AC Resistance Reduction Using Orthogonal Air Gaps in High Frequency Inductors
AC Resistance Reduction Using Orthogonal Air Gaps in High Frequency Inductors
复制标题
在高频电感器中使用正交气隙降低交流电阻
DOI：
10.1109/compel.2019.8769607
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
D. Maksimović
中科院分区：
文献类型：
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作者：
S. Mukherjee;Yucheng Gao;R. Ramos;V. Sankaranarayanan;B. Majmunović;R. Mallik;S. Dutta;Gab;Brian B. Johnson;D. Maksimović
本文提出了一种相对简单的技术，以减少由于高频电感器的边缘场的绕组损耗。在高频电力电子设备中，交流电感器绕组损耗受到趋肤效应和邻近效应的影响，包括由于气隙周围的边缘磁场引起的不均匀电流分布。众所周知，如何使用分布式气隙以非标准芯或绕组几何形状为代价来减轻边缘效应。本文提出的正交气隙方法将平行于绕组的铁芯段中的气隙与垂直于绕组的铁芯段中的气隙相结合。该方法是使用一个一维的分析框架，并验证了二维有限元模拟。分析准则，以优化气隙，以实现最小的交流电阻。作为一个案例研究，一个平面电感器的设计为8千瓦的SiC为基础的降压转换器工作在250 kHz。它示出了如何正交气隙的结果在交流电阻减少45%以上，并大大减少电感器的损失相比，使用标准气隙的设计。实验转换器原型上的损耗测量结果进行了验证。
This paper presents a relatively simple technique to reduce winding losses due to fringing fields in high-frequency inductors. In high-frequency power electronics, ac inductor winding losses are affected by skin and proximity effects, including uneven current distribution due to fringing magnetic fields around airgaps. It is well known how fringing effects can be mitigated using distributed airgaps, at the expense of non-standard core or winding geometry. The orthogonal-airgap approach proposed in this paper combines airgaps in core segments parallel with the windings with airgaps in segments perpendicular to the windings. The approach is developed using a 1D analytical framework and validated by 2D finite-element simulations. Analytical guidelines are presented to optimize the airgaps to achieve minimum ac resistance. As a case study, a planar inductor is designed for an 8 kW SiC-based buck converter operating at 250 kHz. It is shown how the orthogonal airgaps result in more than 45% reduction in ac resistance and substantially reduced inductor losses compared to the design using standard airgaps. The results are verified by loss measurements on an experimental converter prototype.