液电混合驱动电铲提升系统能效特性研究

矿用电铲作业过程中,大质量的工作装置在提升和推压电机驱动下切入物料实现挖掘,在其卸料后下降时,工作装置的重力反驱提升电机发电,发出的电能通过制动电阻以热能形式消耗掉,造成能量浪费。本文提出液电混合驱动电铲提升系统,与提升电机同轴设置液压泵/马达,液压泵/马达的进出油口分别与蓄能器和油箱连接,通过蓄能器的预充压力平衡工作装置的重力。工作装置下降时,液压泵/马达将油箱中的低压油泵入蓄能器中,存储工作装置的重力势能;工作装置提升时,蓄能器释放高压油,液压泵/马达与提升电机共同驱动提升机构,达到降低电机装机功率和能耗的目的。分析了液电混合驱动的电铲提升机构驱动方案及其工作原理,搭建了原理性试验台,对液电混合提升驱动方案进行了验证,进一步建立了电铲整机机电液联合仿真模型,对液电混合电铲提升系统进行仿真分析。结果表明,本文方案可降低提升电机装机功率、峰值功率和能耗,适用于电动机驱动的重型提升装备。

Energy Efficiency Characteristics of Cable Shovel Lifting System Driven by Hydraulic-Electric Hybrid System

Mining shovel is an important equipment in large open pit mining. In lifting operation, the high quality working device is driven by the lifting motor to lift and shovel into the material to realize excavation. When falling, under the gravity force of the working device, the lifting motor generates electricity. This distributed electric energy is often dissipated in the form of thermal energy through brake resistance, causing great waste of energy. In order to solve the above problems, an innovative driving scheme of hydraulic-electric hybrid shovel hoisting mechanism was proposed. A hydraulic pump/motor was added to the hoisting motor coaxially, and the inlet and outlet of the hydraulic pump/motor were connected with an hydraulic accumulator and tank respectively. When falling, under the action of working device gravity force, the hydraulic pump/motor and lifting motor provided braking torque to control the descending speed. At this time, the hydraulic pump pumped the low pressure oil in the tank into the accumulator and the gravitational potential energy of the working device was stored in the accumulator; when lifting the working device, the device released high pressure oil, and the hydraulic pump/motor worked together with the lifting motor to lift the working device, so as to reduce the installed power and energy consumption of the lifting motor. In the research, the working principle of the driving scheme of the hydraulic-electric hybrid driving electric shovel hoisting mechanism was introduced; the principle test bed was set up to verify the hydraulic-electric hybrid driving scheme; the new hydraulic-electric combined simulation model of the electric shovel was established, and the hydraulic-electric hybrid electric shovel hoisting system was simulated and analyzed. The results showed that the installed power, the peak power and the energy consumption of the motor can be reduced by adopting this scheme. The method can be widely applied to all kinds of heavy lifting equipment driven by motors.