Prototype variable transmission system for electric vehicles: Energy consumption issues

In order to explore the performance of variable transmission use on zero emission urban vehicles, targeting low fuel consumption, a new type of a flat-belt driven CVT was developed. The new Electronic Shift Variable Transmission (ESVT) was build in order to be installed and tested on the ER12 prototype hydrogen fuel cell powered urban vehicle, which is developed by the TUC Eco Racing team at the Technical University of Crete. ER12 is used as a testbed vehicle in order to measure fuel consumption and compare results of ESVT use versus the one-stage geared transmission that was previously installed on the vehicle. At first, a description of the proposed system main components and design considerations is presented, in order to provide insight on system operation. Actual road tests are conducted using the prototype vehicle, providing insights regarding fuel consumption measurements and driving performance with and without ESVT. Experimental results are presented, showing significant improvement with the use of the proposed system. ESVT control logic analysis follows, describing the control objectives and rules used towards lower fuel consumption and driving performance. Finally, evaluation of ESVT control operation is presented, using experimental results from the road tests conducted with ER12 prototype vehicle.