Lead-acid battery modeling

I saw the webinar about Battery Modeling in Simulink .

I was wondering:

• if the method of pulsed discharge could be applied also to lead-acid batteries
• what are criteria about choosing intensity of discharge current, the number and the width of current pulses, the rest period,etc.
• if charging tests are necessary (battery should not behave in the same way during charging)

Answer 1

[Hari]

Hi SilverSurfer,

I understand that you are interested in applying the method of pulsed discharge to lead-acid batteries and specifically you are looking for ways to simulate pulsed discharge tests for lead-acid batteries using Simulink.Pulsed Discharge for Lead-Acid Batteries:

Applicability to Lead-Acid Batteries: Pulsed discharge methods can indeed be applied to lead-acid batteries. These methods are used to simulate real-world battery usage patterns and to assess battery performance under intermittent load conditions.

Concise Criteria for Discharge Parameters:

1. Intensity of Discharge Current: Match the real-world use; automotive might need multiple times the C-rate.
2. Number and Width of Current Pulses: Align with usage patterns; short, intense pulses for start-stop systems, longer pulses for energy storage.
3. Rest Periods: Crucial for recovery and assessing capacity and longevity; duration influences battery performance.

Charging Tests Significance: Essential due to differing behavior in charging versus discharging, impacting efficiency, gas generation, and temperature. Understanding both aspects is key for thorough battery modeling.

Implementing in Simulink:

1. Use the Simscape Electrical™ toolbox for modeling the battery. This toolbox provides components for simulating battery cells, including lead-acid types, under various conditions.
2. Implement a custom discharge profile using a combination of Simulink blocks (e.g., Signal Builder or Repeating Sequence blocks) to simulate the desired pulsed discharge pattern.
3. Incorporate thermal models to simulate the impact of repeated pulses and rest periods on battery temperature, which affects performance and longevity.
4. Perform parameter sweeps to explore the effects of varying the discharge current intensity, pulse width, and rest periods on battery performance.

References:

• For an introduction to battery modeling in Simscape Electrical, refer to the documentation: https://www.mathworks.com/help/physmod/sps/powersys/ref/battery.html.
• For insights into parameter sweeps for optimizing battery models, see: https://www.mathworks.com/help/simulink/ug/optimize-estimate-and-sweep-block-parameter-values.html

Hope this helps!