descent gradient meaning in Chinese

下降梯度

A non - linear feed - forward loop is used to realize the coordinated control between the two controlled variables at the two control ends at first . secondly , a constant ac voltage control is implemented for a short period after the ac fault removal . finally , a staggered recovery strategy for different hvdc subsystems is also adopted , with the restart time interval of them optimized using the steepest descent gradient search method
该协调恢复策略的三个特点是：在常规的控制器结构中加入一个基于准稳态工作点的非线性前馈回路；在交流故障被切除后的一个短暂时间内，逆变侧采用定交流电压控制：对不同的直流输电子系统采取一种渐进的恢复策略。