<p>Hydraulic regeneration systems have been considered by the automotive industry for implementation in hybrid vehicles. The combination of an internal combustion engine and a hydraulic system are used in tandem to reduce fuel consumption and increase performance. To achieve this, the energy of the vehicle is stored in and reused from hydraulic accumulators, which use pressurised nitrogen to store the hydraulic energy. The hydraulic accumulator serves as a hydraulic energy battery. The accumulator stores energy in the form of compressed nitrogen which is separated from the oil by the bladder inside the accumulator. The P/M (Hydraulic Pump &amp; Motor) transfers energy between the diesel engine and the hydraulic accumulator depending on the system requirements. The reservoir contains hydraulic oil. The electronic controller monitors the vehicle’s performance and controls hydraulic P/M accordingly. The controller system engages the P/M as a pump when the vehicle transmission has excess kinetic energy, the P/M then applies a negative braking torque on the transmission as the pump fills the accumulators. When the vehicle is accelerating, and there is a need for additional kinetic energy. The control system engages the P/M as a motor, the P/M then applies a positive driving torque to the transmission as the motor converts the stored energy in the accumulators back into kinetic energy in the vehicle.&nbsp;&nbsp; The hydraulic Pump/Motor (P/M) is a critical component in the system and very little is known of its performance characteristics. This storage and usage of kinetic energy in vehicles is termed regenerative braking. This study describes the development of a similar hydraulic hybrid system using an LHD (Load, haul, dump machine) model and a hydraulic hybrid pump/motor (P/M) model. In this work, a model of an LHD vehicle was developed and validated using MATLAB Simulink to implement and test the performance of the hybrid system. This study addresses the gap related to the prediction of the performance of the hydraulic hybrid system and the viability of such a system for unground machines such as the LHD. A novel control system was developed to simulate the drive cycle and predict fuel saving of the hydraulic hybrid system. Variables included accumulator size, hydraulic P/M displacement and accumulator pre-charge, which were adjusted to optimise the hydraulic hybrid system. Fuel consumption before the implementation of the hybrid system was calibrated with the recorded fuel consumption of the collected data. The hydraulic hybrid system was then developed and implemented to the LHD model along with a revised control system. The fuel-saving of a novel hydraulic hybrid control was estimated using MATLAB Simulink. A controller was developed to manage the distribution of energy between the hydraulic system and the diesel engine. The effects of the hybrid system on the brakes and the engine demand were analysed. The results indicated a 45% reduction in diesel engine demand and a 65% decrease in brake usage throughout the drive cycle. The model of the hydraulic hybrid passenger vehicle predicted a fuel saving of approximately 17%. This study shows that the hydraulic hybrid system can potentially improve fuel consumption and optimise engine performance in passenger vehicles.</p>

Development and Performance Assessment of a Hydraulic Hybrid System

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.