Life Assessment Study on Distribution Electric Power Transmission Equipment Based on Harmonic Modified Hot Spot Temperature Calculating Model

摘要

Distribution transformer is widely used as an important energy transmission equipment. With a large number of new energy such as photovoltaic and wind power connected to the grid, the harmonic interference in the power system becomes more and more serious. Harmonic disturbance has a continuous impact on the daily operation of distribution transformers. In this paper, the relationship between harmonic disturbance and service life of distribution transformer is studied. Firstly, combined with harmonic no-load loss and winding skin effect, the hot spot temperature calculation model is improved. Secondly, the temperature rise test is carried out to verify the accuracy of the model. Finally, based on the improved hot spot temperature calculation model, the corresponding life evaluation model of distribution transformer is proposed. The results show that the harmonic current disturbance will cause a sharp increase in the relative aging rate of the transformer and seriously shorten the life of the transformer.