I have a 480VDC Lead Acid Battery Bank (40 x 12VDC 50Ahr Batteries in Series) directly coupled to a 5.0 Kilowatt Solar PV Array [with an output range of 560-580 VDC and maximum output of 8.9 Amps). This simple coupled circuit works well but I want to add a feedback activated control device that limits the Battery Bank Charging Current to precisely 3.0 Amps maximum as the Solar Irradiation and PV Array Output Current varies. I am not concerned with the minimum Charging Current just the 3.0 Amp maximum. Any circuit suggestions would be appreciated.
The schematic shows two simple linear floating current regulators connected in parallel.
With guesses of what the voltage ranges that the circuit has to operate, the voltage differential can be 150V. So the power such a linear regulator has to dissipate would be up to 150V x 3A = 450W.
450W seem like a lot to waste, but the sun energy would have converted to heat outside if it were not collected anyway.
So now, how to have such a floating current regulator dissipates 450W. I think one way is to duplicate it as many times as necessary and connect them in parallel. For example, with 10 of them, each one is set up to pass 0.3A and may dissipate up to 45W.
On one of the regulator, there is a suggestion of how to connect a DC fan.