Despite growing importance of electric forklift truck in warehouse storage, frequent up and down operations of its lifting system constantly convert potential energy into heat energy, resulting in rising temperature of hydraulic system and poor performance and short life of hydraulic components. To overcome this problem, the paper proposes a potential energy recovery system of electric forklift truck driven by asynchronous generator and battery. PI regulating loop is introduced before torque and flux linkage control loop, and direct torque control is based on space vector modulation to study potential energy recovery efficiency under different loads and speeds and build a testing platform for potential energy recovery test study. Experimental results show that recovered potential energy increases by 1286.82 J for every increase of 138 kg in load at the speed of 1200 r/min under the control mode, meaning potential energy recovery efficiency up to 79.29%.%电动叉车在仓库货物存储领域中的地位日益提高,其举升系统频繁的上下往复作业不断将势能转化为热能,造成液压系统的温升,降低液压元器件的使用性能和寿命.针对以上问题,提出一种基于异步发电机和蓄电池的电动叉车势能回收系统,并在转矩、磁链控制环前引入PI调节回路,采用空间矢量调制的直接转矩控制,研究不同负重、不同转速下势能回收效率,搭建试验平台进行势能回收试验研究.试验结果表明:在该控制方式下,转速1200 r/min,负载增加138 kg,回收的势能增加1286.82 J,势能回收效率高达79.29%.
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