Regulator-Controller for 400 VDC

[DVM]

Dear Forum
I have a 390 Volts battery (in-from) a EV car and charge this during the day time with solar panels. I use the AC charger that comes with the car (1771 plug) - no problem - I can charge the battery every day.
At the end of the day the battery has 396 Volts and a capacity of 24 kWh.
The solar system is grid tie type and the inverter can accept DC voltages up to 850 Volts DC on the string inputs.
In the evening I use the battery to power the house, but the inverter sends most of the power into the grid, because my battery can supply a lot of energy.
I need a controller to 1. adjust the power (current) delivered by the battery to minimize the inverter output or
2. adjust the voltage from e.g. 392 Volts to 180- 380 Volts.
This should be done with PWM to have the least losses. Anyone a schematic or hint of components to use? Thank you.

 

[kellys_eye]

If you don't want to send your power to the grid, don't connect it to the inverter.

The cost of such a device would far outweigh any benefits you receive.

 

[DVM]

A grid tie inverter only works when connected to the grid. It has no sinus generator to produce 50 or 60 Hz by itself but copies the present wave- form if present. No connection = no waveform = no start up.
By adjusting the battery power the output of the inverter (connected to the grid) can produce just as much as the house consumes - so it has to be connected to balance this figure. A resistor or semiconductor series regulator could do the job but uses a lot of energy. That is why PWM (pulse width modulation) can probably work successful.
Just need some diagram and a device that is good for the 400 volts and 20 amps.

 

[kellys_eye]

It would be far easier to get a separate inverter (non-grid tied) to power your house in that case. I doubt there would be any difference in cost and it would be CERTAINLY more cost effective than trying to build (safely) a device to control the battery output!