变频液压调速系统的一种磁场定向解耦控制方法

A decoupling schemes used in field oriented control for frequency conversion hydraulic timing system

通过改变液压泵的驱动器以调节液压马达转速,并建立了变频液压调速系统的数学模型和仿真模型,设计了3个PI调节器,在此基础上研究液压系统的主要参数对变频液压调速系统动态特性的影响。仿真结果表明该解耦方法可以改善变频液压调速系统的动态响应;液压马达速度响应的稳态时间为0.5s,超调量小于10%;控制腔容积的变化对系统动态特性影响最大,控制腔容积增加,系统的调整时间延长,超调量和振荡次数增加;液压元件的泄漏系数增加将使系统的调整时间延长;负载取值的变化对系统没有明显影响。

By changing the speed of AC motor, i.e. the driver of hydraulic pump, the speed of hydraulic pump can be changed. The mathematic model and simulation model were founded, three PI controllers were designed; theory analysis and computer simulation analysis were carried out. At the same time, the impact of main parameters of hydraulic system on the dynamic characteristics of variable frequency hydraulic timing system was analyzed. From the simulation, it can be concluded： The decoupling control strategy is satisfying. The adjustable time of hydraulic motor is 0.5s, and the overshooting is less than 10%. The variation of the volume of control valve has a great effect on system dynamic characteristics. The adjustable time of system will be prolonged, the overshooting and surge times increases with the increase of the volume of valve. Adjustable time of the system is prolonged with the increase of leakage coefficient of hydraulic components. Variation of load has little effect on the system performance.