液压抽油机动态功率匹配研究

Research on Dynamic Power Matching of Hydraulic Pumping Unit

基于二次调节技术蓄能器储能式液压抽油机在工作时,悬点速度不稳定,与负载液压缸相连的变量泵/马达输入或输出的功率和与蓄能器相连的变量泵/马达输出或输入的功率不匹配,导致电机功率不稳定,甚至电机反转。根据系统能量转化关系提出基于前馈控制的动态功率补偿原则,仿真结果表明:两个周期内电机功率波动减小,且在悬点速度变化过程中不会逆向运转向电网供电,实现了与蓄能器相连的变量泵/马达排量自适应调节。抽油机悬点载荷受随机的不确定干扰时,采用降维观测器重构负载扰动,并通过前馈控制消除负载扰动对系统输出的影响。仿真结果表明:该控制减小抽油杆速度的超调量,提高了速度稳态精度,实现了与负载液压缸相连的变量泵/马达排量自适应调节。

During the operation of accumulator-type hydraulic pumping unit based on secondary regulation technology,the suspension speed changes,the input or output power of variable pump/motor connected with load hydraulic cylinder and the output or input power of variable pump/motor connected with accumulator mismatch,resulting in motor power instability and even reverse operation.The dynamic power compensation principle based on feedforward control was proposed on the basis of the energy conversion relationship of the system.The simulation results show that the fluctuation of motor power decreases in two cycles,and the power supply to the power grid will not reverse in the process of suspension speed change.The variable displacement pump/motor connected with accumulator can be adjusted adaptively.When the suspension load of pumping unit was disturbed by random uncertainties,the reduced-order observer was used to reconstruct the load disturbance,and the influence of the load disturbance on the output of the system was eliminated by feedforward control.The simulation results show that the control reduces the overshoot of the sucker rod speed and improves the steady-state accuracy of the speed.The variable displacement pump/motor connected with the load hydraulic cylinder can be adjusted adaptively.