Connect a small generator on the EDF network Enedis 50 Hz 230V AC?

[Christophe]

Everything is in the title: what happens when you connect a small generator (say between 1 and 10 kW) on the EDF network live? That is, connect the output of the group to a socket or directly in the electrical panel?

My question concerns synchronization of 50 Hz and voltage alignment?

We grid the generator directly where it synchronizes fast enough naturally not to grill? If so, how to connect? The group must turn before being connected or not?

Or do you need an intermediate device? Inverter type synchronization Hz / V?

I have always seen only generator sets with inverter source (ex EJP), synchronization does not arise in this case!

Sorry if my question may sound stupid and if I pass for a con Old biker than ever!

[fabio.gel]

Hello Christophe

I asked myself the same question at one time.
It seems reasonable to have a separate circuit in the house to use electricity produced by a GE.

I write you this because I learned a lot of things after having mounted my photovoltaic installation.
For example: Photovoltaic inverters are subject to DIN VDE 0126-1-1 / A1, which deals with the automatic disconnection device between a system and the low-voltage public network (more power on the grid = more photovoltaic production) .

http://www.photovoltaique.info/DIN-VDE-0126-1-1-A1.html

Little video Erdf (it's worth what it's worth but it has the merit of being simple) promised I touch nothing above!


https://www.youtube.com/watch?v=Fx7odfsfUWg

Fabio

PS: the current that you produce if you are disconnected from the network will be for you in total, on the other hand if you are connected to the network and that you do not consume everything it is ENEDIS which will sell it to your neighbors

[Forhorse]

To couple 2 alternating generators must be in phase, the manual synchronization is possible but quite delicate.
In practice it would be necessary to play on the speed of the motor driving the group in order to have a frequency barely higher than the network or barely lower (like 50.01Hz or 49.99Hz) so that one can "catch up" the phase of the other and couple the 2 when they are exactly in phase.
At this moment the group locks itself on the network (since this one has a lower impedance, it is he the "master") and it is therefore the network which imposes the speed of the generator. Then it depends on the power with which you drive the generator. If it is too low, it is the network which drives the engine of the group and in this case you consume current on the network, if it is sufficient you produce current which is injected into the network.
A real group that can be connected to the network to a synchronizer that does the operation automatically.
If the coupling is at the wrong time, you create a great short circuit and the generator of your group goes up in smoke.

In time, the ancients did this manually with a simple incandescent lamp. The neutrals of the generator and the network remained coupled, and a lamp (nominal voltage of twice the mains voltage) was placed between the phase of the generator and that of the network. The brightness of the lamp indicated whether the two sources were in phase or not: the more the lamp shone the less they were in phase. The goal of the game was to manage to couple the 2 sources battery when the lamp was off.
I'm sure that by looking a little on youtube we must find a demonstration of this method.

Another method for a generator is to use the generator in motor (starter) like that no problem of coupling or synchronization, the generator is already at the right speed and in phase.
But the heat engine which drives it must be designed to be put into operation "on the fly".
I believe this is the method that is used for rescue groups in sensitive applications.

For the record, I worked in a factory that could not afford unplanned process shutdowns due to a power outage. the losses caused by an unplanned shutdown, and the cleaning and restarting times had justified the installation of 3 huge generators capable of powering the entire plant (the engines were almost the size of a motor of diesel locomotive and the generators were coming out of the 20kV directly)
In the event of a storm, and therefore in the event of a risk of mains failure, we switched over to the groups: after a period of warming up and running the heat engines, the generators were thus synchronized automatically with the network and then coupled to that -this. When this first step had taken place correctly, the plant was decoupled from the network and passed in autonomy the time of the storm.
When the risk was over, we proceeded in the reverse order: we resynchronized the generators with the network, before pairing again the two to finally stop the groups.
Same procedures in case of EJP days, because (at the time anyway) it was cheaper to burn fuel in groups than to pay the current at high prices.

[izentrop]

The problem must be to keep this synchronism when the load varies, causing a drop in engine speed. In this case, it must be assumed that the group must be largely oversized in order not to weaken.
The reaction time being much slower than in the case of a network injection inverter.

[Remundo]

we can not directly couple a generator on the network,

a simple desynchronism will call a huge current and damage the facilities,

it would be possible to charge batteries with gégène, and to connect these batteries to the network via a grid injection inverter which can also be switched into an isolated site inverter. Offers have developed in recent years, under the name "hybrid inverter"

This material is particularly expensive, apart from isolated sites, and the technical / financial interest from a gene seems to me practically nil. It is better to decouple completely your electrical installation from the network, and to connect your generator on it, by consuming directly what it produces.

[Christophe]

Well she was not so stupid my question ... since the answer is not simple !

So all this implies that all European plants (or the same network) are synchronized to the frequency?

[Exnihiloest]

If you want something that works in all cases, you need a generator synchronizable on a reference signal of the frequency and phase.

So if we have three phase: we can use one phase for reference, and reinject on another.
Otherwise one could always obtain the phase reference by a sensor placed somewhere on the network, very far upstream of the point where the current is reinjected, for example a magnetic field sensor under the medium voltage line which feeds us, associated with a radio transmitter that retransmits the pace.

I do not know if the solar energy is bought by EDF at a price higher than the price we would get from a gasoline generator, but if so, surely little clever people will have already thought about that ...

[Forhorse]

You have not read what I wrote?
A generator once synchronized on the network the rest of will or force. You are looking for complications where there are none.
Reminder: all rotating electrical machines are reversible.

[Remundo]

yes I read what you wrote, and these methods do not inspire me much confidence even if they can walk with luck.

moreover I still do not understand the interest of connecting a generator directly on the national electricity grid ...

at worst there are some not too expensive solutions like a battery pack charged to the generator, and inverter grid inverter (GTI) inverters that inject constant power. But you have to manage the batteries under load and overload ...

So-so...

[Christophe]

You have not read what I wrote?
A generator once synchronized on the network the rest of will or force. You are looking for complications where there are none.
Reminder: all rotating electrical machines are reversible.

If I read the different methods you mentioned! (thank you).

One concerns an electro-mechanical synchronization that I had already heard about ...