Input Capacitor for Half Bridge

[LaMontagne]

Good evening,

I am currently working on a Dual Half Bridge converter. At the moment I am a little bit stuck at the capacitor selection (capacitors C1-C4 on the schematic). In particular I am looking for capacitors of about 370uF which can sustain a ripple current of 25A rms (they are placed at the input as well as at the output of the converter).

I was thinking about selecting Aluminum electrolytic capacitors. However I am concerned about the high load current.

Can anybody give me a hint? I am new to practical circuit design, any corrections/tipps are very appreciated

Thank you in advance for any responses.

 

[FvM]

Electrolytic capacitors definitely won't work for the high AC current. Consider polypropylene film capacitors.

 

[humber]

At that current level, you will need to select capacitors with low ESR to avoid self-heating. You could perhaps use a few capacitors in parallel to share the load current, and reduce the overall ESR. With some doubts, I have used multi-layer capacitors in half-bridges. The doubts were the result of not being able to find definitive information concerning the effects of the high ripple current, but they seem to have survived. The suggested film capacitors are safe bet if you have the space for them.