Battery emulation

What does battery emulation actually entail and why would you want it?

A battery is basically a DC power supply/DC load but with some specific properties. For instance, every battery has an internal resistor. The output voltage of the battery also depends on the charge status of the battery. And so there are some other variables that affect it.

A widely used scientific model for battery emulation is shown below and shows how the terminal voltage behaves as a function of current, capacitance and internal resistance.

E= no-load voltage (V)
E0 = battery constant voltage (V)
K = polarisationvoltage (V)
Q = batterycapacity(Ah)
idt= actual battery charge (Ah)
A = exponentialzone amplitude (V)
B = exponentialzone time constant inverse (Ah)−1
Vbatt= batteryvoltage (V)
R = internalresistance(Ω)
i = batterycurrent(A)

With this model, we can make a good emulation of almost all types of batteries.

A discharge curve then looks something like this;

But depending on the number of charging cycles, the capacity of the battery will change. With a standard DC power supply/DC load or bidirectional power supply, we cannot simulate this properly and hence a solution was sought for this by means of battery emulation software.

Why emulate a battery?

One of the reasons to emulate a battery we have just mentioned; a repeatable setting that always gives you the same value.

With certain tests, it is important that we do always offer the same value. For example, in quality checks. Another advantage is that large batteries are often heavy and awkward to use. The biggest advantage, however, lies in the fact that you can easily adjust the voltage, current, capacity and charge status of the battery and thus perform different tests quickly and easily. Want to test at 90% now, then 10% and then 50%? You achieve this in seconds whereas with a real battery you have to go charging or discharging to achieve this.

Yet another advantage is safety. Insurance companies prefer that you don’t use real batteries if you don’t have to because of fire hazards.

For example, cars, trucks, boats and also aircraft are tested with battery emulators and the batteries themselves are only installed just before commissioning.

Which battery emulators does TTMS have in its product portfolio?

We have split this for you into four categories:

  1. Battery cell emulation
  2. Battery module emulation
  3. Battery pack emulation
  4. Battery emulation software

Battery cell emulation
For battery cell emulation, you can work with the instrumentation below, for example.

ModelMax WMax VMax IChannels
IT2800    20W200V1,5A1
IT6400    150W60V10A2

Battery module emulation
For battery module emulation, you can work, for example, with the instrumentation listed below.

ModelMax WMax VMax IChannels
M3400 800W600V30A1
M3600     800W600V30A1
IT6700     3kW1200V110A1

Battery pack emulation
For battery pack emulation, you can work, for example, with the instrumentation below.

ModelMax WMax VMax IChannels
IT6000B     960kW2.250V28kA1

Battery emulation software

The Itech battery emulation software (BSS2000) gives you an easy-to-use tool to do battery emulation for various applications.

The basic version is suitable for li-ion batteries and also lead-acid batteries. With this software, you can easily programme the battery’s curve by entering default values. In addition, you can also load a charge/discharge curve via a .CSV file. Changing the State of Charge (SOC) is then very easy and quick.

With the BBS2000 Pro version, you get even more functionality with almost all battery types pre-programmed as standard. In addition, importing Matlab files is also possible and even the BMS can be simulated so that battery simulation is possible for various applications. Of course, the software also provides protection for you battery with various settings.

For detailed specifications, see the BSS2000 datasheet, suitable for the IT6000B, IT6000C, IT-M3400 and the IT-M3600.

At Cinergia, the Battery emulation software is an option with all DC models. By entering the right parameters, the specific battery curve is created.

Using a .CSV file, load/unload curves can also be programmed. And again, of course, with the necessary safeguards.

For detailed specifications of the Cinergia battery emulation software, please refer to the documents below.

Batterij Test

For a detailed presentation on battery emulation, please refer to this recording.

Related topics:

Battery testing
Testing EV chargers

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