A Novel Energy-Efficient Transmission System and Control Strategy for Hydraulic Machines

Each part of a hydraulic press dissipates a large amount of energy when energy or power is transmitted. Therefore, this study proposes a 3-D vertical arrangement structure for the hydraulic press to reduce their energy dissipation. In the proposed structure, the aboveground and underground spaces are comprehensively utilized, and then the hydraulic equipment are arranged three-dimensionally and set in layers according to the functional requirements. Some equipment is connected directly to minimize the use of valves and pipelines and reduce the transmission distance of hydraulic energy between the pump station and the actuator. Furthermore, a method for scheduling the drive system in the above structure is presented to share a transmission zone with no conflict and shorten their idle time. The composition of each zone is set to match the power demand of each operation to achieve the scheduling schemes. Finally, the proposed scheme is applied to a 31.5 MN hydraulic press as a case study. Results showed that the energy efficiency increased from 43.95% to 85.03%, demonstrating excellent energy-saving potential.