Multi-Port Interleaved DC/DC Converter: Design, Modelling and Control for Hybrid and Electric Drivetrains

Student thesis: Master's Thesis


The aim of this thesis is to investigate the characteristics of a non-isolated multi- port interleaved bidirectional DC/DC converter for automotive applications. This was achieved by analysing mathematical models and behavioural simulations of the particu- lar multi-port converter. Furthermore the results were experimentally verified with the design and development of a scaled 500 W multi-port DC/DC converter.
The theoretical analysis and experimental verification support the proposed benefits of multi-port multi-phase interleaving. This included higher converter efficiency, higher boost ratio, and input and output current ripple reduction, but the investigation of the switching losses showed a notable deviation from the mathematical model. The con- trolled characteristics were also analysed but only in simulations, with multi-port con- trolled topologies showing better dynamic performance, system stability and increased robustness over a wider operating region.
The implication of these results is that the derived averaged small-signal model is suitable for the design of linear closed-loop controllers. However, careful consideration must be made of the effects of the switching frequency on the converter’s behaviour. Secondly, the custom designed and developed scaled multi-port converter succeeded in providing measurements for the proposed converter topology. It is therefore suited for actual converter behaviour validation, converter topology testing and component opti- misation.
Further research is recommended in assessing non-linear control, along with the ac- tual implementation of a closed-loop controller on the scaled multi-port converter. Veri- fication of the proposed benefits of linearly controlled two-port converters should follow. Finally, the derivation and optimisation of a complete multi-port mathematical model concerning the switching losses is advocated for optimal multi-port controller design.
Date of Award4 Sep 2017
Original languageEnglish


  • Power Electronics
  • DC/DC converter
  • Multiport
  • Electric Vehicles

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