Overcoming 253V Voltage Limit in German Standards: VDR AR-N4105, BDEW, VDE 0126

Gentlemen

Which standard for Germany? The voltage sometimes slightly exceeds 253V and I would like to eliminate this problem by increasing the voltage limit. I have such:

Germany VDR AR-N4105
Germany BDEW
Germany VDE 0126

Thank you in advance

Moderated By krzysiek7:

I merged the topics.
3.1.12. Do not post multiple identical topics in the forum, users will not know where to reply.

hermi1 wrote:

Gentlemen

Which standard for Germany? The voltage sometimes slightly exceeds 253V and I would like to eliminate this problem by increasing the voltage limit. I have such:

Germany VDR AR-N4105
Germany BDEW
Germany VDE 0126

Thank you in advance

First, check what is the reason for the voltage increase, whether your section from the measuring system to the meter or the power grid is too soft
As for the norm, you have country 12 in the sofa and it should be selected

theo33 wrote:

hermi1 wrote:

Gentlemen

Which standard for Germany? The voltage sometimes slightly exceeds 253V and I would like to eliminate this problem by increasing the voltage limit. I have such:

Germany VDR AR-N4105
Germany BDEW
Germany VDE 0126

Thank you in advance

First, check what is the reason for the voltage increase, whether your section from the measuring system to the meter or the power grid is too soft
As for the norm, you have country 12 in the sofa and it should be selected

The problem is the network, today I talked to my neighbor and he has the same problem. We will report the matter to PGE, but I wanted to somehow temporarily solve the problem. Changing country won't help?

hermi1 wrote:

We will report the matter to PGE, but I wanted to somehow temporarily solve the problem. Changing country won't help?

Have you thought about what can happen to all kinds of equipment, especially those expensive, connected to the network, both at your place and at your neighbors?

Gentlemen

Calm down, don't be nervous... Maybe I wasn't fully aware of the problem and potential consequences - I won't change anything in that case and I'll try to settle the matter through PGE and ask for lowering the voltage on the transformer. The problem is not permanent and so far the inverter turns off once every few days for several minutes.
But out of pure curiosity, I would still like to know what is the difference between the standards for Germany that I asked about?

hermi1 wrote:

The problem is the network, today I talked to my neighbor and he has the same problem. We will report the matter to PGE, but I wanted to somehow temporarily solve the problem.

Try to change your habits to increase self-consumption during peak production hours.

hermi1 wrote:

I will try to settle the matter through PGE and ask for lowering the voltage on the transformer

And how did PGE respond?

I have a similar problem, a 1-phase inverter, it turns off on sunny days and kiss it. I rummaged in the inverter settings and it turned out that the Dutch standards were set, so I switched to PL, which seems to have helped a little but the inverter still turns off. I called PGE and they said that they have a lot of such reports, but they can't do anything because they would have to install transformers with automatic voltage regulation, and it costs money. What's more, they also said that they have an increasing problem with medium-voltage lines because the mass-installed PVs increase the voltage there and they have to modernize them. Coming back.... the prosumer contract says that the prosumer should consume the energy he produces on an ongoing basis, and any surpluses (note quotes here) the network MAY but DOES NOT HAVE to accept. I, on the other hand, in the regulations ("Regulations for the performance of comprehensive contracts for the sale of electricity, the provision of distribution services and the provision of collection and settlement services for electricity introduced into the DSO network from micro-installations"), I see a provision that "The seller undertakes to the prosumer to: 1. Collect electricity produced in the Microinstallation provided by the prosumer." So I don't know how it is, whether they MUST or CAN .... However, the subsidy program in the municipality for PV is in full swing, the installed PVs do not work because of the high voltage in the grid, ba .... the municipality itself set up a farm that does not work .... and they continue to collect applications for funding .... this is Poland ....
Now I'm trying to figure out how to load the grid so that PV continues to work on sunny days. I'm thinking about some kind of smart socket and water heating.

I don't have this problem with the voltage, but I have a Gosund socket and I heat the water in the boiler for 2-3 hours during the largest production or until the temperature on the regulator is reached. The Gosund socket has app control and electricity and energy consumption measurement. I just don't know if it will help if there is such tension in the whole commune.

A helpful device in switching on the heaters during large PV production is the priority relay with adjustable tripping current and the overvoltage relay. You can couple both devices to optimize the consumption of current production.
In the case of the priority relay with a hole for the measuring cable, there is also a switching function depending on the current consumption by threading the inverter and receivers cable through this hole.

Activate the reactive energy curve. That's what she's there for. Above 250V the inverter should start producing reactive power.

Tomkii wrote:

Activate the reactive energy curve. That's what she's there for. Above 250V the inverter should start producing reactive power.

Can you tell me more about it?

New requirements for inverters require the inverter to "save the grid" in cases of extremely low and extremely high voltages. The curve starts at 207V (30% VAr) goes to 210V (0%), then flat to 250V (0%) and goes to 265V (-30% VAr). As I understand the process correctly, when the voltage increases, the activation of reactive energy production causes the line (and the transformer) to be loaded with the flow of reactive energy, which indirectly reduces the voltage on it. Somewhere I even came across a scientific study on this topic, but I can't remember the link at the moment.
The fact that our inverter did not have this in the requirements (perhaps when it was launched) does not mean that there is no such option built-in. You just need to turn it on. Well, it may not be an ideal solution, but it is better to waste a small part of the power on reactive energy production than not to produce it at all.

Tomkii wrote:

Above 250V the inverter should start producing reactive power.

For the sake of accuracy, I will add: to produce, i.e. in this situation: to take inductive reactive power (cos phi inductive). Then the mains voltage should drop, but probably not more than a few volts.

As for upping the voltage to save a few bucks...
Newly built houses are worth so little to you? It was probably not the increased tension that caused this tragedy, but it can also lead to such events. Then the words: "my equipment burned" start to sound a bit more emphatic.

I found:
https://www.cire.pl/pliki/2/2018/ograniczenie...stu_napiecia____p__kacejko_p__pijarski_zm.pdf

Added after 8 [minutes]:

Michał643 wrote:

For the sake of accuracy, I will add: to produce, i.e. in this situation: to take inductive reactive power (cos phi inductive). Then the mains voltage should drop, but probably not more than a few volts.

Probably capacitive. After all, it is -VAr which indicates capacitive...
But I'm not very conscious, so I could be wrong. These few volts may be enough to keep the inverters working without shutdowns.
Correction.
The voltage drop causes line reactance. It helps mainly with overhead lines, with cable lines too, but not very well.

Tomkii wrote:

Probably capacitive.

That is, to lower the voltage, it should produce capacitive power = consume inductive power (in terms of reactive power, the inverter should behave like an induction motor, not a bank of capacitors).

In the power industry there is an unwritten convention regarding naming so that these powers are not mistaken:
- when we say: "issue/production of reactive power", we always mean generation of inductive power, i.e. de facto capacitive work of the device
- when we say: "reactive power consumption", we always mean inductive power consumption from the network, i.e. the device is an inductive receiver (i.e. the device, by taking inductive reactive power, actually gives capacitive power to the network - as my colleague rightly said - but we do not usually say that, because it seems to be against this unwritten convention ) To avoid confusion, the convention is that when we talk about reactive power consumption or production, we always mean inductive power.

Sorry for my hints, at first I was a bit confused by the production of capacitive power due to the above. Regards

Only how is it when we have inductive, both in production and in reception, and the same with capacitive, there are four quadrants and we have four indications of reactive energy 5.8.0, 6.8.0, 7.8.0 and 8.8.0 Which, of course, should be eliminated to what extent is it possible?

1.8.0 / 2.8.0 how much energy was effectively used (left side of the chart) / delivered to the grid (right side of the chart)
5.8.0 / 7.8.0 how much inductive energy was used (1st square) [VAr+] / delivered to the grid (3rd square) [VAr-]
6.8.0 / 8.8.0 how much capacitive energy was delivered (2nd square) [VAr+] / consumed from the network (4th square) [VAr-]
As we produce (the active flow is TO the network), the reactive one is calculated at 6.8.x [VAr+] and 7.8.x [VAr-].

We are not supposed to eliminate them in home conditions (when we are not billed for it) but to increase line losses just by their increase (in the case of voltage above 250V). When we are billed for reactive energy, the matter is not so obvious...
And of course, if at night we have 250V in the socket, there is no other option than chasing the operator, because it will not be beaten in any way...

theo33 wrote:

Only how it is when we have inductive and in production as well as when receiving and the same is with capacitive

Well, simply: the meter sums up the reactive energy, distinguishing whether this energy was taken at P+ or at P-.
5.8.0 - we downloaded X kvarh of reactive (inductive) energy from the network during active power consumption
6.8.0 - we took X kvarh of reactive (inductive) energy from the network during the production of active power
7.8.0 - we delivered X kvarh of reactive (inductive) energy to the grid during the production of active power
8.8.0 - we delivered X kvarh of reactive (inductive) energy to the grid while taking active power from the grid

theo33 wrote:

Which, of course, can be eliminated?

In order to lower the voltage, reactive power (inductive by default) should be taken, i.e. work in quadrants I or II. Therefore, the consumption of reactive power (Q+) should be maximized by setting the inverter operating mode with inductive cos phi.

However, it should be noted that if we have a 3-phase system, it may happen that we take reactive power on one phase and give it out on the other. Then Q+ and Q- can light up simultaneously. Even all the arrows can light up at once, which shouldn't surprise anyone. Thus, the values of reactive power supplied and consumed can be simultaneously calculated in different registers of the meter, so this must be taken into account during some analyses.

And not in III? I won't cut my head off.
The formula for delta U in a line = P/Un*R + Q/Un*X. To reduce the voltage Q we must go negative because the line has inductive reactance (X of +).

Tomkii wrote:

The formula for delta U in a line = P/Un*R + Q/Un*X.

Okay, so from this formula, if Q is negative, we'll have this equation:
1) dUfaz = P/Ufaz*R - Q/Ufaz*X
and if Q is positive:
2) dUfaz = P/Ufaz*R + Q/Ufaz*X
It can be seen that the second voltage drop is greater than the first, so in the second case the voltage at the consumer is lower, because we have a higher voltage drop on the line. Will it be or not? (because I also notice that something is hard for me lately )

Really