纯电驱液压挖掘机动力源特性试验研究

现有工程机械主要以柴油发动机为原动机,存在燃油效率低,排放严重等问题,新的趋势是采用电动方式代替内燃方式.采用变速异步电动机驱动定量泵作为动力源,针对变频异步电动机动态响应较慢的问题,提出在定量泵出口增设液压蓄能器并将其油液引入液压泵入口的方法,提高电动机动态响应.建立采用蓄能器辅助起制动后电驱动力源的试验系统,对比分析了有无蓄能器辅助时液压泵的起制动特性.在此基础上,将这一动力源用于驱动进出口独立控制的液压挖掘机,对动臂运行特性和能耗特性进行试验研究.与发动机驱动系统相比,采用新型电驱动方式,实现同样的操纵性能,可降低动臂运行成本50%,并显著降低供电电源峰值电流.

Experimental study on power source characteristics of pure electric drive hydraulic excavator

The power sources of the existing construction machinery are mainly diesel engines,which have prob-lems of low fuel efficiency,serious emission and so on. The new trend is using electric motor instead of diesel en-gine. Variable frequency asynchronous motor driving the fixed displacement hydraulic pump is selected as the power source in this paper. Aiming at the problem of variable frequency asynchronous motor slow dynamic re-sponse,a new method that hydraulic accumulator is added to the fixed displacement pump outlet port and the ac-cumulator high-pressure oil is lead to pump inlet port is proposed to improve the dynamic response of electric mo-tor. The experiment system of electro-hydraulic power source using accumulator assisting run-stop is established. The run-stop performances of the power source with or without accumulator are compared and analyzed. Based on that,this power source is used to drive hydraulic excavator with separate meter in and meter out technology and the operating performances and energy consumption characteristics of the boom are studied. Compared with the engine drive system,by using electric motor drive system,the boom operation cost are reduced by 50 percent un-der the premise of the same operating performance,and the peak current of electric source is remarkably reduced.