This article investigates reluctance-based dynamic models for multiphase coupled inductor buck converters. A reluctance-based state-space model is derived based on the inductance dual model of the coupled inductor. The physical core geometry is explicitly related to the circuit's dynamic properties to provide useful insights for coupled inductor design, especially if the number of phases is large. The transfer functions of multiphase coupled inductor buck converters with an arbitrary number of phases are derived based on the inductance dual model. It is shown that a symmetric multiphase coupled inductor buck converter can be modeled as a second-order dynamic system when perturbed with a common-mode duty cycle change, and the duty-cycle-to-output-voltage and duty-cycle-to-output-current transfer functions are determined by the leakage flux path of the coupled inductor. The differential-mode current balancing mechanisms of the multiphase coupled inductor buck converter are decoupled from other system dynamics and are determined only by the winding resistance and the magnetizing flux path. The applicability of the model in cases with structural asymmetry is discussed, with the results supporting the feasibility of scaling the coupled inductor structure to a large number of phases with tolerance for asymmetry. The dynamic models are verified by SPICE simulations and experimental results.

中文翻译：

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多相耦合电感降压转换器的基于磁阻的动态模型


本文研究了多相耦合电感器降压转换器的基于磁阻的动态模型。基于耦合电感器的电感对偶模型导出了基于磁阻的状态空间模型。物理磁芯几何形状与电路的动态特性明确相关，为耦合电感器设计提供有用的见解，特别是在相数很大的情况下。基于电感对偶模型推导了任意相数的多相耦合电感降压变换器的传递函数。结果表明，当受到共模占空比变化的扰动时，对称多相耦合电感器降压转换器可以建模为二阶动态系统，并且占空比与输出电压和占空比与输出电流传递函数由耦合电感器的漏磁通路径决定。多相耦合电感器降压转换器的差模电流平衡机制与其他系统动力学解耦，并且仅由绕组电阻和磁通路径决定。讨论了该模型在结构不对称情况下的适用性，结果支持将耦合电感器结构缩放到具有不对称容限的大量相的可行性。动态模型通过SPICE仿真和实验结果得到验证。