THE DEVELOPMENT OF REGENERATIVE BRAKING SYSTEM FOR MOTOR TANDEM AXLE MODULE IN SERIES HYBRID COMMERCIAL VEHICLES

Resumo

Since the emission reduction and fuel saving have become the main focus of nowadays"™ automotive societies, the utilizations of new highly energy efficient hybrid technology are the irresistible general trend to minimize the load of commercial vehicles engine. This paper will demonstrate the development of regenerative braking system for single motor powered tandem axle module in hybrid commercial vehicles such as refuse trucks and delivery vehicles. The fundamental working principle of this electric motor tandem axle module is based on a dual-rotor electric motor/generator, which has two rotors to deliver same torque from rotor shafts"™ bevel pinion gears to differential gears that connected to front and rear tandem axles"™ wheels. Due to the most of commercial vehicles were used to continually start and stop in designated city routes, the large amount of kinetic energy was lost as heat during the breaking actions. Thus, the energy efficiency cloud also be improved with the assist of converting the kinetic energy to electric power by regenerative braking system. When the brake pedal was pressed, the vehicle's electric motor would be turned into reverse mode, while working as a generator to slowing the vehicle and producing electricity which stored in ultra-capacitor to slowly charge the vehicle's batteries. There are two smaller brake rotors located on the center of each tandem axle for emergency brake, so vehicle weight reduction can be achieved as well as lighter unsprang weight. In this paper, the detailed architecture of this hybrid power system and brake recovery system will be described. The simulations were executed to estimate the certain properties in order to prove the efficiency and suitability of the system including the proportion of energy could be possible recovered. Moreover, the cost analysis will be indicated along with the difficulties and future developments.