Here's the story on frequency regulation of power lines: You can control a few synchronized generators to an external time standard. You will not be able to get phase control unless the electric loads are steady. Think of the load variations as you would temperature variations, except the load can pull the generator out of phase with the external frequency. And you can't insulate a generator from its load.
Power companies bill on time-integrated power - watt-hour meters in the US. Watt-hour meters are still mostly driven by electric clocks, in a way. The frequency does matter. Power networks, large or small, cannot be automatically controlled for frequency - especially not by independent controllers in each powerhouse. Instead, the network is phase controlled by the use of synchronous generators. Any single generator will exchange energy with the network to hold itself in phase with the network. If the loads on the network do not match the steam power from the power plants, then the whole network will rise or fall in frequency until it reaches a balance of power. This is why under-frequency relays are used to disconnect plants and loads from the network in order to save part of the network. The balance of power is so important that network dispatch centers monitor generated and consumed power, doing what they can to maintain balance. They usually lose frequency during the day when loads are large. As the loads fall off during the night, excess generated power is used to raise the frequency. The frequency changes do not exceed 0.1% in large networks. The basis for controlling the frequency is a cycle-counting clock that is compared to a time standard. The goal is to have the clocks match once every 24 hours. This assures fair allocation of the cost of power - it isn't something that the dispatchers just do for fun on the night shift. Based on this: 1. It is unlikely that any power network just lets itself go, with no standard time/frequency to hold. The under-frequency relays would make that hazardous. 2. Point measurements of line frequency are pointless. The cycle count must be integrated over 24 hours. I don't know what time the dispatchers aim for to match clocks. Back in the fifties I was taught that the time of minimum activity is 4:30 AM, according to an Air Force study of the best time to bomb. Traffic counters confirm this number. 3. Leap seconds are easily integrated into the cycle count during the following 24 hours. Regards, Bill Hawkins _______________________________________________ time-nuts mailing list [EMAIL PROTECTED] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
