CAD for three phase ONAN cooling system transformers

This paper presents a Computer-Aided Design method for a three phase power transformer using MATLAB programming environment. The considered transformer is Oil Natural Air Natural cooling system type. During the designing by changing the value of just one single variable implies to recalculate everything. Such operation is time consuming but this drawback can be overcome by fully automating the design procedure, for example using MATLAB. The developed program is written in script format so that it can be easily modified to fit the imposed parameters of the transformer. The designing algorithm of the transformer has been optimized. Thus, it has ten steps with nine validation checkpoints. It may also be used as an educational model. The validations are implemented into the code and are required because there is no sure-fire method for designing a transformer from the first attempt. During the design it is necessary to change various values. Thus, only when all nine verifications are satisfied one may conclude that the transformer is well designed.