers

摘要

In this paper, some models have been introduced for dynamic thermal modeling of cast-resin transformers which are based on genetic algorithm. A typical 400kVA cast-resin transformer has been selected and the model parameters are estimated and validated with the help of experimental data extracted from different load cycles. The estimated models are used to generate a reliability model for cast-resin dry-type transformers and the effects of variation in load, ambient temperature and atmosphere conditions on the reliability of cast-resin transformer are illustrated. As it will be shown in this paper, the effects of working conditions on the life-time of insulation in dry-type transformers is very considerable and because of highest temperature range (in comparison with oil-immersed transformer), reliability is more sensitive to variation of load, ambient temperature and atmosphere conditions.