Battery Charging - How to reduce spike at beginning of charging

Hello,

I am simulating a battery charging system, using MATLAB Simulink. I have the system setup to connect to the battery using a breaker at 0.2 seconds during the simulation, at this time the battery experiances a large spike in curent and voltage (shown in the figure below). I am looking for advice on how to dampen the spike that is experianced at 0.2 seconds. The charging system included a three phase grid source, passing through a step down transformer, into a MOSFET Rectifier, from there is enters a DC/DC Converter to acherive the desired voltage into the battery. The DC/DC controller uses a PI controller to control the MOSFETs. A figure of the DC/DC converter and the battery are included below.

If anyone has experiance working with this sort of setup, or has an idea on reducing the spike in voltage and current please reach out.

Thank you in advance

Answer 1

[Pat Gipper]

You migh start by adding an inductor between the breaker and the battery. This should limit the in-rush current when the breaker closes. You would also need to add a diode across the breaker (cathode on 2, anode to ground) to give a current path for when the breaker opens. The diode breakdown voltage would need to be at least 1000V.

[Bruce Gillespie]

Hi Pat,

Thank you very much for your insight, this helped reduce the spike I was seeing!

[Pat Gipper]

Glad I could help.