Maker Pro
Maker Pro

220v AC from genset to 300vDC converter 3000W

malkcom

Nov 14, 2022
2
Joined
Nov 14, 2022
Messages
2
Hi Friends

I need the genset 2kva to power the solar inverter 5kva at night. Not from mains supply input but from the solar input. If it was 5kva genset then it could power the mains input, no issues. When the solar panels(genset giving DC) can't handle the load (say 4kva) the inverter will take some juice from the batteries to fill the gap.

The ac output of the genset converted to dc will power the solar input of the inverter (max pv string voltage limit is 500vdc). So I need an ac to dc converter. Quite simply connecting a bridge rectifier and capacitor could do the trick, but there are a couple of issues.

1. The genset has AVR and i would like to remove that AVR or disable it somehow. That way it is better, as voltage goes down the MPPT input sensing will reach a point of balance and it will not overload the genset.

2. The load changes the frequency of the genset from 50hz few seconds to 45hz. The simple bridge rectifier will also have a ripple and it could confuse the MPPT solar input

I guess there are modules available on alibaba website for 1000 dollars but i want to build it. Perhaps some chip like LM317 voltage regulator could solve my problems. Thanks for your help.
 

Bluejets

Oct 5, 2014
5,989
Joined
Oct 5, 2014
Messages
5,989
Won't work.
Those grid connect inverters know when they are / are not connected to the grid.
Illegal as well......for obvious reasons.
 

malkcom

Nov 14, 2022
2
Joined
Nov 14, 2022
Messages
2
Won't work.
Those grid connect inverters know when they are / are not connected to the grid.
Illegal as well......for obvious reasons.
It is a wrong assumption bro. My inverter does not feed any power to the grid
 

kellys_eye

Jun 25, 2010
5,107
Joined
Jun 25, 2010
Messages
5,107
Bridge rectifier and smoothing will stop any 'frequency' issues and the MPPT part of the system (DC input) should take care of the rest.

Seems to me like poor practise to go this route though - personally I'd wire the Genset into the consumer unit via the appropriate breakers, ensuring that the load can't exceed the genset capacity i.e. wire it to power ONLY your lighting circuit, water pump and/or one specific loop circuit (set of sockets).

I have 750W and 1800W inverter generators that are cabled to a separate ring main and, via a changeover relay, to the lighting circuit. This way I know that the circuit is fully independent of the mains and the gensets can also be used elsewhere in their native (unmodified) form.
 

kellys_eye

Jun 25, 2010
5,107
Joined
Jun 25, 2010
Messages
5,107
1. The genset has AVR and i would like to remove that AVR or disable it somehow.
No, don't do that. With the AVR working you'll have a steady output and not suffer transients as you would without it.
2. The load changes the frequency of the genset from 50hz few seconds to 45hz.
Not that a DC rectified output would even notice.......
 
Top