Along the advances of wide-bandgap power devices, the pulsewidth modulation (PWM) converters are developing toward higher switching frequencies in recent years. Accurate estimation of the high-frequency power losses of magnetic components, the core loss in particular, has been a challenge for PWM converters. While the conventional approaches based on Steinmetz equation lose the accuracy in PWM excitations, the “loss map” approach has been proposed recently as a practical method to accurately estimate the inductor core loss. To calculate the core loss, the inputs of the loss map need to be retrieved from the steady-state inductor voltage/current waveforms. As a supplement to the loss map approach, this work proposes an analytical method to rapidly generate the inputs (inductor operating space) for the loss map to replace the efforts in building simulation models and experimental rigs. The proposed approach relies on the operation and modulation principles of PWM converters and enables computerized calculation of the operating space and the inductor core loss. The proposed approach is developed for both two-level and three-level converters and validated by experiments. The results reveal that a three-level converter running the same inductor generates less than half the core loss compared to a two-level converter, when the maximum current ripple is kept equivalent. The proposed approach is based on the operation principles of the converter topology and, therefore, can be applied generally regardless of the core material or the design of the inductor, as long as the loss map of the inductor is preproduced.

中文翻译：

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一种快速计算两电平和三电平PWM变换器高频磁芯损耗估计电感工作空间的解析方法

近年来，随着宽带隙功率器件的发展，脉宽调制（PWM）转换器正朝着更高的开关频率发展。准确估计磁性元件的高频功率损耗，尤其是磁芯损耗，一直是 PWM 转换器的挑战。虽然基于 Steinmetz 方程的传统方法会失去 PWM 激励的准确性，但最近提出了“损耗图”方法作为准确估计电感器磁芯损耗的实用方法。要计算磁芯损耗，需要从稳态电感器电压/电流波形中检索损耗图的输入。作为损失图方法的补充，这项工作提出了一种分析方法，可以快速生成损耗图的输入（电感器操作空间），以取代构建仿真模型和实验台的工作。所提出的方法依赖于 PWM 转换器的操作和调制原理，并且能够对操作空间和电感器磁芯损耗进行计算机计算。所提出的方法是为两电平和三电平转换器开发的，并通过实验验证。结果表明，当最大电流纹波保持相等时，与两电平转换器相比，运行相同电感器的三电平转换器产生的磁芯损耗不到一半。所提出的方法基于转换器拓扑的工作原理，因此，