断电之后，先是电容顶几毫秒，再是电池，最后柴油发电机接手。越靠前的一棒反应越快，存的能量越少。真出事多半是在交接那一下，比如所有电源共用的那一根母线。

When the grid drops, capacitors catch the first milliseconds, batteries carry the next minutes and generators take the long haul: the earlier the runner, the faster it reacts and the less energy it holds. In the failures the course covers, the baton drops at the handoffs, like the one bus every power path shares.