A Coupled Inductor Based Multi Port DC DC Converter with Coordinated Duty-Cycle and Phase Shift Control

TL;DR

This paper introduces a novel multi-port DC-DC converter using coupled inductors that enables independent regulation and active control without additional magnetic components, suitable for electrified powertrain applications.

Contribution

It proposes a new topology integrating an actively controlled secondary side with coordinated duty-cycle and phase-shift control, enhancing regulation flexibility and scalability.

Findings

Validated through simulation and experiments on a hardware prototype.

Demonstrated decoupled regulation and improved controllability.

Achieved scalable multi-port power conversion within a unified magnetic framework.

Abstract

Electrified powertrains rely heavily on magnetics for power conversion, where cost, volume, and weight concerns make integrated multi-use designs an attractive solution. With EV powertrain architectures requiring a boost stage being a major market segment, the proposed Coupled Inductor-Based Multi-Port DC-DC Converter (CI-MPC) leverages the existing magnetic framework of a conventional topology to realize independent, isolated, and simultaneously regulated converters without additional magnetic cores or cascaded stages. Unlike existing architectures that use secondary windings solely for voltage gain or passive rectification, the proposed topology integrates an actively controlled full bridge on the secondary side to create a distinct, independently regulated auxiliary converter. Primary output regulation is achieved via duty-cycle control, while the auxiliary converter employs phase-shift modulation synchronized with the primary switching to enable active rectification and flexible voltage or current regulation. A unified control framework ensures decoupled operation with minimal interaction between the primary and auxiliary loops, while also avoiding high step-down conversion ratios from high voltages to lower auxiliary levels. The operating principles and coordinated control strategies are validated through simulation and experimental results on a hardware prototype, demonstrating enhanced controllability, decoupled regulation, and a scalable pathway toward generalized multi-port power conversion within a unified magnetic framework.