电网公司售电量是具有“逐年增长趋势”的离散型随机变量,用传统的平均年增长率计算的指数预测模型,因“增长过快”而易偏离该地区的电源供给能力.文中提出了带有电源供给能力约束条件的回归函数筛选及其综合方法,并由此建立了电网公司售电量的多项式回归预测模型及其检验方法.最后通过一个实例,具体介绍了这一方法的应用. The sales of power grid companies are discrete random variables with “increasing trend year by year”. The index forecasting model calculated by the traditional average annual growth rate tends to deviate from the power supply capability of the region due to “too fast growth”. In this paper, the regression function screening and its synthesis method with constraints of power supply capacity are proposed, and then the polynomial regression prediction model and its test method for the sales of power grid companies are established.At last, an example is given to introduce this method application.