CoupMag Expert


Coupled magnetics model calculator for multiphase PWM converters

Princeton Power Electronics Tool

Coupled magnetics expert calculator

CoupMag Expert evaluates equivalent inductance-dual, inductance-matrix, and multiwinding-transformer parameters for multiphase PWM converter designs.

Operating Point

Interleaving terms are derived from the duty ratio, phase count, and turns per winding.

Interleaving Boosting Inductance \(1/\delta\) --
Number of Overlapped Phases \(k\) --
Interleaving Ripple Compression \(\delta\) --

Design Parameters

Use reluctance in H^-1 and inductance in H. Flux-per-current outputs are reported in Wb/A.

Inductance Dual Model

\(\beta = \mathcal{R}_C/\mathcal{R}_L\) --

Inductance Matrix Model

\(\alpha = -L_M/L_S\) --

Multiwinding Transformer Model

\(\rho = L_\mu/L_l\) --

Model Explorer

Static equations remain visible beside the live numerical results for each modeling view.

$$ N^2 \begin{bmatrix} \frac{di_1}{dt} \\ \frac{di_2}{dt} \\ \vdots \\ \frac{di_M}{dt} \end{bmatrix} = \begin{bmatrix} \mathcal{R}_L + \mathcal{R}_C & \mathcal{R}_C & \ldots & \mathcal{R}_C \\ \mathcal{R}_C & \mathcal{R}_L + \mathcal{R}_C & \ldots & \mathcal{R}_C \\ \vdots & \vdots & \ddots & \vdots \\ \mathcal{R}_C & \ldots & \mathcal{R}_C & \mathcal{R}_L + \mathcal{R}_C \end{bmatrix} \begin{bmatrix} v_1 \\ v_2 \\ \vdots \\ v_M \end{bmatrix} $$
Inductance dual lumped circuit model
Model Parameters
\(\mathcal{R}_L\)\(\mathcal{R}_L\)--
\(\mathcal{R}_C\)\(\mathcal{R}_C\)--
\(L_l\)\(L_l = \frac{N^2}{\mathcal{R}_L + M\mathcal{R}_C}\)--
\(L_\mu\)\(L_\mu = \frac{N^2(M-1)\mathcal{R}_C}{\mathcal{R}_L(\mathcal{R}_L + M\mathcal{R}_C)}\)--
\(L_S\)\(L_S = \frac{N^2(\mathcal{R}_L + (M-1)\mathcal{R}_C)}{\mathcal{R}_L(\mathcal{R}_L + M\mathcal{R}_C)}\)--
\(L_M\)\(L_M = \frac{-N^2\mathcal{R}_C}{\mathcal{R}_L(\mathcal{R}_L + M\mathcal{R}_C)}\)--
\(L_L\)\(L_L = \frac{1}{\mathcal{R}_L}\)--
\(L_C\)\(L_C = \frac{1}{\mathcal{R}_C}\)--
\(L_L^*\)\(L_L^* = \frac{N^2(\mathcal{R}_L + (M-1)\mathcal{R}_C)}{\mathcal{R}_L(\mathcal{R}_L + M\mathcal{R}_C)}\)--
\(L_C^*\)\(L_C^* = \frac{N^2}{\mathcal{R}_L/M + \mathcal{R}_C}\)--
Converter Quantities
\(L_{oss}\)\(\frac{(1-D)DMN^2}{(\mathcal{R}_L + M\mathcal{R}_C)(k + 1 - DM)(DM - k)}\)--
\(L_{pss}\)\(\frac{N^2(1-D)}{-\frac{k^2\mathcal{R}_C}{DM}-\frac{k\mathcal{R}_C}{DM}+2k\mathcal{R}_C-DM\mathcal{R}_C+\mathcal{R}_C-D\mathcal{R}_L+\mathcal{R}_L}\)--
\(L_{otr}\)\(\frac{N^2}{M(\mathcal{R}_L + M\mathcal{R}_C)}\)--
\(L_{ptr}\)\(\frac{N^2}{\mathcal{R}_L + M\mathcal{R}_C}\)--
\(L_{ptr}/L_{pss}\)\(\frac{-\frac{k^2\beta}{DM}-\frac{k\beta}{DM}+2k\beta-DM\beta+\beta-D+1}{(1-D)(1+M\beta)}\)--
\(\Phi_{L,DC}/I_{out}\)\(\frac{N}{M(\mathcal{R}_L + M\mathcal{R}_C)}\)--
\(\Phi_{C,DC}/I_{out}\)\(\frac{N}{\mathcal{R}_L + M\mathcal{R}_C}\)--

Original CoupL v1.0 calculator designed by Seungjae Ryan Lee with Haoran Li, Daniel Zhou, and Minjie Chen.