Of course you can't keep exactly 50Hz, ever been in a power station of the GW class?Kasuha wrote:The truth is, there is not 50 Hz in the mains, the frequency is slightly changing throughout the day. See here for instance. But I don't see how these slight changes might cause the hump, the interference by far cannot go to 3.5 kHz IMO.josch222 wrote:(besides 50Hz
It is pretty impressive (esp. the vibrations of the whole floor in the machine house).
You can switch large electrical loads immediately but it is not possible to apply the
demanded power immediately so the generators speed will go down a bit until the regualtion valves opened and the higher water or gas or steam flow has established.
But I really didn't know that the average is not constant, about 25 years ago
I was told that lower speed during the peak loads would compensated with higher speed
at night so all the mains frequency based clocks would keep the time in the long run.
Maybe that has changed with the integration of eastern european grids and/or the availability of better time bases like internet, time transmitters and GPS.
Or it was never true I remember that I had to readjust my mains based alarm clock
every few weeks, but I thought at that time this were due to bad filtering inside, so
that interference on the mains would cause additional counts or swallow some.