Hα control strategy of motor torque ripple in hybrid electric vehicles: an experimental study

In this study, the authors propose a novel control strategy of torque ripple reduction in hybrid electric vehicles (HEVs). By its periodic cycle of power production, the internal combustion engine used in a hybrid vehicle provides a torque that fluctuates constantly. This is problematic for vehicle manufacturers since this torque ripple creates uncomfortable vibrations and mechanical damage. To achieve this active control, the problem is reformulated in complex notation in the frequency domain with respect to the main order of the fluctuations. A permanent magnet synchronous machine is mounted on the crankshaft in order to generate a torque sequence opposing ripple torque. The control strategy is based on a static output feedback synthesis under & H_∞ performance specification. A complete modelling of the hybrid propulsion from an experimental test bench is achieved. The model is performed at low speed (900 rpm). In fact, at this speed, the ripple is very restrictive. Experimental results highlight the control approach interest.