谐波电流下干式变压器温升及带负载能力的研究

摘要

谐波电流对干式变压器造成损耗增加、温度升高、加速绝缘材料热老化等不良影响.针对上述问题,利用谐波损耗因子计算干式变压器在不同畸变率下的谐波损耗,并应用有限元ANSYS Workbench软件建立了干式变压器三维模型.仿真研究了各电流畸变率下干式变压器谐波损耗对内部各部件的温升影响.通过采取降低干式变压器负载容量的方式,降低因谐波损耗所引起的额外温升,将干式变压器内部各部件的温升有效地控制在限值范围内,并得到了电流畸变率与干式变压器带载能力的关系.计算与仿真结果表明,谐波电流会使干式变压器的各种损耗增加,从而引起各部件温度升高,降低带载能力.%Harmonic currents would cause negative effects on a dry type-transformer,such as loss increase,temperature rise,and accelerated thermal aging of insulation materials.In view of the above problems,harmonic loss factor is used to calculate the harmonic loss of a dry-type transformer at different distortion rates,and a three-dimensional model of dry-type transformer is established by using software ANSYS Workbench.The effects of harmonic loss on the tempera-ture rise of the dry-type transformer's internal components at different distortion rates are studied by simulation.By low-ering the load capacity of the dry-type transformer,the additional temperature rise due to harmonic loss can be re-duced,thus the temperature rise of each component of the dry-type transformer will be effectively controlled within the limit range.Moreover,the relationship between current distortion rate and the load capacity of the dry-type transformer is obtained.Calculation and simulation results show that harmonic current can increase the loss values of the dry-type transformer,which can cause the temperature rise of each component and reduce the load capacity.