应用于多相VRM的新型通用对称耦合电感研究

Research and Universal Design on Symmetric Inductor for Multi-phase VRM

应用于传统电压调理模块(VRM)的并列式多相耦合电感器,因其自身磁芯的结构特点和集成方式,难以实现完全对称化耦合,制约着变换器性能的提升。在此以四相非对称耦合VRM为研究对象,提出各相耦合电感之间对称化程度的量化指标,推导非对称耦合电感下等效稳态和暂态数学方程,给出耦合度、对称度随占空比的归一化变化曲线,得出各相耦合电感非对称度对变换器性能的影响,明确了耦合电感对称化研究的重要性和必要性,进而总结出多相对称化耦合电感的通用设计准则;提出一种新型阵列式多相对称耦合电感器,分析对称化原理,并推广到N相通用型对称耦合电感的设计。最后样机实验结果证明了多相阵列式对称化磁集成理论的正确性和实用性。

For traditional multi-phase parallel coupled inductors applied in voltage regulator module(VRM),completely symmetric coupling is hardly achievable due to the structural characteristics and integration mode of their magnetic cores,which limits the performance upgrading of converter.Taking four-phase asymmetric coupled VRM as research object,the quantitative index for the degree of symmetry between the coupled inductor of each phase is proposed,the mathematical equations of asymmetric coupled inductor are derived,the normalized variation curves for the degrees of coupling and symmetry with the duty cycle are presented,the influence of the asymmetry of coupled inductor on the converter performance is obtained,and the importance and necessity of studying the coupled inductor symmetry are clarified,thereby coming up with the general design criteria for multi-phase symmetric coupled inductors.A novel array multi-phase symmetric coupled inductor is proposed,and the principle of symmetry is analyzed,which is generalized to the design of N-phase general-purpose symmetric coupled inductors.The results of experiment prove the correctness and practicability.