Electric Vehicles Charge

[Skinbleu]

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?

 

[sxdave]

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?

As I am not an expert on three phase car chargers so I will ask what may be some daft questions, how are all theses chargers connected and how is the charger Q04 connected compared to the way the chargers Q01,Q02 & Q03 are connected?

 

[Skinbleu]

As I am not an expert on three phase car chargers so I will ask what may be some daft questions, how are all theses chargers connected and how is the charger Q04 connected compared to the way the chargers Q01,Q02 & Q03 are connected?

With 3 chargers the system is balanced. When adding the fourth charger it becomes unbalanced. And I want to understand how to calculate the line current, now that a fourth charger has been added and each charger needs 32 amp current.

 

[sxdave]

With 3 chargers the system is balanced. When adding the fourth charger it becomes unbalanced. And I want to understand how to calculate the line current, now that a fourth charger has been added and each charger needs 32 amp current.

What does the simulator say when the system has only 2 chargers (eg Q01 nd Q02 only), presenting a different imbalance?
Regarding the car being a star or delta load, I do not see why should this matter unless there is a neutral line present.

 

[oracle]

If you have 3 phases, why not use 3 phase chargers. Using single phase, the 3 loads could be unbalanced anyway, depending on each vehicles charge state, and whether they were all present at the same time, or not.

 

[Risteard]

If you have 3 phases, why not use 3 phase chargers. Using single phase, the 3 loads could be unbalanced anyway, depending on each vehicles charge state, and whether they were all present at the same time, or not.

You should still wire 1 say as L1-L2-L3, the next as L2-L3-L1 and the third as L3-L1-L2 as otherwise any onboard charger only capable of single phase will pull off L1 on each charge point.