## Abstract

This paper investigates the matrix coupled “all-in-one” magnetic structure that combines both series coupling and parallel coupling for pulse-width-modulated (PWM) power conversion. A systematic analysis of the current ripple reduction mechanism is performed. Current ripple steering among asymmetric series coupled windings is discussed. The transient performance of the matrix coupled inductor is demystified, providing insights for analyzing converter dynamics and large- or small-signal modeling. To quantify the benefits of matrix coupling, a figure of merit is defined by comparing the current ripple of a matrix coupled inductor to that of a discrete inductor given the same transient speed. The comparison results indicate that a higher number of phases and a stronger matrix coupling coefficient amplify the benefits of matrix coupling. A 1 V-to-5 V input, 1 V-to-5 V output, four-phase matrix coupled synchronous SEPIC converter with planar PCB integrated magnetics is built and tested. The matrix coupled SEPIC prototype can support load current up to 185 A at 5 V-to-1 V voltage conversion with a maximum power density over 470 W/in<inline-formula><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula>. Compared to commercial discrete inductors, the matrix coupled inductor has a 5.6 times smaller size and 8.5 times faster transient speed with similar current ripple and current rating. The experimental results validate the matrix coupling concept and the theoretical analysis, opening the possibilities toward wide adoption of “All-in-One-Magnetics” in PWM topologies.

Original language | English (US) |
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Pages (from-to) | 1-16 |

Number of pages | 16 |

Journal | IEEE Transactions on Power Electronics |

DOIs | |

State | Accepted/In press - 2022 |

## All Science Journal Classification (ASJC) codes

- Electrical and Electronic Engineering

## Keywords

- Coupled inductor
- Couplings
- Inductors
- Magnetics
- Matrix converters
- PWM converter
- SEPIC converter
- Transmission line matrix methods
- Voltage
- Windings
- current ripple reduction
- inductance dual model
- integrated magnetics
- multiphase interleaving