An Influence Study of Parallel Hybrid Vehicle Propulsion System Configurations

Abstract

The hybrid electric vehicle (HEV) became an alternative to reduce the fuel consumption. The HEV parallel configuration consists of two separated drive systems, such as the engine/powertrain system and an extra electric motors (EMs) system. The addition of an extra electrical power changes the engine operation point and consequently the fuel consumption. However, there are many ways to introduce this electrical power source as a secondary drive system. In this paper, two parallel HEV configurations are studied in a condition where the conventional engine/powertrain system, coupled to the vehicle front wheels, is the main power source and two different configurations of EMs drive system, coupled to the rear wheels, are auxiliary power sources. The first one consists of two in-wheel motors coupled directly to the vehicle rear wheels and the other one is an EM coupled to a differential system similar to the existent in the conventional vehicle powertrain. The aim of this paper is to simulate and compare the HEV behavior with the conventional vehicle behavior, both of them running in the Brazilian urban drive cycle NBR6601, evaluating differences in performance, fuel consumption and battery discharging when applicable. INTRODUTIONThe increasing number of cars may be causing serious effects to the environment and to humans, such as pollution, global warming, depletion of oil reserves, among others The hybrid vehicles use different power sources with various powertrain configurations, including the ICE, electric motors (EMs), electric generators and battery packs [6]. In this paper are studied the hybrid electric vehicles (HEVs) that are one of the solutions proposed to minimize problems associated with the energy crisis and global warming [3]. These vehicles consume less gasoline and emit less pollution than conventional vehicles without decreasing

Fuel consumption and emissions analysis for a hybridized vehicle

“…For the PHEV, the calculation is similar to the one presented for the conventional vehicle, but the Equation 5is replaced by the Equation 14, and the acceleration is then calculated by the Equation 15 (13) and the maximum transmissible torque at the vehicle rear wheels calculated by the Equation (8). In this case, the interactive algorithm that defines the vehicle acceleration uses the Equations (7), (8), (12), (13), (14), (15) and (16). If the EMs required torque a` overcomes the traction limit of the rear tires (2 a`> 5OP ) ), the value of 5OP ) will replace in the Equation (12) or replace a`5OP ) in the Equation (13) and the remaining torque will be fulfilled by the ICE drive system.…”

“…Therefore, the simulations consider the EMs torque characteristics equivalent to the resultant torque and speeds in the vehicle wheels as from the assembly proposed by [13]. The EMs efficiency map is estimated based on the EM described in [15]. The Figure 3 shows the original and equivalent in-wheel EMs torque curves and the efficiency map for the in-wheel EM used during the simulations.…”