基于表面阻抗边界的变压器杂散损耗计算方法

表面阻抗法是基于电磁波理论并将导体表面阻抗作为一种边界条件进行有限元求解的方法,它具有求解规模小、计算效率高等优势。首先借助工程电磁场数值计算软件Magnet,使用有限元法和表面阻抗法对该模型进行仿真,然后基于TEAM Problem 21基准族中的P21-B模型搭建了变压器杂散损耗测试系统,用于测量在不同频率电流激励条件下的变压器杂散损耗。针对现有测量方法的不足,引入温度系数对测量结果进行修正,并采用改进线圈损耗法以得到更准确的杂散损耗测量结果。通过与实验值对比,验证了有限元法与表面阻抗法计算结果的准确性。从计算规模和时间角度分析,表面阻抗法远远小于有限元法,大大节省了计算资源。

Calculation method of transformer stray loss based on surface impedance boundary

Based on the theory of electromagnetic waves, the surface impedance method is a finite element method used surface impedance as a boundary condition, whose advantages are of low calculation and high computational efficiency. Firstly, Magnet is used to simulate the model by finite element method and surface impedance. Then, based on the P21 B model in the TEAM Problem 21 reference family, a stray loss test system is built. The stray loss is measured under different current excitation conditions. The temperature coefficient is introduced to improve the measurement, and the improved coil loss method is adopted to obtain more accurate stray loss measurement results. The calculation results of the finite element method and the surface impedance are verified with experimental measurements. The surface impedance is much smaller than the finite element method in terms of calculation scale and time, which greatly saves computational resources.