Energy Efficiency Optimized in the Dynamic Process of a Variable-speed Variable-displacement Pump Unit

doi:10.3901/JME.2021.07.185

Abstract

Abstract: Hydraulic systems are widely used in construction machinery and hydroforming equipment, but the low energy efficiency caused by the power mismatch between output power of the drive unit and demand power of the actuators cannot be ignored. By cooperatively adjusting the motor speed and pump displacement of a variable-speed variable-displacement pump unit, the power match degree can be improved under the stable operating conditions. In order to further improve energy efficiency of the variable-speed variable-displacement pump unit under complex and variable working conditions, energy consumption model of the drive unit during the dynamic process is established. The relationship between energy consumption and motor acceleration is obtained to acquire the optimum motor accelerations and the minimum energy consumption during dynamic process. Moreover, the stability with different motor accelerations of the hydraulic system is investigated by experiments, and the motor accelerations are selected according to the required working conditions for the preferable energy efficiency and stability. The results indicate that energy efficiency and speed fluctuation of the preferable motor acceleration can be improved by 8.0% and 14.9% respectively, compared with that of the default motor acceleration.

Key words: power matching, dynamic process, energy efficiency, stability, motor acceleration

CLC Number:

TH137

HUANG Haihong, TANG Yunxian, JIN Rui, LI Lei, LI Dacheng, LIU Zhifeng. Energy Efficiency Optimized in the Dynamic Process of a Variable-speed Variable-displacement Pump Unit[J]. Journal of Mechanical Engineering, 2021, 57(7): 185-193.

References

[1] HO T H, AHN K K. Modeling and simulation of hydrostatic transmission system with energy regeneration using hydraulic accumulator[J]. Journal of Mechanical Science and Technology,2010,24(5):1163-1175.
[2] WANG Tao,WANG Qingfeng,LIN Tianliang. Improvement of boom control performance for hybrid hydraulic excavator with potential energy recovery[J]. Automation in Construction,2013,30:161-169.
[3] KWON T S,LEE S W,SUL S K,et al. Power control algorithm for hybrid excavator with supercapacitor[J]. IEEE Transactions on Industry Applications,2008,46(4):1447-55.
[4] LI Lei,HUANG Haihong,ZHAO Fu,et al. Analysis of a novel energy-efficient system with double-actuator for hydraulic press[J]. Mechatronics,2017,47:77-87.
[5] LI Lei,HUANG Haihong,LIU Zhifeng,et al. An energy-saving method to solve the mismatch between installed and demanded power in hydraulic press[J]. Journal of Cleaner Production,2016,139:636-45.
[6] GE Lei,QUAN Long,ZHANG Xiaogang,et al. Power matching and energy efciency improvement of hydraulic excavator driven with speed and displacement variable power source[J]. Chinese Journal of Mechanical Engineering,2019,32(1):100.
[7] SHI Hu,YANG Huayong,GONG Guofang,et al. Energy saving of cutterhead hydraulic drive system of shield tunneling machine[J]. Automation in Construction,2014,37(1):11-21.
[8] HUANG Haihong,JIN Rui,LI Lei,et al. Improving the energy efficiency of a hydraulic press via variable-speed variable-displacement pump unit[J]. Journal of Dynamic Systems,Measurement,and Control,2018,140(11).
[9] WILLKOMM J,WAHLER M,WEBER J. Quadratic programming to optimize energy efficiency of speed-and displacement-variable pumps[C]//8th FPNI Ph.D. Symposium on Fluid Power,Lappeenranta,Finland. June 11-13,2014.
[10] 李泽鹏,权龙,葛磊,等. 液电混合驱动液压挖掘机动臂特性及能效研究[J]. 机械工程学报,2018,54(20):235-241. LI Zepeng,QUAN Long,GE Lei,et al. Research on characteristics and energy efficiency of hydraulic-electric combined driving hydraulic excavator boom[J]. Journal of Mechanical Engineering,2018,54(20):235-241.
[11] SUN Hui,JING Junqing. Research on the system configuration and energy control strategy for parallel hydraulic hybrid loader[J]. Automation in Construction,2010,19(2):213-220.
[12] 闫政,权龙. 变转速变排量双控轴向柱塞泵脉动特性及噪声的研究[J]. 机械工程学报,2016,52(16):176-184. YAN Zheng,QUAN Long. Characteristics of pulsation and noise in the axial piston pump with displacement and speed compound control[J]. Journal of Mechanical Engineering,2016,52(16):176-184.
[13] 胡东明. 液压电梯变转速闭式电液系统速度控制特性研究[D]. 杭州:浙江大学,2009. HU Dongming. Research on speed control characteris-tics of hydraulic elevator variable speed closed electrohy-draulic system[D]. Hangzhou:Zhejiang University,2009.
[14] 刘艳. 液压机冲裁主动减振技术研究[D]. 广州:广东工业大学,2008. LIU Yan. Research on active vibration reducing method of blanking[D]. Guangzhou:Guangdong University of Technology,2008.
[15] 付秀娟. 变速/变载条件下板料冲压成形性能及其变形机理研究[D]. 武汉:华中科技大学,2012. FU Xiujuan. A dissertation submitted in partial fulfillment of the requirements for the degree of doctor of philosophy in engineering[D]. Wuhan:Huazhong University of Science &Technology,2012.
[16] GUO Qing,QIANG Wang,LI Xiaochai. Finite-time convergent control of electrohydraulic velocity servo system under uncertain parameter and external load[J]. IEEE Transactions on Industrial Electronics,2018,66(6):4513-4523.
[17] BAI Baodong,CHEN Dezhi. Inverter IGBT loss analysis and calculation[C]//2013 IEEE International Conference on Industrial Technology (ICIT). IEEE,Cape Town,South Africa 2013:563-569.
[18] CAVALLARO C,DITOMMASO A O,MICELI R,et al. Efficiency enhancement of permanent-magnet synchronous motor drives by online loss minimization approaches[J]. IEEE Transactions on Industrial Electronics,2005,52(4):1153-1160.