直线电机抽油机速度闭环控制系统的研究与设计.pdf

华中科技大学
硕士学位论文
直线电机抽油机速度闭环控制系统的研究与设计
姓名:傅智春
申请学位级别:硕士
专业:测试计量技术及仪器
指导教师:徐振高
20060425
摘要:
抽油机是油田地面生产的主要设备,随着油田采油工艺的改进及现场生产的实
际需求,抽油机朝着节能、智能、大载荷、长冲程等方向发展。直线电机抽油机是 20
世纪末出现的一种新型高效抽油机,顺应了抽油机技术发展的潮流。
直线电机抽油机以永磁同步直线电机作为驱动装置。与传统抽油机相比,在载
荷波动较大的油井上试验时,停机次数偏多,运行不稳定。
针对上述问题,本文首先研究和分析了油田采油工艺及永磁同步直线电机的特
性,建立了永磁同步直线电机的力学模型,提出了一种速度闭环控制系统。
然后根据抽油机的运行环境,完成了速度闭环控制系统的硬、软件设计。该控
制系统的硬件由 MM440 通用变频器、S7-300PLC 和旋转编码器等构成。利用 PLC
检测和永磁同步直线电机连接的旋转编码器的输出脉冲,对直线电机抽油机的运行
速度进行监测。通过电机运行速度的变化反映抽油杆上载荷的变化。根据载荷的变
化来调整变频器的输出电压,从而控制直线电机输出的推力,使得直线电机抽油机
能够响应抽油杆上的载荷波动。解决了直线电机抽油机对变化载荷的响应问题。
最后,对所研制的直线电机抽油机进行了厂内试验及现场应用试验,试验结果
表明,该控制方案是有效、可行的,在载荷波动较大的条件下,能实现直线电机抽
油机的稳定运行。本文的研究结果为直线电机抽油机的推广应用奠定了技术基础,
具有实用价值。
关键词:抽油机直线电机抽油机永磁同步直线电机速度闭环控制系统
I
Abstract
The pumping unit is an important implement for land oil filed. With the development
of the techniques of oil extraction and the requirements of practical field production, the
pumping unit has e more and more economical, intelligent, large-loaded and long-
stroke. The Linear motor pumping unit is a new-style and efficient example emerging at the
end of the 20th century.
The linear motor pumping unit is driven by permanent synchronous linear
motor. When the load fluctuates largely, not only does it run unsteadily, but also it breaks
down more paring with the traditional pumping units.
Firstly aiming at the problems above, the techniques of oil extraction and the
characteristics of the permanent synchronous linear motor are studied, the
mechanics model of the motor is given and the speed feedback control system is proposed.
Then the hardware and software of the system are designed under the running
circumstance of the pumping unit. The hardware of the control system consists of MM440
common transducer, S7-300PLC, rotary encoder and so on. The speed of the linear motor is
inspected by the PLC and the output pulse of the rotary encoder. The change of the motor
speed reflects the change of the load putting on t