I have a Victron system comprising of 9 X 15 kVA Quattros (3 units per phase) with 3 X Smartsolar 450/200 charge controllers and two Fronius symo 15 kVA inverters with 50 X Pylontech uS3000C batteries. All firmwares are up to date apart from the Pylontech batteries. The problem i am having onsite is the generator is being rejected everytime it tries to sync to the Victron system. The longest it has held in is for 5 minutes but most of the time it is rejected straight away. Voltage & frequency seem fine, i have put the generator input current limit to 5 amps per phase to confirm that this isnt the problem (the generator is 90 kVA). I have even swapped out generators in case it was an issue on that side. weak AC input has been enabled, UPS function is disabled.
I should also say this system has been sitting in storage for 4 years and seems to have some battery voltage imbalance issues but I dont think this is related.
I am running out of ideas of what the generator syncing issue could be, any ideas?
Is your system wired like the Victron recommendation?
If so, what are the Quattro setting in VE-config?
I believe the AC input related setting, AC input1/2:
The input with the Generator connected to it, should be set to “no LOM detection”
Then its not a sync issue, since the MP successfully synched to the genset and stayed connected for some time.
But after it connected some parameter changed. Voltage and Frequency of the genset need both to stay inside the acceptable window.
Since you also have two Fronius, is the system setup for ESS or only AC-PV? Since that will change the output frequency of the Quattros depending on the SOC of the battery and the produced/consumed power in the system.
Make sure that the genset star point is grounded. When switching over to genset, the Quattros internal grounding relay will switch off, so star point, or neutral, grounding then needs to be provided by the incoming supply.
Are these Quattro 1 or 2?
The generator is wired to AC input 1 and set as ‘generator’, nothing is wired to AS input 2. this site is Off-grid so the grid code is set to ‘Other’ at the moment the AC input related settings is set to ‘Above selected grid code plus LOM’. I will have to chase up the password to change this if its required.
Since its offgrid, no gridcode should be used. By selecting “Other with LOM” you significantly narrowed the allowed voltage and frequency window
The few times it has connected to the Victron system it went into passthru mode, the Fronius inverters were working with the system ok then but sometimes they would disconnect on high frequency, checking the frequency it was at around 51 Hz. By the ‘system setup’ do you mean have I loaded an assistant for ESS? Currently I have an assistant running for PV inverter support only. The Frequency control of the Fronius inverters is working fine. Frequency was sitting a bit high, around 52 Hz but that wouldnt explain why the generator would be rejected right? wouldnt it just sit connected to the input and idle?
The MEN is in the Main switchboard for the property which the generator is connected to and the ground relay is not enabled in the VE config file.
What other option is there besides ‘other’? In the transfer switch settings Ac low disconnect is 180v, Ac low connect is 187v, AC high connect is 265v and AC high disconnect is 270v. I would have thought these are adequate for the voltage window and the ‘accept wide frequency range’ tab has been enabled to 45-65 Hz
“None” since you dont have a grid, therefore you dont need a gridcode.
Apart from voltage and frequency, the main difference is that “Other” gridcode allows the system to feed back to the grid, or generator in this case. Generator Frequency at idle should be closer to 50Hz, since at 52Hz the AC-PV is already in curtailment.
Its either connected and delivering power, or its disconnected. Being connected and not delivering power would mean that its receiving power (the zero-power-point is very narrow and not easy to hold in an island) which is an invalid state for a generator, but it can happen due to the “Other” gridcode.
Since you have gridcode “Other” selected, i guess you could read out the NS protection log, maybe theres some details about why it disconnected. It could as well be the generator that disconnected first due to reverse reactive or reverse active power.
Do you have a generator controller like Comap, Deif or Deepsea?
Thanks mate, I’ve changed the grid code to ‘None’ now. I reckon you are right about the reverse powering of the generator, I did catch it at one point allowing a small amount of export going back on one of the phases (the site can be heavily imbalanced as it is a camp ground with powered sites).
The generator controller doesnt show any error messages either, its a Powercore TEC-10, the first time I have seen this type of controller.
I will see if this resolves the issue
