Analysis Of Harmonic Effect In Distribution Transformer

With the improvement of power system automation,non-linear equipment and power electronics load are widely used in power grid.These equipment bring a lot of harmonic problems in the operation process,interfere with the normal operation of power grid and adjacent equipment,and bring direct economic losses.The distribution transformer is the main electrical equipment in the power grid.With the serious harmonic problems in the power grid,people will pay attention to the inc.rease of transformer loss,derating operation and slhortened service life,as well as the economic losses caused by these problems.In view of the problems existing in the safe and economic operation of distribution transformer under harmonic environment,this paper focused on the harmonic loss,capacity change,life shortening and economic cost of distribution transformer in power system.The applicability of three main methods for calculating harmonic additional loss was analyzed in this paper when the technical parameters of transformer were different,and the influence of harmonic additional loss on harmonic current distortion rate,load'rate and transformer type were also analyzed.At the same time,the applicability of K factor and K coefficient method in calculating transfomer capacity reduction rate under harmonic background were analyzed,and the influence of harmonic on capacity calculation of distribution transformer was studied,as well as the differenc.es of life evaluation of different types of transformers under harmonic background.The loss increase,derating operat:ion and life shortening of distribution transformer under harmonic background were analyzed and calculated quantitatively in this three aspects.The influencing factors of economic cost were discussed,and the differences between different economic costs were compared and analyzed.Finally,taking a transformer substation as an example,this paper calculated and evaluated the harmonic loss,capacity,life and economic cost of transformer,and verifies the research conclusion of this paper on harmonic effect and economic cost of transformer.Quantitaitive analysis of harmonic effect and economic cost of transformer has important theoretical significance and practical value in reducing harmonic loss,improving efficiency,prolonging service life of transformer,and improving economic operation and safety of transformer.