What is better a Quatro or MP with generator connected to 48V

DIY
, , ,
1

Hello,

I"m building my PV system. I"m living in an area were the grid is not reliable. The system will have 18KW solar panels, 30KW battery system and 3 Victron inverters (3 phases) and a 16KW 380V diesel generator. The generator has not a perfect sinus (but a good one, and the frequency varies a bit depending on the load from 50.5 to 52 Hz.

My questions is what is the 'better" solution: 3 Quarto with the grid and the generator connected to the inverter, or 3 MultiPlus and connect the generator via battery chargers to the DC bus? I talked to several companies that install Victron system, but i get very contradictive statements.

A few of the things that i was told, but i do not know if i should believe:

  1. when the Quatro is powered by the generator, the “dirty sinus” is delivered to the house and it may damage some appliances. I know that some coffee makers use the 50hz for timing of the water, but this i do not consider 'damage"
  2. The generator will run half an hour every week in the winter, independent if there is a grid or not. When the generator is connected to the DC, the energy of the generator is used in the house or to charge the batteries. When the generator is connected to a Quatro, the energy is lost, because the Quatro cannot combine the 2 input sources, and prefers the grid.
  3. Converting 16KW of AC generator power to DC can be done by placing multiple battery chargers in parallel. One company offered to put 6 2KW chargers is parallel. (Detail: this were not Vitcron chargers, and the chargers where not connected to any kind of databus). Another company stated that this is very inefficient and even dangerous (but could not explain in detail why, just that they would never do it like that).

I hope that somebody can give me a founded answer which option (Quatro with generator connected or Multiplus with generator connected via chargers) is best way to go.

thank you very much in advance,
Maurice

2
  1. The Quattro won’t sync up to a source that has a poor waveform. It won’t pass it through. You can change some settings such that the charger might accept the power if it isn’t too bad.
  2. If you put the generator on AC Input 1 and grid on AC Input 2, then if the generator starts even when utility is available, the generator will take priority and you won’t waste the fuel.
  3. Compare the cost of each option to convince yourself. I would not like not having the data from the chargers to compliment the rest of the data.
3

Hello @Maurice

two Ideas:

  1. as a charger you could use used Eltek Flatpack 2 server PSUs. They can be set to constant volage and/or current in th needed range.
  2. maybe you can get a AVR alternator for telco usage. Sincro has the FB-4-48 Range with 200A and 500A which schould suite your needs. With a AVR you can change engines RPM but get stabel DC voltage.
    BR, Björn