液压挖掘机回转制动能量回收系统

为了回收液压挖掘机在回转阶段的制动能量,提出一种基于回转马达进/出口压力差自动识别回转过程所处阶段,决策能量回收的全液压自动控制回转制动能量回收系统.引入一正态分布函数,以蓄能器压力状态（SOP）、液压泵出口压力以及负流量反馈压力为输入信号,根据负载的实时需求功率,提出一种以复合恒功率 负流量动力控制决策发动机和蓄能器主辅动力源的能量分配方法,保证回转机构的正常高效运转.仿真结果表明,当回转系统作为单独执行机构时,采用该回收系统的液压挖掘机,能够实现高达50.0%的再生制动能量用于驱动回转的能量回收利用效率,在相同工况下比同吨位液压挖掘机节能16.3%,不影响操作习惯和操作性能.

Recovering system of swing braking energy in hydraulic excavator

In order to recover the braking energy from the hydraulic excavator during swing phase,an automatic hydraulic-controlled braking energy recovery system was proposed which can automatically identify the swing stage by the pressure difference between inlet and outlet of the swing pump and determining distribution algorithm of the recovering energy.One normal school function was introduced.State of pressure(SOP) of the accumulator,the outlet pressure of the hydraulic pump and the feedback pressure from negative-flow control were considered as input signals.According to the real-time required power of the load,the energy distribution algorithm was proposed based on the comprehensive constant-power negative-flow control between the main power source and the auxiliary power source(that is engine and accumulator),which ensures the normal operation of the swing mechanism.Simulation results show that the hydraulic excavator equipped with the swing recovery system can achieve 16.3% energy saving compared with the baseline under the same working condition,and the overall chain efficiency from the total braking energy to the terminal swing mechanism is as much as 50.0% approximately while the swing is utilized as the actuator alone.