绕组交叉换位排布方式下高频变压器阻抗建模及谐振特性分析

Impedance Modeling and Resonance Characteristics of High-frequency Transformers With Interleaving Winding Arrangements

高频变压器设计中通常采用初、次级绕组交叉换位排布方式来降低漏电感和交流电阻,但是绕组结构改变会同时影响变压器内部寄生电容参数大小和分布情况,进而造成宽频带谐振特性发生变化。为了明确不同交叉换位排布方式对寄生电容、频变漏电感以及谐振频率的影响规律,该文首先结合绕组的排布方式和绕制方法,建立4种典型绕组结构的分布等效电容表征模型,基于能量等效原理推导出相应绕组排布方式下六集总电容表征模型的电容解析计算式。然后,为了计及宽频区间内绕组漏电感参数的频变特性,基于电磁对偶原理建立含频变参数有损电感表征模型,并给出各项参数提取方法。在此基础上,构建不同绕组布置方式下高频变压器宽频带阻抗特性分析模型。将寄生电容、漏电感参数以及开短路阻抗特性和谐振频点计算结果与仿真和实验测量结果进行对比,验证了所提方法的有效性。

In the design of high frequency transformers,the primary and secondary windings are usually interleaved to reduce leakage inductance and AC resistance.However,the change of winding structure will affect the value and distribution of parasitic capacitance parameters,thereby causing changes in broadband resonance characteristics.In order to clarify the affect of winding arrangements on parasitic capacitance,frequency-dependent leakage inductance and resonant frequency,this paper firstly establishes the distributed equivalent capacitance models of four typical winding structures considering the winding arrangement and twisting method.Based on the energy equivalent principle,the capacitance analytical calculation formula of six capacitance models with lumped parameters under different winding arrangements is derived.Then,considering the frequencydependent effect of leakage inductance parameters in the wide frequency range,a lossy inductance model containing frequency-dependent parameters is established based on the principle of electro-magnetic duality principle,and the extraction method for each parameter is given.On this basis,the broadband impedance model of high-frequency transformer with typical winding arrangements is constructed.The calculation results of parasitic capacitance,leakage inductance,open-circuit and short-circuit impedance and resonant frequency are compared with simulation and measurement results to verify the effectiveness of the proposed method.