Study on Harmonic Load Loss Calculation Method of Oil-Paper Insulated Distribution Power Transmission Equipment

At present, there are a large number of nonlinear electrical equipment in the power system, which leads to higher and higher harmonic components in the system. In addition, the large number of new energy access, such as photovoltaic, wind power and so on, also introduces large harmonic interference. Harmonic has a certain influence on the loss of distribution transformer in operation. Based on the principle of harmonic current acting on transformer, the winding resistance loss, winding eddy current loss and stray loss of distribution transformer under non-rated condition are analyzed in this paper. The load loss calculation model in the IEEE Std C57.110 is further revised. Based on the model established in this paper, the selected example transformer is calculated and analyzed. The accuracy of the calculation model established in this paper is verified by the analysis results. The larger the harmonic distortion rate and harmonic frequency, the faster the load loss of distribution transformer increases.