Research on Power System Matching of Super Large Electro-hydraulic Excavator

doi:10.3901/JME.2025.22.317

Abstract

Abstract: In addressing the issue of pressure fluctuation at the pump outlet caused by engine speed drop during heavy load rapid loading for ultra-large electric-hydraulic excavators, taking the example of the boom-raising action, a study is conducted on the dynamic matching characteristics among the engine, main pump, and load. Mathematical models are established for the pump-controlled hydraulic cylinder, equivalent load force, and engine speed drop. Factors affecting the dynamic matching between the engine, variable pump, and load are analyzed. A torque-speed compound coordinated control strategy is proposed: the engine speed drop value is converted into a stall compensation torque value; the sum of the stall compensation torque value and the pump’s natural torque value are subjected to fuzzy PID control with deviations between the sum and the set ideal torque, as well as deviations between the actual speed and the set ideal speed, resulting in torque compensation and speed compensation currents. The larger of these currents is then employed for variable pump displacement compensation control. Experimental results demonstrated that under torque-speed dual control, the proportion of control stall compensation torque ranged from 10% to 35%. Hydraulic pump displacement fluctuation improved by 58%, and pump outlet pressure fluctuation improved by over 30%, thereby enhancing the operational performance of mining hydraulic excavators.

Key words: engine stall, pressure fluctuation, pump control strategy, torque compensation, fuzzy-PID

CLC Number:

TH137

CHEN Junxiang, GAO Chunying, KONG Xiangdong, LI Zhi, AI Chao. Research on Power System Matching of Super Large Electro-hydraulic Excavator[J]. Journal of Mechanical Engineering, 2025, 61(22): 317-328.

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