The use of Saber simulator for non-linear magnetic devices simulation: analysis and improvements

The modeling of transformers, reactors, inductors, and others magnetic devices for use in electrical and electronic circuits requires that the core hysteresis loop be exactly modeled. In this way, this paper is focused on the subject of transformer´s model based on the association of linear and non-linear reluctances. This approach is suitable for use in specific computational packages such as the Saber simulator. This program allows models to be represented in terms of linear or non-linear algebraic or integral-differential equations. The internal library templates of electromagnetic devices already available on this simulator are discussed and applied in their original form. To illustrate the methodology performance, a single-phase core type transformer was considered. A comparison between measured and simulated transformer non-load current wave shape and the associated BH loop shows the necessity of improving the model for the non-linear magnetic core. The Jiles-Atherton approach, as implemented into the simulator, has shown to produce results with applicable discrepancy in relation to the measured values. This suggested the need for improvements on the existing template. An optimization algorithm based on combination of the Hooke-Reeves direct search method and simulated annealing methodology, in conjunction with the original Jiles-Atherton model, is used to achieve parameters to a better presentation of the non-linearity. The single-phase core-type transformer was again simulated and results showed a good agreement between the simulated and measured values.