关键词: 损耗, 负载系数, 散热, 电力变压器

Abstract: Losses and heat dissipation of oil-filled transformer are key operation factors. To gain accurate value of heat dissipation of typical transformer system, the heat dissipation is calculated by using flow convection along a flat plate, natural convection in infinite space and diffuse gray surface radiation model. Heat dissipation characteristics are obtained through calculated results. The results show that heat dissipation is achieved mainly through radiator, accounting for 77.66 %~85.31% of total amount of the transformer system. The transformer heat is primarily dissipated by radiation, accounting for 55.15%~70.25%. However, the heat dissipated for radiator is mainly through convective and only accounts for 2.18%~11.34%. Compared with the transformer system losses, loss empirical formula is suitable for the transformer system because the error margin is less than 10%. Transformer loss is closely related to type and load factor. Different types of transformer have different losses. Under same load factor, the loss increases with the transformer capacity. The loss also increases with the load factor for the same transformer type.

Key words: loss, load factor, heat dissipation, power transformer