Energy Flow and Electric Drive Mode Efficiency Evaluation of Different Generations of Hybrid Vehicles under Diversified Urban Traffic Conditions

Abstract

Hybrid propulsion dedicated to light duty vehicles is seen as an evolutionary change from internal combustion engine (ICE) to electric propulsion. Widespread direct replacement of convection ICEs in the current energy system is impossible because ICEs are vehicles’ main source of mechanical energy. The hybrid powertrain uses the advantages of electric propulsion with the ability to charge the traction battery or have the internal combustion engine assist the system. The article compares different types of hybrid drives (with a small share of plug-in hybrid propulsion) under typical urban driving conditions. Nine vehicles were tested, and the tests were conducted over several months in various cities in Poland. The terms of the research conducted were not under the requirements of the driving test. However, they are authoritative when using the vehicle in real traffic conditions. Such conditions take into account many aspects that are relevant to a road test. It was found that urban conditions are a very suitable environment for hybrid propulsion systems, as they cover more than 50% of the distance in electric mode, regardless of the initial battery charge, in most cases.