Experiment and simulation investigation on energy management of a gasoline vehicle and hybrid turbocharger optimization based on equivalent consumption minimization strategy

The experiment and simulation investigation of vehicle energy management (VEM) were carried out on a passenger car equipped with a turbocharged gasoline engine. The research results show that the vehicle takes on the characteristic of overcharge under urban conditions to guarantee the power by sacrificing economy. Exhaust energy after catalytic converter and the greater circulation heat transfer loss that account for more than one-third of total energy under New European Driving Cycle (NEDC) are wasted without being used, which indicates that the tested vehicle has great potential for recovering the waste heat. To solve these problems, the VEM model coupled multiple physical fields was developed and calibrated. Original turbocharger was reformed to hybrid turbocharger with the aid of simulation model, and its optimal control strategy based on equivalent consumption minimization strategy (ECMS) was designed. The one-dimensional numerical engine model was introduced into algorithms, which opens new windows for the development of VEM optimization strategies. After the transformation of hybrid turbocharger, the overcharge phenomenon under urban driving cycle has been eliminated. The main contribution to fuel saving comes from the reduction of pumping loss and alternator power consumption. The energy saving rate of hybrid turbocharger in different driving cycles ranges from 1% to 5%, which is mainly affected by the deterioration degree of overcharge on the economy of original machine and the characteristics of regeneration conditions in different driving cycles.