THE EFFECT OF DIFFERENT GEAR RATIO SELECTION ALGORITHMS ON THE EFFICIENCY OF CONVENTIONAL AND PARALLEL HYBRID DRIVETRAINS

Road vehicles using electric power sources have become increasingly popular in the last decade. Meanwhile, battery technology is still not mature enough to meet expected vehicle range; thus the transition from ICE vehicle to fully electric vehicle is not imminent. Therefore the concept of hybrid drivetrain technology was introduced. The hybrid powertrain configuration includes at least two different energy converters together with an energy storage medium. In this article, different gear shifting algorithms were introduced to increase ICE efficiency in conventional vehicle. Besides, a parallel hybrid configuration was also introduced to enhance drivetrain efficiency. The Equivalent Energy Minimization Method (ECMS) and Dynamic Programming (DP) algorithms were selected as online and offline implementable optimal control methods for hybrid power sharing management. Totally six different case studies were planned to compare the efficiency of each configuration. Finally, the effect of the gear ratio selection and power split algorithms were compared on conventional and parallel hybrid drivetrains regarding overall efficiency