Principle, design and experimental validation of a flywheel-battery hybrid source for heavy-duty electric vehicles

The design and the integration of an electromechanical storage system into an electric vehicle power train are discussed. The objective of this study is to highlight the interest of sources hybridisation for heavy-duty vehicles with discontinuous mission profiles as garbage collection. This behaviour is characterised by a high peak-to-average battery power ratio. A solution to increase vehicle performances is to maintain the battery power within rated levels for charges and discharges with an auxiliary peak-power source which supplies or recovers the energy during acceleration or braking, respectively. In this case, the battery can be considered as an energy source. The authors have focused on a hybrid source made of a battery and an electromechanical storage system, which behaves as a power source. This principle has been verified with the help of simulations through Matlab/Simulink^reg. To validate the simulation results, an experimental test bench including the hybrid source has been designed. This test bench allows to recreate the dynamic vehicle behaviour on a given mission profile. Experimental results are shown and discussed.