Analysis of electro-hydraulic lifting system's energy efficiency with direct electric drive pump control

• Published in: Automation in construction Vol. 30; pp. 144 - 150
• Main Authors: Minav, Tatiana A., Laurila, Lasse I.E., Pyrhönen, Juha J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.03.2013; Elsevier
• Subjects: Applied sciences; Buildings. Public works; Computation methods. Tables. Charts; Computational fluid dynamics; Construction equipments; Construction works; Control systems; Electric drives; Energy-saving ratio; Exact sciences and technology; Fluid flow; Fork lift trucks; Forklift truck; Hoisting; Hydraulics; Lift; Mobile work machine; Modelling; Payloads; Potential energy recovery system (PERS); Structural analysis. Stresses; SC; DTC; PERS; Potential energy recovery system (PERS); Electric drives; Mobile work machine; Energy-saving ratio; KERS; Modelling; ER; Forklift truck; DC; Measurement result; Energy recovery; Electric drive; Electrohydraulics; Energy savings; Pump; System description; Construction equipment; Simulation model; Hoisting
• ISSN: 0926-5805; 1872-7891
• DOI: 10.1016/j.autcon.2012.11.009

Energy efficiency has become a major research issue in all fields of engineering. Opportunities of utilizing electric servo drives in the control of hydraulic lifting systems directly by an electric-servomotor-driven hydraulic machine and enabling energy recovery in them are studied. In this paper, the modelling and testing of an electro-hydraulic lifting and lowering system and a forklift with two lifting zones are carried out and analyzed. The efficiencies and energy-saving ratios of the experimental drive system are determined for the free lift and the second lift zones of a modified industrial forklift with different speeds and payloads. The maximum achieved energy-saving value in the Potential Energy Recovery System (PERS) was 50% for a maximum tested payload of 1000kg and a maximum fork velocity of 0.5m/s for the second lift zone. The efficiencies and energy consumptions of the experimental drive system and its components are determined. ► Differences between the two different lift zones of the forklift were analyzed. ► The maximum achieved energy-saving value was 50% for the second lift zone. ► In the free lift zone, the energy-saving ratio varies from 0 to 36%. ► The test results favored the second lift zone from the energy-saving point of view. ► The test shows that the direct electric pump drive system has numerous advantages.