No, in standalone mode the PV will supply only as much power as the load draws. Expect only little and short rise in voltage. No chang in freqency in standalone mode. Frequency usually is fix.Let's look to an other scenario: and if the utility grid is disconnected? Let's say the pv panel is operating in a standalone mode. Where would this surplus of generation go, would there be a rise in frequency as well?
To take up the question title, yes changing the load will theoretically affect the instantaneous grid frequency because it accelerates or decelerates the generators. According to the relation of 3 kW to xx GW grid power, it won't by a detectable amount.For example, if the pv panel is supplying loads A and B and for some reason load B is disconnected from the system, there will be a surplus of generation. Let's say power from PV panel = 6 kW, Load A= 3 kW and Load B=3 kW. Will this surplus of generation make the frequency of the utility grid, depicted in the picture, rise?
Let's look to an other scenario: and if the utility grid is disconnected? Let's say the pv panel is operating in a standalone mode. Where would this surplus of generation go, would there be a rise in frequency as well? I guess if it is in a grid-connected mode this surplus of generation would go to the utility grid. ok?
But why in some grid codes is written that the power delivered by the distributed generation should decrease if there is a rise in frequency?
ok. But why in some grid codes is written that the power delivered by the distributed generation should decrease if there is a rise in frequency?
One a generator is synchronized to the grid, it's rpm and generated frequency can't be individually varied. Only the power delivered to the grid can be changed in a first order, but at the same time, the grid frequency is pushed up or pulled down by a very small amount by accelerating or decelerating the distributed generators. The primary and secondary control mechanism described in the link in post #2 is intentionally varying the power of a number of power plants to achieve a grid frequency stabilization.Generator rpm is changed by feeding more or less coal to the burners, or by opening or closing water flow to turbines, etc.
When there is more than one generator, the waveforms must be kept in sync. I'm not sure how they accomplish that, to alter the speed of enormous generators spinning at several rotations per second.
ok. But why in some grid codes is written that the power delivered by the distributed generation should decrease if there is a rise in frequency?
What I still did not understand is why if I decrease the power injected by the pv panel, the frequency of the grid will also decrease. Let's say I have a pv panel at the roof of my house injecting power to the grid so that I can amortize the invoice amount a the end of the month. And if for some reason the grid frequency increases to a value within the interval 50.5<f<52 Hz, so if I decrease the power injected by my pv panel (at the roof of my house) I would decrease the frequency of the whole grid. That sounds very weird to me!
Acording to a simulation for the UCTE area (covering Western and Central Europe), the initial frequency variation caused by a 3 kW load step would be factor 25 larger, about .00000025 Hz (0.25 µHz). Which supports your statement.I hope you understand that the number I used for the increase or decrease of grid voltage and frequency as a result of your equipment injecting power into the grid (.00000001% or .00000001 Hz) is just a made up number intended to show how small is the effect of your equipment.
Acording to a simulation for the UCTE area (covering Western and Central Europe), the initial frequency variation caused by a 3 kW load step would be factor 25 larger, about .00000025 Hz (0.25 µHz). Which supports your statement.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?