基于改进损耗分离模型的铁磁材料损耗特性研究

Research on Magnetic Losses Characteristics of Ferromagnetic Materials Based on Improvement Loss Separation Model

为了在较宽频率和磁通密度范围内实现铁磁材料损耗的准确预测,为电力变压器的优化设计提供参考,该文以经典Bertotti损耗分离模型为基础,提出一种既能考虑铁磁材料非线性,又能准确模拟谐波激励条件下材料损耗的计算模型。首先,基于正弦激励下测量的铁损数据,采用二频率法计算低频低磁通密度条件下的磁滞损耗,并求得磁滞损耗表达式。然后,根据磁通密度变化率的有效值提出动态损耗因子以计算剩余损耗,实现了铁损分离。在此基础上,考虑到磁通密度较高时铁磁材料的非线性,引入非线性修正项对损耗进行修正。最后,针对铁磁材料的实际工作条件,计算1000Hz频率范围内以及不同谐波激励工况下的损耗。结果表明,损耗计算值与实验测量值吻合度较高,验证了模型的有效性。

In order to provide a reference for the optimal design of power transformers,a calculation model is proposed based on the classical Bertotti loss separation model for accurate prediction of ferromagnetic material losses over a wide range of frequencies and magnetic flux densities.The proposed model can not only consider the nonlinearity of ferromagnetic materials,but accurately simulate iron losses under harmonic excitation conditions.Firstly,based on the magnetic loss data measured under sinusoidal excitation,two-frequency method is used to calculate the hysteresis loss at low frequency and low magnetic density,and the hysteresis loss expression is solved.Then,according to the equivalent magnetic flux density variation,a dynamic loss factor is proposed to calculate the excess losses.Considering the nonlinearity when magnetic flux density is high,a nonlinear correction term is introduced to compensate the losses.Finally,according to the actual working conditions,the proposed model was used to calculate ferromagnetic material losses within the frequency range of 1000Hz and under different harmonic excitation conditions,respectively.The results show that the calculated values are in good agreement with the experimental measured values,which verifies the validity of the model.