1) underfrequency protection
欠频保护
2) under-voltage protection
欠压保护
1.
New solutions of abnormal settings of WKBCI device under-voltage protection for electric power capacitor;
WKBCI装置电力电容器欠压保护动作电压异常的新解决方案
2.
Through the analysis of high pressure explosion suppression swich at under-voltage protection deferred time,the author pointed the influence of high pressure explosion suppression swich at under-voltage protection deferred time to supply electricity.
通过对煤矿井下高压隔爆开关欠压保护动作的原因分析,指出了目前煤矿井下使用的高压隔爆开关欠压释放保护装置对井下供电可靠性的影响,提出了对井下高压隔爆开关欠压释放保护装置具体的两种技术改造方案,对改善煤矿井下大面积停电事故,提高供电可靠性有重要意义。
3.
An auxiliary functions control system is designed with electric braking,under-voltage protection,overaccelerate vibration avoidance,blocking protection,cruise,1∶1 assistance functions.
研究电动自行车用无刷直流电动机辅助功能控制系统,提出如何利用脉宽调制PWM和综合译码控制来实现电动自行车无刷直流电动机的电子刹车、欠压保护、过加速防抖动、堵转保护、巡航及1∶1助力等辅助功能。
3) the drawback of protection
保护缺欠
5) under-protection(UP)
欠保护
6) Over & Under Voltage Safeguard
过欠压保护
补充资料：冲击波超压与动压