The frequency does not provide an indication of load. The frequency can be 60.00Hz with 20,000 MW load in Ontario or with 10,000MW.
Changes in frequency provide a measure of changes in the balance between generation and load.
The generator’s prime mover’s governor has a droop function set so that typically a 5% change in frequency will result in a 100% change in output. This is how most generators on the grid arrest changes in frequency, but they would not restore the frequency to 60Hz. The droop allows for a steady state frequency error.
A handful of special generators are used to restore the frequency to 60Hz or balance the generation and load in an area.
The precise frequency does not matter, if one generator thinks the frequency is 59.99 and another thinks it is 60.01 their outputs will only be a little higher and lower than their load setpoint. It does not matter if they share changes in load perfectly evenly, so long as generators on the system in bulk respond according to their capabilities.
Yes, they use the frequency as a common signal to respond to changes in load, that is correct.
With gps synchronized clocks and high speed waveform measurement we can see the propagation delay in the frequency across the country when there is a big event. Pretty neat!
The frequency does not provide an indication of load. The frequency can be 60.00Hz with 20,000 MW load in Ontario or with 10,000MW.
Changes in frequency provide a measure of changes in the balance between generation and load.
The generator’s prime mover’s governor has a droop function set so that typically a 5% change in frequency will result in a 100% change in output. This is how most generators on the grid arrest changes in frequency, but they would not restore the frequency to 60Hz. The droop allows for a steady state frequency error.
A handful of special generators are used to restore the frequency to 60Hz or balance the generation and load in an area.
The precise frequency does not matter, if one generator thinks the frequency is 59.99 and another thinks it is 60.01 their outputs will only be a little higher and lower than their load setpoint. It does not matter if they share changes in load perfectly evenly, so long as generators on the system in bulk respond according to their capabilities.