中文摘要：

针对目前由实测电参数预测示功图存在的精度不高的问题，根据最小二乘拟合原理，综合考虑抽油机平衡方式、传动效率和运动件惯性对系统动态参数的影响，建立了悬点载荷与实测电功率关系的仿真模型。以悬点载荷扭矩误差平方和最小为优化设计目标函数，建立了悬点载荷扭矩优化模型。该模型可以避免使用扭矩系数法计算悬点载荷，有效解决了悬点示功图在上、下死点附近不收敛的问题。优化结果表明，优化悬点载荷扭矩可以提高示功图的拟合精度；拟合示功图与实测示功图非常接近，两曲线相对误差在±10％以内。

英文摘要：

There is currently a low precision in predicting the indicator diagram with measured electrical param- eter. Therefore, the simulation model of the relation of polished rod load to measured electrical power was estab- lished. The model was based on the least square fitting principle, taking into consideration comprehensively the effects of the pumping unit＇ s balance mode, transmission efficiency and moving part inertia on the dynamic param- eters of the system. Taking the minimum quadratic sum of polished rod load torque error as the objective function of optimal design, the optimal model of polished rod load torque was established. The model can avoid using the torque coefficient method to calculate polished rod load, thus effectively solving the convergence problem of indica- tor diagram near upper and lower dead centers. The optimization shows that the optimized polished rod load torque can improve the fitting precision of indicator diagram. And it is necessary to optimize polished rod load torque when electrical power is used to simulate indicator diagram.