Figure 19 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Source publication
The conventional electric loader uses a motor instead of an engine, which aligns with the current energy−saving and emission−reduction trend. However, the motor’s speed control performance and overload capacity are under−utilized, and the actuator suffers from the potential energy waste problem of the boom arm. This study proposes a variable pressu...
Citations
Facing the development trend of electrification of construction machinery, in view of the drawbacks of the existing electro-hydraulic-load-sensitive system in terms of dynamic characteristics and usage of energy, based on the drive source of a servo motor-driven quantitative pump, an electro-hydraulic-load-sensitive system on the basis of torque open-loop control was proposed. Firstly, the working principle of the system was introduced and the system’s operating characteristics and energy consumption characteristics were theoretically analyzed. Secondly, in order to balance the system’s energy usage and maneuverability, a control strategy with a variable pressure margin was designed. Meanwhile, in order to solve the problem that the hydraulic pump’s mechanical efficiency causes system pressure control deviation, a torque compensation method based on offline data and speed prediction was proposed. Finally, simulation and testing were used to confirm the viability of the control strategy. The test results show that: the system could realize stable pressure margin control, and the response rise time was within 0.7 s under a variety of flow circumstances; the system could follow the control instruction to change linearly and the flow rate changed smoothly in the adjustable pressure gap control; after using the compensation method, the deviation of the pressure gap control was within 2%.
In response to the problem of large energy waste in the loader actuator, a hybrid loader boom arm energy recovery and regeneration system is proposed, which adopts a supercapacitor as the energy storage element. Firstly, the working principle of the hybrid loader boom arm energy recovery and regeneration system is analyzed. Secondly, the mathematical model of the components is analyzed. Finally, AMESim is used to model the system. The simulation is carried out under typical working conditions with the LiuGong ZL50C loader as the simulation object and compared with the conventional system. The simulation results show that the hybrid power system does not affect the motion characteristics of the loader boom arm system compared with the conventional system. The hybrid power system can perform energy recovery regardless of the mode of operation, and the energy recovery efficiency reaches 55.7 %. When the system enters the hybrid mode, the supercapacitor SOC fluctuates less, and the energy regeneration efficiency reaches 90 %. The hybrid power system can effectively reduce engine fuel consumption and pollutant emissions, with the system's energy-saving efficiency of 44.4 % and CO, HC, and NOx emissions reduced by 41.1 %, 47 %, and 19.8 %, respectively. The system provides a reference for the research of energy-saving technology of the loaders, effectively reducing the operating cost of the loaders.
