Abstract:

   Hybrid electric vehicles have two different powertrain systems with different characteristics, electric motor, and engine (ICE). These two powertrain systems can be arranged in serial, parallel or serial-parallel according to different vehicle characteristics. Nowadays, a serial-parallel drive system is widely used which optimally combines the advantages of both serial and parallel powertrain systems. The power split mechanism is used to manage the power transfer strategy of the electric motor and the ICE in the serial-parallel powertrain system. In this study, it is aimed to analyze the powertrain strategy depending on the speed range by adopting an ICE which can obtain constant torque at a certain speed range to the power split mechanism. In the power split mechanism, the ratio of ring/sun gear is kept constant. However, the motor/generator states of the motogenerators and the charge/discharge states of the battery system for different speed and power requirements for the vehicle have been calculated and discussed for different speeds of the ICE. As a result, for the power split mechanism, the effects of ICE speed on fixed torque and the parameters affecting ICE speed are determined.

Keywords: