Grid Frequency Problems??

[the_uglydog]

Lately we have been having issues with the grid frequency going out of the tolerated limits of our Growatt grid tie inverter. Here in this part of The Philippines we use the US type split phase system of two 110v lines to make the 220v with 60hz the frequency. Here it's not like in the US where complaints about high/low voltages or slightly off frequency will be serviced. If the power is between 170v and 270v and the frequency is between 55hz and 65hz, it's considered OK, Ours usual operates at 220-240v and from 58hz to 61.5hz. Does anyone know of a product that can be put in the utility line to stabilize the frequency to within .5hz? The inverter can be set to operate between 270v and 100v so that isn't an issue, but the frequency tolerance is only 1hz and can't be reset. Any suggestions? Thanks thedog

 

[DIYrich]

Does anyone know of a product that can be put in the utility line to stabilize the frequency to within .5hz?

Not possible.

What you can do is:
1) Use a charger to Convert AC to DC (battery)
2) Use inverter to Convert DC back to AC

Basically an On-Line UPS. This will clean up the power, but cost you in conversion losses.

You could reduce conversion losses by pass-though grid when it is in range.
Go to battery when out of range.
Set the Charger to charge battery at 75% SOC (or equivalent voltage).

 

[1201]

Lately we have been having issues with the grid frequency going out of the tolerated limits of our Growatt grid tie inverter. Here in this part of The Philippines we use the US type split phase system of two 110v lines to make the 220v with 60hz the frequency. Here it's not like in the US where complaints about high/low voltages or slightly off frequency will be serviced. If the power is between 170v and 270v and the frequency is between 55hz and 65hz, it's considered OK, Ours usual operates at 220-240v and from 58hz to 61.5hz. Does anyone know of a product that can be put in the utility line to stabilize the frequency to within .5hz? The inverter can be set to operate between 270v and 100v so that isn't an issue, but the frequency tolerance is only 1hz and can't be reset. Any suggestions? Thanks thedog

Which inverter do you have? On mine you can log in as an installer and change the frequency limits

 

[time2roll]

Best way to extract grid power with bad frequency is to get a charger that does not care much and charge the battery direct.
Same goes for voltage. Although not everything goes to 270. My Meanwell says 90 to 264v and 47 to 63 Hz.

 

[the_uglydog]

Which inverter do you have? On mine you can log in as an installer and change the frequency limits

Hi, It's an 8000MTLP-US on grid unit. It's about 10 years old. It has adjustments available for the voltages, but not the frequency. I met the Growatt engineers last month and they said that on this older model the hz can't be adjusted since it had to be compatible. They said some of the newer ones can be adjusted for a wider hz as well as the voltages. I've got it set to the widest voltage range possible, but it still shuts down when the hz gets above or below .1hz of 60. It's a pain, they installed a new transformer on the utility line to correct the extremely low voltage and ever since, the voltage is OK now but the hz is sometimes out of range all day. My other inverters that can run off-grid with batteries aren't affected at all. I was hoping someone knew of something that could be installed in the line to stabilize the frequency. thedog

 

[wpns]

Hi, It's an 8000MTLP-US on grid unit. It's about 10 years old. It has adjustments available for the voltages, but not the frequency. I met the Growatt engineers last month and they said that on this older model the hz can't be adjusted since it had to be compatible. They said some of the newer ones can be adjusted for a wider hz as well as the voltages. I've got it set to the widest voltage range possible, but it still shuts down when the hz gets above or below .1hz of 60. It's a pain, they installed a new transformer on the utility line to correct the extremely low voltage and ever since, the voltage is OK now but the hz is sometimes out of range all day. My other inverters that can run off-grid with batteries aren't affected at all. I was hoping someone knew of something that could be installed in the line to stabilize the frequency. thedog

Do you want to run everything at 60.0 Hz or do you want to prevent your inverter from going offline when the grid frequency is too far out of spec?

If the former it’s double-conversion (EG4 18Kpv, PowerPro batteries, and ChargeVerters.

If it’s the latter then you need an inverter that you can change the settings on arbitrarily, and those are hard to come by. Manufacturers seem to want to keep their UL1741 and other listings for some reason . My ancient SMA WR11TU20 from 2007 lets me set wide margins, but my recent GoodWe inverters lock me into their selection of grid parameters, and tech support just says I have to get the PoCo to fix it. As if. I’m going completely off-grid with ChargeVerters to buy dirty power and charge my batteries as required.

 

[the_uglydog]

This system is entirely grid tie, it has no batteries. The inverters with the batteries don't seem to care what, if anything comes from the utility, what Growatt told me was it needed to be accurate since it feeds all excess back into the grid. It saves us about $700/month on what it runs and it's been very reliable and I'd really hate to have to replace it only because of the grid being a bit unstable.

 

[dac07800]

Which inverter do you have? On mine you can log in as an installer and change the frequency limits

Do you increase the frequency limit and if so by how much? I have similar issues and can access the installer mode using the setapp to make adjustments.

 

[Suijkerbuijk]

Lately we have been having issues with the grid frequency going out of the tolerated limits of our Growatt grid tie inverter. Here in this part of The Philippines we use the US type split phase system of two 110v lines to make the 220v with 60hz the frequency. Here it's not like in the US where complaints about high/low voltages or slightly off frequency will be serviced. If the power is between 170v and 270v and the frequency is between 55hz and 65hz, it's considered OK, Ours usual operates at 220-240v and from 58hz to 61.5hz. Does anyone know of a product that can be put in the utility line to stabilize the frequency to within .5hz? The inverter can be set to operate between 270v and 100v so that isn't an issue, but the frequency tolerance is only 1hz and can't be reset. Any suggestions? Thanks thedog

Yes you can .
I life on a boat and one thing is not stabel is wallpower from the port.

My solution is easy .
I use a victron Isolation Transformers.
That go power in from the wall that is in the winter about 210volt and on the summer go up to 250 volt.
With this unit on my boat it will always be 243 volt.

This unit can do 220volt or 120 volt .
It can even do 120 volt to 220 volt.
Reason it is use in a boat.
So you can always use your stuff on it.

Link

Isolation Transformers - Victron Energy

Isolation transformers are essential in professional ship installations and prevent electrolytic corrosion. Ensure a safe electrical system.

www.victronenergy.com

Use in a house you de use the earth wire connect to the ground.
On a boat we do not or the boat will be on land than we bridge the earth over
Well i use a switch to select if i need earth so i do not need to open it.

One thing you can not use it if you sent solar energie back to the grid.
Its really one way systeem .

 

[1201]

Do you increase the frequency limit and if so by how much? I have similar issues and can access the installer mode using the setapp to make adjustments.

I didn't have to change frequency limits on mine but the software allows changes

 

[the_uglydog]

The unit I have is about 10 years old and Growatt says it can't be adjusted for frequency, only voltage. I've been watching it and it seems sometimes the frequency is spot on 60hz and it still doesn't come on, maybe there's something else wrong with it. I'll talk to Growatt some more maybe they will have an answer.