Design and impacts of high power density DC-DC converter in automotive powertrain: a methodological approach

This thesis work was realized in collaboration with HPE Coxa provider of engineering services and precision manufacturing for automotive, motorsport, automation solution, aerospace and defense sectors. Specifically, this work has been carried out inside the company Control and System Engineering Department. The aim of this work is to describe a methodological approach for the design of an High Density Power DC-DC Converter for high performance electric powertrain and to describe the dependency that exist between system design and performance indicator and which are the consideration that have to be done by the engineers during design phase, following the System Engineering workflow. In order to achieve this purpose, Model-Based Design approach has been used to realize a simulation framework that allow to analyse the overall electric propulsion system behaviour and extract all the data that allow to evaluate the system performance. Specifically, taking into account a real Mission Profile, with Matlab and Simulink tools, the behaviour of the system and the related energy transfer during vehicle acceleration and regenerative breaking phase has been simulated. Thanks to these analysis the requirement for the converter was established and with the support of Electric Simulation Tools, it has been designed the electrical architecture of specific converter. In order to optimize the energy managment phase, a Four-Phase Bidirectional Interleaved architecture has been selected. Moreover it has been highlighted the main aspects related to the integration of the converter in the powertrain system in terms of structural and thermal features.