Determining the harmonic effects of nonlinear loads on parallel connected transformers in terms of power factor

This paper presents determination of the actual values of the apparent resistance and reactance components of two loaded single phase transformers operated in parallel, and how the load is distributed between them. The input voltage waveform and both the individual and total input current waveforms of the two transformers were obtained with the aid of an ADC card, and their harmonics through a harmonic analysis programme. The current and voltage harmonics were then used to find the R and X parameters of each transformer for each harmonic. Then the effective R and X values of each transformer were determined