Battery simulation hardware-equipment

[GeoAVR]

Dear all,

I want to design an equipment that simulates a battery supply system (multiple battery cells connected together for a Vout =20V).
The problem is that I want to implement a Charge and Discharge function with controlled charging and discharging impedance.

Is it possible to do this with a Programmable power supply i.e. from NI using Labview?

Do I also need a programmable power electronic load connected in parallel with power supply?

What design would you recommend?


Thank you in advance.

 

[D.A.(Tony)Stewart]

Do you want to know the Electrochemical impedance of the battery to model it throughout the SOC cycle?

 

[Anna Conda]

You need a controlled electronic load to simulate a battery charging, and to simulate a battery discharging you need a controlled (programmable) power supply, sometimes easier to use a real battery.

 

[ahsan_i_h]

The problem is that I want to implement a Charge and Discharge function with controlled charging and discharging impedance.

The primary requirement should be "To implement a Charge and Discharge function with controlled charging and discharging cell voltage."

Is "Charging and discharging impedance" really necessary ?

 

[GeoAVR]

Do you want to know the Electrochemical impedance of the battery to model it throughout the SOC cycle?

I have to model different battery array and I have to simulate different impedances when charging and discharging. (i.e. change impedance from 0.1 to 1 Ohm with 0.1 step)

The problem is that I am not sure how to program the power supply and power load for simulating a battery array.



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The primary requirement should be "To implement a Charge and Discharge function with controlled charging and discharging cell voltage."

Is "Charging and discharging impedance" really necessary ?

Yes it is, unfortuanatelly



Ps. We are talking about 20-30V and 50A battery simulator

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You need a controlled electronic load to simulate a battery charging, and to simulate a battery discharging you need a controlled (programmable) power supply, sometimes easier to use a real battery.

I know, but the have to be in parallel operation since during tests we will simulate both charge and discharge at the same cycle. The transitions should be smooth.
Additionally, we also have the constraint of two impedances (charge, discharge)

 

[ahsan_i_h]

If you can adjust the simulated cell voltage according to charging/discharging current, then the effect of charging/discharging impedance can be achieved. For this, additionally you will need a current sensor (Hall type or resistive shunt type).

 

[GeoAVR]

If you can adjust the simulated cell voltage according to charging/discharging current, then the effect of charging/discharging impedance can be achieved. For this, additionally you will need a current sensor (Hall type or resistive shunt type).

But when in charging mode, a voltage will be applied to the battery simulation equipment by an external supply (ie. the charger). Therefore, the power supply cannot have a different voltage, is like connecting in parallel to power supplies of different voltages

 

[D.A.(Tony)Stewart]

The primary requirement should be "To implement a Charge and Discharge function with controlled charging and discharging cell voltage."

Is "Charging and discharging impedance" really necessary ?

ESR rises more than an order of magnitude as SOC reduces to 0 and rises more than an order of magnitude with aging and more than an order of magnitude as temperature drops below 0'C

But this usually just affects the charge time or cell degradation from mismatch with aging and consequent single cell overcharge and over discharge.

The faster the charger , the more critical cell matching becomes and if not, the faster battery lifespan reduces.

Ideally you don't need a simulator, if you know what you are doing.

If you want a theoretical charge simulator factor the Ah capacity into Farads and include a memory effect with 10x F but 10x ESR for an approximation.
This is why you see voltage return after a pulse load with a long time constant and also why Charge cycle is in 3 phases, CC CV and float or off.

 

[schmitt trigger]

National instruments has a 4 quadrant source/load which, with the proper software (labview) you should be able to properly simulate a battery.

 

[GeoAVR]

National instruments has a 4 quadrant source/load which, with the proper software (labview) you should be able to properly simulate a battery.

For which instrument are you talking about? I think it doesn't have enough current sink capabilities

 

[ahsan_i_h]

But when in charging mode, a voltage will be applied to the battery simulation equipment by an external supply (ie. the charger). Therefore, the power supply cannot have a different voltage, is like connecting in parallel to power supplies of different voltages

Two voltage sources with different voltages can not be connected in parallel, but a voltage source and a current source can be connected in parallel. During constant current (CC) charging mode, the charger works as a current source, and there is no problem if the battery voltage varies. Also in all other charging modes, the charger current does not exceed CC setting.

 

[Anna Conda]

Using a real battery, and discharging it overnight, looks to be the fastest solution to your problem.