Open Access

Development of a Series Hybrid Electrified Powertrain for a High Speed Tracked Vehicle Based on Driving Cycle Simulation

Journal Article
2022-01-0367
ISSN: 2641-9645, e-ISSN: 2641-9645
Published March 29, 2022 by SAE International in United States
Development of a Series Hybrid Electrified Powertrain for a High Speed Tracked Vehicle Based on Driving Cycle Simulation
Sector:
Citation: Zhu, Q., Kumar, A., Sundar, A., Egan, D. et al., "Development of a Series Hybrid Electrified Powertrain for a High Speed Tracked Vehicle Based on Driving Cycle Simulation," SAE Int. J. Adv. & Curr. Prac. in Mobility 4(4):1403-1412, 2022, https://doi.org/10.4271/2022-01-0367.
Language: English

Abstract:

Series hybrid powertrain design and control strategies for high-speed, tracked, off-road vehicles depend on driving conditions, requiring a comprehensive approach to defining operational parameters prior to the design process. Although some vehicle speed and road grade profiles are available for tracked vehicles, these driving cycles are insufficient for hybrid powertrain characterization since they often neglect highly transient torque requirements for differential speed steering. Generating a difference in track speeds requires high traction torque, often with opposite directions, to overcome immense friction and is a significant contributor to both powertrain design and control decisions. This research presents a track model based on Finite Element Analysis (FEA) to calculate the steering load, which is then incorporated with ground speed and grade information to formulate more realistic driving cycles for tracked vehicles. The additional driving cycle information is then utilized to optimize powertrain component sizing using a simulation-based design process. This research leverages the characteristics of a series hybrid powertrain and separates the design process into two subsections of the vehicle: upstream and downstream of the DC link. This method significantly reduces the design space exploration and enables efficient identification of optimal solutions. This research also investigates the benefits of using two motors to provide traction torque to each track. Compared to the single motor design, the dual-motor design allows for the manipulation of the torque split strategy for driven and braking regeneration during cornering. This added degree of freedom improves energy efficiency by 3.4% when evaluated with the proposed driving cycles. A rule-based supervisory control is developed and tuned for each powertrain design to fairly compare a range of engine and battery sizes. The impact of steering load on control strategy and vehicle performance is also discussed.