The maximum charging power that the inverter can achieve?

Column:Industry News Time:2020-12-25
I have some questions about using an inverter for charging.
After searching my question on the forum, I decided to share my inquiry about the open inverter charging mode.

I have some questions about using an inverter for charging.

 

After searching my question on the forum, I decided to share my inquiry about the open inverter charging mode.

 

(First of all, I'm talking about the "boost" mode, because most rectified household AC voltage will eventually be lower than most modern commercial EV battery pack voltage 350-420VDC)

 

If a brave guy has good inverter hardware (considering the power range of the most modern electric cars, peak power is 80kW to 160kW), with a working V2 or V3 control board, and a correctly set electric motor of the same power , Proper cooling, cable size, etc. A feasible configuration.

 

Q: What is the theoretical limiting factor? What is the maximum charging power for such a setting in enhanced mode?

 

We do not discuss whether it is right or wrong to do this and create a large non-isolated charger, nor whether there is enough power on the single-phase 230-240VAC in the home to meet this theoretical charging setting. I know that using only OEM or aftermarket car chargers, it will be safer, completely isolated, less noisy, and so is the EMI/EMC friendly and proven design; my question is only about open All scientific issues on inverter hardware: use the inverter + motor combination as a powerful charger.

 

For the purpose of dialogue, let us assume:

-There is unlimited AC power available on 230VAC phase,

-There is a suitable size isolation transformer in the room to keep it in good condition and isolation;

-There is also a GFCI in the circuit;

-There is an isolation monitoring device in the vehicle to ensure that the DC link is 1-2 megohms away from the chassis. /Earth,

-Enough cooling space for inverter and motor

-All this happened in the Faraday garage I know,

 

 

In the boost mode, only one of the three IGBT pairs is used, so the limitation may come from there, but the official Wiki page explaining the charging mode states that it is "at least for low-power charging (for example, less than 5kW)". Where does this restriction come from? How can we prevent a good motor-inverter combination (which can provide 50-60kW of power for a long time) to provide 15-20kW of charging power (one third of its limit)?