Energy Consumption Analysis and Thermal Equilibrium Research of High-Voltage Lithium Battery Electric Forklifts

Abstract

Featured Application: The proposed high-voltage lithium battery powertrain solution can effectively extend the operating endurance of electric forklifts while reducing system-wide energy losses. With the escalation of global warming and environmental pollution, electric products characterized by zero emissions, low vibration, and minimal pollution are increasingly favored by consumers. As a pivotal loading and transportation tool, the electrification of forklifts progressed earlier and is relatively mature. However, the prevalent low-voltage systems (72 V or 80 V) in current electric forklifts exhibit issues such as elevated heat loss, restricted motor instantaneous power due to voltage constraints, susceptibility to electrical erosion, and challenges in achieving rapid charging. To address these challenges, a powertrain solution employing high-voltage lithium batteries (320 V) as energy storage units for electric forklifts is proposed. The key parameters of the high-voltage lithium battery were meticulously calculated and selected. The powertrain architecture of the high-voltage lithium battery electric forklift was analyzed, and operational conditions were thoroughly examined. To verify the superior energy efficiency performance of the proposed high-voltage electric forklift in comparison to its low-voltage counterparts, a test prototype was constructed, and comprehensive tests, including average energy consumption and thermal equilibrium assessments, were conducted. The test results demonstrated that under average energy consumption conditions, the operational duration ranged from 8.89 to 13.34 h, surpassing the 7.5 h achieved by low-voltage electric forklifts. The thermal equilibrium temperatures of all electrical control units remained below 43 °C, significantly lower than the 80 °C shutdown protection threshold allowed for low-voltage forklifts. These findings indicate that the proposed high-voltage lithium battery electric forklift exhibits relatively low energy consumption, significantly enhances overall operational efficiency, and ensures stable operation, providing a viable solution and reference for the electrification of forklifts and other construction machinery.