Greetings everyone

I work at a company that sells chargers for electric vehicles and I'm working on the electrical projects.
The chargers I work with, are alternating current (AC) and the main mode here is a three-phase installation 220 V, at 7.04 kW with a current of 32 amps.

If the system only had three chargers (Q01, Q02, Q03), the current for each would be 32 amps.
Using a simulator, when adding the fourth charger(Q4), the current goes to 84 amps and I wanted to understand why.
I tried to draw the three-phase circuit to make an equivalence of loads, but I couldn't get to that value.
Does an electric car behave like a delta or star load?

 

Running separate Chargers on Single-Phase-Power is a tragic waste of the
Efficiency that could be had by using 3-Phase derived DC.
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following your schematic, how many amps did you calculate with 3 chargers, before adding the 4th?
Delta or Y is irrelevant.

 

Using a simulator, when adding the fourth charger(Q4), the current goes to 84 amps and I wanted to understand why.

Because, in the absence of other massive loads on all three phases (as would be found in a real-world mains supply), your fourth 32A individual load is unbalancing the phases. Try adding a few hundred Amps load to each phase and you will see approximately the same 32A in each of your four loads.

 

following your schematic, how many amps did you calculate with 3 chargers, before adding the 4th?
Delta or Y is irrelevant.

For three chargers I planned 32 amps for each phase. But using a simulator, the software said I need to plan 84 amps. With that all the 4 chargers will have 32 amps.

 

Because, in the absence of other massive loads on all three phases (as would be found in a real-world mains supply), your fourth 32A individual load is unbalancing the phases. Try adding a few hundred Amps load to each phase and you will see approximately the same 32A in each of your four loads.

I would like to know how to calculate this 84 current. My professor said I have to do a phasor diagram, but I don't know how to start it, once I don't know what's the load impedance (the load in this case it's the car).

 

Running separate Chargers on Single-Phase-Power is a tragic waste of the
Efficiency that could be had by using 3-Phase derived DC.
.
.
.

Where I live we use more the AC system. DC it's only for the fast chargers

 

Where I live we use more the AC system. DC it's only for the fast chargers

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I think You misunderstood what I was saying ...........

ALL Chargers Output DC, because they are charging Batteries.

Getting DC from a Single-Phase-AC-Supply is less efficient and more expensive than
getting DC from a 3-Phase-AC-Supply.
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I would like to know how to calculate this 84 current. My professor said I have to do a phasor diagram, but I don't know how to start it, once I don't know what's the load impedance (the load in this case it's the car).View attachment 260311

I wouldn’t bother with phasors. 3 chargers represent a balanced load on the 3 phase system, resulting in some line current. You know the load, the voltage, and that it’s balanced, so it’s a simple calc. The last charger is directly added to that existing load, on two phases.