抽油机曲柄平衡的调整计算及效果预测

Balance adjustment and calculation of pumping unit with crank.

分析了抽油机平衡调整的本质和最终目标 ,提出了抽油机新的平衡调整方法 ,即通过对电动机功率曲线进行傅立叶分析 ,确定平衡块重心位置的方法。分析了电动机均方根功率与功率曲线谐波分量的关系 ,给出了平衡调整后的电流、电功率、均方根功率的预测公式 ,编写了PMTS2 0抽油机系统效率分析软件。通过平衡调整前后测量对比 ,证明了新的平衡调整方法原理正确 ,误差较小。但这种平衡调整只对功率曲线的一阶正弦分量起作用 ,对一阶余弦分量不起作用。对负功率出现在光杆行程上下死点附近的井 。

The essence and ultimate target of balance adjustment of a pumping unit are analyzed, and a new balance adjustment method is presented, i.e. determining the center of gravity of the counterbalance by means of Fourier analysis of power curve of the electric motor. By analyzing the relationship between the mean effective power and harmonic component of power curve, the equations for predicting the current, power and mean effective power after balance adjustment are given. In addition, the software for analyzing the efficiency of the pumping system is programmed. The result of measurement and contrast shows that the criterion of this balance adjustment method is correct and the error is rather small.