Co-Design Approach and Optimization for Plug-In Hybrid Electric Buses

Student thesis: Master's Thesis


Hybrid vehicles are a promising solution to reduce the contribution of the transport sector to the global warming. However, the eciency of this powertrain hybridiza- tion is achieved by developing a Control and Design [Co-Design] framework adapted to the target application. Therefore, this thesis aims to minimize the powertrain Total Cost of Ownership [pTCO] of a Plug-in Hybrid Electric Bus [PHEB] by consid- ering its operation on a given transport assignment using a facing-forward approach. A bilevel optimization framework is used in order to handle the coupling between the control and design layer. This consists in a control loop nested in a design loop. An Adaptive Equivalent Consumption Management Strategy [A-ECMS] was chosen for the control algorithm for its ability to globally minimize the energy consumption while being implementable in real-time. It intends to implement a charge-blended discharging strategy by following a reference SoC. The sizing of the powertrain com- ponents is handled by a Genetic Algorithm [GA] ensuring a respect of the restrictive driving requirements though a penalty function. This proposed Co-Design frame- work show good results by decreasing the CAPEX of 21.7% and OPEX of 5.4% w.r.t initial design. A new adaptive charging strategy and SoC trajectory have been pro- posed in order to decrease the factors influencing the battery lifetime. The results are discussed qualitatively due to the lack of battery degradation model. This latter might be subject to future works along with the use of a multi-objective genetic algorithm for a more accurate pTCO computation.
Date of Award2 Sep 2019
Original languageEnglish


  • Co-design optimization
  • PHEVs
  • control system
  • pTCO
  • A-ECMS
  • Genetic Algorithm [GA]

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