> If the demand rises by the same amount over the course of 3 seconds, you'll get a much bigger voltage drop and the power plant has much less time to speed thi

> If the demand rises by the same amount over the course of 3 seconds, you'll get a much bigger voltage drop and the power plant has much less time to speed things up. More than that, if the voltage drops too low, like from a sudden large power draw, you could get a brownout or even a blackout in severe cases. Voltage level is monitored and wild swings indicate instability which trips various safety systems.