Optimal Regenerative Braking with a push-belt CVT : an Experimental Study

Abstract

This paper describes the approach and the results of efficiency experiments on a push-belt Continuously Variable Transmission (CVT) in a new hybrid drive train. The hybrid drive train uses the push-belt CVT to “charge” a flywheel, with the kinetic energy of the vehicle during regenerative braking and “discharge” during flywheel driving. The experiments are performed on a test rig with two electric machines following prescribed speed and torque trajectories, representing the flywheel and vehicle load. The approach includes the design of a control strategy for the variator, which enables regenerative braking. The experiments show that the CVT can be used very efficiently in the proposed hybrid drive train.