第十七

By using the optimal power flow,the relation between the electricity purchasing cost change and the line stability limit which is the product of the stability limit factor and the basic stability limit of the line,is described by the derivative of the augmented lagrangian function with respect to the line stability limit factor.

以最优潮流为工具，将线路的稳定限额看作是基准传输容量限值与稳定限额因子的乘积，通过增广拉格朗日函数对线路稳定限额因子的导数描述了系统购电成本的变化与线路稳定限额因子和线路基准稳定限额乘积的关系。

Change is part of life and the making of character, hon.

试译：变化是生活的一部分，而且也塑造了人的意志品德，亲爱的。