基于DGM的油浸式变压器热点温度计算

Calculation of Winding Hot Spot Temperature of Oil Immersed Transformer by the Discontinuous Galerkin Method

为了准确计算油浸式变压器的热点温度,在对比了有限元法(FEM)和有限体积法(FVM)计算变压器热点温度各自特点的基础上,提出了基于间断式伽辽金方法(discontinuous Galerkin method,DGM)的一种计算变压器热点温度的全新计算方法;并以天威合肥变压器厂的一台180 MV·A-220 kV变压器为例,计算了变压器的绕组热点温度。为校验计算方法的准确性,笔者对这台主变进行了变压器绕组温升试验,监测了绕组的热点温度数据,并将利用DGM的计算结果分别与实际监测数据、IEEE导则计算数据、使用FEM算法计算出的数据以及使用FVM算法计算出的数据进行了对比。对比结果表明,利用DGM的计算结果与实际监测数据的标准差只有1.46℃,而利用IEEE导则模型计算结果、FEM算法计算结果以及FVM算法计算结果与实际监测数据的标准差分别高达4.81、3.71、2.58℃。DGM的计算精度明显高于IEEE导则模型、FEM算法和FVM算法,证明了DGM能更准确地计算油浸式变压器绕组热点温度。

In order to accurately calculate the winding hot spot temperature field of oil immersed transformers,on the basis of comparison of the finite element method（FEM）and finite volume method（FVM）to calculate transformer winding hot spot temperature characteristics, a new method of discontinuous Galerkin method（DGM）based on discontinuous finite element method to calculate the winding hot spot temperature in transformer is proposed. Taking a 180 MV·A-220 kV transformer as example, the transformer winding hot spot temperature is calculated by use of DGM. In order to verify the accuracy of this calculation method, the winding temperature rise test of the transformer is carried out and the winding hot spot temperature are detected. The calculated results by DGM are compared to the detected data, calculated data by IEEE guide recommendation,by FEM method and by FVM method. The contrast results show that the standard error between the calculated value by DGM and the detected value is only 1.46 ℃; while the errors corresponding to the IEEE guide method, FEM method and FVM method are 4.81 ℃, 3.71 ℃ and 2.58 ℃ respectively. The calculation accuracy of the hybrid algorithm（DGM）is significantly higher than the other methods, which means that the internal temperature field of this hybrid method can accurately calculate the winding hot spot temperature of the oil immersed transformer.