基于PLC的抽油机变频自适应系统研究

发布时间：2018-10-08 06:52

【摘要】：我国石油资源进入开采中后期,在开采中抽油机电动机传动的平均载荷效率低,带来了能量的巨大浪费。变频调速自适应技术的发展使游梁式抽油机具有较好的抽油性能,能提高产量、降低采油成本、提高经济效益等,是抽油机节能发展的主流和方向。据此,本文在实验室环境下研究了游梁式抽油机变频节能控制系统。为了实时掌握抽油机在采油过程中负载与电机频率情况,必须对变频自适应系统的关键参数——负载频率,进行实时准确的测量。实时准确测定在负载运行时电机的频率,频率根据负载成线性变化,这对于提高采油率及节约能源都有重要的意义。本文基于电机频率随负载变化的特点,提出了一种基于变频节能新方法,进而对抽油机采油节能的研究开拓了新思路。通过设计和优化抽油机变频系统结构,进行多次负载变频测试试验,系统研究抽油机电机频率与抽油机负载内在联系,揭示抽油机电机频率与抽油机负载的响应规律。随着抽油机负载的增加电机频率的变化,对实验测得数据进行验证,得到相应电机频率值。熟知电机频率的变化规律为充分了解抽油机负载特性、优化开采方案、提高节能率提供了理论指导,为使用新型变频节能系统的应用奠定了理论基础。根据系统要实现的功能和性能指标,变频自适应控制系统采用西门子S7-300处理器为核心,抽油机模型为被控对象,根据负载的情况控制变频器,调节电机运转速度,采用光电编码器、载荷传感器、对信号进行采集。将采集的信号反馈给PLC,最终构建成闭环自适应控制系统,实现抽油机电机变频调速控制,反映出频率值随着负载的变化趋势。从实验室试验结果来看,设计的抽油机变频自适应系统实现了电机频率实时反馈测量。测量结果显示负载增加电机的频率变化,加上模糊PID调节,使频率稳定,在测量过程中误差在1%,测量系统运行稳定可靠,精度较高,满足了抽油机变频自适应测量的需求。
[Abstract]:In the middle and late stage of exploitation of petroleum resources in China, the average load efficiency of motor drive of pumping unit is low, which brings a huge waste of energy. With the development of frequency conversion adaptive technology, beam pumping unit has better pumping performance, which can increase the output, reduce the cost of oil production and increase the economic benefit. It is the mainstream and direction of energy saving development of pumping unit. Accordingly, this paper studies the frequency conversion energy saving control system of beam pumping unit in laboratory environment. In order to grasp the load and motor frequency of pumping unit in the process of oil recovery, it is necessary to measure the load frequency, which is the key parameter of frequency conversion adaptive system, in real time and accurately. It is very important to determine the frequency and frequency of the motor when the load is running accurately and linearly according to the load, which is of great significance for improving the oil recovery rate and saving energy. Based on the characteristics of motor frequency varying with load, a new energy-saving method based on frequency conversion is proposed in this paper. Through the design and optimization of the structure of the pumping unit frequency conversion system, several load frequency conversion tests were carried out, and the inherent relationship between the frequency of the pumping unit motor and the pumping unit load was systematically studied, and the response law of the pumping unit motor frequency to the pumping unit load was revealed. With the increase of the motor frequency of pumping unit load, the experimental data are verified and the corresponding motor frequency values are obtained. Knowing the frequency variation of motor provides theoretical guidance for fully understanding the load characteristics of pumping unit, optimizing mining scheme and increasing energy saving rate, and lays a theoretical foundation for the application of new type frequency conversion energy saving system. According to the function and performance index of the system, the frequency conversion adaptive control system adopts Siemens S7-300 processor as the core, the pumping unit model as the controlled object, controls the frequency converter according to the load, and adjusts the motor running speed. The signal is collected by photoelectric encoder and load sensor. The collected signals are fed back to PLC, to form a closed loop adaptive control system to realize the variable frequency speed control of the pumping unit motor, which reflects the change trend of the frequency value with the load. The experimental results show that the designed frequency conversion adaptive system of the pumping unit realizes the real-time frequency feedback measurement of the motor. The measurement results show that the load increases the frequency variation of the motor and the fuzzy PID adjusts, which makes the frequency stable. The error is 1 in the measurement process. The measurement system runs stably and reliably, and the accuracy is high, which meets the needs of the self-adaptive measurement of the pumping unit frequency conversion.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE938;TP273

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