Energy Management Strategy for an Electromechanical-Hydraulic Coupled Power Electric Vehicle Considering the Optimal Speed Threshold

Abstract

Considering the problems of the low energy recovery efficiency and the short driving range of pure electric vehicles, a new electromechanical–hydraulic coupled power electric vehicle is proposed. First, we develop an electromechanical–hydraulic coupled power electric vehicle model and design an energy management strategy to match it. On this basis, an optimization strategy is proposed with the goal of improving the braking energy recovery efficiency and avoiding the impact of high-speed braking energy recovery on the hydraulic system. The energy recovery mode conversion is optimized for different vehicle speeds when braking. Finally, the proposed optimization strategy is verified by joint simulation. The results show that when the vehicle speed is higher than 10 m/s for energy recovery mode switching, the total recovery efficiency of the whole vehicle increases to 97.273% and the SOC of the power battery increases by 0.14%. This provides strong support for improving the driving range of electromechanical–hydraulic coupled power electric vehicles.

Electrohydraulic Power Switching Control for Mechatronics–Electrohydraulic Power Coupling Electric Vehicles Considering Optimal Speed Thresholds

“…Although the concept of mechatronics-electro-hydraulic power coupling electric vehicles (MEHPC-EV) has been proposed and studied, [20,21] several challenges and problems still exist in the development and practical testing of this device that cannot be ignored. First, no completely quantitative research has been conducted on the interaction of mechanohydraulic technology with economic performance, power performance, and hydraulic characteristics, which is the frontier research direction where relevant research results are urgently needed.…”

“…As shown in published article, [20,21,27] the drive modes of the MEHPC-EV are hydrodynamic drive mode (HD mode), electrodynamic drive mode (ED mode), and electrohydraulic drive mode (EHD mode): [34] 1) The vehicle enters HD mode at start-up to avoid the impact of high current and high power on the battery. The hydraulic motor realizes the conversion of hydraulic energy to mechanical energy through the plunger's reciprocating motion, which takes full advantage of the high power density of the hydraulic accumulator.…”

“…In addition, these parameter configurations can be found in some of our other related studies. [20,21,29,30,34]…”

“…The feasibility and superiority of the mechatronics‐electro‐hydraulic electricity coupling electric vehicle (MEH‐PCEV) were additionally verified via evaluating it with the AMESim certified PEV. Meng et al [ 21 ] proposed a new MEH‐PCEV for PEVs with low energy recovery efficiency and short driving range. When switching energy recovery mode with vehicle speed greater than the braking threshold, the recovery efficiency improved to 97.273% and the battery state of charge (SOC) improved by 0.14%.…”

Research on Braking Efficiency of Master-Slave Electro-Hydraulic Hybrid Electric Vehicle

“…According to the different braking speeds of the vehicle, the conversion of energy recovery mode is optimized. Finally, the feasibility of the proposed control strategy is verified by simulation of AMESim and Simulink [26].…”