变转速混合动力液压机能效特性仿真分析及实验

Simulation analysis and experiment of energy efficiency characteristics for variable revolving speed hybrid power hydraulic press

为了弥补液压机中传动电驱液压泵引起的节流与溢流损失,提出了一种变转速混合动力液压系统控制方式。系统配备蓄能器后可实现电液电机的能量回收,达到系统泄漏的补偿作用,以及对液压执行器发挥预压紧的功能,可以精确调控运行速率与位置。在Simulation X软件中构建了仿真模型,并从动态特性和能效特性两个方面展开分析。研究结果表明:2.5 s后两电机均发生正向旋转,从而得到总压力;2.7 s时系统压力达到9.1 MPa;介于2.7~6.0 s之间时,压力稳定变化;6.6 s时,总压力信号减小至0。该液压系统表现出了优异的运行特性,形成了平稳的速度曲线。电动机驱动过程中形成了稳定的功率变化,以液压-电气方式进行能量回收时,系统达到了最高的能量回收率,表现出最优的节能效果。开展实验测试可知,该系统可以精确定位,速度曲线运行平稳,基本无冲击,整个系统运行特性良好。

In order to compensate for the loss of throttling and overflow caused by the transmission electric drive hydraulic pump of hydraulic press,a control method of variable revolving speed hybrid hydraulic system was proposed.Then,after the system was equipped with an accumulator,it realized the energy recovery of electro-hydraulic motor,achieved the compensation effect of system leakage and the pre-compression function of hydraulic actuator,and accurately controlled the operating speed and position.Furthermore,the simulation model was built by software Simulation X,and the analysis was carried out from two aspects of dynamic characteristics and energy efficiency characteristics.The results show that after 2.5 s,the two motors both rotate in a positive direction to get the total pressure,and the system pressure reaches 9.1 MPa at 2.7 s.However,the pressure changes stably between 2.7-6.0 s,and the total pressure signal decreases to zero at 6.6 s.Therefore,the system shows excellent operating characteristics and forms a smooth velocity curve,and the steady power change is formed during the driving process of electric motor.When the energy recovery is carried out in a hydraulic-electric way,the system achieves the highest energy recovery rate and shows the best energy-saving effect.The experimental test shows that the system can accurately locate,the speed curve runs smoothly,there is basically no impact,and the entire system has good operating characteristics.