Hybrid drivetrain with dual energy regeneration and collaborative control of driving and lifting for construction machinery

Abstract

The push for a more sustainable logistics industry has been driving heavy machinery manufacturers to develop electric construction machinery (ECM). To improve energy efficiency of ECM, we propose a multistage parallel hybrid drivetrain (MPHD) that combines a parallel hybrid lifting system (PHLS) with an electrohydraulic driving system. The proposed MPHD can recover both gravitational and braking energy through a network of hydraulic accumulators. To optimize power distribution of MPHD under various conditions, an energy management strategy with an adjustable degree of hybridization (DOH) is developed to collaboratively control lifting and driving systems. In addition, experiments and simulations are conducted to verify the feasibility and energy efficiency of MPHD. Taking a MPHD-equipped 2.5-t electric forklift as example, a co-simulation platform is built to demonstrate its performance in a designed cycle based on Chinese standard JB/T3300–2010. Compared with electric forklifts without energy recovery, the MPHD-equipped 2.5-t forklift displays an energy consumption reduction of 28%–35% and a dual energy regeneration efficiency of 73%–76%.