Cálculo de pérdidas adicionales causadas por la circulación de armónicas de corriente en los transformadores de distribución.

In the present project, it´s analized the main effects of the harmonic current distortion in the monophase distribution transformers immersed in oil of 10, 15, 25 and 37.5 kVA are analyzed 24 hours a day, from a characteristic harmonic spectrum. According to the revised technical literature, the current harmonics generate an additional increase in the losses and the decrease of the nominal power of the transformers due to the high content of non-linear loads. A bibliographic review is presented regarding: single-phase distribution transformers and their losses, harmonic distortion and the effects of current harmonics in the distribution transformers. The methodology of the algorithm for calculating additional losses caused by the circulation of current harmonics in the single-phase distribution transformers is defined, the solution algorithm is developed and the sequence of calculations is automated in a dichromatic scheme and the chapter is programmed calculation sequence in the MATLAB GUI tool. Finally, the results obtained are presented applying the procedure developed from the ANSI / IEE C57.110TM-2008 standard and the results obtained with the GUI application. The results presented are the report of the increase in losses and the adequate power of the transformer in the presence of non-sinusoidal currents. Based on the recommendations of the ANSI / IEEE C57.110 standard, a procedure was developed to calculate the total losses in the single-phase transformer when it feeds non-linear loads. With the proposed procedure, a sequence of calculations was developed, that is, a calculation algorithm based on the recommendations of Lee and Christensen methodology. With the GUIDE tool of the MATLAB engineering software and with the proposed calculation procedure, a graphical user interface (GUI) was developed, it allows to calculate the additional losses caused by the circulation of current harmonics in 10-phase single-phase distribution transformers, 15, 25 and 37.5 kVA automatically. For the evaluation of the previously described transformers before a characteristic harmonic spectrum, the analytical methodology obtained from the ANSI / IEEE C57.110 standard and the automatic methodology (GUI) is used, determining the capacity reduction and the permissible current of the transformer for non-linear loads, and finally a comparison of the results obtained is carried out.