(D+A)组合控制多泵源液压系统构型与冲击特性仿真研究

摘要

针对大型锻造液压机阀控液压系统中由于泵源输出与负载流量需求不匹配问题,在数字泵PCM控制概念的基础上提出了一种基于数字和模拟(D+A)组合控制的多泵源液压系统的构型思想.该系统能够实现泵源输出流量的实时连续变化,使系统具有容积调速的特征,为解决锻造液压机阀控系统传动效率低下问题开辟了一条新途径.同时,针对该多泵源系统中泵组状态切换时存在的流量冲击问题,提出了时间差延迟控制策略.仿真结果表明:该控制策略使得系统流量冲击程度降低了约50％ ～ 75％.%In order to solve the flow mismatch problem between the pumping source output and the workload demand in forging hydraulic press,we introduce a configuration approach suitable for the digital and analog (D + A) combination controlled multi-pump hydraulic system based on the PCM control in the concept of digital pump.As the multi-pump source flow can be regulated continuously and in real time,the system shows the characteristic of volumetric speed control,which could solve the poor efficiency problem in the hydraulic system.Besides,a time delay control strategy is proposed to reduce the instantaneous flow impact when the pump unit state changes.Simulation results show that the degree of the flow impact can be reduced by 50％ ～ 75％ via the proposed control strategy.