纯电驱动工程机械自动怠速系统参数优化与试验

Parameters Optimization and Experiment of Idle-speed Control System of Construction Machinery Driven by Electric Power

摘要:

针对工程机械节能需求，考虑挖掘机的典型工况，以保证在取消怠速恢复工作时执行器入口能快速建立压力为目标，提出一种基于蓄能器的二级怠速控制系统，通过检测先导手柄压力、液压泵出口压力、执行器入口压力和蓄能器压力等作为判断条件，制定驱动电机转速切换规则。对影响怠速过程的关键元件液压蓄能器的性能参数进行分析，以选定的蓄能器参数在某1.5t纯电驱动挖掘机上进行试验，结果表明所提出的二级自动怠速控制系统能在两级怠速之间切换，且具有蓄能器的自动怠速系统，与无自动怠速控制的系统相比，节能达36%；与无蓄能器的自动怠速系统相比，恢复工作时执行器压力建立更迅速，压力更平稳，具有较好的操作稳定性。

Abstract:

Considering energy saving and typical working condition of construction machinery, a two-level idle-speed control system based on hydraulic accumulator was proposed to ensure the quick pressure rising at inlet of working chamber of actuator when the idle speed was canceled and the actuator started a new working cycle. The mathematical model of the proposed idle speed control system was developed. The values of the two-level motor speed were obtained according to motor response and characteristics of the pump. The rules of motor speed switch between the two-level idle-speed and the normal working speed were made by detecting the pressures of joystick, pump, two chambers of actuator and accumulator. The parameters of the hydraulic accumulator which was the key component of the idle-speed control system were analyzed through simulation. The experiment was carried out on a 1.5t hydraulic excavator driven by electric power using the obtained parameters of hydraulic accumulator. The comparisons between the idle speed control system with and without hydraulic accumulator and the system without idle speed control were carried out on the testing. The test results showed that the proposed two-level idle-speed control system worked well. Compared with the system without idle-speed control, the proposed control system with hydraulic accumulator can save up to 36% energy. While compared with the idle-speed control without hydraulic accumulator, the inlet pressure of the actuator was raised more quickly and steadily in the proposed control system. This indicated that the proposed system can achieve good energy saving and control performance.