Electrified Powertrain with Multiple Planetary Gears and Corresponding Energy Management Strategy

Abstract

Modern hybrid electric vehicles (HEVs) like the fourth generation of Toyota Prius incorporate multiple planetary gears (PG) to interconnect various power components. Previous studies reported that increasing the number of planetary gears from one to two reduces energy consumption. However, these studies did not compare one PG and two PGs topologies at their optimal operation. Moreover, the size of the powertrain components are not the same and hence the source of reduction in energy consumption is not clear. This paper investigates the effect of the number of planetary gears on energy consumption under optimal operation of the powertrain components. The powertrains with one and two PGs are considered and an optimal simultaneous torque distribution and mode selection strategy is proposed. The proposed energy management strategy (EMS) optimally distributes torque demands amongst the power components whilst also controlling clutches (i.e., mode selection). Results show that increasing from one to two PGs reduces energy consumption by 4%.

Influence of Energy Management System Control Strategies on the Battery State of Health in Hybrid Electric Vehicles

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“…These management algorithms generally include a fully electric driving and a fully thermal driving mode, and other hybrid modes. In hybrid modes, the thermal engine may have the task of supporting traction, and at the same time recharging the battery, or simply a marginal role in the traction or operating at predefined working points [13][14][15][16][17].…”